Efficiency and Safety of Dextran-PAMAM/siMMP-9 Complexes for Decreasing Matrix Metalloproteinase-9 Expression and Promoting Wound Healing in Diabetic Rats

Difficult healing of diabetic foot ulcers is associated with overexpression of matrix metalloproteinase 9 (MMP-9) in the local wound. Therefore, strategies aimed at downregulation of MMP-9 levels in ulcer sites may promote tissue regeneration and accelerate healing of diabetic foot ulcers (DFU). To fulfill this aim, we exploited dextran conjugated with poly(amidoamine) (Dextran-PAMAM) as a gene carrier to deliver MMP-9 targeted siRNA (siMMP-9). The prepared complexes could be efficiently endocytosed with low cytotoxicity to HaCat cells. Dextran-PAMAM could efficiently deliver siMMP-9 and significantly inhibit MMP-9 expression in vitro. Diabetic rats wound models showed that topical application of the Dextran-PAMAM/siMMP-9 complex effectively knocked down MMP-9 expression in skin wound tissue, thus accelerating wound healing. Taken together, this study demonstrates that the Dextran-PAMAM/siMMP-9 complex possesses high potential for wound healing and could serve as a promising regenerative platform for improving DFU healing.