Effects of enzymatic treatments on the depth-dependent viscoelastic shear properties of articular cartilage
ABSTRACT Osteoarthritis (OA) is a disease that involves the erosion and structural weakening of articular cartilage. OA is characterized by the degradation of collagen and proteoglycans in the extracellular matrix (ECM), particularly at the articular surface by proteinases including matrix metallopr...
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Published in | Journal of orthopaedic research Vol. 32; no. 12; pp. 1652 - 1657 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Blackwell Publishing Ltd
01.12.2014
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Subjects | |
Online Access | Get full text |
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Summary: | ABSTRACT
Osteoarthritis (OA) is a disease that involves the erosion and structural weakening of articular cartilage. OA is characterized by the degradation of collagen and proteoglycans in the extracellular matrix (ECM), particularly at the articular surface by proteinases including matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs).1 Degradation of collagen and proteoglycans is known to alter shear mechanical properties of cartilage, but study of this phenomenon has been focused on bulk tissue properties. The purpose of this study was to assess microscale cartilage damage induced by trypsin or collagenase using a technique to measure the local shear viscoelastic properties. Safranin‐O histology revealed a decrease in proteoglycans near the articular surface after collagenase and trypsin digestions, with proteoglycan depletion increasing in time. Similarly, confocal reflectance micrographs showed increasing collagen degradation in collagenase treated samples, although the collagen network remained intact after trypsin treatment. Both treatments induced changes in shear modulus that were confined to a narrow range (∼400µm) near tissue surface. In addition, collagenase altered the total energy dissipation distribution by up to a factor of 100, with longer digestion times corresponding to higher energy dissipation. The ability to detect local mechanical signatures in tissue composition and mechanics is an important tool for understanding the spatially non‐uniform changes that occur in articular cartilage diseases such as OA. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1652–1657, 2014. |
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Bibliography: | istex:8AFDEE293D057CF4B36D2AFCBE587AC91B186F38 Cornell University, NIH - No. R21-AR054867 and R21-AR062677 ark:/67375/WNG-WQJFL3WZ-6 ArticleID:JOR22713 NIH NIAMS - No. 3R01AR053571-0351 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0736-0266 1554-527X |
DOI: | 10.1002/jor.22713 |