REPOPULATION OF LASER-PERFORATED CHONDROEPIPHYSEAL MATRIX WITH XENOGENEIC CHONDROCYTES - AN EXPERIMENTAL-MODEL

Growth of chondrocytes into a xenogeneic chondroepiphyseal matrix was investigated in an in vitro experimental model by combining viable cal f chondrocytes with chick epiphyseal matrix devoid of viable chondrocy tes. The chondrocytes were harvested from the wrist joints of newborn calves and cultured for 2 days. The epiphyses were harvested from the distal femurs and the proximal tibias of fetal chicks after developmen t was arrested at 17 days by freezing, The epiphyseal specimens were p repared in four ways. These included femoral and tibial epiphyses with out holes and femoral and tibial epiphyses with holes made by a laser, These epiphyseal specimens were co-cultured with calf chondrocytes fo r various periods. After digestion of the epiphyseal matrix, viable ch ondrocytes were counted in suspension, Chondrocyte division in the mat rix was assessed by [H-3]thymidine incorporation. The growth of calf c hondrocytes into the xenogeneic chick matrix was evaluated by fluoresc ence microscopy on fresh thick epiphyseal sections, The percentage of viable chondrocytes in the xenogeneic epiphyseal matrix increased with culture time to a maximum al day 21. The addition of laser-drilled ho les was found to extend a plateau of chondrocyte viability until day 2 9. A decrease in cell viability was detected at later observation poin ts. This study demonstrates that xenogeneic matrix may serve as a morp hogenetic scaffold for chondrocytic growth.