Chondrocyte transplantation using PGLA/polydioxanon fleeces

The transplantation of chondrogenic cells in a supportive carrier structure proved to be a promising alternative for the treatment of cartilage defect s. In the study presented we focused on the transplantation of allogeneic c hondrocytes in a biodegradable polymer scaffold (PGLA/Polydioxanon) in arti cular cartilage defects in a rabbit defect model. Isolated allogeneic chond rocytes embedded in a PGLA polymer scaffold were transplanted into osteocho ndrogenic defects of the patellar groove and compared with empty defects an d transplants of polymer scaffolds without cells. The histological and hist ochemical analysis was performed after 4 and 12 weeks. The transplant integ ration and the architecture of the newly formed cartilage were evaluated wi th a semiquantitative score. After 4 weeks the development of a hyaline-lik e cartilage tissue of the cell-polymer-transplants was observed, after 12 w eeks the defects were nearly completely filled with hyaline-like cartilage. The biodegradation of the polymer construct did not affect the histologica l structure of the transplant area. Defects of the groups with empty defect and polymer transplants without cells revealed no or insufficient healing indices. The study demonstrated that biodegradable polymers served as suita ble carriers for the chondrocyte transplantation, which is due to the in-vi tro establishment of a semi-solid cartilage transplant and the resulting ef fective transplant fixation into the defect. In-vivo the polymer cell trans plants seem to provide a supportive microenvironment for the development of hyaline cartilage. The controlled release of morphogenic factors or bioact ive molecules and the use of pluripotent mesenchymal progenitor cells opens new perspectives for the optimization of cartilage repair procedures.