(100e) Healing Wounds with Self-Assembled Bioactive Films

Diabetes is a serious chronic disease that is increasing in the U.S. By 2050, the prevalence of diabetes is projected to increase to as high as 33%. A devastating complication of diabetes is the formation of diabetic ulcers, which affects 25% of diabetic patients. Unlike in normal wounds, there is a disregulation of multiple growth factors in diabetic wounds that affects downstream processes, impairing the wound healing process. The only FDA approved growth factor therapy used to treat diabetic ulcers leads to ineffective, bolus releases of platelet-­derived growth factor-­BB (PDGF­-BB). This study successfully created bioactive dressings that exhibit controlled and synchronized release of PDGF-­BB and vascular endothelial growth factor (VEGF). The bioactive dressings are made using the layer­-by-­layer process to self­-assemble nanostructured polymer films on conventional bandages. Interdiffusion within the films is controlled by conjugating L­-cysteine to the poly(acrylic acid). In vitro testing shows that PDGF­-BB released from the dressings actively phosphorylates PDGF­-Rβ receptors following release. Furthermore, growth factors released up to at least 11 days in solution promote human dermal fibroblast migration. We are currently testing the dressings in ongoing in vivo trials in a mouse model of type­ II diabetes. Initial data shows a doubling in the amount of granulation tissue and vasculature formed in the wound bed. This research may significantly impact the lives of patients with diabetic ulcers and has the potential to give insights in the treatment of other chronic wounds, including pressure and venous ulcers.