Cotransplantation of autologous bone marrow stromal cells and chondrocytes as a novel therapy for reconstruction of condylar cartilage

Condylar cartilage is absolutely necessary for the normal function of temporomandibular joint (TMJ). Unfortunately, condylar cartilage defect or missing is also one of the common clinical problems. Repair or reconstruction of cartilage is always a hot topic. Cell based cartilage regeneration is suggested as novel therapies in cartilage tissue engineering, and autologous chondrocytes were initially regarded as the ideal cell source. However, there are some disadvantages such as its limited augmentation capability for culture in vitro and may differentiate to other types of cells. On the other hand, bone marrow stromal cells (BMSCs) have gained special interest in tissue engineering. Because they can be obtained easily, cause relatively minor trauma and show the potential of long-run ex vivo expansion capacity. What most important is their capacity of multi-directional differentiation. They can differentiate into a variety of other types of cells when there are supplement exogenous factors or genes, but their clinical use is limited by safety concerns such as toxicity, insertional teratogenic, uncontrollable gene expression. Fortunately, the chondrocytes microenvironment has been demonstrated that could induce BMSCs to structure cartilage when culture in vitro or reimplanted in nude mice subcutaneously area. So in this article, we hypothesize that cotransplantation of autologous BMSCs and chondrocytes, which coculture with extracellular scaffolds, is a novel therapy for reconstruction of TMJ condylar cartilage. In our strategy, advantages of two types of cells are utilized and shortcomings are avoided, which strongly improve the feasibility and clinical safety, finally bring great hope to the patients with TMJ disease.