Passaged goat costal chondrocytes provide a feasible cell source for temporomandibular joint tissue engineering

Costal cartilage is commonly harvested for various types of facial reconstructive surgery. The ability of costal chondrocytes (CCs) to produce relevant extracellular matrix, including glycosaminoglycans (GAGs) and collagens, makes them an appealing cell source for fibrocartilage engineering. In order to obtain enough cells for tissue engineering, however, cell expansion will likely be necessary. This study examined CCs at passages 0, 1, 3, and 5, as well as temporomandibular (TMJ) disc cells, in a scaffoldless tissue engineering approach. It was hypothesized that earlier passage constructs would have more cartilaginous proteins and less fibrocartilaginous proteins. TMJ disc constructs had over twice the collagen content of any other group, as well as the largest tensile properties; however, the substantial contraction of the constructs and limited cell numbers make it a non-feasible cell source for tissue engineering. In general, statistical differences in mechanical properties or collagen content of the various CC groups were not observed; however, significantly more GAG was produced in the passaged CCs than the primary CCs. More collagen type II was also observed in some of the passaged groups. These results suggest not only feasibility but potential superiority of passaged CCs over primary CCs, which may lead to functional engineered fibrocartilage.