The purpose of this study was to evaluate the (ultra-) morphology, biochemical behavior, and activity of ovine chondrocytes seeded on a matrix consisting of three types of collagen (I, II, III) with two different degrees of UV crosslinking. Ovine articular chondrocytes were isolated from stifle joints and seeded on both types of UV-crosslinked collagen matrices, as well as on non-crosslinked sponges, and cultured for 12 h, 7 days, 14 days, and 21 days. Histological analysis, electron microscopy, biochemical assays for glycosaminoglycans, and real-time quantitative PCR for collagens were performed for cell-seeded and unseeded matrices. There was no dramatic difference in the morphology and bioactivity of the cells; however, concerning handling characteristics and integrative stability, both types of crosslinked sponges were superior to non-crosslinked constructs. The results demonstrate that ovine articular chondrocytes express their phenotype in a sponge consisting of collagen; furthermore, because of mechanical reasons, non-crosslinked matrices cannot be recommended for implantation in vivo.
Copyright 2004 Wiley Periodicals, Inc.