eCM (Eur Cell Mater / e Cells & Materials) Not-for-profit Open Access
Created by Scientists, for Scientists
 ISSN:1473-2262         NLM:100973416 (link)         DOI:10.22203/eCM

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)
DOI: 10.22203/eCM.v023a17