Composite of Cell Sheet Fragments and Fibrin Gel for Cartilage Engineering

Previous studies have demonstrated that cell sheet is an efficient technique in cartilage tissue engineering. However, it is difficult to fabricate cartilage with specific shape without scaffold materials to maintain the spatial shape. In this study, we applied fibrin gel to suspend and congeal the chondrocyte cell sheet fragments for cartilage engineering. Chondrocyte cell sheets were formed via continuous culturing using auricular chondrocytes from rabbits. The cell sheets were then harvested and minced into fragments. The cell sheet fragments and isolated chondrocytes were suspended with the precursor solutions of fibrin gel. Gelatinous chondroid discs were constructed, and then in vitro cultured, and implanted into nude mice. After 8 weeks, the samples were explanted. Cartilage discs were obtained. No obvious distortion was observed during the in vitro culturing and implantation in nude mice. Histologically, the cartilage discs appeared non-uniform cartilaginous tissue that was comprise of regenerated cartilage islands with different size and irregular shape. Among the cartilage islands, the gaps were filled with fibrin gel that had not degraded. These results suggest that application of fibrin gel and cell sheets could engineer cartilage with specific shape.