1
|
Davis S, Karali A, Balcaen T, Zekonyte J, Pétré M, Roldo M, Kerckhofs G, Blunn G. Comparison of two contrast-enhancing staining agents for use in X-ray imaging and digital volume correlation measurements across the cartilage-bone interface. J Mech Behav Biomed Mater 2024; 152:106414. [PMID: 38277908 DOI: 10.1016/j.jmbbm.2024.106414] [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: 03/08/2023] [Revised: 12/11/2023] [Accepted: 01/19/2024] [Indexed: 01/28/2024]
Abstract
OBJECTIVE The pathogenesis of osteoarthritis (OA) is associated with subchondral bone changes, which is linked to abnormal strain distribution in the overlying articular cartilage. This highlights the importance of understanding mechanical interaction at the cartilage-bone interface. The aim of this study is to compare solutions of two contrast-enhancing staining agents (CESA) for combining high-resolution Contrast-Enhanced X-ray microfocus Computed Tomography (CECT) with Digital Volume Correlation (DVC) for full-field strain measurements at the cartilage-bone interface. DESIGN Bovine osteochondral plugs were stained with phosphotungstic acid (PTA) in 70% ethanol or 1:2 hafnium-substituted Wells-Dawson polyoxometalate (Hf-WD POM) in PBS. Mechanical properties were assessed using micromechanical probing and nanoindentation. Strain uncertainties (from CECT data) were evaluated following two consecutive unloaded scans. Residual strains were computed following unconfined compression (ex situ) testing. RESULTS PTA and Hf-WD POM enabled the visualisation of structural features in cartilage, allowing DVC computation on the CECT data. Residual strains up to ∼10,000 μɛ were detected up to the tidemark. Nanoindentation showed that PTA-staining caused an average ∼6-fold increase in articular cartilage stiffness, a ∼19-fold increase in reduced modulus and ∼7-fold increase in hardness, whereas Hf-WD POM-stained specimens had mechanical properties similar to pre-stain tissue. Micromechanical probing showed a 77% increase in cartilage surface stiffness after PTA-staining, in comparison to a 16% increase in stiffness after staining with Hf-WD POM. CONCLUSION Hf-WD POM is a more suitable CESA solution compared to PTA for CECT imaging combined with DVC as it allowed visualisation of structural features in the cartilage tissue whilst more closely maintaining tissue mechanical properties.
Collapse
Affiliation(s)
- Sarah Davis
- School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth, PO1 2DT, UK; School of Mechanical and Design Engineering, University of Portsmouth, PO1 3DJ, UK.
| | - Aikaterina Karali
- School of Mechanical and Design Engineering, University of Portsmouth, PO1 3DJ, UK
| | - Tim Balcaen
- Biomechanics Lab, Institute of Mechanics, Materials and Civil Engineering, UCLouvain, Louvain-la-Neuve, Belgium; Pole of Morphology, Institute of Experimental and Clinical Research, UCLouvain, Brussels, Belgium; Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Jurgita Zekonyte
- School of Mechanical and Design Engineering, University of Portsmouth, PO1 3DJ, UK
| | - Maïté Pétré
- Biomechanics Lab, Institute of Mechanics, Materials and Civil Engineering, UCLouvain, Louvain-la-Neuve, Belgium; Pole of Morphology, Institute of Experimental and Clinical Research, UCLouvain, Brussels, Belgium; Biomechanics Section, Department of Mechanical Engineering, KU Leuven, Heverlee, Belgium
| | - Marta Roldo
- School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth, PO1 2DT, UK
| | - Greet Kerckhofs
- Biomechanics Lab, Institute of Mechanics, Materials and Civil Engineering, UCLouvain, Louvain-la-Neuve, Belgium; Pole of Morphology, Institute of Experimental and Clinical Research, UCLouvain, Brussels, Belgium; Department of Materials Engineering, KU Leuven, Heverlee, Belgium; Prometheus, Division for Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
| | - Gordon Blunn
- School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth, PO1 2DT, UK
| |
Collapse
|
2
|
Yu Y, Fischenich KM, Schoonraad SA, Weatherford S, Uzcategui AC, Eckstein K, Muralidharan A, Crespo-Cuevas V, Rodriguez-Fontan F, Killgore JP, Li G, McLeod RR, Miller NH, Ferguson VL, Bryant SJ, Payne KA. A 3D printed mimetic composite for the treatment of growth plate injuries in a rabbit model. NPJ Regen Med 2022; 7:60. [PMID: 36261516 PMCID: PMC9581903 DOI: 10.1038/s41536-022-00256-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 10/05/2022] [Indexed: 11/08/2022] Open
Abstract
Growth plate injuries affecting the pediatric population may cause unwanted bony repair tissue that leads to abnormal bone elongation. Clinical treatment involves bony bar resection and implantation of an interpositional material, but success is limited and the bony bar often reforms. No treatment attempts to regenerate the growth plate cartilage. Herein we develop a 3D printed growth plate mimetic composite as a potential regenerative medicine approach with the goal of preventing limb length discrepancies and inducing cartilage regeneration. A poly(ethylene glycol)-based resin was used with digital light processing to 3D print a mechanical support structure infilled with a soft cartilage-mimetic hydrogel containing chondrogenic cues. Our biomimetic composite has similar mechanical properties to native rabbit growth plate and induced chondrogenic differentiation of rabbit mesenchymal stromal cells in vitro. We evaluated its efficacy as a regenerative interpositional material applied after bony bar resection in a rabbit model of growth plate injury. Radiographic imaging was used to monitor limb length and tibial plateau angle, microcomputed tomography assessed bone morphology, and histology characterized the repair tissue that formed. Our 3D printed growth plate mimetic composite resulted in improved tibial lengthening compared to an untreated control, cartilage-mimetic hydrogel only condition, and a fat graft. However, in vivo the 3D printed growth plate mimetic composite did not show cartilage regeneration within the construct histologically. Nevertheless, this study demonstrates the feasibility of a 3D printed biomimetic composite to improve limb lengthening, a key functional outcome, supporting its further investigation as a treatment for growth plate injuries.
Collapse
Affiliation(s)
- Yangyi Yu
- Colorado Program for Musculoskeletal Research, Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Shenzhen Key Laboratory of Musculoskeletal Tissue Reconstruction and Function Restoration, Department of Bone and Joint Surgery, Shenzhen People's Hospital (The Second Clinical Medical College Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, China
| | - Kristine M Fischenich
- Colorado Program for Musculoskeletal Research, Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Sarah A Schoonraad
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, CO, USA
| | - Shane Weatherford
- Colorado Program for Musculoskeletal Research, Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Asais Camila Uzcategui
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, CO, USA
| | - Kevin Eckstein
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Archish Muralidharan
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, CO, USA
| | - Victor Crespo-Cuevas
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Francisco Rodriguez-Fontan
- Colorado Program for Musculoskeletal Research, Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Jason P Killgore
- Applied Chemicals and Materials Division (647), National Institute of Standards and Technology (NIST), Boulder, CO, USA
| | - Guangheng Li
- Shenzhen Key Laboratory of Musculoskeletal Tissue Reconstruction and Function Restoration, Department of Bone and Joint Surgery, Shenzhen People's Hospital (The Second Clinical Medical College Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, China
| | - Robert R McLeod
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, CO, USA
- Department of Electrical, Computer and Energy Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Nancy Hadley Miller
- Colorado Program for Musculoskeletal Research, Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Musculoskeletal Research Center, Children's Hospital Colorado, Aurora, CO, USA
| | - Virginia L Ferguson
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, CO, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA
| | - Stephanie J Bryant
- Materials Science and Engineering Program, University of Colorado Boulder, Boulder, CO, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Karin A Payne
- Colorado Program for Musculoskeletal Research, Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
- Gates Center for Regenerative Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| |
Collapse
|
3
|
Hasan MM, Johnson CL, Dunn AC. Soft Contact Mechanics with Gradient-Stiffness Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:9454-9465. [PMID: 35895905 DOI: 10.1021/acs.langmuir.2c00296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The stiffness in the top surface of many biological entities like cornea or articular cartilage, as well as chemically cross-linked synthetic hydrogels, can be significantly lower or more compliant than the bulk. When such a heterogeneous surface comes into contact, the contacting load is distributed differently from typical contact models. The mechanical response under indentation loading of a surface with a gradient of stiffness is a complex, integrated response that necessarily includes the heterogeneity. In this work, we identify empirical contact models between a rigid indenter and gradient elastic surfaces by numerically simulating quasi-static indentation. Three key case studies revealed the specific ways in which (I) continuous gradients, (II) laminate-layer gradients, and (III) alternating gradients generate new contact mechanics at the shallow-depth limit. Validation of the simulation-generated models was done by micro- and nanoindentation experiments on polyacrylamide samples synthesized to have a softer gradient surface layer. The field of stress and stretch in the subsurface as visualized from the simulations also reveals that the gradient layers become confined, which pushes the stretch fields closer to the surface and radially outward. Thus, contact areas are larger than expected, and average contact pressures are lower than predicted by the Hertz model. The overall findings of this work are new contact models and the mechanisms by which they change. These models allow a more accurate interpretation of the plethora of indentation data on surface gradient soft matter (biological and synthetic) as well as a better prediction of the force response to gradient soft surfaces. This work provides examples of how gradient hydrogel surfaces control the subsurface stress distribution and loading response.
Collapse
Affiliation(s)
- Md Mahmudul Hasan
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, 1206 W Green St., Urbana, Illinois 61801, United States
| | - Christopher L Johnson
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, 1206 W Green St., Urbana, Illinois 61801, United States
| | - Alison C Dunn
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, 1206 W Green St., Urbana, Illinois 61801, United States
| |
Collapse
|
4
|
Angiogenic Potential of Co-Cultured Human Umbilical Vein Endothelial Cells and Adipose Stromal Cells in Customizable 3D Engineered Collagen Sheets. J Funct Biomater 2022; 13:jfb13030107. [PMID: 35997445 PMCID: PMC9397038 DOI: 10.3390/jfb13030107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/21/2022] [Accepted: 07/26/2022] [Indexed: 01/25/2023] Open
Abstract
The wound healing process is much more complex than just the four phases of hemostasis, inflammation, proliferation, and maturation. Three-dimensional (3D) scaffolds made of biopolymers or ECM molecules using bioprinting can be used to promote the wound healing process, especially for complex 3D tissue lesions like chronic wounds. Here, a 3D-printed mold has been designed to produce customizable collagen type-I sheets containing human umbilical vein endothelial cells (HUVECs) and adipose stromal cells (ASCs) for the first time. In these 3D collagen sheets, the cellular activity leads to a restructuring of the collagen matrix. The upregulation of the growth factors Serpin E1 and TIMP-1 could be demonstrated in the 3D scaffolds with ACSs and HUVECs in co-culture. Both growth factors play a key role in the wound healing process. The capillary-like tube formation of HUVECs treated with supernatant from the collagen sheets revealed the secretion of angiogenic growth factors. Altogether, this demonstrates that collagen type I combined with the co-cultivation of HUVECs and ACSs has the potential to accelerate the process of angiogenesis and, thereby, might promote wound healing.
Collapse
|
5
|
Eckstein KN, Thomas SM, Scott AK, Neu CP, Payne KA, Ferguson VL. The heterogeneous mechanical properties of adolescent growth plate cartilage: A study in rabbit. J Mech Behav Biomed Mater 2022; 128:105102. [PMID: 35203020 PMCID: PMC9047008 DOI: 10.1016/j.jmbbm.2022.105102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/08/2022] [Accepted: 01/21/2022] [Indexed: 01/01/2023]
Abstract
The growth plate is a cartilaginous tissue that functions to lengthen bones in children. When fractured, however, the growth plate can lose this critical function. Our understanding of growth plate fracture and mechanobiology is currently hindered by sparse information on the growth plate's microscale spatial gradients in mechanical properties. In this study, we performed microindentation across the proximal tibia growth plate of 9-week-old New Zealand White rabbits (n = 15) to characterize spatial variations in mechanical properties using linear elastic and nonlinear poroelastic material models. Mean indentation results for Hertz reduced modulus ranged from 380 to 690 kPa, with a peak in the upper hypertrophic zone and significant differences (p < 0.05) between neighboring zones. Using a subset of these animals (n = 7), we characterized zonal structure and extracellular matrix content of the growth plate through confocal fluorescent microscopy and Raman spectroscopy mapping. Comparison between mechanical properties and matrix content across the growth plate showed that proteoglycan content correlated with compressive modulus. This study is the first to measure poroelastic mechanical properties from microindentation across growth plate cartilage and to discern differing mechanical properties between the upper and lower hypertrophic zones. This latter finding may explain the location of typical growth plate fractures. The spatial variation in our reported mechanical properties emphasize the heterogeneous structure of the growth plate which is important to inform future regenerative implant design and mechanobiological models.
Collapse
|
6
|
Islam MR, Virag J, Oyen ML. Micromechanical poroelastic and viscoelastic properties of ex-vivo soft tissues. J Biomech 2020; 113:110090. [PMID: 33176223 DOI: 10.1016/j.jbiomech.2020.110090] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/01/2020] [Accepted: 10/16/2020] [Indexed: 11/16/2022]
Abstract
Soft biological tissues demonstrate strong time-dependent mechanical behavior, arising from their intrinsic viscoelasticity and fluid flow-induced poroelasticity. It is increasingly recognized that time-dependent mechanical properties of soft tissues influence their physiological functions and are linked to several pathological processes. Nevertheless, soft tissue time-dependent characteristics, especially their micromechanical variation with tissue composition and location, remain poorly understood. Nanoindentation is a well-established technique to measure local elastic properties but has not been fully explored to determine micro-scale time-dependent properties of soft tissues. Here, a nanoindentation-based experimental strategy is implemented to characterize the micro-scale poroelastic and viscoelastic behavior of mouse heart, kidney, and liver tissues. It is demonstrated that heart tissue exhibits substantial mechanical heterogeneity where the elastic modulus varies spatially from 1 to 30 kPa. In contrast, both kidney and liver tissues show relatively homogeneous response with elastic modulus 0.5-3 kPa. All three tissues demonstrate marked load relaxation under constant indentation, where the relaxation behavior is observed to be largely dominated by tissue viscoelasticity. Intrinsic permeability varies among different tissues, where heart tissue is found to be less permeable compared to kidney and liver tissues. Overall, the results presented herein provide key insights into the time-dependent micromechanical behavior of different tissues and can therefore contribute to studies of tissue pathology and tissue engineering applications.
Collapse
Affiliation(s)
- Mohammad R Islam
- Department of Engineering, East Carolina University, Greenville, NC 27834, United States
| | - Jitka Virag
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States
| | - Michelle L Oyen
- Department of Engineering, East Carolina University, Greenville, NC 27834, United States.
| |
Collapse
|
7
|
Whiteley JP, Gaffney EA. Modelling the inclusion of swelling pressure in a tissue level poroviscoelastic model of cartilage deformation. MATHEMATICAL MEDICINE AND BIOLOGY-A JOURNAL OF THE IMA 2020; 37:389-428. [PMID: 32072158 DOI: 10.1093/imammb/dqaa001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 11/12/2019] [Accepted: 01/02/2020] [Indexed: 11/13/2022]
Abstract
Swelling pressure in the interstitial fluid within the pores of cartilage tissue is known to have a significant effect on the rheology of cartilage tissue. The swelling pressure varies rapidly within thin regions inside pores known as Debye layers, caused by the presence of fixed charge, as observed in cartilage. Tissue level calculation of cartilage deformation therefore requires resolution of three distinct spatial scales: the Debye lengthscale within individual pores; the lengthscale of an individual pore; and the tissue lengthscale. We use asymptotics to construct a leading order approximation to the swelling pressure within pores, allowing the swelling pressure to be systematically included within a fluid-solid interaction model at the level of pores in cartilage. We then use homogenization to derive tissue level equations for cartilage deformation that are very similar to those governing the finite deformation of a poroviscoelastic body. The equations derived permit the spatial variations in porosity and electric charge that occur in cartilage tissue. Example solutions are then used to confirm the plausibility of the model derived and to consider the impact of fixed charge heterogeneity, illustrating that local fixed charge loss is predicted to increase deformation gradients under confined compression away from, rather than at, the site of loss.
Collapse
Affiliation(s)
- Jonathan P Whiteley
- Department of Computer Science, University of Oxford, Wolfson Building, Parks Road, Oxford OX1 3QD, UK
| | - Eamonn A Gaffney
- Mathematical Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter, Woodstock Rd, Oxford OX2 6GG, UK
| |
Collapse
|
8
|
Articular cartilage regeneration by activated skeletal stem cells. Nat Med 2020; 26:1583-1592. [PMID: 32807933 DOI: 10.1038/s41591-020-1013-2] [Citation(s) in RCA: 167] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 07/07/2020] [Indexed: 02/07/2023]
Abstract
Osteoarthritis (OA) is a degenerative disease resulting in irreversible, progressive destruction of articular cartilage1. The etiology of OA is complex and involves a variety of factors, including genetic predisposition, acute injury and chronic inflammation2-4. Here we investigate the ability of resident skeletal stem-cell (SSC) populations to regenerate cartilage in relation to age, a possible contributor to the development of osteoarthritis5-7. We demonstrate that aging is associated with progressive loss of SSCs and diminished chondrogenesis in the joints of both mice and humans. However, a local expansion of SSCs could still be triggered in the chondral surface of adult limb joints in mice by stimulating a regenerative response using microfracture (MF) surgery. Although MF-activated SSCs tended to form fibrous tissues, localized co-delivery of BMP2 and soluble VEGFR1 (sVEGFR1), a VEGF receptor antagonist, in a hydrogel skewed differentiation of MF-activated SSCs toward articular cartilage. These data indicate that following MF, a resident stem-cell population can be induced to generate cartilage for treatment of localized chondral disease in OA.
Collapse
|
9
|
Ihnatouski M, Pauk J, Karev B, Karev D. Nanomechanical Properties of Articular Cartilage Due to the PRP Injection in Experimental Osteoarthritis in Rabbits. Molecules 2020; 25:molecules25163734. [PMID: 32824204 PMCID: PMC7463443 DOI: 10.3390/molecules25163734] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/10/2020] [Accepted: 08/14/2020] [Indexed: 01/08/2023] Open
Abstract
The purpose of this study was twofold. Firstly, we proposed a measurement protocol for the atomic force microscopy (AFM) method to determine the nanomechanical properties of articular cartilage in experimental osteoarthritis in rabbits. Then, we verified if mechanical properties can be evaluated with AFM shortly after platelet-rich plasma (PRP) injection. We hypothesized that the modulus determined by AFM indentation experiments could be utilized as a progressive disease marker during the treatment of osteoarthritis. The rabbits were equally divided into three groups of six: control (group 1); injections of saline (0.5 mL) and 10% surgical talc (Talcum Pharmaceutical®, Minsk, Belarus) were delivered into the right knee under the patella (group 2 and 3); and PRP was injected into the right knee (group 3). In group 2, the arithmetic average of absolute values (Ra) change was a 25% increase; the maximum peak height (Rp) increased by over 102%, while the mean spacing between local peaks (S) increased by 28% (p < 0.05). In group 3, Ra increased by 14% and Rp increased by 32%, while S decreased by 75% (p < 0.05). The Young’s modulus of the surface layers decreased by 18% as a result of induced model of osteoarthritis (IMO) (p < 0.05), and it increased by 9% (p < 0.05) as a result of PRP therapy, which means that the mechanical properties of cartilage were partially recovered. This research demonstrates that Young’s modulus utilized on a nanometer scale has potential to be a progressive disease marker during the treatment of osteoarthritis.
Collapse
Affiliation(s)
- Mikhail Ihnatouski
- Scientific and Research Department, Yanka Kupala State University of Grodno, Grodno, Ozheshko str., 22, 230023 Grodno, Belarus;
| | - Jolanta Pauk
- Mechanical Engineering Department, Bialystok University of Technology, Biomedical Engineering Institute, Wiejska 45A, 15-351 Bialystok, Poland
- Correspondence:
| | - Boris Karev
- Department of Orthopedic and Traumatology, Grodno City Emergency Hospital, Sovietskih Pogranichnikov str., 115, 230027 Grodno, Belarus;
| | - Dmitrij Karev
- Department of Traumatology, Orthopedics and Field Surgery, Grodno State Medical University, Gorkogo str. 80, 230009 Grodno, Belarus;
| |
Collapse
|
10
|
Mieloch AA, Richter M, Trzeciak T, Giersig M, Rybka JD. Osteoarthritis Severely Decreases the Elasticity and Hardness of Knee Joint Cartilage: A Nanoindentation Study. J Clin Med 2019; 8:jcm8111865. [PMID: 31684201 PMCID: PMC6912408 DOI: 10.3390/jcm8111865] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 01/19/2023] Open
Abstract
The nanoindentation method was applied to determine the elastic modulus and hardness of knee articular cartilage. Cartilage samples from both high weight bearing (HWB) and low weight bearing (LWB) femoral condyles were collected from patients diagnosed with osteoarthritis (OA). The mean elastic modulus of HWB cartilage was 4.46 ± 4.44 MPa in comparison to that of the LWB region (9.81 ± 8.88 MPa, p < 0.001). Similarly, the hardness was significantly lower in HWB tissue (0.317 ± 0.397 MPa) than in LWB cartilage (0.455 ± 0.434 MPa, p < 0.001). When adjusted to patients’ ages, the mean elastic modulus and hardness were both significantly lower in the age group over 70 years (p < 0.001). A statistically significant difference in mechanical parameters was also found in grade 3 and 4 OA. This study provides an insight into the nanomechanical properties of the knee articular cartilage and provides a starting point for personalized cartilage grafts that are compatible with the mechanical properties of the native tissue.
Collapse
Affiliation(s)
- Adam Aron Mieloch
- Center for Advanced Technology, Adam Mickiewicz University in Poznan, Uniwersytetu Poznańskiego 10 Street, 61-614 Poznan, Poland.
- Faculty of Chemistry, Adam Mickiewicz University in Poznan, Uniwersytetu Poznańskiego 8 Street, 61-614 Poznan, Poland.
| | - Magdalena Richter
- Center for Advanced Technology, Adam Mickiewicz University in Poznan, Uniwersytetu Poznańskiego 10 Street, 61-614 Poznan, Poland.
| | - Tomasz Trzeciak
- Department of Orthopedics and Traumatology, Poznan University of Medical Sciences, 28 czerwca 1956r. Street No. 135/147, 61-545 Poznan, Poland.
| | - Michael Giersig
- Center for Advanced Technology, Adam Mickiewicz University in Poznan, Uniwersytetu Poznańskiego 10 Street, 61-614 Poznan, Poland.
- Department of Physics, Institute of Experimental Physics, Freie Universität, Arnimallee 14, 14195 Berlin, Germany.
| | - Jakub Dalibor Rybka
- Center for Advanced Technology, Adam Mickiewicz University in Poznan, Uniwersytetu Poznańskiego 10 Street, 61-614 Poznan, Poland.
| |
Collapse
|
11
|
Abstract
Glycoinformatics is a critical resource for the study of glycobiology, and glycobiology is a necessary component for understanding the complex interface between intra- and extracellular spaces. Despite this, there is limited software available to scientists studying these topics, requiring each to create fundamental data structures and representations anew for each of their applications. This leads to poor uptake of standardization and loss of focus on the real problems. We present glypy, a library written in Python for reading, writing, manipulating, and transforming glycans at several levels of precision. In addition to understanding several common formats for textual representation of glycans, the library also provides application programming interfaces (APIs) for major community databases, including GlyTouCan and UnicarbKB. The library is freely available under the Apache 2 common license with source code available at https://github.com/mobiusklein/ and documentation at https://glypy.readthedocs.io/ .
Collapse
Affiliation(s)
- Joshua Klein
- Program for Bioinformatics , Boston University , Boston , Massachusetts 02215 , United States
| | - Joseph Zaia
- Program for Bioinformatics , Boston University , Boston , Massachusetts 02215 , United States.,Department of Biochemistry , Boston University , Boston , Massachusetts 02215 , United States
| |
Collapse
|
12
|
Panteli PA, Patrickios CS, Constantinou M, Constantinides G. Multiple Network Hydrogels: A Study of Their Nanoindentation Hardness. ACTA ACUST UNITED AC 2019. [DOI: 10.1002/masy.201800201] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | | | - Marios Constantinou
- Department of Mechanical Engineering and Materials Science and EngineeringCyprus University of TechnologyP. O. Box 503293603 LimassolCyprus
| | - Georgios Constantinides
- Department of Mechanical Engineering and Materials Science and EngineeringCyprus University of TechnologyP. O. Box 503293603 LimassolCyprus
| |
Collapse
|
13
|
Ohashi T, Sato T, Nakajima T, Junkong P, Ikeda Y. Necessity of two-dimensional visualization of validity in the nanomechanical mapping of atomic force microscopy for sulphur cross-linked rubber. RSC Adv 2018; 8:32930-32941. [PMID: 35547720 PMCID: PMC9086381 DOI: 10.1039/c8ra06669h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 09/18/2018] [Indexed: 11/21/2022] Open
Abstract
The importance of the two-dimensional (2D) visualization of validity for nanomechanical mapping in atomic force microscopy (AFM) for sulphur cross-linked rubber is emphasized for accurately interpreting the nanoscale physical properties on the surface of the soft material. The “R-factor,” evaluated to be the difference between the experimental and theoretical force–deformation curves, was considered to be the reliability index of the AFM analysis for all data points on the sample surface. A small R-factor corresponds to high accuracy. The advantage of the R-factor mapping method is demonstrated using nanomechanical mapping data of the inhomogeneous isoprene rubber network by the Johnson–Kendall–Roberts and the Derjaguin, Muller, and Toporov contact mechanics models. The 2D R-factor mapping clearly and correctly supported the roles of sulphur cross-linking reagents to control the network morphology of vulcanizates. Additionally, the blanket effect, which is induced by the rubber layer on the hard part and influences experimental force–deformation curves, is firstly proposed in this study. Nanomechanical mapping with 2D reliability indexes is expected to contribute to an advance in AFM studies on soft matter such as rubber materials, leading to a more accurate understanding of the structural characteristics of the rubber networks. Thus, this validity confirmation method is necessary for developing rubber science and technology. The two-dimensional visualization of validity for nanomechanical mapping in atomic force microscopy for sulphur cross-linked rubber is emphasized for accurately interpreting the nanoscale physical properties on the surface of the soft material.![]()
Collapse
Affiliation(s)
- Takumi Ohashi
- Graduate School of Science and Technology
- Kyoto Institute of Technology
- Kyoto 606-8585
- Japan
- Center for Rubber Science and Technology
| | - Tomoyuki Sato
- Graduate School of Science and Technology
- Kyoto Institute of Technology
- Kyoto 606-8585
- Japan
| | - Taichi Nakajima
- Graduate School of Science and Technology
- Kyoto Institute of Technology
- Kyoto 606-8585
- Japan
| | - Preeyanuch Junkong
- Center for Rubber Science and Technology
- Kyoto Institute of Technology
- Kyoto 606-8585
- Japan
- Research Strategy Promotion Center
| | - Yuko Ikeda
- Center for Rubber Science and Technology
- Kyoto Institute of Technology
- Kyoto 606-8585
- Japan
- Faculty of Molecular Chemistry and Engineering
| |
Collapse
|