One major barrier that prevents cartilage integration following mosaic arthroplasty is the presence of a zone of chondrocyte death (ZCD) that is generated upon osteochondral graft harvest, which can extend up to 400 μm into the cartilaginous portion of the graft. In order for cartilage integration to occur, chondrocytes must be present at the graft periphery; however chondrocyte migration through the ZCD to the graft periphery is inhibited by the dense extracellular matrix (ECM) of cartilage. The purpose of this study was to develop a method for increasing the number of chondrocytes within the ZCD and at the periphery of a cartilage graft. This method used a combination of collagenase treatment (as a means of degrading the ECM within the ZCD) and chondrocyte chemotaxis (as a means of improving chondrocyte migration into the ZCD and to the cartilage periphery). Results indicate that treating bovine articular cartilage with 0.6 % collagenase for 10 min decreased with extent of the ZCD by approximately 35% (collagenase: 109 ± 13 μm; control: 175 ± 13 μm). Each of the chemotactic agents tested (PDGF-bb, bFGF, and IGF-I) were found to induce bovine chondrocyte chemotaxis at concentrations of 25 ng/mL in modified Boyden chamber experiments. However, in bovine articular cartilage samples that were pre-treated with collagenase (0.6% for 10 min), supplementation with 25 ng/mL of either PDGF-bb or bFGF had no apparent effect on the ZCD relative to samples treated only with collagenase (PDGF-bb: 85 ± 10 μm; bFGF: 88 ± 10 μm). Alternatively, bovine articular cartilage samples pre-treated with collagenase (0.6% for 10 min) and supplementation with 25 ng/mL IGF-I resulted in an approximately 65% reduction in the ZCD relative to samples treated only with collagenase (IGF-1: 38 ± 5 μm). Thus, treating osteochondral grafts with collagenase and IGF-1 induces chondrocyte repopulation of the zone of chondrocyte death generated by osteochondral graft harvesting, and could enhance cartilage integration after implantation. / Thesis (Master, Chemical Engineering) -- Queen's University, 2009-12-21 20:16:05.815
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/5369 |
| Date | 23 December 2009 |
| Creators | McGregor, Aaron |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | 2106833 bytes, application/pdf |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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