Engineering of cartilage tissue using bioresorbable polymer carriers in perfusion culture

Bioresorbable polymer fleeces with a high internal surface area were used as temporary matrices to establish three-dimensional cultures of isolated human articular chondrocytes. The polymer surface was coated with poly-L-lysine to support cell attachment. The resulting cell-polymer tissues were cultured in perfusion culture chambers to achieve a constant supply of nutrients by diffusion. Retention and accumulation of extracellular matrix components synthesized by the chondrocytes were improved by encapsulation of the cell-polymer integrate in agarose gel. The cell-polymer tissues formed abundant collagen fibrils in vitro with a typical cross-triation clearly visible in electron microscopy analysis. Chondrocytes and intercellular matrix stained positively with monoclonal antibodies specific for differentiated chondrocytes and type II collagen. Synthesis of proteoglycans and collagen was also evident by further analysis with alcian blue and azan staining of cell-polymer tissue sections. The presented experimental tissue culture technique offers a novel concept for the in vitro formation of vital cartilage implants for reconstructive surgery or treatment of destructive joint diseases and possibly for the in vitro engineering of human tissues in general, with applications in drug testing and replacement of animal experiments.