Biomimetic gene delivery system coupled with extracellular vesicle–encapsulated AAV for improving diabetic wound through promoting vascularization and remodeling of inflammatory microenvironment
Shan He, Zhenhao Li, Lei Xie, Rongtian Lin, Biying Yan, Bixiang Li, Luo Li, Youshan Xv, Huangding Wen, Yaxuan Liang, Cong Huang, Zhiqing Li
Abstract
Adeno-associated virus (AAV)-mediated gene transfer has demonstrated potential in effectively promoting re-epithelialization and angiogenesis. AAV vector has a safety profile; however, the relatively low delivery efficacy in chronic wound with an inflammatory microenvironment and external exposure has limited its prospective clinical translation. Here, we generated AAV-containing EVs (EV-AAVs) from cultured HEK 293T cells and confirmed that the gene transfer efficiency of VEGF-EV-AAV significantly surpassed that of free AAV. Subsequently, a biomimetic gene delivery system VEGF-EV-AAV/MSC-Exo@FHCCgel developing, and synergistically enhances anti-inflammation and transfection efficiency in the combination of human umbilical cord mesenchymal stem cell-derived exosomes (hUC-MSC-Exo). Upon reaching physiological temperature, this hydrogel system transitions to a gel state, maintaining AAV bioactivity and facilitating a sustained release of the encapsulated vesicles. The encapsulation strategy enables the vesicles to rapidly fuse with endothelial cell membranes, ensuring controlled expression of endogenous VEGF. Results revealed that VEGF-EV-AAV/MSC-Exo@FHCCgel alleviates mitochondrial function in endotheliocyte under oxidative stress. Furthermore, it eliminates senescent macrophages by inhabitation of cyclic GMP-AMP (cGAMP) synthase (cGAS)-stimulator of interferon genes (STING) pathway to promote efferocytosis. The system increases Treg cells accumulation, leading to a reduction of inflammatory cytokines. Collectively, the biomimetic gene delivery system represents a promising multi-faceted strategy for chronic wound healing.