The influence of cyclic strain on the differentiation of rat bone marrow derived mesenchymal stem cells to vascular smooth muscle

One of the major failings in vascular tissue engineering is the limited capacity of autologous differentiated cells to reconstitute tissues. A logical solution is the use of pluripotent stem cells, whose use in vascular treatments is yet to be fully realized. Although biochemical stimulation has been explored to differentiate bone marrow derived mesenchymal stem cells MeSCs to smooth muscle, the use of biomechanical forces in differentiation remains largely unexplored. We have begun preliminary investigations into the role of physiological levels of cyclic strain on MeSCs differentiation. Populations of cells were isolated from rat bone marrow by their adherence to tissue culture plastic. After 14 days in culture, the cells grew in colonies and the cells labelled positive for CD34, CD90 and CD117. Cells were cultured at sub-confluent levels and stimulated with 10% strain at 1Hz for 7 days. Observations showed that cyclic strain inhibited proliferation and aligned the cells perpendicular to the direction of strain. In addition, cyclic stretch switched on vascular smooth muscle actin and h-calponin. These preliminary studies demonstrate the potential of physiologic biomechanical stimulation in the differentiation of MeSCs to cells of the vascular lineage, and this could have important implications for vascular tissue engineering.