2012 Volume No 23 – pages 222-236
|
Title: Influence of in vitro maturation of engineered cartilage on the outcome of osteochondral repair in a goat model |
Author: S Miot, W Brehm, S Dickinson, T Sims, A Wixmerten, C Longinotti, AP Hollander, P Mainil-Varlet, I Martin |
|
Address: Tissue Engineering Laboratory, Institute for Surgical Research and Hospital Management, University Hospital Basel, Hebelstrasse 20, 4031 Basel, Switzerland
|
|
E-mail: imartin at uhbs.ch |
|
Key Words: Tissue engineering, osteochondral composite, functional graft, scaffold, autologous cells, animal model |
|
Publication date: April 5th 2012 |
|
Abstract: This study was designed to determine if the maturation stage of engineered cartilage implanted in a goat model of cartilage injury influences the repair outcome. Goat engineered cartilage was generated from autologous chondrocytes cultured in hyaluronic acid scaffolds using 2 d, 2 weeks or 6 weeks of pre-culture and implanted above hydroxyapatite/hyaluronic acid sponges into osteochondral defects. Control defects were left untreated or treated with cell-free scaffolds. The quality of repair tissues was assessed 8 weeks or 8 months post implantation by histological staining, modified O’Driscoll scoring and biochemical analyses. Increasing pre-culture time resulted in progressive maturation of the grafts in vitro. After 8 weeks in vivo, the quality of the repair was not improved by any treatment. After 8 months, O’Driscoll histology scores indicated poor cartilage architecture for untreated (29.7 ± 1.6) and cell-free treated groups (24.3 ± 5.8). The histology score was improved when cellular grafts were implanted, with best scores observed for grafts pre-cultured for 2 weeks (16.3 ± 5.8). As compared to shorter pre-culture times, grafts cultured for 6 weeks (histology score: 22.3 ± 6.4) displayed highest type II/I collagen ratios but also inferior architecture of the surface and within the defect, as well as lower integration with native cartilage. Thus, pre-culture of engineered cartilage for 2 weeks achieved a suitable compromise between tissue maturity and structural/integrative properties of the repair tissue. The data demonstrate that the stage of development of engineered cartilage is an important parameter to be considered in designing cartilage repair strategies. |
|
Article download: Pages
222-236 (PDF file) |
|