Background: Skin and soft tissue expansion is a procedure that stimulates skin regeneration by applying continuous mechanical stretching of normal donor skin for reconstruction purposes. We have reported that topical transplantation of bone marrow-derived mesenchymal stem cells (MSCs) can accelerate mechanical stretch induced skin regeneration. However, it is unclear how circulating MSCs respond to mechanical stretch in skin tissue. Methods: MSCs from luciferase-Tg Lewis rats were transplanted into a rat tissue expansion model and tracked in vivo by luminescence imaging. Expression levels of chemokines including macrophage inflammatory protein-1a, thymus and activation-regulated chemokine, secondary lymphoid tissue chemokine, cutaneous T-cell attracting chemokine, and stromal-derived factor-1a (SDF-1a) were elevated in mechanically stretched tissues, as were their related chemokine receptors in MSCs. Chemotactic assays were conducted in vitro and in vivo to assess the impact of

Combined use of hyaluronidase and urokinase can help increase the flap survival rate when administered intravenously in intraarterial hyaluronic acid occlusion cases. Both red thrombus and hyaluronic acid emboli must be dissolved for flap reperfusion. This method shows a promising effect for future application.