Sonoporation of the Minicircle-VEGF165 for Wound Healing of Diabetic Mice

The purpose of this study is to examine the efficiency of sonoporation with minicircle DNA for the skin wound healing in diabetic mice. Minicircle DNA containing the human VEGF(165) was constructed and tested in vitro. Diabetes was induced in 2-week old male C57BL/6J mice via streptozotocin (STZ) injection. 6 mm circular skin wounds were made on the mice back. After the subcutaneous injection of the minicircle DNA at the edge of the wound, the mice were exposed to the ultrasound irradiation for the sonoporation. Wound areas were analyzed until the day 12. Blood perfusion and angiogenesis were evaluated using a laser Doppler imaging and CD31 immunostaining, respectively. Re-epithelialization was assessed by histochemical analysis using hematoxylin and eosin staining. Accelerated wound closure was observed in the mice receiving sonoporation of minicircle-VEGF(165), which corresponds to the markedly increased skin blood perfusion and CD31 expression. Histological analysis revealed that the minicircle treated wound tissues showed fully restored normal architectures as compared with the non-treated diabetic controls with the markedly edematous and chaotic morphologies. Ultrasound mediated gene therapy with the minicircle-VEGF(165) is effective for the healing of the skin wound of the diabetic mice.