Osteochondral repair using the combination of fibroblast growth factor and amorphous calcium phosphate/poly(L-lactic acid) hybrid materials

A novel amorphous calcium phosphate (ACP)/poly(L-lactic acid) (PLLA) material, which can experience morphological variations in the microstructure is supposed to be a suitable candidate as scaffold for cartilage tissue-engineering. The purpose of this study was to evaluate the efficacy of this scaffold combined with basic fibroblast growth factor (bFGF) to repair articular cartilage defects in a rabbit model. Forty-two osteochondral defects created in the femoral condyles were (a) left untreated, (b) treated by PLLA combined with bFGF, or (c) ACP/PLLA loaded with bFGF. The treatment of PLLA incorporated with bFGF improved defect filling compared with that left untreated, while the regenerated tissue was mainly fibrocartilage and showed little bone formation with only a small amount of collagen type II (Col II) and no aggrecan gene message measured. When implanted with ACP/PLLA and bFGF, most of the defects were filled with a well-established layer of cartilage tissue with abundance of cartilaginous extracellular matrix accumulation observed. Positive immunohistochemical staining of Col II was observed. High levels of Col II and aggrecan message were also detected by RT-PCR. These results indicate the feasibility of using the combination of ACP/PLLA with bFGF for cartilage repair.