ENGINEERING OF CARTILAGE TISSUE USING BIORESORBABLE POLYMER FLEECES AND PERFUSION CULTURE

Replacement of injured or diseased skeletal tissues by either autograf t or allograft cartilage has increased steadily during recent decades. The ideal method is to use autologous cartilage; however, this is ext remely limited due to the scarcity of donor sites. We present a new ap proach to the in vitro formation of cartilage grafts for autologous gr afting in reconstructive surgery. Bioresorbable polymer fleeces of pol ylactic acid were used as temporary cell carrier matrices to establish three-dimensional cultures of human chondrocytes. The polymer surface was coated with poly-L-lysine before cell integration. These cell-pol ymer tissue constructs were encapsulated with low melting point agaros e and then placed in perfusion culture chambers to provide a constant supply of nutrients into the cultures. The culture medium consisted of Ham's F12 supplemented with 2% fetal calf serum and 50 mu g/ml ascorb ic acid. The cell-polymer tissues were harvested and frozen for toloud ine and alcian blue staining as well as electron microscopic examinati on after different periods of time in culture. A monoclonal antibody s pecific for collagen type II was used to characterize the cell phenoty pe. With this culture procedure chondrocytes maintained a differentiat ed phenotype with synthesis of collagen and proteoglycan. Collagen fib rils with clear cross-striation were evident in electron microscopic i mages. The results show that our organotypic cell culture method allow s the in vitro production of bioartificial cartilage for transplantati on.