ENGINEERING HUMAN CARTILAGE TISSUE USING A PERFUSION CHAMBER

In the field of otolaryngology cartilage grafting is commonly performed to reconstruct skeletal defects. Knowledge of chondrocyte growth and differentiation call now be used to engineer cartilage tissue for grafting. The first condition is that chondrocytes maintain their differentiated phenotype besides being able to produce a new cartilage matrix. The target of this study was to evelop a three-dimensional culture system for in-vitro formation of vital cartilage transplants. Chondrocytes were isolated by digesting the cartilage matrix with collagenase and hyaluronidase. After embedding in ''low-melting'' agarose, the chondrocytes were placed into a perfusion culture chamber to provide a constant supply of nutrients to the cultures. The peristaltic pump was operated with on/off intervals of 30 min. Ham's F12 supplemented with 2% FCS and 50 mu g/ml ascorbic acid was employed as culture medium. Monoclonal antibodies specific to collagens type I and type II were used to characterise cells and matrix synthesis. Synthesis of proteoglycans and collagens was achieved using toluidine blue and azan staining. Under the described culture conditions, the chondrocytes maintained a differentiated phenotype (expression of collagen type II) with synthesis of collagens and proteoglycans. An accumulation of matrix products was achieved pericellularly. After 2-8 weeks the obtained tissue exhibited an excellent histological appearance showing the typical features of cartilage tissue. The results show that the perfusion chamber allows a quick in-vitro fabrication of a piece of pure cartilage tissue for transplantation.