Suppression the glucose-induced ferroptosis in endothelial cells by 4OI-loading exosomes hydrogel for the treatment of diabetic foot ulcer

The prevalence of diabetic foot ulcer in individuals with diabetes is approximately 15%, and it is frequently accompanied by vascular dysfunction and infection. The management challenges make it the primary cause for amputation; however, the underlying mechanisms remain poorly understood, thereby impeding the advancement of novel wound dressings and medication. Herein, single-cell sequencing analysis revealed that ferroptosis induced by high glucose levels in vascular endothelial cells (VECs) represents a significant molecular pathological feature in diabetic foot ulcer (DFU) tissue. Furthermore, 4-Octyl itaconate (4OI) exhibited a pronounced protective effect against VECs injury induced by high glucose (HG), and its underlying molecular mechanisms involve the mitigation of HG-induced reactive oxygen species (ROS) injury and ferroptosis in VECs through the regulation Keap1/Nrf2/GPX4. For enhanced application, incubation at 37℃ was used to load 4OI into exosomes, which were subsequently encapsulated within an Alg-DA/GelMA-based hydrogel matrix. Remarkably, the utilization of 4OI-Exo-Gel not only expedited wound healing but also significantly improved the overall quality of healing in DFU. In conclusion, these findings not only demonstrate, for the first time, the remarkable ability of 4OI to enhance diabetic wound healing by mitigating VECs ferroptosis induced by HG, but also provide evidence for the potential clinical translation of a 4OI-loaded exosomes hydrogel in diabetic wound therapy.