Adult human chondrocytes in alginate culture. Preservation of the phenotype for further use in transplantation models

Abstract

Successful and cartilage-specific cultivation of chondrocytes requires a stable phenotype during the in vitro culture period. This is based on a differentiated extracellular matrix synthesis. The alginate system as a three-dimensional support is a useful system to culture chondrocytes and to analyze the biochemical processes in this system. Talar cartilage from the talocrural joints of 40 different donors were obtained through the Regional Organ Bank of Illinois within 24 hours of death. In 65% of the tissues the cartilage was classified as being undamaged. In these studies we were interested in the results of short-term culture over 14 days. Cell proliferation, total collagen content and total proteoglycan content were measured in the different matrix compartments and were visualized by histology and immunohistochemistry. Already after 7 days in culture the adult human chondroctes looked intact and formed a stable and cell-associated cartilage-specific extracellular matrix in the presence of 10% calf serum. This could be also demonstrated in the presence of IGF-I. With regards to the collagen content IGF-I at a concentration of 50 ng/ml seemed to induce an equal effect to 10% serum; with regards to the proteoglycan content IGF-I at a concentration of 20 ng/ml was equivalent. These encouraging preliminary results may lead to a new approach in tissue engineering for chondrocyte transplantation in combination with their extracellular matrix.