Gas-injection of gold nanoparticles and anti-oxidants promotes diabetic wound healing

Diabetic ulcers and unhealed bedsores have resulted in serious complications all around the world. Antioxidant epigallocatechin gallate (EGCG) has been proved beneficial in diabetic studies. However, the low bioavailability of EGCG is always a problem for human application. In this study, topical gas-injection of a EGCG and gold nanoparticle (AuNP) liquid mixture (AuE) using the GNT GoldMed (TM) Liquid Drug Delivery System significantly accelerated the wound healing on wild-type and streptozotocin-induced diabetic mouse skin. Immunoblotting of the diabetic wound tissue showed a significant increase of the vascular endothelial cell growth factor on day 7 and the Cu/Zn superoxide dismutase expression from day 3 to day 7. Furthermore, the epidermal growth factor receptor and collagen I & III protein expression both increased significantly in the wound area. After gas-injection of the AuE liquid, hyaluronic acid (HA) expression also significantly increased on day 7 as measured by immunohistochemistry analysis. In conclusion, gas-injection of AuE significantly increases the rate of wound healing both in wild-type and diabetic mice. This study may provide a new approach for improving the EGCG bioavailability on diabetic wounds.