1
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Ristaniemi A, Šećerović A, Grad S, Ferguson SJ. A Novel Fiber-Reinforced Poroviscoelastic Bovine Intervertebral Disc Finite Element Model for Organ Culture Experiment Simulations. J Biomech Eng 2023; 145:121006. [PMID: 37773639 DOI: 10.1115/1.4063557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/28/2023] [Indexed: 10/01/2023]
Abstract
Intervertebral disc (IVD) degeneration and methods for repair and regeneration have commonly been studied in organ cultures with animal IVDs under compressive loading. With the recent establishment of a novel multi-axial organ culture system, accurate predictions of the global and local mechanical response of the IVD are needed for control system development and to aid in experiment planning. This study aimed to establish a finite element model of bovine IVD capable of predicting IVD behavior at physiological and detrimental load levels. A finite element model was created based on the dimensions and shape of a typical bovine IVD used in the organ culture. The nucleus pulposus (NP) was modeled as a neo-Hookean poroelastic material and the annulus fibrosus (AF) as a fiber-reinforced poroviscoelastic material. The AF consisted of 10 lamella layers and the material properties were distributed in the radial direction. The model outcome was compared to a bovine IVD in a compressive stress-relaxation experiment. A parametric study was conducted to investigate the effect of different material parameters on the overall IVD response. The model was able to capture the equilibrium response and the relaxation response at physiological and higher strain levels. Permeability and elastic stiffness of the AF fiber network affected the overall response most prominently. The established model can be used to evaluate the response of the bovine IVD at strain levels typical for organ culture experiments, to define relevant boundaries for such studies, and to aid in the development and use of new multi-axial organ culture systems.
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Affiliation(s)
- Aapo Ristaniemi
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland
| | - Amra Šećerović
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland
| | - Sibylle Grad
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland
| | - Stephen J Ferguson
- Institute for Biomechanics, ETH Zürich, Hönggerbergring 64, Zürich 8093, Switzerland
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2
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Vernengo A, Bumann H, Kluser N, Soubrier A, Šećerović A, Gewiess J, Jansen JU, Neidlinger-Wilke C, Wilke HJ, Grad S. Chemonucleolysis combined with dynamic loading for inducing degeneration in bovine caudal intervertebral discs. Front Bioeng Biotechnol 2023; 11:1178938. [PMID: 37711456 PMCID: PMC10499327 DOI: 10.3389/fbioe.2023.1178938] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 08/01/2023] [Indexed: 09/16/2023] Open
Abstract
Chemonucleolysis has become an established method of producing whole organ culture models of intervertebral disc (IVD) degeneration. However, the field needs more side-by-side comparisons of the degenerative effects of the major enzymes used in chemonucleolysis towards gaining a greater understanding of how these organ culture models mimic the wide spectrum of characteristics observed in human degeneration. In the current work we induced chemonucleolysis in bovine coccygeal IVDs with 100 µL of papain (65 U/mL), chondroitinase ABC (chABC, 5 U/mL), or collagenase II (col'ase, 0.5 U/mL). Each enzyme was applied in a concentration projected to produce moderate levels of degeneration. After 7 days of culture with daily dynamic physiological loading (0.02-0.2 MPa, 0.2 Hz, 2 h), the cellular, biochemical and histological properties of the IVDs were evaluated in comparison to a PBS-injected control. Papain and collagenase, but not chABC, produced macroscopic voids in the tissues. Compared to day 0 intact IVDs, papain induced the greatest magnitude glycosaminoglycan (GAG) loss compared to chABC and col'ase. Papain also induced the greatest height loss (3%), compared to 0.7%, 1.2% and 0.4% for chABC, col'ase, and PBS, respectively. Cell viability in the region adjacent to papain and PBS-injection remained at nearly 100% over the 7-day culture period, whereas it was reduced to 60%-70% by chABC and col'ase. Generally, enzyme treatment tended to downregulate gene expression for major ECM markers, type I collagen (COL1), type II collagen (COL2), and aggrecan (ACAN) in the tissue adjacent to injection. However, chABC treatment induced an increase in COL2 gene expression, which was significant compared to the papain treated group. In general, papain and col'ase treatment tended to recapitulate aspects of advanced IVD degeneration, whereas chABC treatment captured aspects of early-stage degeneration. Chemonucleolysis of whole bovine IVDs is a useful tool providing researchers with a robust spectrum of degenerative changes and can be utilized for examination of therapeutic interventions.
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Affiliation(s)
| | | | | | | | | | - Jan Gewiess
- AO Research Institute Davos, Davos, Switzerland
| | - Jan Ulrich Jansen
- Institute of Orthopaedic Research and Biomechanics, Ulm University, Ulm, Germany
| | | | - Hans-Joachim Wilke
- Institute of Orthopaedic Research and Biomechanics, Ulm University, Ulm, Germany
| | - Sibylle Grad
- AO Research Institute Davos, Davos, Switzerland
- Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
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3
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Ristaniemi A, Šećerović A, Dischl V, Crivelli F, Heub S, Ledroit D, Weder G, Grad S, Ferguson SJ. Physiological and degenerative loading of bovine intervertebral disc in a bioreactor: A finite element study of complex motions. J Mech Behav Biomed Mater 2023; 143:105900. [PMID: 37201227 DOI: 10.1016/j.jmbbm.2023.105900] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 04/28/2023] [Accepted: 05/07/2023] [Indexed: 05/20/2023]
Abstract
Intervertebral disc (IVD) degeneration and regenerative therapies are commonly studied in organ-culture experiments with uniaxial compressive loading. Recently, in our laboratory, we established a bioreactor system capable of applying loads in six degrees-of-freedom (DOF) to bovine IVDs, which replicates more closely the complex multi-axial loading of the IVD in vivo. However, the magnitudes of loading that are physiological (able to maintain cell viability) or mechanically degenerative are unknown for load cases combining several DOFs. This study aimed to establish physiological and degenerative levels of maximum principal strains and stresses in the bovine IVD tissue and to investigate how they are achieved under complex load cases related to common daily activities. The physiological and degenerative levels of maximum principal strains and stresses were determined via finite element (FE) analysis of bovine IVD subjected to experimentally established physiological and degenerative compressive loading protocols. Then, complex load cases, such as a combination of compression + flexion + torsion, were applied on the FE-model with increasing magnitudes of loading to discover when physiological and degenerative tissue strains and stresses were reached. When applying 0.1 MPa of compression and ±2-3° of flexion and ±1-2° of torsion the investigated mechanical parameters remained at physiological levels, but with ±6-8° of flexion in combination with ±2-4° of torsion, the stresses in the outer annulus fibrosus (OAF) exceeded degenerative levels. In the case of compression + flexion + torsion, the mechanical degeneration likely initiates at the OAF when loading magnitudes are high enough. The physiological and degenerative magnitudes can be used as guidelines for bioreactor experiments with bovine IVDs.
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Affiliation(s)
| | | | - Vincent Dischl
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Francesco Crivelli
- CSEM, Swiss Center for Electronics and Microtechnology, Alpnach, Switzerland
| | - Sarah Heub
- CSEM, Swiss Center for Electronics and Microtechnology, Neuchâtel, Switzerland
| | - Diane Ledroit
- CSEM, Swiss Center for Electronics and Microtechnology, Neuchâtel, Switzerland
| | - Gilles Weder
- CSEM, Swiss Center for Electronics and Microtechnology, Neuchâtel, Switzerland
| | - Sibylle Grad
- AO Research Institute Davos, Davos, Switzerland; Institute for Biomechanics, ETH Zürich, Zürich, Switzerland.
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4
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Lazaro-Pacheco D, Mohseni M, Rudd S, Cooper-White J, Holsgrove TP. The role of biomechanical factors in models of intervertebral disc degeneration across multiple length scales. APL Bioeng 2023; 7:021501. [PMID: 37180733 PMCID: PMC10168717 DOI: 10.1063/5.0137698] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 04/24/2023] [Indexed: 05/16/2023] Open
Abstract
Low back pain is the leading cause of disability, producing a substantial socio-economic burden on healthcare systems worldwide. Intervertebral disc (IVD) degeneration is a primary cause of lower back pain, and while regenerative therapies aimed at full functional recovery of the disc have been developed in recent years, no commercially available, approved devices or therapies for the regeneration of the IVD currently exist. In the development of these new approaches, numerous models for mechanical stimulation and preclinical assessment, including in vitro cell studies using microfluidics, ex vivo organ studies coupled with bioreactors and mechanical testing rigs, and in vivo testing in a variety of large and small animals, have emerged. These approaches have provided different capabilities, certainly improving the preclinical evaluation of these regenerative therapies, but challenges within the research environment, and compromises relating to non-representative mechanical stimulation and unrealistic test conditions, remain to be resolved. In this review, insights into the ideal characteristics of a disc model for the testing of IVD regenerative approaches are first assessed. Key learnings from in vivo, ex vivo, and in vitro IVD models under mechanical loading stimulation to date are presented alongside the merits and limitations of each model based on the physiological resemblance to the human IVD environment (biological and mechanical) as well as the possible feedback and output measurements for each approach. When moving from simplified in vitro models to ex vivo and in vivo approaches, the complexity increases resulting in less controllable models but providing a better representation of the physiological environment. Although cost, time, and ethical constraints are dependent on each approach, they escalate with the model complexity. These constraints are discussed and weighted as part of the characteristics of each model.
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Affiliation(s)
- Daniela Lazaro-Pacheco
- Department of Engineering, University of Exeter, Harrison Building, Streatham Campus, North Park Road, Exeter EX4 4QF, United Kingdom
| | - Mina Mohseni
- School of Chemical Engineering, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Samuel Rudd
- School of Chemical Engineering, The University of Queensland, St. Lucia QLD 4072, Australia
| | | | - Timothy Patrick Holsgrove
- Department of Engineering, University of Exeter, Harrison Building, Streatham Campus, North Park Road, Exeter EX4 4QF, United Kingdom
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5
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Tang SN, Bonilla AF, Chahine NO, Colbath AC, Easley JT, Grad S, Haglund L, Le Maitre CL, Leung V, McCoy AM, Purmessur D, Tang SY, Zeiter S, Smith LJ. Controversies in spine research: Organ culture versus in vivo models for studies of the intervertebral disc. JOR Spine 2022; 5:e1235. [PMID: 36601369 PMCID: PMC9799089 DOI: 10.1002/jsp2.1235] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/30/2022] Open
Abstract
Intervertebral disc degeneration is a common cause of low back pain, the leading cause of disability worldwide. Appropriate preclinical models for intervertebral disc research are essential to achieving a better understanding of underlying pathophysiology and for the development, evaluation, and translation of more effective treatments. To this end, in vivo animal and ex vivo organ culture models are both widely used by spine researchers; however, the relative strengths and weaknesses of these two approaches are a source of ongoing controversy. In this article, members from the Spine and Preclinical Models Sections of the Orthopedic Research Society, including experts in both basic and translational spine research, present contrasting arguments in support of in vivo animal models versus ex vivo organ culture models for studies of the disc, supported by a comprehensive review of the relevant literature. The objective is to provide a deeper understanding of the respective advantages and limitations of these approaches, and advance the field toward a consensus with respect to appropriate model selection and implementation. We conclude that complementary use of several model types and leveraging the unique advantages of each is likely to result in the highest impact research in most instances.
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Affiliation(s)
- Shirley N. Tang
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
| | - Andres F. Bonilla
- Preclinical Surgical Research Laboratory, Department of Clinical SciencesColorado State UniversityFort CollinsColoradoUSA
| | - Nadeen O. Chahine
- Departments of Orthopedic Surgery and Biomedical EngineeringColumbia UniversityNew YorkNew YorkUSA
| | - Aimee C. Colbath
- Department of Clinical Sciences, College of Veterinary MedicineCornell UniversityIthacaNew YorkUSA
| | - Jeremiah T. Easley
- Preclinical Surgical Research Laboratory, Department of Clinical SciencesColorado State UniversityFort CollinsColoradoUSA
| | | | | | | | - Victor Leung
- Department of Orthopaedics and TraumatologyThe University of Hong KongHong KongSARChina
| | - Annette M. McCoy
- Department of Veterinary Clinical MedicineUniversity of IllinoisUrbanaIllinoisUSA
| | - Devina Purmessur
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
| | - Simon Y. Tang
- Department of Orthopaedic SurgeryWashington University in St LouisSt LouisMissouriUSA
| | | | - Lachlan J. Smith
- Departments of Orthopaedic Surgery and NeurosurgeryUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Translational Musculoskeletal Research CenterCorporal Michael J. Crescenz VA Medical CenterPhiladelphiaPennsylvaniaUSA
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6
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Šećerović A, Ristaniemi A, Cui S, Li Z, Soubrier A, Alini M, Ferguson SJ, Weder G, Heub S, Ledroit D, Grad S. Toward the Next Generation of Spine Bioreactors: Validation of an Ex Vivo Intervertebral Disc Organ Model and Customized Specimen Holder for Multiaxial Loading. ACS Biomater Sci Eng 2022; 8:3969-3976. [PMID: 35977717 PMCID: PMC9472220 DOI: 10.1021/acsbiomaterials.2c00330] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
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A new generation of bioreactors with integrated six degrees
of
freedom (6 DOF) aims to mimic more accurately the natural intervertebral
disc (IVD) load. We developed and validated in a biological and mechanical
study a specimen holder and corresponding ex vivo IVD organ model
according to the bioreactor requirements for multiaxial loading and
a long-term IVD culture. IVD height changes and cell viability were
compared between the 6 DOF model and the standard 1 DOF model throughout
the 3 weeks of cyclic compressive loading in the uniaxial bioreactor.
Furthermore, the 6 DOF model and holder were loaded for 9 days in
the multiaxial bioreactor under development using the same conditions,
and the IVDs were evaluated for cell viability. The interface of the
IVD model and specimen holder, enhanced with fixation screws onto
the bone, was tested in compression, torsion, lateral bending, and
tension. Additionally, critical motions such as tension and bending
were assessed for a combination of side screws and top screws or side
screws and adhesive. The 6 DOF model loaded in the uniaxial bioreactor
maintained similar cell viability in the IVD regions as the 1 DOF
model. The viability was high after 2 weeks throughout the whole IVD
and reduced by more than 30% in the inner annulus fibrous after 3
weeks. Similarly, the IVDs remained highly viabile when cultured in
the multiaxial bioreactor. In both models, IVD height changes after
loading were in the range of typical physiological conditions. When
differently directed motions were applied, the holder-IVD interface
remained stable under hyper-physiological loading levels using a side
screw approach in compression and torsion and the combination of side
and top screws in tension and bending. We thus conclude that the developed
holding system is mechanically reliable and biologically compatible
for application in a new generation of multiaxial bioreactors.
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Affiliation(s)
- Amra Šećerović
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland
| | - Aapo Ristaniemi
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland
| | - Shangbin Cui
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland.,Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Zhen Li
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland
| | - Astrid Soubrier
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland
| | - Mauro Alini
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland
| | | | - Gilles Weder
- CSEM, Swiss Center for Electronics and Microtechnology, Rue Jaquet-Droz 1, Neuchatel 2002, Switzerland
| | - Sarah Heub
- CSEM, Swiss Center for Electronics and Microtechnology, Rue Jaquet-Droz 1, Neuchatel 2002, Switzerland
| | - Diane Ledroit
- CSEM, Swiss Center for Electronics and Microtechnology, Rue Jaquet-Droz 1, Neuchatel 2002, Switzerland
| | - Sibylle Grad
- AO Research Institute Davos, Clavadelerstrasse 8, Davos 7270, Switzerland
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7
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Bermudez-Lekerika P, Crump KB, Tseranidou S, Nüesch A, Kanelis E, Alminnawi A, Baumgartner L, Muñoz-Moya E, Compte R, Gualdi F, Alexopoulos LG, Geris L, Wuertz-Kozak K, Le Maitre CL, Noailly J, Gantenbein B. Immuno-Modulatory Effects of Intervertebral Disc Cells. Front Cell Dev Biol 2022; 10:924692. [PMID: 35846355 PMCID: PMC9277224 DOI: 10.3389/fcell.2022.924692] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 05/20/2022] [Indexed: 11/29/2022] Open
Abstract
Low back pain is a highly prevalent, chronic, and costly medical condition predominantly triggered by intervertebral disc degeneration (IDD). IDD is often caused by structural and biochemical changes in intervertebral discs (IVD) that prompt a pathologic shift from an anabolic to catabolic state, affecting extracellular matrix (ECM) production, enzyme generation, cytokine and chemokine production, neurotrophic and angiogenic factor production. The IVD is an immune-privileged organ. However, during degeneration immune cells and inflammatory factors can infiltrate through defects in the cartilage endplate and annulus fibrosus fissures, further accelerating the catabolic environment. Remarkably, though, catabolic ECM disruption also occurs in the absence of immune cell infiltration, largely due to native disc cell production of catabolic enzymes and cytokines. An unbalanced metabolism could be induced by many different factors, including a harsh microenvironment, biomechanical cues, genetics, and infection. The complex, multifactorial nature of IDD brings the challenge of identifying key factors which initiate the degenerative cascade, eventually leading to back pain. These factors are often investigated through methods including animal models, 3D cell culture, bioreactors, and computational models. However, the crosstalk between the IVD, immune system, and shifted metabolism is frequently misconstrued, often with the assumption that the presence of cytokines and chemokines is synonymous to inflammation or an immune response, which is not true for the intact disc. Therefore, this review will tackle immunomodulatory and IVD cell roles in IDD, clarifying the differences between cellular involvements and implications for therapeutic development and assessing models used to explore inflammatory or catabolic IVD environments.
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Affiliation(s)
- Paola Bermudez-Lekerika
- Tissue Engineering for Orthopaedics and Mechanobiology, Bone and Joint Program, Department for BioMedical Research (DBMR), Faculty of Medicine, University of Bern, Bern, Switzerland.,Department of Orthopaedic Surgery and Traumatology, Inselspital, Bern University Hospital, Medical Faculty, University of Bern, Bern, Switzerland
| | - Katherine B Crump
- Tissue Engineering for Orthopaedics and Mechanobiology, Bone and Joint Program, Department for BioMedical Research (DBMR), Faculty of Medicine, University of Bern, Bern, Switzerland.,Department of Orthopaedic Surgery and Traumatology, Inselspital, Bern University Hospital, Medical Faculty, University of Bern, Bern, Switzerland
| | | | - Andrea Nüesch
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, United Kingdom
| | - Exarchos Kanelis
- ProtATonce Ltd., Athens, Greece.,School of Mechanical Engineering, National Technical University of Athens, Zografou, Greece
| | - Ahmad Alminnawi
- GIGA In Silico Medicine, University of Liège, Liège, Belgium.,Skeletal Biology and Engineering Research Center, KU Leuven, Leuven, Belgium
| | | | | | - Roger Compte
- Twin Research and Genetic Epidemiology, St Thomas' Hospital, King's College London, London, United Kingdom
| | - Francesco Gualdi
- Institut Hospital Del Mar D'Investigacions Mèdiques (IMIM), Barcelona, Spain
| | - Leonidas G Alexopoulos
- ProtATonce Ltd., Athens, Greece.,School of Mechanical Engineering, National Technical University of Athens, Zografou, Greece
| | - Liesbet Geris
- GIGA In Silico Medicine, University of Liège, Liège, Belgium.,Skeletal Biology and Engineering Research Center, KU Leuven, Leuven, Belgium.,Biomechanics Research Unit, KU Leuven, Leuven, Belgium
| | - Karin Wuertz-Kozak
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, United States.,Spine Center, Schön Klinik München Harlaching Academic Teaching Hospital and Spine Research Institute of the Paracelsus Private Medical University Salzburg (Austria), Munich, Germany
| | - Christine L Le Maitre
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, United Kingdom
| | | | - Benjamin Gantenbein
- Tissue Engineering for Orthopaedics and Mechanobiology, Bone and Joint Program, Department for BioMedical Research (DBMR), Faculty of Medicine, University of Bern, Bern, Switzerland.,Department of Orthopaedic Surgery and Traumatology, Inselspital, Bern University Hospital, Medical Faculty, University of Bern, Bern, Switzerland
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8
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Raines BT, Stannard JT, Stricklin OE, Stoker AM, Choma TJ, Cook JL. Effects of Caffeine on Intervertebral Disc Cell Viability in a Whole Organ Culture Model. Global Spine J 2022; 12:61-69. [PMID: 32935580 PMCID: PMC8965308 DOI: 10.1177/2192568220948031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
STUDY DESIGN Controlled laboratory study. OBJECTIVE To investigate the impact of exposure to physiologically relevant caffeine concentrations on intervertebral disc (IVD) cell viability and extracellular matrix composition (ECM) in a whole organ culture model as potential contributing mechanisms in development and progression of IVD disorders in humans. Primary outcome measures were IVD viable cell density (VCD) and ECM composition. METHODS A total of 190 IVD whole organ explants from tails of 16 skeletally mature rats-consisting of cranial body half, endplate, IVD, endplate, and caudal body half-were harvested. IVD explants were randomly assigned to 1 of 2 groups: uninjured (n = 90) or injured (20G needle disc puncture/aspiration method, n = 100). Explants from each group were randomly assigned to 1 of 3 treatment groups: low caffeine (LCAF: 5 mg/L), moderate caffeine (MCAF: 10 mg/L), and high caffeine (HCAF: 15 mg/L) concentrations. RESULTS Cell viability was significantly higher in the low-caffeine group compared with the high-caffeine group at day 7 (P = .037) and in the low-caffeine group compared with the medium- and high-caffeine groups at day 21 (P ≤ .004). Analysis of ECM showed that all uninjured and control groups had significantly higher (P < .05) glycosaminoglycan concentrations compared with all injured groups. Furthermore, we observed a temporal, downward trend in proteoglycan to collagen ratio for the caffeine groups. CONCLUSIONS Caffeine intake may be a risk factor for IVD degeneration, especially in conjunction with disc injury. Mechanisms for caffeine associated disc degeneration may involve cell and ECM, and further studies should elucidate mechanistic pathways and potential benefits for caffeine restriction.
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Affiliation(s)
- Benjamin T. Raines
- University of Missouri, Columbia, MO, USA,University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | | | | | | | | | - James L. Cook
- University of Missouri, Columbia, MO, USA,James L Cook, Department of Orthopaedic Surgery, University of Missouri, 1100 Virginia Avenue, Columbia, MO 65212, USA.
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9
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LePage EC, Stoker AM, Kuroki K, Cook JL. Effects of cyclic compression on intervertebral disc metabolism using a whole-organ rat tail model. J Orthop Res 2021; 39:1945-1954. [PMID: 33073417 DOI: 10.1002/jor.24886] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 10/07/2020] [Accepted: 10/14/2020] [Indexed: 02/04/2023]
Abstract
Many factors contribute to the development and progression of intervertebral disc (IVD) degeneration. This study was designed to assess the effects of compressive load magnitude on IVD metabolism. It was hypothesized that as load magnitude increased, there would be a significant increase in release of proinflammatory and degradative biomarkers, and a significant decrease in tissue proteoglycan (GAG) and collagen contents compared with unloaded controls. IVD whole organ functional spinal units (FSU) consisting of cranial and caudal body halves, cartilage endplates, and IVD (n = 36) were harvested from the tails of six Sprague Dawley rats, and FSUs were cultured at 0.0 MPa, 0.5 MPa, or 1.0 MPa at 0.5 Hz for 3 days. After culture, media were collected for biomarker analysis and FSUs were analyzed for extracellular matrix composition. Significant differences were determined using a one-way analysis of variance or Kruskal-Wallis test and post hoc analyses. Media concentrations of IFN-γ, IL-6, IL-1β, and MMP-8 were significantly higher in the 0.5 MPa compared with the 0.0 MPa group. Media concentrations of PGE2 and TIMP-1 were significantly higher in the 1.0 MPa group compared with the 0.0 MPa group, and media PGE2 was significantly higher in the 1.0 MPa group compared with the 0.5 MPa group. Media GAG content was significantly higher in the 1.0 MPa group compared with the 0.0 MPa group, and percent GAG in the tissue was significantly lower in 0.5 MPa and 1.0 MPa groups compared with the 0.0 MPa group. Clinical Significance: These data suggest that there are magnitude-dependent inflammatory and degradative IVD responses to cyclic loading, which may contribute to IVD degeneration.
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Affiliation(s)
- Emma C LePage
- Department of Orthopaedic Surgery, University of Missouri, Columbia, Missouri, USA.,Department of Orthopaedic Surgery, Thompson Laboratory for Regenerative Orthopaedics, University of Missouri, Columbia, Missouri, USA
| | - Aaron M Stoker
- Department of Orthopaedic Surgery, University of Missouri, Columbia, Missouri, USA.,Department of Orthopaedic Surgery, Thompson Laboratory for Regenerative Orthopaedics, University of Missouri, Columbia, Missouri, USA
| | - Keiichi Kuroki
- Department of Orthopaedic Surgery, Thompson Laboratory for Regenerative Orthopaedics, University of Missouri, Columbia, Missouri, USA
| | - James L Cook
- Department of Orthopaedic Surgery, University of Missouri, Columbia, Missouri, USA.,Department of Orthopaedic Surgery, Thompson Laboratory for Regenerative Orthopaedics, University of Missouri, Columbia, Missouri, USA
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10
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Zwambag DP, Laird BN, DeWitte-Orr SJ, Gregory DE. Unloaded Organ Culturing Has a Detrimental Effect on the Axial Mechanical Properties of the Intervertebral Disc. J Biomech Eng 2021; 143:084501. [PMID: 33764444 DOI: 10.1115/1.4050635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Indexed: 11/08/2022]
Abstract
Healthy function of intervertebral discs (IVDs) depends on their tissue mechanical properties. Native cells embedded within IVD tissues are responsible for building, maintaining, and repairing IVD structures in response to genetic, biochemical, and mechanical signals. Organ culturing provides a method for investigating how cells respond to these stimuli in their natural architectural environment. The purpose of this study was to determine how organ culturing affects the mechanical characteristics of functional spine units (FSUs) across the entire range of axial loading, including the neutral zone (NZ), using a rat tail model. Rat tail FSUs were organ cultured at 37 °C in an unloaded state in standard culture media for either 1-day (n = 8) or 6-days (n = 12). Noncultured FSUs (n = 12) were included as fresh control specimens. Axial mechanical properties were tested by applying cyclical compression and tension. A novel mathematical approach was developed to fully characterize the relationship between load, stiffness, and deformation through the entire range of loading. Culturing FSUs for 1-day did not affect any of the axial mechanical outcome measures compared to noncultured IVDs; however, culturing for 6 days increased the size of NZ by 112% and decreased the stiffness in NZ, compressive, and tensile regions by 53%, 19%, and 15%, respectively, compared to noncultured FSUs. These results highlight the importance of considering how the mechanical integrity of IVD tissues may affect the transmission of mechanical signals to cells in unloaded organ culturing experiments.
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Affiliation(s)
- Derek P Zwambag
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON N2L3C5, Canada
| | - Brigitte N Laird
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON N2L3C5, Canada
| | - Stephanie J DeWitte-Orr
- Department of Health Sciences, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON N2L3C5, Canada; Department of Biology, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON N2L3C5, Canada
| | - Diane E Gregory
- Department of Kinesiology and Physical Education, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON N2L3C5, Canada; Department of Health Sciences, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON N2L3C5, Canada
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11
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McDonnell EE, Buckley CT. Investigating the physiological relevance of ex vivo disc organ culture nutrient microenvironments using in silico modeling and experimental validation. JOR Spine 2021; 4:e1141. [PMID: 34337330 PMCID: PMC8313156 DOI: 10.1002/jsp2.1141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/22/2021] [Accepted: 01/28/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Ex vivo disc organ culture systems have become a valuable tool for the development and pre-clinical testing of potential intervertebral disc (IVD) regeneration strategies. Bovine caudal discs have been widely selected due to their large availability and comparability to human IVDs in terms of size and biochemical composition. However, despite their extensive use, it remains to be elucidated whether their nutrient microenvironment is comparable to human degeneration. AIMS This work aims to create the first experimentally validated in silico model which can be used to predict and characterize the metabolite concentrations within ex vivo culture systems. MATERIALS & METHODS Finite element models of cultured discs governed by previously established coupled reaction-diffusion equations were created using COMSOL Multiphysics. Experimental validation was performed by measuring oxygen, glucose and pH levels within discs cultured for 7 days, in a static compression bioreactor. RESULTS The in silico model was successfully validated through good agreement between the predicted and experimentally measured concentrations. For an ex vivo organ cultured in high glucose medium (4.5 g/L or 25 mM) and normoxia, a larger bovine caudal disc (Cd1-2 to Cd3-4) had a central concentration of ~2.6 %O2, ~8 mM of glucose and a pH value of 6.7, while the smallest caudal discs investigated (Cd6-7 and Cd7-8), had a central concentration of ~6.5 %O2, ~12 mM of glucose and a pH value of 6.9. DISCUSSION This work advances the knowledge of ex vivo disc culture microenvironments and highlights a critical need for optimization and standardization of culturing conditions. CONCLUSION Ultimately, for assessment of cell-based therapies and successful clinical translation based on nutritional demands, it is imperative that the critical metabolite values within organ cultures (minimum glucose, oxygen and pH values) are physiologically relevant and comparable to the stages of human degeneration.
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Affiliation(s)
- Emily E. McDonnell
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College DublinThe University of DublinDublinIreland
- Discipline of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College DublinThe University of DublinDublinIreland
| | - Conor T. Buckley
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College DublinThe University of DublinDublinIreland
- Discipline of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College DublinThe University of DublinDublinIreland
- Advanced Materials and Bioengineering Research (AMBER) Centre, Royal College of Surgeons in Ireland and Trinity College DublinThe University of DublinDublinIreland
- Tissue Engineering Research Group, Department of Anatomy and Regenerative MedicineRoyal College of Surgeons in IrelandDublinIreland
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12
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Zhan JW, Wang SQ, Feng MS, Gao JH, Wei X, Yu J, Yin XL, Yin H, Sun K, Chen M, Xie R, Zhang P, Zhu LG. Effects of Axial Compression and Distraction on Vascular Bud and VEGFA Expression in the Vertebral Endplate of an Ex Vivo Rabbit Spinal Motion Segment Culture Model. Spine (Phila Pa 1976) 2021; 46:421-432. [PMID: 33186278 DOI: 10.1097/brs.0000000000003816] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN An ex vivo study of the rabbit's vertebral endplate. OBJECTIVE The aim of this study was to assess the effect of axial compression and distraction on vascular buds and vascular endothelial growth factor (VEGFA) expression of the vertebral endplate (VEP). SUMMARY OF BACKGROUND DATA The abnormal load can lead to intervertebral disc degeneration (IDD), whereas axial distraction can delay this process. The effects of different mechanical loads on the intervertebral disc (IVD) have been hypothesized to be related to changes in the vascular buds of the VEP; moreover, the process that might involve the vascular endothelial growth factor (VEGF) within the VEP. METHODS Rabbit spinal segments (n = 40) were harvested and randomly classified into four groups: Control group, no stress was applied; Group A, a constant compressive load applied; Group B, compression load removed for a fixed time daily on a continuous basis, and substituted with a distraction load for 30 minutes; and Group C, compression removed for 30 minutes for a fixed period daily on a continuous basis. Tissue specimens were collected before the culture (day 0) and on day 14 post-culture of each group for analysis of IVDs' morphology, and protein and mRNA expression of Aggrecan, COL2al, VEGFA, and vascular endothelial growth factor receptor 2 of the VEPs. RESULTS Application of axial distraction and dynamic load compression significantly delayed time- and constant compression-mediated VEP changes and IDD. Moreover, the degree of degeneration was associated with loss of vascular buds, as well as the downregulation of VEGFA and its receptor. CONCLUSION The regulation of vascular buds and VEGF expression in the VEP represents one of the mechanisms of axial distraction and dynamic loading.Level of Evidence: N/A.
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Affiliation(s)
- Jia-Wen Zhan
- General Orthopedics Department, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
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13
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Zhang P, Liu X, Guo P, Li X, He Z, Li Z, Stoddart MJ, Grad S, Tian W, Chen D, Zou X, Zhou Z, Liu S. Effect of cyclic mechanical loading on immunoinflammatory microenvironment in biofabricating hydroxyapatite scaffold for bone regeneration. Bioact Mater 2021; 6:3097-3108. [PMID: 33778191 PMCID: PMC7960680 DOI: 10.1016/j.bioactmat.2021.02.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 12/19/2022] Open
Abstract
It has been proven that the mechanical microenvironment can impact the differentiation of mesenchymal stem cells (MSCs). However, the effect of mechanical stimuli in biofabricating hydroxyapatite scaffolds on the inflammatory response of MSCs remains unclear. This study aimed to investigate the effect of mechanical loading on the inflammatory response of MSCs seeded on scaffolds. Cyclic mechanical loading was applied to biofabricate the cell-scaffold composite for 15 min/day over 7, 14, or 21 days. At the predetermined time points, culture supernatant was collected for inflammatory mediator detection, and gene expression was analyzed by qRT-PCR. The results showed that the expression of inflammatory mediators (IL1B and IL8) was downregulated (p < 0.05) and the expression of ALP (p < 0.01) and COL1A1 (p < 0.05) was upregulated under mechanical loading. The cell-scaffold composites biofabricated with or without mechanical loading were freeze-dried to prepare extracellular matrix-based scaffolds (ECM-based scaffolds). Murine macrophages were seeded on the ECM-based scaffolds to evaluate their polarization. The ECM-based scaffolds that were biofabricated with mechanical loading before freeze-drying enhanced the expression of M2 polarization-related biomarkers (Arginase 1 and Mrc1, p < 0.05) of macrophages in vitro and increased bone volume/total volume ratio in vivo. Overall, these findings demonstrated that mechanical loading could dually modulate the inflammatory responses and osteogenic differentiation of MSCs. Besides, the ECM-based scaffolds that were biofabricated with mechanical loading before freeze-drying facilitated the M2 polarization of macrophages in vitro and bone regeneration in vivo. Mechanical loading may be a promising biofabrication strategy for bone biomaterials. Compressive mechanical loading is applied to biofabricate the MSCs-hydroxyapatite composites for bone regeneration. Mechanical loading can modulate the inflammatory responses and osteogenic differentiation of MSCs seeded on scaffold. ECM-based scaffolds from initially loading biofabrication facilitated the M2 polarization of macrophages and bone repair. Mechanical loading may be a promising biofabrication strategy for bone biomaterials.
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Affiliation(s)
- Penghui Zhang
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China.,Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute /Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Xizhe Liu
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute /Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Peng Guo
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China.,Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute /Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Xianlong Li
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China.,Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute /Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Zhongyuan He
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China.,Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute /Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Zhen Li
- AO Research Institute Davos, Clavadelerstrasse 8, Davos, 7270, Switzerland
| | - Martin J Stoddart
- AO Research Institute Davos, Clavadelerstrasse 8, Davos, 7270, Switzerland
| | - Sibylle Grad
- AO Research Institute Davos, Clavadelerstrasse 8, Davos, 7270, Switzerland
| | - Wei Tian
- Laboratory of Bone Tissue Engineering, Beijing Laboratory of Biomedical Materials, Beijing Research Institute of Orthopaedics and Traumatology, Beijing JiShuiTan Hospital, Beijing, 100035, China
| | - Dafu Chen
- Laboratory of Bone Tissue Engineering, Beijing Laboratory of Biomedical Materials, Beijing Research Institute of Orthopaedics and Traumatology, Beijing JiShuiTan Hospital, Beijing, 100035, China
| | - Xuenong Zou
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute /Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Zhiyu Zhou
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China.,Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute /Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Shaoyu Liu
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China.,Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute /Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
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Che YJ, Hou JJ, Guo JB, Liang T, Zhang W, Lu Y, Yang HL, Hao YF, Luo ZP. Low energy extracorporeal shock wave therapy combined with low tension traction can better reshape the microenvironment in degenerated intervertebral disc regeneration and repair. Spine J 2021; 21:160-177. [PMID: 32800896 DOI: 10.1016/j.spinee.2020.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/07/2020] [Accepted: 08/07/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND Low-tension traction is more effective than high-tension traction in restoring the height and rehydration of a degenerated disc and to some extent the bony endplate. This might better reshape the microenvironment for disc regeneration and repair. However, the repair of the combination of endplate sclerosis, osteophyte formation, and even collapse leading to partial or nearly complete occlusion of the nutrient channel is greatly limited. PURPOSE To evaluate the effectiveness of low-intensity extracorporeal shock wave therapy (ESWT) combined with low tension traction for regeneration and repair of moderately and severely degenerated discs; to explore the possible mechanism of action. STUDY DESIGN Animal study of a rat model of degenerated discs. METHODS A total of thirty-five 6-month old male Sprague-Dawley rats were randomly assigned to one of five groups (n=7, each group). In Group A (model group), caudal vertebrae were immobilized using a custom-made external device to fix four caudal vertebrae (Co7-Co10) whereas Co8-Co9 underwent 4 weeks of compression to induce moderate disc degeneration. In Group B (experimental control group), as in Group A, disc degeneration was successfully induced after which the fixed device was removed for 8 weeks of self-recovery. The remaining three groups of rats represented the intervention Groups (C-E): after successful generation of disc degeneration in Group C (com - 4w/tra - 4w) and Group D (com - 4w/ESWT), as described for group A, low-tension traction (in-situ traction) or low-energy ESWT was administered for 4 weeks (ESWT parameters: intensity: 0.15 Mpa; frequency: 1 Hz; impact: 1,000 each time; once/week, 4 times in total); Group E (com - 4w/tra - 4w/ESWT): disc degeneration as described for group A, low-tension traction combined with low-energy ESWT was conducted (ESWT parameters as Group D). After experimentation, caudal vertebrae were harvested and disc height, T2 signal intensity, disc morphology, total glycosaminoglycan (GAG) content, gene expression, structure of the Co8-Co9 bony endplates and elastic moduli of the discs were measured. RESULTS After continuous low-tension traction, low energy ESWT intervention or combined intervention, the degenerated discs effectively recovered their height and became rehydrated. However, the response in Group D was weaker than in the other intervention groups in terms of restoration of intervertebral disc (IVD) height, whereas Group E was superior in disc rehydration. Tissue regeneration was evident in Groups C to E using different interventions. No apparent tissue regeneration was observed in the experimental control group (Group B). The histological scores of the three intervention groups (Groups C-E) were lower than those of Groups A or B (p<.0001), and the scores of Groups C and E were significantly lower than those of Group D (p<.05), but not Group C versus Group E (p>.05). Compared with the intervention groups (Groups C-E), total GAG content of the nucleus pulposus (NP) in Group B did not increase significantly (p>.05). There was also no significant difference in the total GAG content between Groups A and B (p>.05). Of the three intervention groups, the recovery of NP GAG content was greatest in Group E. The expression of collagen I and II, and aggrecan in the annulus fibrosus (AF) was up-regulated (p<.05), whereas the expression of MMP-3, MMP-13, and ADAMTS-4 was down-regulated (p<.05). Of the groups, Group E displayed the greatest degree of regulation. The trend in regulation of gene expression in the NP was essentially consistent with that of the AF, of which Group E was the greatest. In the intervention groups (Groups C-E), compared with Group A, the pore structure of the bony endplate displayed clear changes. The number of pores in the endplate in Groups C to E was significantly higher than in Group A (p<.0001), among which Group C versus Group D (p=.9724), and Group C versus Group E (p=.0116). There was no significant difference between Groups A and B (p=.5261). In addition, the pore diameter also increased, the trend essentially the same as that of pore density. There was no significant difference between the three intervention groups (p=.7213). It is worth noting that, compared with Groups A and B, peripheral pore density and size in Groups D and E of the three intervention groups recovered significantly. The elastic modulus and diameter of collagen fibers in the AF and NP varied with the type of intervention. Low tension traction combined with ESWT resulted in the greatest impact on the diameter and modulus of collagen fibers. CONCLUSIONS Low energy ESWT combined with low tension traction provided a more stable intervertebral environment for the regeneration and repair of moderate and severe degenerative discs. Low energy ESWT promoted the regeneration of disc matrix by reducing MMP-3, MMP-13, and ADAMTS-4 resulting in inhibition of collagen degradation. Although axial traction promoted the recovery of height and rehydration of the IVD, combined with low energy ESWT, the micro-nano structure of the bony endplate underwent positive reconstruction, tension in the annulus of the AF and nuclear stress of the NP declined, and the biomechanical microenvironment required for IVD regeneration and repair was reshaped.
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Affiliation(s)
- Yan-Jun Che
- Orthopaedic Institute, Department of Orthopaedics, The First Affiliated Hospital of SooChow University, 708 Renmin Rd, Suzhou, Jiangsu 215007, People's Republic of China; Department of Orthopedics, Heping Hospital Affiliated to Changzhi Medical College, Changzhi, Shanxi, People's Republic of China
| | - Jun-Jun Hou
- Department of Geriatrics, Xinghu Hospital, SuZhou industrial park, Suzhou, Jiangsu, People's Republic of China; Department of Endocrinology, The First Affiliated Hospital of SooChow University, Suzhou, Jiangsu, People's Republic of China
| | - Jiang-Bo Guo
- Orthopaedic Institute, Department of Orthopaedics, The First Affiliated Hospital of SooChow University, 708 Renmin Rd, Suzhou, Jiangsu 215007, People's Republic of China
| | - Ting Liang
- Orthopaedic Institute, Department of Orthopaedics, The First Affiliated Hospital of SooChow University, 708 Renmin Rd, Suzhou, Jiangsu 215007, People's Republic of China
| | - Wen Zhang
- Orthopaedic Institute, Department of Orthopaedics, The First Affiliated Hospital of SooChow University, 708 Renmin Rd, Suzhou, Jiangsu 215007, People's Republic of China
| | - Yan Lu
- Department of Endocrinology, The First Affiliated Hospital of SooChow University, Suzhou, Jiangsu, People's Republic of China
| | - Hui-Lin Yang
- Orthopaedic Institute, Department of Orthopaedics, The First Affiliated Hospital of SooChow University, 708 Renmin Rd, Suzhou, Jiangsu 215007, People's Republic of China
| | - Yue Feng Hao
- Orthopedics and Sports medicine center, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou 215000, Jiangsu, People's Republic of China
| | - Zong-Ping Luo
- Orthopaedic Institute, Department of Orthopaedics, The First Affiliated Hospital of SooChow University, 708 Renmin Rd, Suzhou, Jiangsu 215007, People's Republic of China.
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15
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Lee NN, Kramer JS, Stoker AM, Bozynski CC, Cook CR, Stannard JT, Choma TJ, Cook JL. Canine models of spine disorders. JOR Spine 2020; 3:e1109. [PMID: 33392448 PMCID: PMC7770205 DOI: 10.1002/jsp2.1109] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/18/2020] [Accepted: 06/30/2020] [Indexed: 12/15/2022] Open
Abstract
Neck and low back pain are common among the adult human population and impose large social and economic burdens on health care and quality of life. Spine-related disorders are also significant health concerns for canine companions with etiopathogeneses, clinical presentations, and diagnostic and therapeutic options that are very similar to their human counterparts. Historically, induced and spontaneous pathology in laboratory rodents, dogs, sheep, goats, pigs, and nonhuman primates have been used for study of human spine disorders. While each of these can serve as useful preclinical models, they all have inherent limitations. Spontaneously occurring spine disorders in dogs provide highly translatable data that overcome many of the limitations of other models and have the added benefit of contributing to veterinary healthcare as well. For this scoping review, peer-reviewed manuscripts were selected from PubMed and Google Scholar searches using keywords: "intervertebral disc," "intervertebral disc degeneration," "biomarkers," "histopathology," "canine," and "mechanism." Additional keywords such as "injury," "induced model," and "nucleus degeneration" were used to further narrow inclusion. The objectives of this review were to (a) outline similarities in key features of spine disorders between dogs and humans; (b) describe relevant canine models; and (c) highlight the applicability of these models for advancing translational research and clinical application for mechanisms of disease, diagnosis, prognosis, prevention, and treatment, with a focus on intervertebral disc degeneration. Best current evidence suggests that dogs share important anatomical, physiological, histological, and molecular components of spinal disorders in humans, such that induced and spontaneous canine models can be very effective for translational research. Taken together, the peer-reviewed literature supports numerous advantages for use of canine models for study of disorders of the spine when the potential limitations and challenges are addressed.
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Affiliation(s)
- Naomi N. Lee
- Department of Orthopaedic SurgeryUniversity of MissouriColumbiaMissouriUSA
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
- Comparative Medicine ProgramUniversity of MissouriColumbiaMissouriUSA
| | - Jacob S. Kramer
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
| | - Aaron M. Stoker
- Department of Orthopaedic SurgeryUniversity of MissouriColumbiaMissouriUSA
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
| | - Chantelle C. Bozynski
- Department of Orthopaedic SurgeryUniversity of MissouriColumbiaMissouriUSA
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
| | - Cristi R. Cook
- Department of Orthopaedic SurgeryUniversity of MissouriColumbiaMissouriUSA
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
| | - James T. Stannard
- Department of Orthopaedic SurgeryUniversity of MissouriColumbiaMissouriUSA
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
| | - Theodore J. Choma
- Department of Orthopaedic SurgeryUniversity of MissouriColumbiaMissouriUSA
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
| | - James L. Cook
- Department of Orthopaedic SurgeryUniversity of MissouriColumbiaMissouriUSA
- Thompson Laboratory for Regenerative OrthopaedicsUniversity of MissouriColumbiaMissouriUSA
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16
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Takeoka Y, Kang JD, Mizuno S. In vitro nucleus pulposus tissue model with physicochemical stresses. JOR Spine 2020; 3:e1105. [PMID: 33015578 PMCID: PMC7524234 DOI: 10.1002/jsp2.1105] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/12/2020] [Accepted: 06/04/2020] [Indexed: 12/21/2022] Open
Abstract
Intervertebral discs (IVDs) are exposed to changes in physicochemical stresses including hydrostatic and osmotic pressure via diurnal spinal motion. Homeostasis, degeneration, and regeneration in IVDs have been studied using in vitro, ex vivo, and animal models. However, incubation of nucleus pulposus (NP) cells in medium has limited capability to reproduce anabolic turnover and regeneration under physicochemical stresses. We developed a novel pressure/perfusion cell culture system and a semipermeable membrane pouch device for enclosing isolated NP cells for in vitro incubation under physicochemical stresses. We assessed the performance of this system to identify an appropriate stress loading regimen to promote gene expression and consistent accumulation of extracellular matrices by bovine caudal NP cells. Cyclic hydrostatic pressure (HP) for 4 days followed by constant HP for 3 days in high osmolality (HO; 450 mOsm/kg H2O) showed a trend towards upregulated aggrecan expression and dense accumulation of keratan sulfate without gaps by the NP cells. Furthermore, a repetitive regimen of cyclic HP for 2 days followed by constant HP for 1 day in HO (repeated twice) significantly upregulated gene expression of aggrecan (P < .05) compared to no pressure and suppressed matrix metalloproteinase-13 expression (P < .05) at 6 days. Our culture system and pouches will be useful to reproduce physicochemical stresses in NP cells for simulating anabolic, catabolic, and homeostatic turnover under diurnal spinal motion.
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Affiliation(s)
- Yoshiki Takeoka
- Department of Orthopaedic SurgeryBrigham and Women's Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - James D. Kang
- Department of Orthopaedic SurgeryBrigham and Women's Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Shuichi Mizuno
- Department of Orthopaedic SurgeryBrigham and Women's Hospital and Harvard Medical SchoolBostonMassachusettsUSA
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17
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Zhan JW, Wang SQ, Feng MS, Wei X, Yu J, Yin XL, Han T, Zhu LG. Constant compression decreases vascular bud and VEGFA expression in a rabbit vertebral endplate ex vivo culture model. PLoS One 2020; 15:e0234747. [PMID: 32584845 PMCID: PMC7316323 DOI: 10.1371/journal.pone.0234747] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 06/02/2020] [Indexed: 12/30/2022] Open
Abstract
SUMMARY OF BACKGROUND DATA The vascular buds in the vertebral endplate (VEP) are the structural foundation of nutrient exchange in the intervertebral disc (IVD). VEGF is closely related to angiogenesis in the endplate and intervertebral disc degeneration (IDD). OBJECTIVE To investigate the effects of static load on vascular buds and VEGF expression in the VEP and to further clarify the relation between IDD and VEGF. METHODS IVD motion segments were harvested from rabbit lumbar spines and cultured under no-loading conditions (controls) or in custom-made apparatuses under a constant compressive load (0.5 MPa) for up to 14 days. Tissue integrity and the number of vascular buds were determined, and the concentrations and expression of Aggrecan, COL2a1, and VEGFA in the VEPs were assessed after 3, 7, and 14 days of culturing and then compared with those of fresh tissues. RESULTS Under the constant compression, the morphological integrity of the VEPs was gradually disrupted, and immunohistochemistry results showed a significant decrease in the levels of Agg and COL2a1. During the static load, the number of vascular buds in the VEPs was gradually reduced from the early stage of culture, and ELISA showed that the constant compressive load caused a significant decrease in the VEGFA and VEGFR2 protein concentrations, which were consistent with the immunohistochemistry results. Western blot and RT-PCR results also showed that the loading state caused a significant decrease in VEGFA expression compared with that of fresh and control samples. CONCLUSIONS Constant compression caused degeneration of the VEP as well as a decreased number of vascular buds, thereby accelerating disc degeneration. VEGFA is involved in this process. We anticipate that regulating the expression of VEGFA may improve the condition of the lesions to the vascular buds in the endplates, thus enhancing the nutritional supply function in IVD and providing new therapeutic targets and strategies for the effective prevention and treatment of IDD.
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Affiliation(s)
- Jia-Wen Zhan
- General Orthopedics Department, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Shang-Quan Wang
- General Orthopedics Department, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Min-Shan Feng
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xu Wei
- Scientific Research Office, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jie Yu
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xun-Lu Yin
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Tao Han
- General Orthopedics Department, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Li-Guo Zhu
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
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18
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Li Z, Gehlen Y, Heizmann F, Grad S, Alini M, Richards RG, Kubosch D, Südkamp N, Izadpanah K, Kubosch EJ, Lang G. Preclinical ex-vivo Testing of Anti-inflammatory Drugs in a Bovine Intervertebral Degenerative Disc Model. Front Bioeng Biotechnol 2020; 8:583. [PMID: 32587853 PMCID: PMC7298127 DOI: 10.3389/fbioe.2020.00583] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/13/2020] [Indexed: 01/06/2023] Open
Abstract
Discogenic low back pain (LBP) is a main cause of disability and inflammation is presumed to be a major driver of symptomatic intervertebral disc degeneration (IDD). Anti-inflammatory agents are currently under investigation as they demonstrated to alleviate symptoms in patients having IDD. However, their underlying anti-inflammatory and regenerative activity is poorly explored. The present study sought to investigate the potential of Etanercept and Tofacitinib for maintaining disc homeostasis in a preclinical intervertebral disc (IVD) organ culture model within IVD bioreactors allowing for dynamic loading and nutrient exchange. Bovine caudal IVDs were cultured in a bioreactor system for 4 days to simulate physiological or degenerative conditions: (1) Phy—physiological loading (0.02–0.2 MPa; 0.2 Hz; 2 h/day) and high glucose DMEM medium (4.5 g/L); (2) Deg+Tumor necrosis factor α (TNF-α)—degenerative loading (0.32–0.5 MPa; 5 Hz; 2 h/day) and low glucose DMEM medium (2 g/L), with TNF-α injection. Etanercept was injected intradiscally while Tofacitinib was supplemented into the culture medium. Gene expression in the IVD tissue was measured by RT-qPCR. Release of nitric oxide (NO), interleukin 8 (IL-8) and glycosaminoglycan (GAG) into the IVD conditioned medium were analyzed. Cell viability in the IVD was assessed using lactate dehydrogenase and ethidium homodimer-1 staining. Immunohistochemistry was performed to assess protein expression of IL-1β, IL-6, IL-8, and collagen type II in the IVD tissue. Etanercept and Tofacitinib downregulated the expression of IL-1β, IL-6, IL-8, Matrix metalloproteinase 1 (MMP1), and MMP3 in the nucleus pulposus (NP) tissue and IL-1β, MMP3, Cyclooxygenase-2 (COX2), and Nerve growth factor (NGF) in the annulus fibrosus (AF) tissue. Furthermore, Etanercept significantly reduced the IL-1β positively stained cells in the outer AF and NP regions. Tofacitinib significantly reduced IL-1β and IL-8 positively stained cells in the inner AF region. Both, Etanercept and Tofacitinib reduced the GAG loss to the level under physiological culture condition. Etanercept and Tofacitinib are able to neutralize the proinflammatory and catabolic environment in the IDD organ culture model. However, combined anti-inflammatory and anabolic treatment may be required to constrain accelerated IDD and relieving inflammation-induced back pain.
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Affiliation(s)
- Zhen Li
- AO Research Institute Davos, Davos, Switzerland
| | - Yannik Gehlen
- AO Research Institute Davos, Davos, Switzerland.,Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - Albert-Ludwigs-University of Freiburg, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Fabian Heizmann
- AO Research Institute Davos, Davos, Switzerland.,Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - Albert-Ludwigs-University of Freiburg, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | | | - Mauro Alini
- AO Research Institute Davos, Davos, Switzerland
| | - R Geoff Richards
- AO Research Institute Davos, Davos, Switzerland.,Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - Albert-Ludwigs-University of Freiburg, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - David Kubosch
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - Albert-Ludwigs-University of Freiburg, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Norbert Südkamp
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - Albert-Ludwigs-University of Freiburg, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Kaywan Izadpanah
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - Albert-Ludwigs-University of Freiburg, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Eva Johanna Kubosch
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - Albert-Ludwigs-University of Freiburg, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Gernot Lang
- Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - Albert-Ludwigs-University of Freiburg, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
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19
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The circadian rhythm in intervertebral disc degeneration: an autophagy connection. Exp Mol Med 2020; 52:31-40. [PMID: 31983731 PMCID: PMC7000407 DOI: 10.1038/s12276-019-0372-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/01/2019] [Accepted: 09/17/2019] [Indexed: 02/08/2023] Open
Abstract
There is one circadian clock in the central nervous system and another in the peripheral organs, and the latter is driven by an autoregulatory molecular clock composed of several core clock genes. The height, water content, osmotic pressure and mechanical characteristics of intervertebral discs (IVDs) have been demonstrated to exhibit a circadian rhythm (CR). Recently, a molecular clock has been shown to exist in IVDs, abolition of which can lead to stress in nucleus pulposus cells (NPCs), contributing to intervertebral disc degeneration (IDD). Autophagy is a fundamental cellular process in eukaryotes and is essential for individual cells or organs to respond and adapt to changing environments; it has also been demonstrated to occur in human NPCs. Increasing evidence supports the hypothesis that autophagy is associated with CR. Thus, we review the connection between CR and autophagy and the roles of these mechanisms in IDD.
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20
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Pfannkuche JJ, Guo W, Cui S, Ma J, Lang G, Peroglio M, Richards RG, Alini M, Grad S, Li Z. Intervertebral disc organ culture for the investigation of disc pathology and regeneration - benefits, limitations, and future directions of bioreactors. Connect Tissue Res 2019; 61:304-321. [PMID: 31556329 DOI: 10.1080/03008207.2019.1665652] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Low back pain is the leading cause of disability worldwide and in many patients the source of pain can be attributed to pathological changes within the intervertebral disc (IVD). As present treatment options fail to address the underlying biological problem, novel therapies are currently subject to intense research. The physiologic IVD microenvironment features a highly complex interaction of biochemical and mechanical factors influencing cell metabolism and extracellular matrix turnover and is therefore difficult to simulate for research purposes on IVD pathology. The first whole organ culture models were not able to sufficiently replicate human in vivo conditions as mechanical loading, the predominant way of IVD nutrient supply and waste exchange, remained disregarded. To mimic the unique IVD niche more realistically, whole organ culture bioreactors have been developed, allowing for dynamic loading of IVDs and nutrient exchange. Recent advancements on bioreactor systems have facilitated whole organ culture of various IVDs for extended periods. IVD organ culture bioreactors have the potential to bridge the gap between in vitro and in vivo systems and thus may give valuable insights on IVD pathology and/or potential novel treatment approaches if the respective model is adjusted according to a well-defined research question. In this review, we outline the potential of currently utilized IVD bioreactor systems and present suggestions for further developments to more reliably investigate IVD biology and novel treatment approaches.
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Affiliation(s)
- Judith-Johanna Pfannkuche
- AO Research Institute Davos, Davos, Switzerland.,Department of Orthopedic and Trauma Surgery, University Medical Center Freiburg, Albert-Ludwigs University of Freiburg, Freiburg, Germany
| | - Wei Guo
- AO Research Institute Davos, Davos, Switzerland.,The first affiliated hospital of Sun Yat-sen University, Guangzhou, China
| | - Shangbin Cui
- AO Research Institute Davos, Davos, Switzerland.,The first affiliated hospital of Sun Yat-sen University, Guangzhou, China
| | - Junxuan Ma
- AO Research Institute Davos, Davos, Switzerland
| | - Gernot Lang
- Department of Orthopedic and Trauma Surgery, University Medical Center Freiburg, Albert-Ludwigs University of Freiburg, Freiburg, Germany
| | | | - R Geoff Richards
- AO Research Institute Davos, Davos, Switzerland.,Department of Orthopedic and Trauma Surgery, University Medical Center Freiburg, Albert-Ludwigs University of Freiburg, Freiburg, Germany
| | - Mauro Alini
- AO Research Institute Davos, Davos, Switzerland
| | | | - Zhen Li
- AO Research Institute Davos, Davos, Switzerland
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21
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Ura K, Sudo H, Iwasaki K, Tsujimoto T, Ukeba D, Iwasaki N. Effects of Intradiscal Injection of Local Anesthetics on Intervertebral Disc Degeneration in Rabbit Degenerated Intervertebral Disc. J Orthop Res 2019; 37:1963-1971. [PMID: 31106893 DOI: 10.1002/jor.24347] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 05/14/2019] [Indexed: 02/04/2023]
Abstract
Analgesic discoblock is widely used for the diagnosis or treatment of discogenic low back pain by injecting local anesthetics. The purpose of this study was to investigate the deleterious effects of local anesthetics on degenerated rabbit intervertebral disks (IVDs) using an organotypic culture model and in vivo long-term follow-up model. To induce IVD degeneration, a rabbit annular puncture model was used. For the organotypic culture model, degenerated IVDs were harvested 1 month after the initial annular puncture and cultured for 3 or 7 days after intradiscal injection of local anesthetics (1% lidocaine and 0.5% bupivacaine). To perform in vivo analysis, local anesthetics were injected into degenerated IVDs, and IVDs were prepared for histological analysis after 6 or 12 months. In the organotypic model, terminal deoxynucleotidyl transferase dUTP nick end labeling-positive nucleus pulposus (NP) cells were significantly increased in the bupivacaine group compared with the other groups. In the in vivo study, the number of NP cells was significantly decreased in the saline and local anesthetics groups compared with the untreated control and puncture-only groups. However, there was no significant difference among the saline, lidocaine, and bupivacaine groups. In addition, histological analysis showed no significant difference of IVD degeneration among the puncture-only, saline, lidocaine, and bupivacaine groups. Although bupivacaine induced apoptotic NP cell death in the organotypic culture model, in vivo observations did not show any definitive proof to suggest that local anesthetics were capable of promoting degeneration in the degenerated IVD, except for pressurized injection-induced damage. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1963-1971, 2019.
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Affiliation(s)
- Katsuro Ura
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hideki Sudo
- Department of Advanced Medicine for Spine and Spinal Cord Disorders, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, North-15, West-7, Sapporo, 060-8638, Japan
| | - Koji Iwasaki
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Takeru Tsujimoto
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Daisuke Ukeba
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Norimasa Iwasaki
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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22
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Shah BS, Chahine NO. Dynamic Hydrostatic Pressure Regulates Nucleus Pulposus Phenotypic Expression and Metabolism in a Cell Density-Dependent Manner. J Biomech Eng 2019; 140:2666887. [PMID: 29247254 DOI: 10.1115/1.4038758] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Indexed: 11/08/2022]
Abstract
Dynamic hydrostatic pressure (HP) loading can modulate nucleus pulposus (NP) cell metabolism, extracellular matrix (ECM) composition, and induce transformation of notochordal NP cells into mature phenotype. However, the effects of varying cell density and dynamic HP magnitude on NP phenotype and metabolism are unknown. This study examined the effects of physiological magnitudes of HP loading applied to bovine NP cells encapsulated within three-dimensional (3D) alginate beads. Study 1: seeding density (1 M/mL versus 4 M/mL) was evaluated in unloaded and loaded (0.1 MPa, 0.1 Hz) conditions. Study 2: loading magnitude (0, 0.1, and 0.6 MPa) applied at 0.1 Hz to 1 M/mL for 7 days was evaluated. Study 1: 4 M/mL cell density had significantly lower adenosine triphosphate (ATP), glycosaminoglycan (GAG) and collagen content, and increased lactate dehydrogenase (LDH). HP loading significantly increased ATP levels, and expression of aggrecan, collagen I, keratin-19, and N-cadherin in HP loaded versus unloaded groups. Study 2: aggrecan expression increased in a dose dependent manner with HP magnitude, whereas N-cadherin and keratin-19 expression were greatest in low HP loading compared to unloaded. Overall, the findings of the current study indicate that cell seeding density within a 3D construct is a critical variable influencing the mechanobiological response of NP cells to HP loading. NP mechanobiology and phenotypic expression was also found to be dependent on the magnitude of HP loading. These findings suggest that HP loading and culture conditions of NP cells may require complex optimization for engineering an NP replacement tissue.
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Affiliation(s)
- Bhranti S Shah
- Department of Orthopedic Surgery, Columbia University, New York, NY 10032
| | - Nadeen O Chahine
- Department of Orthopedic Surgery, Columbia University, 650 West 168th Street, 14-1408E, New York, NY 10032.,Department of Biomedical Engineering, Columbia University, New York, NY 10032 e-mail:
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23
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Sampson SL, Sylvia M, Fields AJ. Effects of dynamic loading on solute transport through the human cartilage endplate. J Biomech 2018; 83:273-279. [PMID: 30554819 DOI: 10.1016/j.jbiomech.2018.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 11/07/2018] [Accepted: 12/03/2018] [Indexed: 12/29/2022]
Abstract
Nutrient and metabolite transport through the cartilage endplate (CEP) is important for maintaining proper disc nutrition, but the mechanisms of solute transport remain unclear. One unresolved issue is the role of dynamic loading. In comparison to static loading, dynamic loading is thought to enhance transport by increasing convection. However, the CEP has a high resistance to fluid flow, which could limit solute convection. Here we measure solute transport through site-matched cadaveric human lumbar CEP tissues under static vs. dynamic loading, and we determine how the degree of transport enhancement from dynamic loading depends on CEP porosity and solute size. We found that dynamic loading significantly increased small and large solute transport through the CEP: on average, dynamic loading increased the transport of sodium fluorescein (376 Da) by a factor of 1.85 ± 0.64 and the transport of a large dextran (4000 Da) by a factor of 4.97 ± 3.05. Importantly, CEP porosity (0.65 ± 0.07; range: 0.47-0.76) strongly influenced the degree of transport enhancement. Specifically, for both solutes, transport enhancement was greater for CEPs with low porosity than for CEPs with high porosity. This is because the CEPs with low porosity were susceptible to larger improvements in fluid flow under dynamic loading. The CEP becomes less porous and less hydrated with aging and as disc degeneration progresses. Together, these findings suggest that as those changes occur, dynamic loading has a greater effect on solute transport through the CEP compared to static loading, and thus may play a larger role in disc nutrition.
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Affiliation(s)
- Sara L Sampson
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA
| | - Meghan Sylvia
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA
| | - Aaron J Fields
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA.
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24
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Thorpe AA, Bach FC, Tryfonidou MA, Le Maitre CL, Mwale F, Diwan AD, Ito K. Leaping the hurdles in developing regenerative treatments for the intervertebral disc from preclinical to clinical. JOR Spine 2018; 1:e1027. [PMID: 31463447 PMCID: PMC6686834 DOI: 10.1002/jsp2.1027] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 06/07/2018] [Accepted: 06/28/2018] [Indexed: 12/11/2022] Open
Abstract
Chronic back and neck pain is a prevalent disability, often caused by degeneration of the intervertebral disc. Because current treatments for this condition are less than satisfactory, a great deal of effort is being applied to develop new solutions, including regenerative strategies. However, the path from initial promising idea to clinical use is fraught with many hurdles to overcome. Many of the keys to success are not necessarily linked to science or innovation. Successful translation to clinic will also rely on planning and awareness of the hurdles. It will be essential to plan your entire path to clinic from the outset and to do this with a multidisciplinary team. Take advice early on regulatory aspects and focus on generating the proof required to satisfy regulatory approval. Scientific demonstration and societal benefits are important, but translation cannot occur without involving commercial parties, which are instrumental to support expensive clinical trials. This will only be possible when intellectual property can be protected sufficiently to support a business model. In this manner, commercial, societal, medical, and scientific partners can work together to ultimately improve patient health. Based on literature surveys and experiences of the co-authors, this opinion paper presents this pathway, highlights the most prominent issues and hopefully will aid in your own translational endeavors.
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Affiliation(s)
- Abbey A. Thorpe
- Biomolecular Sciences Research CentreSheffield Hallam UniversitySheffieldUK
| | - Frances C. Bach
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| | - Marianna A. Tryfonidou
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| | | | - Fackson Mwale
- Department of SurgeryMcGill UniversityMontrealCanada
| | - Ashish D. Diwan
- Spine Service, Department of Orthopaedic SurgerySt. George & Sutherland Clinical School, University of New South WalesSydneyAustralia
| | - Keita Ito
- Orthopaedic Biomechanics Division, Department of Biomedical EngineeringEindhoven University of TechnologyEindhoventhe Netherlands
- Department of OrthopedicsUniversity Medical Centre UtrechtUtrechtthe Netherlands
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25
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Abstract
Mechanical loading of the intervertebral disc (IVD) initiates cell-mediated remodeling events that contribute to disc degeneration. Cells of the IVD, nucleus pulposus (NP) and anulus fibrosus (AF), will exhibit various responses to different mechanical stimuli which appear to be highly dependent on loading type, magnitude, duration, and anatomic zone of cell origin. Cells of the NP, the innermost region of the disc, exhibit an anabolic response to low-moderate magnitudes of static compression, osmotic pressure, or hydrostatic pressure, while higher magnitudes promote a catabolic response marked by increased protease expression and activity. Cells of the outer AF are responsive to physical forces in a manner that depends on frequency and magnitude, as are cells of the NP, though they experience different forces, deformations, pressure, and osmotic pressure in vivo. Much remains to be understood of the mechanotransduction pathways that regulate IVD cell responses to loading, including responses to specific stimuli and also differences among cell types. There is evidence that cytoskeletal remodeling and receptor-mediated signaling are important mechanotransduction events that can regulate downstream effects like gene expression and posttranslational biosynthesis, all of which may influence phenotype and bioactivity. These and other mechanotransduction events will be regulated by known and to-be-discovered cell-matrix and cell-cell interactions, and depend on composition of extracellular matrix ligands for cell interaction, matrix stiffness, and the phenotype of the cells themselves. Here, we present a review of the current knowledge of the role of mechanical stimuli and the impact upon the cellular response to loading and changes that occur with aging and degeneration of the IVD.
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Affiliation(s)
- Bailey V Fearing
- Department of Biomedical Engineering & Orthopedic Surgery, Washington University in St. Louis, St. Louis, Missouri
| | - Paula A Hernandez
- Department of Orthopaedic Surgery, University of Texas Southwestern, Dallas, Texas
| | - Lori A Setton
- Department of Biomedical Engineering & Orthopedic Surgery, Washington University in St. Louis, St. Louis, Missouri
| | - Nadeen O Chahine
- Department of Orthopedic Surgery & Biomedical Engineering, Columbia University, New York, New York
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26
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Lu T, Luo C, Ouyang B, Chen Q, Deng Z. Effects of C5/C6 Intervertebral Space Distraction Height on Pressure on the Adjacent Intervertebral Disks and Articular Processes and Cervical Vertebrae Range of Motion. Med Sci Monit 2018; 24:2533-2540. [PMID: 29693646 PMCID: PMC5939602 DOI: 10.12659/msm.909868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background This study aimed to investigate the association between range of motion of the cervical vertebrae and various C5/C6 intervertebral space distraction heights. Material/Methods The cervical vertebrae from 6 fresh adult human cadavers were used to prepare the models. Changes in C4/C5 and C6/C7 intervertebral disk pressures, articular process pressure, and range of motion of the cervical vertebrae before and after the distraction of the C5/C6 intervertebral space at benchmark heights of 100%, 120%, 140%, and 160% were tested under different exercise loads. Results The pressure on the adjacent intervertebral disks was highest with the standing upright position before distraction, varied with different positions of the specimens and distraction heights after distraction, and was closest to that before distraction at a distraction height of 120% (P<0.05). The pressure of the adjacent articular processes was highest with left and right rotations before distraction, varied with different positions of the specimens and distraction heights after distraction, and was lowest under the same exercise load with different positions at a distraction height of 120% (P<0.05). The ranges of motion of the cervical vertebrae and intervertebral disks were largest without distraction and at a distraction height of 120% after distraction, respectively (P<0.05). Conclusions When removing the C5/C6 intervertebral disk and implanting an intervertebral bone graft, a benchmark height of 120% had little influence on the pressure of the adjacent intervertebral disks and articular processes and range of motion of the cervical vertebrae and is therefore an appropriate intervertebral space distraction height.
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Affiliation(s)
- Tingsheng Lu
- Department of Orthopaedic Surgery, Guizhou Orthopedics Hospital, Guiyang, Guizhou, China (mainland)
| | - Chunshan Luo
- Department of Orthopaedic Surgery, Guizhou Orthopedics Hospital, Guiyang, Guizhou, China (mainland)
| | - Beiping Ouyang
- Department of Orthopaedic Surgery, Guizhou Orthopedics Hospital, Guiyang, Guizhou, China (mainland)
| | - Qiling Chen
- Department of Orthopaedic Surgery, Guizhou Orthopedics Hospital, Guiyang, Guizhou, China (mainland)
| | - Zhongliang Deng
- Department of Orthopaedic Surgery, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China (mainland)
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27
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Biomechanical response of intact, degenerated and repaired intervertebral discs under impact loading – Ex-vivo and In-Silico investigation. J Biomech 2018; 70:26-32. [DOI: 10.1016/j.jbiomech.2018.01.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 01/09/2018] [Accepted: 01/14/2018] [Indexed: 01/30/2023]
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28
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Peroglio M, Gaspar D, Zeugolis DI, Alini M. Relevance of bioreactors and whole tissue cultures for the translation of new therapies to humans. J Orthop Res 2018; 36:10-21. [PMID: 28718947 DOI: 10.1002/jor.23655] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/30/2017] [Indexed: 02/04/2023]
Abstract
The purpose of this review is to provide a brief overview of bioreactor-based culture systems as alternatives to conventional two- and three-dimensional counterparts. The role, challenges, and future aspirations of bioreactors in the musculoskeletal field (e.g., cartilage, intervertebral disc, tendon, and bone) are discussed. Bioreactors, by recapitulating physiological processes, can be used effectively as part of the initial in vitro screening, reducing that way the number of animal required for preclinical assessment, complying with the 3R principles and, in most cases, allowing working with human tissues. The clinical significance of bioreactors is that, by providing more physiologically relevant conditions to customarily used two- and three-dimensional cultures, they hold the potential to provide a testing platform that is more predictable of a whole tissue response, thereby facilitating the screening of treatments before the initiation of clinical trials. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:10-21, 2018.
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Affiliation(s)
- Marianna Peroglio
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
| | - Diana Gaspar
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), National University of Ireland Galway (NUI Galway), Galway, Ireland.,Science Foundation Ireland (SFI), Centre for Research in Medical Devices (CÚRAM), National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Dimitrios I Zeugolis
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), National University of Ireland Galway (NUI Galway), Galway, Ireland.,Science Foundation Ireland (SFI), Centre for Research in Medical Devices (CÚRAM), National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Mauro Alini
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland
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29
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Li P, Hou G, Zhang R, Gan Y, Xu Y, Song L, Zhou Q. High-magnitude compression accelerates the premature senescence of nucleus pulposus cells via the p38 MAPK-ROS pathway. Arthritis Res Ther 2017; 19:209. [PMID: 28923094 PMCID: PMC5604423 DOI: 10.1186/s13075-017-1384-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 07/07/2017] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Mechanical overloading can lead to disc degeneration. Nucleus pulposus (NP) cell senescence is aggravated within the degenerated disc. This study was designed to investigate the effects of high compression on NP cell senescence and the underlying molecular mechanism of this process. METHODS Rat NP cells seeded in decalcified bone matrix were subjected to non-compression (control) or compression (2% or 20% deformation, 1.0 Hz, 6 hours/day). The reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) and the p38 MAPK inhibitor SB203580 were used to investigate the roles of the ROS and p38 MAPK pathway under high-magnitude compression. Additionally, we studied the effects of compression (0.1 or 1.3 MPa, 1.0 Hz, 6 hours/day) in a rat disc organ culture. RESULTS Both in scaffold and organ cultures, high-magnitude compression (20% deformation or 1.3 MPa) increased senescence-associated β-galactosidase (SA-β-Gal) activity, senescence marker (p16 and p53) expression, G1 cell cycle arrest, and ROS generation, and decreased cell proliferation, telomerase activity and matrix (aggrecan and collagen II) synthesis. Further analysis of the 20% deformation group showed that NAC inhibited NP cell senescence but had no obvious effect on phospho-p38 MAPK expression and that SB203580 significantly attenuated ROS generation and NP cell senescence. CONCLUSIONS High-magnitude compression can accelerate NP cell senescence through the p38 MAPK-ROS pathway.
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Affiliation(s)
- Pei Li
- Department of Orthopaedic Surgery, No. 89 hospital of PLA, Weifang, Shandong, 261026, China.,Department of Orthopaedic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Gang Hou
- Department of Orthopaedics, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510700, China
| | - Ruijie Zhang
- Department of Respiratory Medicine, the Third Xiangya Hospital, Central South University, Changsha, Hunan, 410013, China.
| | - Yibo Gan
- Department of Orthopaedic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Yuan Xu
- Department of Orthopaedic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, China
| | - Lei Song
- Department of Orthopaedic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Qiang Zhou
- Department of Orthopaedic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China.
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Long RG, Rotman SG, Hom WW, Assael DJ, Illien-Jünger S, Grijpma DW, Iatridis JC. In vitro and biomechanical screening of polyethylene glycol and poly(trimethylene carbonate) block copolymers for annulus fibrosus repair. J Tissue Eng Regen Med 2017; 12:e727-e736. [PMID: 27860368 DOI: 10.1002/term.2356] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/08/2016] [Accepted: 11/09/2016] [Indexed: 12/23/2022]
Abstract
Herniated intervertebral discs (IVDs) are a common cause of back and neck pain. There is an unmet clinical need to seal annulus fibrosus (AF) defects, as discectomy surgeries address acute pain but are complicated by reherniation and recurrent pain. Copolymers of polyethylene glycol with trimethylene carbonate (TMC) and hexamethylene diisocyanate (HDI) end-groups were formulated as AF sealants as the HDI form covalent bonds with native AF tissue. TMC adhesives were evaluated and optimized using the design criteria: stable size, strong adherence to AF tissue, high cytocompatibility, restoration of IVD biomechanics to intact levels following in situ repair, and low extrusion risk. TMC adhesives had high adhesion strength as assessed with a pushout test (150 kPa), and low degradation rates over 3 weeks in vitro. Both TMC adhesives had shear moduli (220 and 490 kPa) similar to, but somewhat higher than, AF tissue. The adhesive with three TMC moieties per branch (TMC3) was selected for additional in situ testing because it best matched AF shear properties. TMC3 restored torsional stiffness, torsional hysteresis area and axial range of motion to intact states. However, in a failure test of compressive deformation under fixed 5 ° flexion, some herniation risk was observed with failure strength of 5.9 MPa compared with 13.5 MPa for intact samples; TMC3 herniated under cyclic organ culture testing. These TMC adhesives performed well during in vitro and in situ testing, but additional optimization to enhance failure strength is required to further this material to advanced screening tests, such as long-term degradation. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Rose G Long
- Leni & Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Annulus Fibrosus Rupture Program of AO Foundation, Davos, Switzerland
| | - Stijn G Rotman
- Department of Biomaterials Science and Technology, University of Twente, Enschede, the Netherlands
| | - Warren W Hom
- Leni & Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Dylan J Assael
- Leni & Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Svenja Illien-Jünger
- Leni & Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Dirk W Grijpma
- Annulus Fibrosus Rupture Program of AO Foundation, Davos, Switzerland.,Department of Biomaterials Science and Technology, University of Twente, Enschede, the Netherlands.,Department of Biomedical Engineering, University of Groningen, University Medical Centre Groningen, Groningen, the Netherlands
| | - James C Iatridis
- Leni & Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Annulus Fibrosus Rupture Program of AO Foundation, Davos, Switzerland
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Zhu LG, Feng MS, Zhan JW, Zhang P, Yu J. Effect of Static Load on the Nucleus Pulposus of Rabbit Intervertebral Disc Motion Segment in Ex vivo Organ Culture. Chin Med J (Engl) 2017; 129:2338-46. [PMID: 27647194 PMCID: PMC5040021 DOI: 10.4103/0366-6999.190666] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Background: The development of mechanically active culture systems helps increase the understanding of the role of mechanical stress in intervertebral disc (IVD) degeneration. Motion segment cultures allow for preservation of the native IVD structure, and adjacent vertebral bodies facilitate the application and control of mechanical loads. The purpose of this study was to establish loading and organ culture methods for rabbit IVD motion segments to study the effect of static load on the whole disc organ. Methods: IVD motion segments were harvested from rabbit lumbar spines and cultured in no-loading 6-well plates (control conditions) or custom-made apparatuses under a constant, compressive load (3 kg, 0.5 MPa) for up to 14 days. Tissue integrity, matrix synthesis, and the matrix gene expression profile were assessed after 3, 7, and 14 days of culturing and compared with those of fresh tissues. Results: The results showed that ex vivo culturing of motion segments preserved tissue integrity under no-loading conditions for 14 days whereas the static load gradually destroyed the morphology after 3 days. Proteoglycan contents were decreased under both conditions, with a more obvious decrease under static load, and proteoglycan gene expression was also downregulated. However, under static load, immunohistochemical staining intensity and collagen Type II alpha 1 (COL2A1) gene expression were significantly enhanced (61.54 ± 5.91, P = 0.035) and upregulated (1.195 ± 0.040, P = 0.000), respectively, compared with those in the controls (P < 0.05). In contrast, under constant compression, these trends were reversed. Our initial results indicated that short-term static load stimulated the synthesis of collagen Type II alpha 1; however, sustained constant compression led to progressive degeneration and specifically to a decreased proteoglycan content. Conclusions: A loading and organ culture system for ex vivo rabbit IVD motion segments was developed. Using this system, we were able to study the effects of mechanical stimulation on the biology of IVDs, as well as the pathomechanics of IVD degeneration.
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Affiliation(s)
- Li-Guo Zhu
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing 100102; Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing 100102, China
| | - Min-Shan Feng
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing 100102; Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing 100102, China
| | - Jia-Wen Zhan
- Key Laboratory of Beijing of Palasy Technology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing 100102; General Orthopedics Department, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing 100102, China
| | - Ping Zhang
- Department of Pathology, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing 100102, China
| | - Jie Yu
- Spine Department 2, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing 100102, China
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32
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Li P, Gan Y, Wang H, Xu Y, Song L, Wang L, Ouyang B, Zhou Q. A Substance Exchanger-Based Bioreactor Culture of Pig Discs for Studying the Immature Nucleus Pulposus. Artif Organs 2017; 41:E308-E319. [PMID: 28188657 DOI: 10.1111/aor.12834] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 06/17/2016] [Accepted: 07/19/2016] [Indexed: 12/11/2022]
Abstract
Various research models have been developed to study the biology of disc cells. Recently, the adult disc nucleus pulposus (NP) has been well studied. However, the immature NP is underinvestigated due to a lack of a suitable model. This study aimed to establish an organ culture of immature porcine disc by optimizing culture conditions and using a self-developed substance exchanger-based bioreactor. Immature porcine discs were first cultured in the bioreactor for 7 days at various levels of glucose (low, medium, high), osmolarity (hypo-, iso-, hyper-) and serum (5, 10, 20%) to determine the respective optimal level. The porcine discs were then cultured under the optimized conditions in the novel bioreactor, and were compared with fresh discs at day 14. For high-glucose, iso-osmolarity, or 10% serum, cell viability, the gene expression profile (for anabolic genes and catabolic genes), and glycosaminoglycan (GAG) and hydroxyproline (HYP) contents were more favorable than for other levels of glucose, osmolarity, and serum. When the immature discs were cultured under the optimized conditions using the novel bioreactor for 14 days, the viability of the immature NP was maintained based on histology, cell viability, GAG and HYP contents, and matrix molecule expression. In conclusion, the viability of the immature NP in organ culture could be maintained under the optimized culture conditions (high-glucose, iso-osmolarity, and 10% serum) in the substance exchanger-based bioreactor.
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Affiliation(s)
- Pei Li
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University
| | - Yibo Gan
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University
| | - Haoming Wang
- Department of Orthopedic Surgery, Chongqing Three Gorges Central Hospital
| | - Yuan Xu
- Department of Orthopedic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Lei Song
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University
| | - Liyuan Wang
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University
| | - Bin Ouyang
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University
| | - Qiang Zhou
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University
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Antunes JC, Pereira CL, Teixeira GQ, Silva RV, Caldeira J, Grad S, Gonçalves RM, Barbosa MA. Poly(γ-glutamic acid) and poly(γ-glutamic acid)-based nanocomplexes enhance type II collagen production in intervertebral disc. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2017; 28:6. [PMID: 27885573 DOI: 10.1007/s10856-016-5787-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 01/12/2016] [Indexed: 06/06/2023]
Abstract
Intervertebral disc (IVD) degeneration often leads to low back pain, which is one of the major causes of disability worldwide, affecting more than 80% of the population. Although available treatments for degenerated IVD decrease symptoms' progression, they fail to address the underlying causes and to restore native IVD properties. Poly(γ-glutamic acid) (γ-PGA) has recently been shown to support the production of chondrogenic matrix by mesenchymal stem/stromal cells. γ-PGA/chitosan (Ch) nanocomplexes (NCs) have been proposed for several biomedical applications, showing advantages compared with either polymer alone. Hence, this study explores the potential of γ-PGA and γ-PGA/Ch NCs for IVD regeneration. Nucleotomised bovine IVDs were cultured ex vivo upon injection of γ-PGA (pH 7.4) and γ-PGA/Ch NCs (pH 5.0 and pH 7.4). Tissue metabolic activity and nucleus pulposus DNA content were significantly reduced when NCs were injected in acidic-buffered solution (pH 5.0). However, at pH 7.4, both γ-PGA and NCs promoted sulphated glycosaminoglycan production and significant type II collagen synthesis, as determined at the protein level. This study is a first proof of concept that γ-PGA and γ-PGA/Ch NCs promote recovery of IVD native matrix, opening new perspectives on the development of alternative therapeutic approaches for IVD degeneration.
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Affiliation(s)
- Joana C Antunes
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, Porto, 4200-465, Portugal
| | - Catarina Leite Pereira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, Porto, 4050-313, Portugal
| | - Graciosa Q Teixeira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, Porto, 4050-313, Portugal
| | - Ricardo V Silva
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
| | - Joana Caldeira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
| | - Sibylle Grad
- AO Research Institute, Davos, Clavadelerstrasse 8, Davos, 7270, Switzerland
| | - Raquel M Gonçalves
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
| | - Mário A Barbosa
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal.
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal.
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, Porto, 4050-313, Portugal.
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Nikkhoo M, Wang JL, Abdollahi M, Hsu YC, Parnianpour M, Khalaf K. A regenerative approach towards recovering the mechanical properties of degenerated intervertebral discs: Genipin and platelet-rich plasma therapies. Proc Inst Mech Eng H 2016; 231:127-137. [PMID: 28019241 DOI: 10.1177/0954411916681597] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Degenerative disc disease, associated with discrete structural changes in the peripheral annulus and vertebral endplate, is one of the most common pathological triggers of acute and chronic low back pain, significantly depreciating an individual's quality of life and instigating huge socioeconomic costs. Novel emerging therapeutic techniques are hence of great interest to both research and clinical communities alike. Exogenous crosslinking, such as Genipin, and platelet-rich plasma therapies have been recently demonstrated encouraging results for the repair and regeneration of degenerated discs, but there remains a knowledge gap regarding the quantitative degree of effectiveness and particular influence on the mechanical properties of the disc. This study aimed to investigate and quantify the material properties of intact (N = 8), trypsin-denatured (N = 8), Genipin-treated (N = 8), and platelet-rich plasma-treated (N = 8) discs in 32 porcine thoracic motion segments. A poroelastic finite element model was used to describe the mechanical properties during different treatments, while a meta-model analytical approach was used in combination with ex vivo experiments to extract the poroelastic material properties. The results revealed that both Genipin and platelet-rich plasma are able to recover the mechanical properties of denatured discs, thereby affording promising therapeutic modalities. However, platelet-rich plasma-treated discs fared slightly, but not significantly, better than Genipin in terms of recovering the glycosaminoglycans content, an essential building block for healthy discs. In addition to investigating these particular degenerative disc disease therapies, this study provides a systematic methodology for quantifying the detailed poroelastic mechanical properties of intervertebral disc.
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Affiliation(s)
- Mohammad Nikkhoo
- 1 Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Jaw-Lin Wang
- 2 Institute of Biomedical Engineering, College of Medicine and Engineering, National Taiwan University, Taipei, Taiwan, ROC
| | - Masoud Abdollahi
- 3 Laboratory of Wearable Technologies & Neuromusculoskeletal Research, Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Yu-Chun Hsu
- 2 Institute of Biomedical Engineering, College of Medicine and Engineering, National Taiwan University, Taipei, Taiwan, ROC
| | - Mohamad Parnianpour
- 3 Laboratory of Wearable Technologies & Neuromusculoskeletal Research, Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Kinda Khalaf
- 4 Department of Biomedical Engineering, Khalifa University of Science, Technology and Research, Abu Dhabi, UAE
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35
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Effect of Static Load on the Nucleus Pulposus of Rabbit Intervertebral Disc Motion Segment in an Organ Culture. BIOMED RESEARCH INTERNATIONAL 2016; 2016:2481712. [PMID: 27872846 PMCID: PMC5107879 DOI: 10.1155/2016/2481712] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 08/06/2016] [Accepted: 08/21/2016] [Indexed: 01/07/2023]
Abstract
The development of mechanically active culture systems helps in understanding of the role of mechanical stress in intervertebral disc (IVD) degeneration. Motion segment cultures facilitate the application and control of mechanical loads. The purpose of this study was to establish a culturing method for rabbit IVD motion segments to observe the effect of static load on the whole disc organ. Segments were cultured in custom-made apparatuses under a constant, compressive load (3 kg) for 2 weeks. Tissue integrity, matrix synthesis, and matrix gene expression profile were assessed and compared with fresh one. The results showed ex vivo culturing of samples gradually destroyed the morphology. Proteoglycan contents and gene expression were decreased and downregulated obviously. However, immunohistochemical staining intensity and collagen type II gene expression were significantly enhanced and upregulated. In contrast, these trends were reversed under constant compression. These results indicated short-term static load stimulated the synthesis of type II collagen; however, constant compression led to progressive degeneration and specifically to proteoglycan. Through this study a loading and organ-culturing system for ex vivo rabbit IVD motion segments was developed, which can be used to study the effects of mechanical stimulation on the biology of IVDs and the pathomechanics of IVD degeneration.
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36
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Iwasaki K, Sudo H, Kasahara Y, Yamada K, Ohnishi T, Tsujimoto T, Iwasaki N. Effects of Multiple Intra-articular Injections of 0.5% Bupivacaine on Normal and Osteoarthritic Joints in Rats. Arthroscopy 2016; 32:2026-2036. [PMID: 27132778 DOI: 10.1016/j.arthro.2016.02.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 01/30/2016] [Accepted: 02/01/2016] [Indexed: 02/02/2023]
Abstract
PURPOSE To determine the in vivo effects of multiple local anesthetic injections of 0.5% bupivacaine on normal and osteoarthritic articular cartilage. METHODS Rats with normal knee joints received an intra-articular injection of 0.9% saline solution or 0.5% bupivacaine in their right knees joint once a week for 5 consecutive weeks, starting 4 weeks after the beginning of the experiment. Rats were humanely killed at 8, 16, and 24 weeks. In a parallel experiment, rats underwent anterior cruciate ligament transection to induce osteoarthritic changes. These rats were subjected to the same protocol as those with normal knee joints, starting 4 weeks after the procedure. Static weight-bearing tests were performed on both hind limbs to evaluate changes in weight-bearing ability throughout the experiments. Rats were humanely killed at 8 and 16 weeks. Cell viability was assessed with confocal microscopy, using samples from the distal femur. Histologic assessment of osteoarthritis was performed using samples from the tibial plateau based on the Osteoarthritis Research Society International (OARSI) cartilage histopathology assessment system (i.e., OARSI score). RESULTS Static weight-bearing tests showed no significant changes after intra-articular injection of saline solution or bupivacaine, and bupivacaine injection did not increase weight bearing compared with saline solution injection, regardless of whether there were osteoarthritic changes. There were also no significant differences in cell viability, cell density, or OARSI scores between the saline solution and bupivacaine groups at each time point, regardless of whether osteoarthritic changes were induced. CONCLUSIONS This study suggested that single or intermittent intra-articular bupivacaine injections might not have deleterious effects on either osteoarthritic or normal joints. CLINICAL RELEVANCE There is no strong evidence that intra-articular bupivacaine injection induces degenerative changes in articular cartilage. Therefore, these results may apply to normal and osteoarthritic joints.
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Affiliation(s)
- Koji Iwasaki
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Hideki Sudo
- Department of Advanced Medicine for Spine and Spinal Cord Disorders, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
| | - Yasuhiko Kasahara
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Katsuhisa Yamada
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Takashi Ohnishi
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Takeru Tsujimoto
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Norimasa Iwasaki
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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37
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Abraham AC, Liu JW, Tang SY. Longitudinal changes in the structure and inflammatory response of the intervertebral disc due to stab injury in a murine organ culture model. J Orthop Res 2016; 34:1431-8. [PMID: 27273204 PMCID: PMC5324835 DOI: 10.1002/jor.23325] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 06/05/2016] [Indexed: 02/04/2023]
Abstract
Despite the significant public health impact of intervertebral disc (IVD) degeneration and low back pain, it remains challenging to investigate the multifactorial molecular mechanisms that drive the degenerative cascade. Organ culture model systems offer the advantage of allowing cells to live and interact with their native extracellular matrix, while simultaneously reducing the amount of biological variation and complexity present at the organismal level. Murine organ cultures in particular also allow the use of widely available genetically modified animals with molecular level reporters that would reveal insights on the degenerative cascade. Here, we utilize an organ culture system of murine lumbar functional spinal units where we are able to maintain the cellular, metabolic, and structural, and mechanical stability of the whole organ over a 21-day period. Furthermore, we describe a novel approach in organ culture by using tissues from animals with an NF-κB-luc reporter in combination with a mechanical injury model, and are able to show that proinflammatory factors and cytokines such as NF-κB and IL-6 produced by IVD cells can be monitored longitudinally during culture in a stab injury model. Taken together, we utilize a murine organ culture system that maintains the cellular and tissue level behavior of the intervertebral disc and apply it to transgenic animals that allow the monitoring of the inflammatory profile of IVDs. This approach could provide important insights on the molecular and metabolic mediators that regulate the homeostasis of the IVD. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1431-1438, 2016.
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Affiliation(s)
- Adam C. Abraham
- Department of Orthopedic Surgery, Washington University in St. Louis, 660 S. Euclid, Campus Box 8233, St. Louis 63103, Missouri
| | - Jennifer W. Liu
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, Whitaker Hall, Campus Box 1097, St. Louis 63130, Missouri
| | - Simon Y. Tang
- Department of Orthopedic Surgery, Washington University in St. Louis, 660 S. Euclid, Campus Box 8233, St. Louis 63103, Missouri
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, Whitaker Hall, Campus Box 1097, St. Louis 63130, Missouri
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri
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38
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Li P, Gan Y, Wang H, Xu Y, Song L, Zhang C, Li S, Zhou Q. Biological Responses of the Immature Annulus Fibrosus to Dynamic Compression in a Disc Perfusion Culture. Cells Tissues Organs 2016; 202:296-306. [PMID: 27415834 DOI: 10.1159/000446363] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2016] [Indexed: 11/19/2022] Open
Abstract
Mechanical stimuli participate in disc development and remodelling. However, the effects of mechanical load on the immature annulus fibrosus (AF) are largely unclear. This study aimed to investigate how the immature AF responded to dynamic compressive magnitude and duration. Immature porcine discs were bioreactor-cultured for 7 days and then dynamically compressed at various magnitudes (0.1, 0.2, 0.4, 0.8 and 1.3 MPa at a frequency of 1.0 Hz for 2 h/day) and durations (1, 2, 4 and 8 h/day at a magnitude of 0.4 MPa and a frequency of 1.0 Hz). Non-compressed discs were used as controls. The immature AF tissue was analysed for histology, gene expression (aggrecan, collagen I, ADAMTS-4, MMP-3, TIMP-1 and TIMP-3), biochemical content of glycosaminoglycans (GAG) and hydroxyproline (HYP) and aggrecan immunohistochemical staining. In the lower-compressive-magnitude groups (0.1, 0.2 and 0.4 MPa), the immature AF showed an up-regulation in the expression of matrix genes, GAG and HYP content and aggrecan deposition. In the compression duration groups, the GAG and HYP content and aggrecan deposition declined to a minimum in the 8-hour group, in which a catabolic gene expression profile was found. In conclusion, this study indicated that the effects of dynamic compression on the immature AF are magnitude and duration dependent and that catabolic remodelling within the immature AF can be induced by high compressive magnitudes and long compressive durations.
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39
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Grant M, Epure LM, Salem O, AlGarni N, Ciobanu O, Alaqeel M, Antoniou J, Mwale F. Development of a Large Animal Long-Term Intervertebral Disc Organ Culture Model That Includes the Bony Vertebrae for Ex Vivo Studies. Tissue Eng Part C Methods 2016; 22:636-43. [PMID: 27216856 DOI: 10.1089/ten.tec.2016.0049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Intervertebral disc (IVD) degeneration is a common cause of low back pain. Testing potential therapeutics in the regeneration of the disc requires the use of model systems. Although several animal models have been developed to investigate IVD degeneration, they are technically challenging to prepare, expensive, present with limitations when performing biomechanical studies on the disc, and are impractical in large-scale screening of novel anabolic and scaffolding agents. An IVD organ culture system offers an inexpensive alternative. In the current paradigm, the bony endplates are removed to allow for nutrient diffusion and maintenance of disc cell viability. Although this is an excellent system for testing biologics, it results in concave cartilage endplates and, as such, requires special platens for loading purposes in a bioreactor as flat ones can overload the annular disc region leading to improper loading. Furthermore, the absence of bone makes it unsuitable for applying complex cyclic loading, a topic of interest in the study of chronic progressive degeneration, as multiaxial loading is more representative of daily forces encountered by the IVD. We have developed and validated a novel long-term IVD organ culture model that retains vertebral bone and is easy to prepare. Our model is ideal for testing potential drugs and alternate-based therapies, in addition to investigating the long-term effects of loading paradigms on disc degeneration and repair.
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Affiliation(s)
- Michael Grant
- 1 Department of Surgery, McGill University , Montreal, Canada .,2 Orthopaedic Research Laboratory, Lady Davis Institute for Medical Research , Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Canada
| | - Laura M Epure
- 2 Orthopaedic Research Laboratory, Lady Davis Institute for Medical Research , Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Canada
| | - Omar Salem
- 1 Department of Surgery, McGill University , Montreal, Canada .,2 Orthopaedic Research Laboratory, Lady Davis Institute for Medical Research , Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Canada
| | - Nizar AlGarni
- 1 Department of Surgery, McGill University , Montreal, Canada .,2 Orthopaedic Research Laboratory, Lady Davis Institute for Medical Research , Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Canada
| | - Ovidiu Ciobanu
- 2 Orthopaedic Research Laboratory, Lady Davis Institute for Medical Research , Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Canada
| | - Motaz Alaqeel
- 1 Department of Surgery, McGill University , Montreal, Canada .,2 Orthopaedic Research Laboratory, Lady Davis Institute for Medical Research , Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Canada
| | - John Antoniou
- 1 Department of Surgery, McGill University , Montreal, Canada .,2 Orthopaedic Research Laboratory, Lady Davis Institute for Medical Research , Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Canada
| | - Fackson Mwale
- 1 Department of Surgery, McGill University , Montreal, Canada .,2 Orthopaedic Research Laboratory, Lady Davis Institute for Medical Research , Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Canada
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Li P, Shi R, Chen D, Gan Y, Xu Y, Song L, Li S, Zhou Q. Surgical removal and controlled trypsinization of the outer annulus fibrosus improves the bioactivity of the nucleus pulposus in a disc bioreactor culture. BMC Musculoskelet Disord 2016; 17:133. [PMID: 27000557 PMCID: PMC4802625 DOI: 10.1186/s12891-016-0990-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/17/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The maintenance of nucleus pulposus (NP) viability in vitro is difficult. The annulus fibrosus (AF) pathway reflects one nutrient transport channel and may have an important effect on NP viability in disc organ cultures. The present study describes a feasible disc pre-treatment involving the AF and investigates its efficacy in improving NP bioactivity in an in vitro disc bioreactor culture. METHODS Rabbit discs that were randomly assigned to the experimental group (EG) were pretreated via the surgical removal and controlled trypsinization of the outer AF. The discs in the control group (CG) did not receive any special treatment. All discs were organ-cultured in a self-developed bioreactor. Solute transport into the central NP was measured using a methylene blue solution. On days 7 and 14, histological properties, cell viability, cell membrane damage, gene expression and matrix composition within the NP in these two groups were compared with each other and with the corresponding parameters of fresh NP samples. Additionally, the structures of the outer AF and the cartilage endplate (CEP) following pre-treatment were also assessed. RESULTS The outer AF in the EG became disorganized, but no specific changes occurred in the CEP or the inner AF following pre-treatment. The discs in the EG exhibited increased penetration of methylene blue into the central NP. On days 7 and 14, the NP bioactivity in the EG was improved compared with that of the CG in terms of cell viability, cell membrane damage, gene expression profile and matrix synthesis. Moreover, cell viability and matrix synthesis parameters in the EG were more similar to those of fresh samples than they were to the same parameters in the CG on day 14. CONCLUSIONS Using this disc pre-treatment, i.e., the surgical removal and controlled trypsinization of the outer AF, NP bioactivity was better maintained for up to 14 days in an in vitro disc bioreactor culture.
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Affiliation(s)
- Pei Li
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University, Gao Tan Yan 29, Chongqing, 400038, China
| | - Rongmao Shi
- Department of Orthopedic Surgery, Kunming General Hospital of Chengdu Command, Kunming, Yunnan, 650032, China
| | - Daosen Chen
- The 91245 Troops of the Chinese People's Liberation Army, Huludao, Liaoning, 125000, China
| | - Yibo Gan
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University, Gao Tan Yan 29, Chongqing, 400038, China
| | - Yuan Xu
- Department of Orthopedic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Lei Song
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University, Gao Tan Yan 29, Chongqing, 400038, China
| | - Songtao Li
- Department of Orthopedic Surgery, No. 181 hospital of PLA, Guilin, Guangxi, 541002, China
| | - Qiang Zhou
- Department of Orthopedic Surgery, Southwest Hospital, Third Military Medical University, Gao Tan Yan 29, Chongqing, 400038, China.
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Gantenbein B, Illien-Jünger S, Chan SCW, Walser J, Haglund L, Ferguson SJ, Iatridis JC, Grad S. Organ culture bioreactors--platforms to study human intervertebral disc degeneration and regenerative therapy. Curr Stem Cell Res Ther 2016; 10:339-52. [PMID: 25764196 DOI: 10.2174/1574888x10666150312102948] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 02/25/2015] [Accepted: 03/01/2015] [Indexed: 12/31/2022]
Abstract
In recent decades the application of bioreactors has revolutionized the concept of culturing tissues and organs that require mechanical loading. In intervertebral disc (IVD) research, collaborative efforts of biomedical engineering, biology and mechatronics have led to the innovation of new loading devices that can maintain viable IVD organ explants from large animals and human cadavers in precisely defined nutritional and mechanical environments over extended culture periods. Particularly in spine and IVD research, these organ culture models offer appealing alternatives, as large bipedal animal models with naturally occurring IVD degeneration and a genetic background similar to the human condition do not exist. Latest research has demonstrated important concepts including the potential of homing of mesenchymal stem cells to nutritionally or mechanically stressed IVDs, and the regenerative potential of "smart" biomaterials for nucleus pulposus or annulus fibrosus repair. In this review, we summarize the current knowledge about cell therapy, injection of cytokines and short peptides to rescue the degenerating IVD. We further stress that most bioreactor systems simplify the real in vivo conditions providing a useful proof of concept. Limitations are that certain aspects of the immune host response and pain assessments cannot be addressed with ex vivo systems. Coccygeal animal disc models are commonly used because of their availability and similarity to human IVDs. Although in vitro loading environments are not identical to the human in vivo situation, 3D ex vivo organ culture models of large animal coccygeal and human lumbar IVDs should be seen as valid alternatives for screening and feasibility testing to augment existing small animal, large animal, and human clinical trial experiments.
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Affiliation(s)
- Benjamin Gantenbein
- Institute for Surgical Technology & Biomechanics, Medical Faculty, University, Stauffacherstrasse 78, CH-3014 Bern, Switzerland.
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Oxland TR. Fundamental biomechanics of the spine--What we have learned in the past 25 years and future directions. J Biomech 2015; 49:817-832. [PMID: 26706717 DOI: 10.1016/j.jbiomech.2015.10.035] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/10/2015] [Accepted: 10/23/2015] [Indexed: 12/20/2022]
Abstract
Since the publication of the 2nd edition of White and Panjabi׳s textbook, Clinical Biomechanics of the Spine in 1990, there has been considerable research on the biomechanics of the spine. The focus of this manuscript will be to review what we have learned in regards to the fundamentals of spine biomechanics. Topics addressed include the whole spine, the functional spinal unit, and the individual components of the spine (e.g. vertebra, intervertebral disc, spinal ligaments). In these broad categories, our understanding in 1990 is reviewed and the important knowledge or understanding gained through the subsequent 25 years of research is highlighted. Areas where our knowledge is lacking helps to identify promising topics for future research. In this manuscript, as in the White and Panjabi textbook, the emphasis is on experimental research using human material, either in vivo or in vitro. The insights gained from mathematical models and animal experimentation are included where other data are not available. This review is intended to celebrate the substantial gains that have been made in the field over these past 25 years and also to identify future research directions.
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Affiliation(s)
- Thomas R Oxland
- Departments of Orthopaedics and Mechanical Engineering, University of British Columbia, Canada; International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Canada.
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Stannard JT, Edamura K, Stoker AM, O'Connell GD, Kuroki K, Hung CT, Choma TJ, Cook JL. Development of a whole organ culture model for intervertebral disc disease. J Orthop Translat 2015; 5:1-8. [PMID: 30035069 PMCID: PMC5987001 DOI: 10.1016/j.jot.2015.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/13/2015] [Accepted: 08/03/2015] [Indexed: 01/08/2023] Open
Abstract
Background/Objective Whole organ in vitro intervertebral disc models have been associated with poor maintenance of cell viability. No previous studies have used a rotating wall vessel bioreactor for intervertebral disc explants culture. The purpose of this study was to develop and validate an in vitro model for the assessment of biological and biomechanical measures of intervertebral disc health and disease. Methods To this end, endplate-intervertebral disc-endplate whole organ explants were harvested from the tails of rats. For the injured group, the annulus fibrosus was penetrated with a 20G needle to the nucleus pulposus and aspirated. Explants were cultured in a rotating wall vessel bioreactor for 14 days. Results Cell viability and histologic assessments were performed at Day 0, Day 1, Day 7, and Day 14. Compressive mechanical properties of the intervertebral disc were assessed at Day 0 and Day 14. In the annulus fibrosus and nucleus pulposus cells, the uninjured group maintained high viability through 14 days of culture, whereas cell viability in annulus fibrosus and nucleus pulposus of the injured intervertebral discs was markedly lower at Day 7 and Day 14. Histologically, the uninjured intervertebral discs maintained cell viability and tissue morphology and architecture through 14 days, whereas the injured intervertebral discs showed areas of cell death, loss of extracellular matrix integrity, and architecture by Day 14. Stiffness values for uninjured intervertebral discs were similar at Day 0 and Day 14, whereas the stiffness for the injured intervertebral discs was approximately 2.5 times greater at Day 14. Conclusion These results suggest that whole organ intervertebral discs explants can be successfully cultured in a rotating wall vessel bioreactor to maintain cell viability and tissue architecture in both annulus fibrosus and nucleus pulposus for at least 14 days. In addition, the injury used produced pathologic changes consistent with those seen in degenerative intervertebral disc disease in humans. This model will permit further study into potential future treatments and other mechanisms of addressing intervertebral disc disease.
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Affiliation(s)
- James T. Stannard
- Comparative Orthopaedic Laboratory, University of Missouri, Columbia, MO, USA
| | - Kazuya Edamura
- Comparative Orthopaedic Laboratory, University of Missouri, Columbia, MO, USA
- Laboratory of Veterinary Surgery, Nihon University, Fujisawa, Kanagawa, Japan
| | - Aaron M. Stoker
- Comparative Orthopaedic Laboratory, University of Missouri, Columbia, MO, USA
| | - Grace D. O'Connell
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Keiichi Kuroki
- Comparative Orthopaedic Laboratory, University of Missouri, Columbia, MO, USA
| | - Clark T. Hung
- Laboratory of Veterinary Surgery, Nihon University, Fujisawa, Kanagawa, Japan
| | - Theodore J. Choma
- Department of Orthopaedic Surgery, University of Missouri, Columbia, MO, USA
| | - James L. Cook
- Comparative Orthopaedic Laboratory, University of Missouri, Columbia, MO, USA
- Corresponding author. Comparative Orthopaedic Laboratory, University of Missouri, 900 East Campus Drive, Columbia, MO 65211, USA.
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Vadalà G, Russo F, Pattappa G, Peroglio M, Stadelmann VA, Roughley P, Grad S, Alini M, Denaro V. A Nucleotomy Model with Intact Annulus Fibrosus to Test Intervertebral Disc Regeneration Strategies. Tissue Eng Part C Methods 2015; 21:1117-24. [PMID: 26035644 DOI: 10.1089/ten.tec.2015.0086] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
INTRODUCTION New cells/hydrogel-based treatments for intervertebral disc (IVD) regeneration need to be tested on animal models before clinical translation. Ovine IVD represents a good model but does not allow the injection of a significant volume into intact IVD. The aim of this study was to compare different methods to create a cavity into ovine nucleus pulposus (NP) by enzymatic digestion (E), mechanical nucleotomy (N), or a combining technique (E+N), as a model to study IVD regeneration strategies with intact annulus fibrosus (AF) in functional spinal units (FSUs) in vitro. METHODS The transpedicular approach via the endplate route (2 mm tunnel) was performed on ovine FSU (IVD and superior and inferior endplate) to access the NP. FSUs were treated by N (Arthroscopic shaver), E (Trypsin/Collagenase), or E+N. Treatments were evaluated macro- and microscopically. The degradation of proteoglycan (PG) around the cavity was assessed by gel electrophoresis. Cell viability was evaluated using the lactate dehydrogenase (LDH) assay. Cavity volume was quantified through computerized tomography after injection of agarose gel/contrast agent. RESULTS A cavity with intact AF was successfully created with all three methods. The N group showed high reproducibility, low PG degradation, and no endplate thinning. Histological analysis demonstrated NP matrix degradation in enzyme-treated groups, while the PG content was homogenous using mechanical discectomy. Cell viability was affected only in the E group. The cavity volume normalized to the total IVD volume was 5.2% ± 1.6% in E, 5.0% ± 1.4% in E+N, and 4.2% ± 0.1% in N. CONCLUSIONS Mechanical nucleotomy leads to a more reproducible and less destructive cavity in the NP. Enzymatic methods perform better in terms of cavity volume; however, the cells and PG of the surrounding tissue may be affected. The mechanical nucleotomy enables the creation of a cavity into the IVD while keeping the AF intact, allowing the injection of reproducible volumes of hydrogel and tissue engineering construct for preclinical tests.
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Affiliation(s)
- Gianluca Vadalà
- 1 Department of Orthopedic and Trauma Surgery, Campus Bio-Medico University of Rome , Rome, Italy .,2 Cell Factory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico , Milan, Italy
| | - Fabrizio Russo
- 1 Department of Orthopedic and Trauma Surgery, Campus Bio-Medico University of Rome , Rome, Italy
| | - Girish Pattappa
- 3 AO Research Institute Davos , Davos, Switzerland .,4 INSERM UMRS 791, LIOAD, Research Center for Osteoarticular and Dental Tissue Engineering , Nantes, France
| | | | | | | | - Sibylle Grad
- 3 AO Research Institute Davos , Davos, Switzerland
| | - Mauro Alini
- 3 AO Research Institute Davos , Davos, Switzerland
| | - Vincenzo Denaro
- 1 Department of Orthopedic and Trauma Surgery, Campus Bio-Medico University of Rome , Rome, Italy
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Walter BA, Likhitpanichkul M, Illien-Junger S, Roughley PJ, Hecht AC, Iatridis JC. TNFα transport induced by dynamic loading alters biomechanics of intact intervertebral discs. PLoS One 2015; 10:e0118358. [PMID: 25734788 PMCID: PMC4348425 DOI: 10.1371/journal.pone.0118358] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 12/19/2014] [Indexed: 12/18/2022] Open
Abstract
Objective Intervertebral disc (IVD) degeneration is an important contributor to the development of back pain, and a key factor relating pain and degeneration are the presence of pro-inflammatory cytokines and IVD motion. There is surprisingly limited understanding of how mechanics and inflammation interact in the IVD. This study investigated interactions between mechanical loading and pro-inflammatory cytokines in a large animal organ culture model to address fundamental questions regarding (i.) how inflammatory mediators arise within the IVD, (ii.) how long inflammatory mediators persist, and (iii.) how inflammatory mediators influence IVD biomechanics. Methods Bovine caudal IVDs were cultured for 6 or 20-days under static & dynamic loading with or without exogenous TNFα in the culture medium, simulating a consequence of inflammation of the surrounding spinal tissues. TNFα transport within the IVD was assessed via immunohistochemistry. Changes in IVD structural integrity (dimensions, histology & aggrecan degradation), biomechanical behavior (Creep, Recovery & Dynamic stiffness) and pro-inflammatory cytokines in the culture medium (ELISA) were assessed. Results TNFα was able to penetrate intact IVDs when subjected to dynamic loading but not static loading. Once transported within the IVD, pro-inflammatory mediators persisted for 4–8 days after TNFα removal. TNFα exposure induced changes in IVD biomechanics (reduced diurnal displacements & increased dynamic stiffness). Discussion This study demonstrated that exposure to TNFα, as might occur from injured surrounding tissues, can penetrate healthy intact IVDs, induce expression of additional pro-inflammatory cytokines and alter IVD mechanical behavior. We conclude that exposure to pro-inflammatory cytokine may be an initiating event in the progression of IVD degeneration in addition to being a consequence of disease.
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Affiliation(s)
- Benjamin A. Walter
- Leni & Peter W. May Department of Orthopaedics at the Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States of America
| | - Morakot Likhitpanichkul
- Leni & Peter W. May Department of Orthopaedics at the Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | - Svenja Illien-Junger
- Leni & Peter W. May Department of Orthopaedics at the Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | | | - Andrew C. Hecht
- Leni & Peter W. May Department of Orthopaedics at the Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | - James C. Iatridis
- Leni & Peter W. May Department of Orthopaedics at the Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
- * E-mail:
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Genetic and functional studies of the intervertebral disc: a novel murine intervertebral disc model. PLoS One 2014; 9:e112454. [PMID: 25474689 PMCID: PMC4256369 DOI: 10.1371/journal.pone.0112454] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 10/06/2014] [Indexed: 12/21/2022] Open
Abstract
Intervertebral disc (IVD) homeostasis is mediated through a combination of micro-environmental and biomechanical factors, all of which are subject to genetic influences. The aim of this study is to develop and characterize a genetically tractable, ex vivo organ culture model that can be used to further elucidate mechanisms of intervertebral disc disease. Specifically, we demonstrate that IVD disc explants (1) maintain their native phenotype in prolonged culture, (2) are responsive to exogenous stimuli, and (3) that relevant homeostatic regulatory mechanisms can be modulated through ex-vivo genetic recombination. We present a novel technique for isolation of murine IVD explants with demonstration of explant viability (CMFDA/propidium iodide staining), disc anatomy (H&E), maintenance of extracellular matrix (ECM) (Alcian Blue staining), and native expression profile (qRT-PCR) as well as ex vivo genetic recombination (mT/mG reporter mice; AdCre) following 14 days of culture in DMEM media containing 10% fetal bovine serum, 1% L-glutamine, and 1% penicillin/streptomycin. IVD explants maintained their micro-anatomic integrity, ECM proteoglycan content, viability, and gene expression profile consistent with a homeostatic drive in culture. Treatment of genetically engineered explants with cre-expressing adenovirus efficaciously induced ex vivo genetic recombination in a variety of genetically engineered mouse models. Exogenous administration of IL-1ß and TGF-ß3 resulted in predicted catabolic and anabolic responses, respectively. Genetic recombination of TGFBR1fl/fl explants resulted in constitutively active TGF-ß signaling that matched that of exogenously administered TGF-ß3. Our results illustrate the utility of the murine intervertebral disc explant to investigate mechanisms of intervertebral disc degeneration.
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Castro APG, Paul CPL, Detiger SEL, Smit TH, van Royen BJ, Pimenta Claro JC, Mullender MG, Alves JL. Long-Term Creep Behavior of the Intervertebral Disk: Comparison between Bioreactor Data and Numerical Results. Front Bioeng Biotechnol 2014; 2:56. [PMID: 25485264 PMCID: PMC4239653 DOI: 10.3389/fbioe.2014.00056] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 11/04/2014] [Indexed: 11/13/2022] Open
Abstract
The loaded disk culture system is an intervertebral disk (IVD)-oriented bioreactor developed by the VU Medical Center (VUmc, Amsterdam, The Netherlands), which has the capacity of maintaining up to 12 IVDs in culture, for approximately 3 weeks after extraction. Using this system, eight goat IVDs were provided with the essential nutrients and submitted to compression tests without losing their biomechanical and physiological properties, for 22 days. Based on previous reports (Paul et al., 2012, 2013; Detiger et al., 2013), four of these IVDs were kept in physiological condition (control) and the other four were previously injected with chondroitinase ABC (CABC), in order to promote degenerative disk disease (DDD). The loading profile intercalated 16 h of activity loading with 8 h of loading recovery to express the standard circadian variations. The displacement behavior of these eight IVDs along the first 2 days of the experiment was numerically reproduced, using an IVD osmo-poro-hyper-viscoelastic and fiber-reinforced finite element (FE) model. The simulations were run on a custom FE solver (Castro et al., 2014). The analysis of the experimental results allowed concluding that the effect of the CABC injection was only significant in two of the four IVDs. The four control IVDs showed no signs of degeneration, as expected. In what concerns to the numerical simulations, the IVD FE model was able to reproduce the generic behavior of the two groups of goat IVDs (control and injected). However, some discrepancies were still noticed on the comparison between the injected IVDs and the numerical simulations, namely on the recovery periods. This may be justified by the complexity of the pathways for DDD, associated with the multiplicity of physiological responses to each direct or indirect stimulus. Nevertheless, one could conclude that ligaments, muscles, and IVD covering membranes could be added to the FE model, in order to improve its accuracy and properly describe the recovery periods.
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Affiliation(s)
- A P G Castro
- Center for Mechanical and Materials Technologies, Department of Mechanical Engineering, University of Minho , Guimarães , Portugal ; INSIGNEO Institute for in silico Medicine, Department of Mechanical Engineering, University of Sheffield , Sheffield , UK
| | - C P L Paul
- Department of Orthopaedic Surgery, VU Medical Center , Amsterdam , Netherlands ; Research Institute MOVE, Faculty of Human Movement Sciences, VU Medical Center , Amsterdam , Netherlands
| | - S E L Detiger
- Department of Orthopaedic Surgery, VU Medical Center , Amsterdam , Netherlands ; Research Institute MOVE, Faculty of Human Movement Sciences, VU Medical Center , Amsterdam , Netherlands ; Skeletal Tissue Engineering Group Amsterdam, VU Medical Center , Amsterdam , Netherlands
| | - T H Smit
- Department of Orthopaedic Surgery, VU Medical Center , Amsterdam , Netherlands ; Research Institute MOVE, Faculty of Human Movement Sciences, VU Medical Center , Amsterdam , Netherlands ; Skeletal Tissue Engineering Group Amsterdam, VU Medical Center , Amsterdam , Netherlands
| | - B J van Royen
- Department of Orthopaedic Surgery, VU Medical Center , Amsterdam , Netherlands ; Research Institute MOVE, Faculty of Human Movement Sciences, VU Medical Center , Amsterdam , Netherlands ; Skeletal Tissue Engineering Group Amsterdam, VU Medical Center , Amsterdam , Netherlands
| | - J C Pimenta Claro
- Center for Mechanical and Materials Technologies, Department of Mechanical Engineering, University of Minho , Guimarães , Portugal
| | - M G Mullender
- Department of Orthopaedic Surgery, VU Medical Center , Amsterdam , Netherlands ; Research Institute MOVE, Faculty of Human Movement Sciences, VU Medical Center , Amsterdam , Netherlands ; Department of Plastic, Reconstructive and Hand Surgery, VU Medical Center , Amsterdam , Netherlands
| | - J L Alves
- Center for Mechanical and Materials Technologies, Department of Mechanical Engineering, University of Minho , Guimarães , Portugal
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O'Connell GD, Newman IB, Carapezza MA. Effect of long-term osmotic loading culture on matrix synthesis from intervertebral disc cells. Biores Open Access 2014; 3:242-9. [PMID: 25371861 PMCID: PMC4215332 DOI: 10.1089/biores.2014.0021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The intervertebral disc is a highly hydrated tissue that acts to absorb and distribute large complex loads placed on the spine. Diurnal loading and disc degeneration causes significant changes in water volume and proteoglycan content, which alters the internal osmotic environment. Short-term osmotic loading alters disc cell gene expression; however, the long-term effect of osmotic loading on disc cell matrix synthesis is not well understood. The objective of this study was to determine the effect of long-term osmotic loading on matrix turnover and proliferation by juvenile and adult cells from the nucleus pulposus (NP) and the cartilaginous endplate (EP). Matrix synthesis was evaluated using pellets and a 3D agarose system, which has been used for developing engineered tissues. Intervertebral discs were acquired from juvenile and adult cows. Cells were acquired through enzymatic digestion and expanded in culture. Pellets were formed through centrifugation, and constructs were created by encapsulating cells within 2% w/v agarose hydrogel. Pellets and constructs were cultured up to 42 days in chemically defined medium with the osmolality adjusted to 300, 400, or 500 mOsm/kg. EP cells were evaluated as a chondrocyte comparison to chondrocyte-like NP cells. Pellet and agarose cultures of juvenile NP and EP cells demonstrated similarities with respect to cell proliferation and functional mechanical properties. Cell proliferation decreased significantly with increased osmotic loading. The final compressive Young's modulus of juvenile NP cells was 10–40× greater than initial properties (i.e., day 0) and was greater than the final Young's modulus of adult NP and juvenile EP constructs. In juvenile NP constructs, there were no significant differences in GAG content with respect to osmotic loading. However, GAG synthesis and mechanical properties were greatest for the 400 mOsm/kg group in adult NP constructs. Taken together, the results presented here suggest a tradeoff between cell proliferation and matrix production under osmotic loading conditions. In conclusion, culturing disc cells in an osmotic environment that best mimics the healthy disc environment (400 mOsm/kg) may be ideal for balancing cell proliferation, matrix production, and mechanical properties of engineered disc tissues.
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Affiliation(s)
- Grace D O'Connell
- Department of Mechanical Engineering, University of California , Berkeley, California
| | - Isabella B Newman
- Department of Biomedical Engineering, Columbia University , New York, New York
| | - Michael A Carapezza
- Department of Biomedical Engineering, Columbia University , New York, New York
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Iwasaki K, Sudo H, Yamada K, Higashi H, Ohnishi T, Tsujimoto T, Iwasaki N. Effects of single injection of local anesthetic agents on intervertebral disc degeneration: ex vivo and long-term in vivo experimental study. PLoS One 2014; 9:e109851. [PMID: 25286407 PMCID: PMC4186881 DOI: 10.1371/journal.pone.0109851] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/03/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Analgesic discography (discoblock) can be used to diagnose or treat discogenic low back pain by injecting a small amount of local anesthetics. However, recent in vitro studies have revealed cytotoxic effects of local anesthetics on intervertebral disc (IVD) cells. Here we aimed to investigate the deteriorative effects of lidocaine and bupivacaine on rabbit IVDs using an organotypic culture model and an in vivo long-term follow-up model. METHODS For the organotypic culture model, rabbit IVDs were harvested and cultured for 3 or 7 days after intradiscal injection of local anesthetics (1% lidocaine or 0.5% bupivacaine). Nucleus pulposus (NP) cell death was measured using confocal microscopy. Histological and TUNEL assays were performed. For in vivo study, each local anesthetic was injected into rabbit lumbar IVDs under a fluoroscope. Six or 12 months after the injection, each IVD was prepared for magnetic resonance imaging (MRI) and histological analysis. RESULTS In the organotypic culture model, both anesthetic agents induced time-dependent NP cell death; when compared with injected saline solution, significant effects were detected within 7 days. Compared with the saline group, TUNEL-positive NP cells were significantly increased in the bupivacaine group. In the in vivo study, MRI analysis did not show any significant difference. Histological analysis revealed that IVD degeneration occurred to a significantly level in the saline- and local anesthetics-injected groups compared with the untreated control or puncture-only groups. However, there was no significant difference between the saline and anesthetic agents groups. CONCLUSIONS/SIGNIFICANCE In the in vivo model using healthy IVDs, there was no strong evidence to suggest that discoblock with local anesthetics has the potential of inducing IVD degeneration other than the initial mechanical damage of the pressurized injection. Further studies should be performed to investigate the deteriorative effects of the local injection of analgesic agents on degenerated IVDs.
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Affiliation(s)
- Koji Iwasaki
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Hideki Sudo
- Department of Advanced Medicine for Spine and Spinal Cord Disorders, Hokkaido University Graduate School of Medicine, Sapporo, Japan
- * E-mail:
| | - Katsuhisa Yamada
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Hideaki Higashi
- Division of Infection and Immunity, Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan
| | - Takashi Ohnishi
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Takeru Tsujimoto
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Norimasa Iwasaki
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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Likhitpanichkul M, Dreischarf M, Illien-Junger S, Walter BA, Nukaga T, Long RG, Sakai D, Hecht AC, Iatridis JC. Fibrin-genipin adhesive hydrogel for annulus fibrosus repair: performance evaluation with large animal organ culture, in situ biomechanics, and in vivo degradation tests. Eur Cell Mater 2014; 28:25-37; discussion 37-8. [PMID: 25036053 PMCID: PMC4409328 DOI: 10.22203/ecm.v028a03] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Annulus fibrosus (AF) defects from annular tears, herniation, and discectomy procedures are associated with painful conditions and accelerated intervertebral disc (IVD) degeneration. Currently, no effective treatments exist to repair AF damage, restore IVD biomechanics and promote tissue regeneration. An injectable fibrin-genipin adhesive hydrogel (Fib-Gen) was evaluated for its performance repairing large AF defects in a bovine caudal IVD model using ex vivo organ culture and biomechanical testing of motion segments, and for its in vivo longevity and biocompatibility in a rat model by subcutaneous implantation. Fib-Gen sealed AF defects, prevented IVD height loss, and remained well-integrated with native AF tissue following approximately 14,000 cycles of compression in 6-day organ culture experiments. Fib-Gen repair also retained high viability of native AF cells near the repair site, reduced nitric oxide released to the media, and showed evidence of AF cell migration into the gel. Biomechanically, Fib-Gen fully restored compressive stiffness to intact levels validating organ culture findings. However, only partial restoration of tensile and torsional stiffness was obtained, suggesting opportunities to enhance this formulation. Subcutaneous implantation results, when compared with the literature, suggested Fib-Gen exhibited similar biocompatibility behaviour to fibrin alone but degraded much more slowly. We conclude that injectable Fib-Gen successfully sealed large AF defects, promoted functional restoration with improved motion segment biomechanics, and served as a biocompatible adhesive biomaterial that had greatly enhanced in vivo longevity compared to fibrin. Fib-Gen offers promise for AF repairs that may prevent painful conditions and accelerated degeneration of the IVD, and warrants further material development and evaluation.
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Affiliation(s)
- M. Likhitpanichkul
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Collaborative Research Partner Annulus Fibrosus Rupture Program of AO Foundation, Davos, Switzerland
| | - M. Dreischarf
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - S. Illien-Junger
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Collaborative Research Partner Annulus Fibrosus Rupture Program of AO Foundation, Davos, Switzerland
| | - B. A. Walter
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - T. Nukaga
- Collaborative Research Partner Annulus Fibrosus Rupture Program of AO Foundation, Davos, Switzerland,Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
| | - R. G Long
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Collaborative Research Partner Annulus Fibrosus Rupture Program of AO Foundation, Davos, Switzerland
| | - D. Sakai
- Collaborative Research Partner Annulus Fibrosus Rupture Program of AO Foundation, Davos, Switzerland,Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
| | - A. C. Hecht
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - J. C. Iatridis
- Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Collaborative Research Partner Annulus Fibrosus Rupture Program of AO Foundation, Davos, Switzerland,Address for correspondence: James C. Iatridis, PhD, Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box1188, New York, NY 10029, USA, Telephone Number: 1-212-241-1517, FAX Number: 1-212-876-3168,
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