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Dejea H, Pierantoni M, Orozco GA, B Wrammerfors ET, Gstöhl SJ, Schlepütz CM, Isaksson H. In Situ Loading and Time-Resolved Synchrotron-Based Phase Contrast Tomography for the Mechanical Investigation of Connective Knee Tissues: A Proof-of-Concept Study. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308811. [PMID: 38520713 DOI: 10.1002/advs.202308811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 02/26/2024] [Indexed: 03/25/2024]
Abstract
Articular cartilage and meniscus transfer and distribute mechanical loads in the knee joint. Degeneration of these connective tissues occurs during the progression of knee osteoarthritis, which affects their composition, microstructure, and mechanical properties. A deeper understanding of disease progression can be obtained by studying them simultaneously. Time-resolved synchrotron-based X-ray phase-contrast tomography (SR-PhC-µCT) allows to capture the tissue dynamics. This proof-of-concept study presents a rheometer setup for simultaneous in situ unconfined compression and SR-PhC-µCT of connective knee tissues. The microstructural response of bovine cartilage (n = 16) and meniscus (n = 4) samples under axial continuously increased strain, or two steps of 15% strain (stress-relaxation) is studied. The chondrocyte distribution in cartilage and the collagen fiber orientation in the meniscus are assessed. Variations in chondrocyte density reveal an increase in the top 40% of the sample during loading, compared to the lower half. Meniscus collagen fibers reorient perpendicular to the loading direction during compression and partially redisperse during relaxation. Radiation damage, image repeatability, and image quality assessments show little to no effects on the results. In conclusion, this approach is highly promising for future studies of human knee tissues to understand their microstructure, mechanical response, and progression in degenerative diseases.
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Affiliation(s)
- Hector Dejea
- Department of Biomedical Engineering, Lund University, Box 118, Lund, 221 00, Sweden
- MAX IV Laboratory, Lund University, Lund, 224 84, Sweden
| | - Maria Pierantoni
- Department of Biomedical Engineering, Lund University, Box 118, Lund, 221 00, Sweden
| | - Gustavo A Orozco
- Department of Biomedical Engineering, Lund University, Box 118, Lund, 221 00, Sweden
| | | | - Stefan J Gstöhl
- Swiss Light Source, Paul Scherrer Institute, Villigen PSI, 5232, Switzerland
| | | | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Box 118, Lund, 221 00, Sweden
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2
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B Wrammerfors ET, Törnquist E, Pierantoni M, Sjögren A, Tengattini A, Kaestner A, Zandt RI', Englund M, Isaksson H. Exploratory neutron tomography of articular cartilage. Osteoarthritis Cartilage 2024; 32:702-712. [PMID: 38447631 DOI: 10.1016/j.joca.2024.02.889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 02/28/2024] [Accepted: 02/28/2024] [Indexed: 03/08/2024]
Abstract
OBJECTIVE To investigate the feasibility of using neutron tomography to gain new knowledge of human articular cartilage degeneration in osteoarthritis (OA). Different sample preparation techniques were evaluated to identify maximum intra-tissue contrast. DESIGN Human articular cartilage samples from 14 deceased donors (18-75 years, 9 males, 5 females) and 4 patients undergoing total knee replacement due to known OA (all female, 61-75 years) were prepared using different techniques: control in saline, treated with heavy water saline, fixed and treated in heavy water saline, and fixed and dehydrated with ethanol. Neutron tomographic imaging (isotropic voxel sizes from 7.5 to 13.5 µm) was performed at two large scale facilities. The 3D images were evaluated for gradients in hydrogen attenuation as well as compared to images from absorption X-ray tomography, magnetic resonance imaging, and histology. RESULTS Cartilage was distinguishable from background and other tissues in neutron tomographs. Intra-tissue contrast was highest in heavy water-treated samples, which showed a clear gradient from the cartilage surface to the bone interface. Increased neutron flux or exposure time improved image quality but did not affect the ability to detect gradients. Samples from older donors showed high variation in gradient profile, especially from donors with known OA. CONCLUSIONS Neutron tomography is a viable technique for specialized studies of cartilage, particularly for quantifying properties relating to the hydrogen density of the tissue matrix or water movement in the tissue.
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Affiliation(s)
| | - Elin Törnquist
- Department of Biomedical Engineering, Lund University (LU), Sweden
| | - Maria Pierantoni
- Department of Biomedical Engineering, Lund University (LU), Sweden
| | - Amanda Sjögren
- Clinical Epidemiology Unit, Orthopedics, Department of Clinical Sciences Lund, LU, Sweden
| | | | - Anders Kaestner
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut (PSI), Switzerland
| | | | - Martin Englund
- Clinical Epidemiology Unit, Orthopedics, Department of Clinical Sciences Lund, LU, Sweden
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University (LU), Sweden
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3
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Sensini A, Stamati O, Marchiori G, Sancisi N, Gotti C, Giavaresi G, Cristofolini L, Focarete ML, Zucchelli A, Tozzi G. Full-field strain distribution in hierarchical electrospun nanofibrous poly-L(lactic) acid/collagen scaffolds for tendon and ligament regeneration: A multiscale study. Heliyon 2024; 10:e26796. [PMID: 38444492 PMCID: PMC10912460 DOI: 10.1016/j.heliyon.2024.e26796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 02/19/2024] [Accepted: 02/20/2024] [Indexed: 03/07/2024] Open
Abstract
Regeneration of injured tendons and ligaments (T/L) is a worldwide need. In this study electrospun hierarchical scaffolds made of a poly-L (lactic) acid/collagen blend were developed reproducing all the multiscale levels of aggregation of these tissues. Scanning electron microscopy, microCT and tensile mechanical tests were carried out, including a multiscale digital volume correlation analysis to measure the full-field strain distribution of electrospun structures. The principal strains (εp1 and εp3) described the pattern of strains caused by the nanofibers rearrangement, while the deviatoric strains (εD) revealed the related internal sliding of nanofibers and bundles. The results of this study confirmed the biomimicry of such electrospun hierarchical scaffolds, paving the way to further tissue engineering and clinical applications.
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Affiliation(s)
- Alberto Sensini
- Department of Complex Tissue Regeneration and cell Biology-Inspired Tissue Regeneration, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands
- Department of Industrial Engineering, Alma Mater Studiorum—Università di Bologna, Bologna, Italy
| | | | - Gregorio Marchiori
- Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Nicola Sancisi
- Department of Industrial Engineering, Alma Mater Studiorum—Università di Bologna, Bologna, Italy
| | - Carlo Gotti
- Advanced Mechanics and Materials – Interdepartmental Center for Industrial Research (CIRI-MAM), Alma Mater Studiorum—University of Bologna, Bologna, Italy
| | - Gianluca Giavaresi
- Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Luca Cristofolini
- Department of Complex Tissue Regeneration and cell Biology-Inspired Tissue Regeneration, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands
- Health Sciences and Technologies—Interdepartmental Center for Industrial Research (HST-ICIR), Alma Mater Studiorum—Università di Bologna, I-40064, Ozzano dell'Emilia, Bologna, Italy
| | - Maria Letizia Focarete
- Health Sciences and Technologies—Interdepartmental Center for Industrial Research (HST-ICIR), Alma Mater Studiorum—Università di Bologna, I-40064, Ozzano dell'Emilia, Bologna, Italy
- Department of Chemistry 'G. Ciamician' and National Consortium of Materials Science and Technology (INSTM, Bologna RU), Alma Mater Studiorum—Università di Bologna, Bologna, Italy
| | - Andrea Zucchelli
- Department of Industrial Engineering, Alma Mater Studiorum—Università di Bologna, Bologna, Italy
- Advanced Mechanics and Materials – Interdepartmental Center for Industrial Research (CIRI-MAM), Alma Mater Studiorum—University of Bologna, Bologna, Italy
| | - Gianluca Tozzi
- Centre for Advanced Manufacturing and Materials, School of Engineering, University of Greenwich, Chatham Maritime, United Kingdom
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4
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Silva Barreto I, Pierantoni M, Nielsen LC, Hammerman M, Diaz A, Novak V, Eliasson P, Liebi M, Isaksson H. Micro- and nanostructure specific X-ray tomography reveals less matrix formation and altered collagen organization following reduced loading during Achilles tendon healing. Acta Biomater 2024; 174:245-257. [PMID: 38096959 DOI: 10.1016/j.actbio.2023.12.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/25/2023]
Abstract
Recovery of the collagen structure following Achilles tendon rupture is poor, resulting in a high risk for re-ruptures. The loading environment during healing affects the mechanical properties of the tendon, but the relation between loading regime and healing outcome remains unclear. This is partially due to our limited understanding regarding the effects of loading on the micro- and nanostructure of the healing tissue. We addressed this through a combination of synchrotron phase-contrast X-ray microtomography and small-angle X-ray scattering tensor tomography (SASTT) to visualize the 3D organization of microscale fibers and nanoscale fibrils, respectively. The effect of in vivo loading on these structures was characterized in early healing of rat Achilles tendons by comparing full activity with immobilization. Unloading resulted in structural changes that can explain the reported impaired mechanical performance. In particular, unloading led to slower tissue regeneration and maturation, with less and more disorganized collagen, as well as an increased presence of adipose tissue. This study provides the first application of SASTT on soft musculoskeletal tissues and clearly demonstrates its potential to investigate a variety of other collagenous tissues. STATEMENT OF SIGNIFICANCE: Currently our understanding of the mechanobiological effects on the recovery of the structural hierarchical organization of injured Achilles tendons is limited. We provide insight into how loading affects the healing process by using a cutting-edge approach to for the first time characterize the 3D micro- and nanostructure of the regenerating collagen. We uncovered that, during early healing, unloading results in a delayed and more disorganized regeneration of both fibers (microscale) and fibrils (nanoscale), as well as increased presence of adipose tissue. The results set the ground for the development of further specialized protocols for tendon recovery.
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Affiliation(s)
| | - Maria Pierantoni
- Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - Leonard C Nielsen
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Malin Hammerman
- Department of Biomedical Engineering, Lund University, Lund, Sweden; Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Ana Diaz
- Photon Science Division, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Vladimir Novak
- Photon Science Division, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Pernilla Eliasson
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Marianne Liebi
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden; Photon Science Division, Paul Scherrer Institute, Villigen PSI, Switzerland; Institute of materials, Ecole Polytechnique fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden
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5
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Furlani M, Riberti N, Gatto ML, Giuliani A. High-Resolution Phase-Contrast Tomography on Human Collagenous Tissues: A Comprehensive Review. Tomography 2023; 9:2116-2133. [PMID: 38133070 PMCID: PMC10748183 DOI: 10.3390/tomography9060166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/07/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023] Open
Abstract
Phase-contrast X-ray imaging is becoming increasingly considered since its first applications, which occurred almost 30 years ago. Particular emphasis was placed on studies that use this technique to investigate soft tissues, which cannot otherwise be investigated at a high resolution and in a three-dimensional manner, using conventional absorption-based settings. Indeed, its consistency and discrimination power in low absorbing samples, unified to being a not destructive analysis, are pushing interests on its utilization from researchers of different specializations, from botany, through zoology, to human physio-pathology research. In this regard, a challenging method for 3D imaging and quantitative analysis of collagenous tissues has spread in recent years: it is based on the unique characteristics of synchrotron radiation phase-contrast microTomography (PhC-microCT). In this review, the focus has been placed on the research based on the exploitation of synchrotron PhC-microCT for the investigation of collagenous tissue physio-pathologies from solely human samples. Collagen tissues' elasto-mechanic role bonds it to the morphology of the site it is extracted from, which could weaken the results coming from animal experimentations. Encouraging outcomes proved this technique to be suitable to access and quantify human collagenous tissues and persuaded different researchers to approach it. A brief mention was also dedicated to the results obtained on collagenous tissues using new and promising high-resolution phase-contrast tomographic laboratory-based setups, which will certainly represent the real step forward in the diffusion of this relatively young imaging technique.
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Affiliation(s)
- Michele Furlani
- Department DISCO, Università Politecnica delle Marche, Via Brecce Bianche 12, 60131 Ancona, Italy;
| | - Nicole Riberti
- Neuroscience Imaging and Clinical Sciences Department, University of Chieti-Pescara, 66100 Chieti, Italy;
| | - Maria Laura Gatto
- Department DIISM, Università Politecnica delle Marche, Via Brecce Bianche 12, 60131 Ancona, Italy;
| | - Alessandra Giuliani
- Department DISCO, Università Politecnica delle Marche, Via Brecce Bianche 12, 60131 Ancona, Italy;
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Pierantoni M, Silva Barreto I, Hammerman M, Novak V, Diaz A, Engqvist J, Eliasson P, Isaksson H. Multimodal and multiscale characterization reveals how tendon structure and mechanical response are altered by reduced loading. Acta Biomater 2023; 168:264-276. [PMID: 37479155 DOI: 10.1016/j.actbio.2023.07.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/30/2023] [Accepted: 07/14/2023] [Indexed: 07/23/2023]
Abstract
Tendons are collagen-based connective tissues where the composition, structure and mechanics respond and adapt to the local mechanical environment. Adaptation to prolonged inactivity can result in stiffer tendons that are more prone to injury. However, the complex relation between reduced loading, structure, and mechanical performance is still not fully understood. This study combines mechanical testing with high-resolution synchrotron X-ray imaging, scattering techniques and histology to elucidate how reduced loading affects the structural properties and mechanical response of rat Achilles tendons on multiple length scales. The results show that reduced in vivo loading leads to more crimped and less organized fibers and this structural inhomogeneity could be the reason for the altered mechanical response. Unloading also seems to change the fibril response, possibly by altering the strain partitioning between hierarchical levels, and to reduce cell density. This study elucidates the relation between in vivo loading, the Achilles tendon nano-, meso‑structure and mechanical response. The results provide fundamental insights into the mechanoregulatory mechanisms guiding the intricate biomechanics, tissue structural organization, and performance of complex collagen-based tissues. STATEMENT OF SIGNIFICANCE: Achilles tendon properties allow a dynamic interaction between muscles and tendon and influence force transmission during locomotion. Lack of physiological loading can have dramatic effects on tendon structure and mechanical properties. We have combined the use of cutting-edge high-resolution synchrotron techniques with mechanical testing to show how reduced loading affects the tendon on multiple hierarchical levels (from nanoscale up to whole organ) clarifying the relation between structural changes and mechanical performance. Our findings set the first step to address a significant healthcare challenge, such as the design of tailored rehabilitations that take into consideration structural changes after tendon immobilization.
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Affiliation(s)
- Maria Pierantoni
- Department of Biomedical Engineering, Lund University, Box 118, 221 00 Lund, Sweden.
| | | | - Malin Hammerman
- Department of Biomedical Engineering, Lund University, Box 118, 221 00 Lund, Sweden; Department of Biomedical and Clinical Sciences, Linköping University, 581 83 Linköping, Sweden
| | | | - Ana Diaz
- Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Jonas Engqvist
- Department of Solid Mechanics, Lund University, Box 118, 221 00 Lund, Sweden
| | - Pernilla Eliasson
- Department of Biomedical and Clinical Sciences, Linköping University, 581 83 Linköping, Sweden; Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Box 118, 221 00 Lund, Sweden
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7
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Tits A, Blouin S, Rummler M, Kaux JF, Drion P, van Lenthe GH, Weinkamer R, Hartmann MA, Ruffoni D. Structural and functional heterogeneity of mineralized fibrocartilage at the Achilles tendon-bone insertion. Acta Biomater 2023; 166:409-418. [PMID: 37088163 DOI: 10.1016/j.actbio.2023.04.018] [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: 12/21/2022] [Revised: 03/30/2023] [Accepted: 04/13/2023] [Indexed: 04/25/2023]
Abstract
A demanding task of the musculoskeletal system is the attachment of tendon to bone at entheses. This region often presents a thin layer of fibrocartilage (FC), mineralized close to the bone and unmineralized close to the tendon. Mineralized FC deserves increased attention, owing to its crucial anchoring task and involvement in enthesis pathologies. Here, we analyzed mineralized FC and subchondral bone at the Achilles tendon-bone insertion of rats. This location features enthesis FC anchoring tendon to bone and sustaining tensile loads, and periosteal FC facilitating bone-tendon sliding with accompanying compressive and shear forces. Using a correlative multimodal investigation, we evaluated potential specificities in mineral content, fiber organization and mechanical properties of enthesis and periosteal FC. Both tissues had a lower degree of mineralization than subchondral bone, yet used the available mineral very efficiently: for the same local mineral content, they had higher stiffness and hardness than bone. We found that enthesis FC was characterized by highly aligned mineralized collagen fibers even far away from the attachment region, whereas periosteal FC had a rich variety of fiber arrangements. Except for an initial steep spatial gradient between unmineralized and mineralized FC, local mechanical properties were surprisingly uniform inside enthesis FC while a modulation in stiffness, independent from mineral content, was observed in periosteal FC. We interpreted these different structure-property relationships as a demonstration of the high versatility of FC, providing high strength at the insertion (to resist tensile loading) and a gradual compliance at the periosteal surface (to resist contact stresses). STATEMENT OF SIGNIFICANCE: Mineralized fibrocartilage (FC) at entheses facilitates the integration of tendon in bone, two strongly dissimilar tissues. We focus on the structure-function relationships of two types of mineralized FC, enthesis and periosteal, which have clearly distinct mechanical demands. By investigating them with multiple high-resolution methods in a correlative manner, we demonstrate differences in fiber architecture and mechanical properties between the two tissues, indicative of their mechanical roles. Our results are relevant both from a medical viewpoint, targeting a clinically relevant location, as well as from a material science perspective, identifying FC as high-performance versatile composite.
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Affiliation(s)
- Alexandra Tits
- Mechanics of Biological and Bioinspired Materials Laboratory, Department of Aerospace and Mechanical Engineering, University of Liège, Liège, Belgium.
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria
| | - Maximilian Rummler
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany
| | - Jean-François Kaux
- Department of Physical Medicine and Sports Traumatology, University of Liège and University Hospital of Liège, Liège, Belgium
| | - Pierre Drion
- Experimental Surgery unit, GIGA & Credec, University of Liège, Liège, Belgium
| | | | - Richard Weinkamer
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria
| | - Davide Ruffoni
- Mechanics of Biological and Bioinspired Materials Laboratory, Department of Aerospace and Mechanical Engineering, University of Liège, Liège, Belgium.
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8
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Disney CM, Vo NT, Bodey AJ, Bay BK, Lee PD. Image quality and scan time optimisation for in situ phase contrast x-ray tomography of the intervertebral disc. J Mech Behav Biomed Mater 2023; 138:105579. [PMID: 36463809 DOI: 10.1016/j.jmbbm.2022.105579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 11/20/2022]
Abstract
In-line phase contrast synchrotron tomography combined with in situ mechanical loading enables the characterisation of soft tissue micromechanics via digital volume correlation (DVC) within whole organs. Optimising scan time is important for reducing radiation dose from multiple scans and to limit sample movement during acquisition. Also, although contrasted edges provided by in-line phase contrast tomography of soft tissues are useful for DVC, the effect of phase contrast imaging on its accuracy has yet to be investigated. Due to limited time at synchrotron facilities, scan parameters are often decided during imaging and their effect on DVC accuracy is not fully understood. Here, we used previously published data of intervertebral disc phase contrast tomography to evaluate the influence of i) fibrous image texture, ii) number of projections, iii) tomographic reconstruction method, and iv) phase contrast propagation distance on DVC results. A greater understanding of how image texture influences optimal DVC tracking was obtained by visualising objective function mapping, enabling tracking inaccuracies to be identified. When reducing the number of projections, DVC was minimally affected by image high frequency noise but with a compromise in accuracy. Iterative reconstruction methods improved image signal-to-noise and consequently significantly lowered DVC displacement uncertainty. Propagation distance was shown to affect DVC accuracy. Consistent DVC results were achieved within a propagation distance range which provided contrast to the smallest scale features, where; too short a distance provided insufficient features to track, whereas too long led to edge effect inconsistencies, particularly at greater deformations. Although limited to a single sample type and image setup, this study provides general guidelines for future investigations when optimising image quality and scan times for in situ phase contrast x-ray tomography of fibrous connective tissues.
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Affiliation(s)
- C M Disney
- Mechanical Engineering, University College London, UK; Diamond Light Source, UK.
| | - N T Vo
- Diamond Light Source, UK; National Synchrotron Light Source II, Brookhaven National Laboratory, USA
| | | | - B K Bay
- School of Mechanical, Industrial & Manufacturing Engineering, Oregon State University, USA
| | - P D Lee
- Mechanical Engineering, University College London, UK
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9
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Pierantoni M, Hammerman M, Silva Barreto I, Andersson L, Novak V, Isaksson H, Eliasson P. Heterotopic mineral deposits in intact rat Achilles tendons are characterized by a unique fiber-like structure. J Struct Biol X 2023; 7:100087. [PMID: 36938139 PMCID: PMC10018562 DOI: 10.1016/j.yjsbx.2023.100087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 02/16/2023] [Accepted: 02/19/2023] [Indexed: 02/26/2023] Open
Abstract
Heterotopic mineralization entails pathological mineral formation inside soft tissues. In human tendons mineralization is often associated with tendinopathies, tendon weakness and pain. In Achilles tendons, mineralization is considered to occur through heterotopic ossification (HO) primarily in response to tendon pathologies. However, refined details regarding HO deposition and microstructure are unknown. In this study, we characterize HO in intact rat Achilles tendons through high-resolution phase contrast enhanced synchrotron X-ray tomography. Furthermore, we test the potential of studying local tissue injury by needling intact Achilles tendons and the relation between tissue microdamage and HO. The results show that HO occurs in all intact Achilles tendons at 16 weeks of age. HO deposits are characterized by an elongated ellipsoidal shape and by a fiber-like internal structure which suggests that some collagen fibers have mineralized. The data indicates that deposition along fibers initiates in the pericellular area, and propagates into the intercellular area. Within HO deposits cells are larger and more rounded compared to tenocytes between unmineralized fibers, which are fewer and elongated. The results also indicate that multiple HO deposits may merge into bigger structures with time by accession along unmineralized fibers. Furthermore, the presence of unmineralized regions within the deposits may indicate that HOs are not only growing, but mineral resorption may also occur. Additionally, phase contrast synchrotron X-ray tomography allowed to distinguish microdamage at the fiber level in response to needling. The needle injury protocol could in the future enable to elucidate the relation between local inflammation, microdamage, and HO deposition.
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Affiliation(s)
- Maria Pierantoni
- Department of Biomedical Engineering, Lund University, Box 118, 221 00 Lund, Sweden
- Corresponding author.
| | - Malin Hammerman
- Department of Biomedical Engineering, Lund University, Box 118, 221 00 Lund, Sweden
- Department of Biomedical and Clinical Sciences, Linköping University, 581 83 Linköping, Sweden
| | | | - Linnea Andersson
- Department of Biomedical Engineering, Lund University, Box 118, 221 00 Lund, Sweden
| | - Vladimir Novak
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Box 118, 221 00 Lund, Sweden
| | - Pernilla Eliasson
- Department of Biomedical and Clinical Sciences, Linköping University, 581 83 Linköping, Sweden
- Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden
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10
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Dejea H, Schlepütz CM, Méndez-Carmona N, Arnold M, Garcia-Canadilla P, Longnus SL, Stampanoni M, Bijnens B, Bonnin A. A tomographic microscopy-compatible Langendorff system for the dynamic structural characterization of the cardiac cycle. Front Cardiovasc Med 2022; 9:1023483. [PMID: 36620622 PMCID: PMC9815149 DOI: 10.3389/fcvm.2022.1023483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 12/07/2022] [Indexed: 12/24/2022] Open
Abstract
Introduction Cardiac architecture has been extensively investigated ex vivo using a broad spectrum of imaging techniques. Nevertheless, the heart is a dynamic system and the structural mechanisms governing the cardiac cycle can only be unveiled when investigating it as such. Methods This work presents the customization of an isolated, perfused heart system compatible with synchrotron-based X-ray phase contrast imaging (X-PCI). Results Thanks to the capabilities of the developed setup, it was possible to visualize a beating isolated, perfused rat heart for the very first time in 4D at an unprecedented 2.75 μm pixel size (10.6 μm spatial resolution), and 1 ms temporal resolution. Discussion The customized setup allows high-spatial resolution studies of heart architecture along the cardiac cycle and has thus the potential to serve as a tool for the characterization of the structural dynamics of the heart, including the effects of drugs and other substances able to modify the cardiac cycle.
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Affiliation(s)
- Hector Dejea
- Paul Scherrer Institute, Villigen, Switzerland,Institute for Biomedical Engineering, University and ETH Zürich, Zurich, Switzerland,*Correspondence: Hector Dejea ✉
| | | | - Natalia Méndez-Carmona
- Department of Cardiac Surgery, Inselspital, Bern University Hospital, Bern, Switzerland,Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Maria Arnold
- Department of Cardiac Surgery, Inselspital, Bern University Hospital, Bern, Switzerland,Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Patricia Garcia-Canadilla
- BCNatal-Barcelona Center for Maternal-Fetal and Neonatal Medicine, Hospital Sant Joan de Déu and Hospital Clínic, University of Barcelona, Barcelona, Spain,Cardiovascular Diseases and Child Development, Institut de Recerca Sant Joan de Déu, Esplugues de Llobregat, Spain
| | - Sarah L. Longnus
- Department of Cardiac Surgery, Inselspital, Bern University Hospital, Bern, Switzerland,Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Marco Stampanoni
- Paul Scherrer Institute, Villigen, Switzerland,Institute for Biomedical Engineering, University and ETH Zürich, Zurich, Switzerland
| | - Bart Bijnens
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain,Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Anne Bonnin
- Paul Scherrer Institute, Villigen, Switzerland
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Einarsson E, Pierantoni M, Novak V, Svensson J, Isaksson H, Englund M. Phase-contrast enhanced synchrotron micro-tomography of human meniscus tissue. Osteoarthritis Cartilage 2022; 30:1222-1233. [PMID: 35750240 DOI: 10.1016/j.joca.2022.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/27/2022] [Accepted: 06/13/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the feasibility of synchrotron radiation-based phase contrast enhanced micro-computed tomography (SR-PhC-μCT) for imaging of human meniscus. Quantitative parameters related to fiber orientation and crimping were evaluated as potential markers of tissue degeneration. DESIGN Human meniscus specimens from 10 deceased donors were prepared using different preparation schemes: fresh frozen and thawed before imaging or fixed and paraffin-embedded. The samples were imaged using SR-PhC-μCT with an isotropic voxel size of 1.625 μm. Image quality was evaluated by visual inspection and spatial resolution. Fiber voxels were defined using a grey level threshold and a structure tensor analysis was applied to estimate collagen fiber orientation. The area at half maximum (FAHM) was calculated from angle histograms to quantify orientation distribution. Crimping period was calculated from the power spectrum of image profiles of crimped fibers. Parameters were compared to degenerative stage as evaluated by Pauli histopathological scoring. RESULTS Image quality was similar between frozen and embedded samples and spatial resolutions ranged from 5.1 to 5.8 μm. Fiber structure, including crimping, was clearly visible in the images. Fibers appeared to be less organized closer to the tip of the meniscus. Fiber density might decrease slightly with degeneration. FAHM and crimping period did not show any clear association with histopathological scoring. CONCLUSION SR-PhC-μCT is a feasible technique for high-resolution 3D imaging of fresh frozen meniscus tissue. Further work is needed to establish quantitative parameters that relate to tissue degeneration, but this imaging technique is promising for future studies of meniscus structure and biomechanical response.
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Affiliation(s)
- E Einarsson
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Malmö, Sweden; Clinical Epidemiology Unit, Orthopedics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden.
| | - M Pierantoni
- Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - V Novak
- Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland
| | - J Svensson
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Malmö, Sweden; Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - H Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - M Englund
- Clinical Epidemiology Unit, Orthopedics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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Dall'Ara E, Bodey AJ, Isaksson H, Tozzi G. A practical guide for in situ mechanical testing of musculoskeletal tissues using synchrotron tomography. J Mech Behav Biomed Mater 2022; 133:105297. [PMID: 35691205 DOI: 10.1016/j.jmbbm.2022.105297] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 05/03/2022] [Accepted: 05/25/2022] [Indexed: 02/07/2023]
Abstract
Musculoskeletal tissues are complex hierarchical materials where mechanical response is linked to structural and material properties at different dimensional levels. Therefore, high-resolution three-dimensional tomography is very useful for assessing tissue properties at different scales. In particular, Synchrotron Radiation micro-Computed Tomography (SR-microCT) has been used in several applications to analyze the structure of bone and biomaterials. In the past decade the development of digital volume correlation (DVC) algorithms applied to SR-microCT images and its combination with in situ mechanical testing (four-dimensional imaging) have allowed researchers to visualise, for the first time, the deformation of musculoskeletal tissues and their interaction with biomaterials under different loading scenarios. However, there are several experimental challenges that make these measurements difficult and at high risk of failure. Challenges relate to sample preparation, imaging parameters, loading setup, accumulated tissue damage for multiple tomographic acquisitions, reconstruction methods and data processing. Considering that access to SR-microCT facilities is usually associated with bidding processes and long waiting times, the failure of these experiments could notably slow down the advancement of this research area and reduce its impact. Many of the experimental failures can be avoided with increased experience in performing the tests and better guidelines for preparation and execution of these complex experiments; publication of negative results could help interested researchers to avoid recurring mistakes. Therefore, the goal of this article is to highlight the potential and pitfalls in the design and execution of in situ SR-microCT experiments, involving multiple scans, of musculoskeletal tissues for the assessment of their structural and/or mechanical properties. The advice and guidelines that follow should improve the success rate of this type of experiment, allowing the community to reach higher impact more efficiently.
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Affiliation(s)
- E Dall'Ara
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, UK; INSIGNEO Institute for in Silico Medicine, University of Sheffield, UK.
| | | | - H Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - G Tozzi
- School of Engineering, London South Bank University, London, UK
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Muro S, Kim J, Tsukada S, Akita K. Significance of the broad non-bony attachments of the anterior cruciate ligament on the tibial side. Sci Rep 2022; 12:6844. [PMID: 35477722 PMCID: PMC9046205 DOI: 10.1038/s41598-022-10806-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 04/12/2022] [Indexed: 11/09/2022] Open
Abstract
Knowledge of the anatomy of the anterior cruciate ligament (ACL) is important to understand the function and pathology of the knee joint. However, on the tibial side of ACL, its structural relationships with the articular cartilage and lateral meniscus remain unclear. Furthermore, conventional research methods are limited to analyzing the bone attachments. We provide a comprehensive, three-dimensional anatomical description of the tibial side of the ACL that questions the principle that “a ligament is necessarily a structure connecting a bone to another bone.” In our study, 11 knees from 6 cadavers were used for macroscopic anatomical examinations, serial-section histological analyses, and three-dimensional reconstructions. The attachments of the tibial side of ACL consisted of attachments to the bone (102.6 ± 27.5 mm2), articular cartilage (40.9 ± 13.6 mm2), and lateral meniscus (6.5 ± 4.6 mm2), suggesting that the ACL has close structural relationships with the articular cartilage and lateral meniscus. Our study demonstrates that the tibial side of the ACL is not attached to the bone surface only and provides new perspectives on ligamentous attachments. Considering its attachment to the articular cartilage would enable more accurate functional evaluations of the mechanical tensioning of the ACL.
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Affiliation(s)
- Satoru Muro
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
| | - Jiyoon Kim
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Sachiyuki Tsukada
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Keiichi Akita
- Department of Clinical Anatomy, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
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Zhang G, Li J, Deng K, Yue S, Xie W. Reweighted L1-norm regularized phase retrieval for x-ray differential phase contrast radiograph. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:043706. [PMID: 35489897 DOI: 10.1063/5.0081145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
Talbot-Lau x-ray grating interferometry greatly decreases the requirements on x-ray sources to realize differential phase contrast imaging and has found many applications in industrial and medical imaging. Phase retrieval from the noisy differential signal is crucial for quantitative analysis, comparison, and fusion with other imaging modalities. In this paper, we introduce a reweighted L1-norm based nonlinear regularization method for the phase retrieval problem. Both simulation and experimental results demonstrated that, comparing with the widely used L1-norm based regularization method and Wiener filter method, the proposed method is more effective both in eliminating the strip noises and in preserving the image detail.
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Affiliation(s)
- Guangya Zhang
- Chinese Academy of Engineering Physics, Institute Fluid Physics, Mianyang 621999, China
| | - Jing Li
- Chinese Academy of Engineering Physics, Institute Fluid Physics, Mianyang 621999, China
| | - Kai Deng
- Chinese Academy of Engineering Physics, Institute Fluid Physics, Mianyang 621999, China
| | - Songjie Yue
- Chinese Academy of Engineering Physics, Institute Fluid Physics, Mianyang 621999, China
| | - Weiping Xie
- Chinese Academy of Engineering Physics, Institute Fluid Physics, Mianyang 621999, China
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