COMPARATIVE-STUDY OF THE USE OF POLY(GLYCOLIC ACID), CALCIUM ALGINATEAND PLURONICS IN THE ENGINEERING OF AUTOLOGOUS PORCINE CARTILAGE

New cartilage formation has been successfully achieved by a technology referred to as tissue engineering. Polymers and hydrogels such as pol y(glycolic acid), calcium alginate, and poly(ethylene) and poly(propyl ene) hydrogels have been used as cell carriers to regenerate cartilage in the nude mouse model. The next step toward human applications of e ngineered cartilage is to demonstrate their potential in immunocompete nt animal models. This study compared the suitability of three polymer s for generating tissue engineered elastic cartilage using autologous cells in an immune-competent porcine animal model. Auricular cartilage was obtained from pigs. Chondrocytes were isolated and seeded onto fi ber based poly(glycolic acid) (PGA) scaffolds or suspended in calcium alginate or pluronic F127 gel at constant concentrations. Chondrocyte- polymer constructs were either implanted (PGA) or injected (calcium al ginate and pluronic) as autologous implants subcutaneously into the pi gs from which the cells had been isolated. Specimens were harvested an d analyzed grossly and histologically after 6 weeks in vivo. All expla nts demonstrated cartilage formation to a variable degree. When using PGA or calcium alginate, the overall histological appearance of the ti ssue formed is that of fibrocartilage with thick bundles of collagen d ispersed in the tissue. When using pluronics as scaffold, histologic f eatures resemble those of native elastic cartilage, showing a more org anized arrangement of the cells, which seems to correlate to functiona l properties as elastin presence in the tissue engineered cartilage. E lastic cartilage engineered in an immunocompetent animal model varies with the type of polymer used. The behavior of the cell-polymer constr ucts is not fully understood and outcome seems to be related to severa l factors, including inflammatory reaction. Further studies with simil ar models are needed to determine the feasibility of engineering tissu e generated from different cell-polymer constructs prior to human appl ication.