Feasibility and efficacy of bone tissue engineering using human bone marrow stromal cells cultivated in serum-free conditions.

Current standard techniques for bone tissue engineering utilize ex vivo expanded osteogenic cells. However, ex vivo expansion requires serum, which may hinder clinical applications. Here, we report the feasibility and efficacy of bone tissue engineering with human bone marrow stromal cells (BMSCs) expanded in serum-free conditions. Bone marrow was aspirated from 4 healthy donors and adherent cells were cultured in either serum-free medium (STEMPRO((R)) MSC SFM) or conventional serum-containing medium (alpha-MEM supplemented with 10% serum). Efficacy of expansion was greater in serum-free medium. Phenotypically, serum-free expanded BMSCs were smaller in cell-size and showed expression of CD105(++) and CD146(dim). After osteogenic induction, serum-free expanded BMSCs showed lower alkaline phosphatase activity. However, they showed higher responsiveness to induction. In vivo bone-forming ability was also confirmed. In conclusion, bone tissue engineering with serum-free expanded BMSCs is feasible and as efficient as that obtained with BMSCs expanded in conventional serum-containing medium.