Engineering Bone with Mesenchymal Stem Cells: Challenges and Obstacles

Repair and reconstruction of large bone defects remain a significant challenge. Cell construct, containing mesenchymal stem cells (MSCs) and scaffold, is a promising strategy for addressing and treating major orthopedic clinical conditions. However, the design of an ideal cell construct for engineering bone faces two critical challenges (i) matching the scaffold degradation rate to that of new bone formation and (ii) preventing the massive cell death post-implantation (caused by disruption of oxygen and nutrient supply). We will hereby primarily focus on the challenge of survival of MSCs post-implantation. Increasing evidence indicates that metabolic regulation plays a critical role in cell fate and functions. In cell metabolism, glucose is considered the major metabolic substrate to produce ATP via glycolysis when the availability of oxygen is limited. In this paper, we delineate the essential roles of glucose on MSC survival. We aim to provide a different perspective which highlights the importance of considering glucose in the development of tissue engineering strategies in order to improve the efficiency of MSC-based cell constructs in the repair of large bone defects.