Basic fibroblast growth factor enhances osteogenic and chondrogenic differentiation of human bone marrow mesenchymal stem cells in coral scaffold constructs

Temporomandibular joint (TMJ) disorders are commonly occurring degenerative joint diseases that require surgical replacement of the mandibular condyle in severe cases. Transplantation of tissue-engineered mandibular condyle constructs may solve some of the current surgical limitations to TMJ repair. We evaluated the feasibility of mandibular condyle constructs engineered from human bone marrow-derived mesenchymal cells (BMSCs). Specifically, human BMSCs were transfected with basic FGF (bFGF) gene-encoding plasmids and induced to differentiate into osteoblasts and chondroblasts. The cells were seeded onto mandibular condyle-shaped porous coral scaffolds and evaluated for osteogenic/chondrogenic differentiation, cell proliferation, collagen deposition and tissue vascularization. Transfected human BMSCs expressed bFGF and were highly proliferative. Osteogenesis was irregular, showing neovascularization around new bone tissue. There was no evidence of bilayered osteochondral tissue present in normal articulating surfaces. Collagen deposition, characteristic of bone and cartilage, was observed. Subcutaneous transplantation of seeded coral/hydrogel hyaluran constructs into nude mice resulted in bone formation and collagen type I and type II deposition. Neovascularization was observed around newly formed bone tissue; bFGF expression was detected in implanted constructs seeded with bFGF expressing hBMSCs. This report demonstrates that engineered porous coral constructs using bFGF gene-transfected human BMSCs may be a feasible option for surgical transplantation in TMJ repair.