Prodigiosin Loaded SN-PB@PG NPs-Based Multimodal Therapy for the Healing of Bacterial Infected Chronic Wounds

Healing of infected chronic wounds faces dual challenges: persistent inflammation and impaired angiogenesis. To address these, SN-PB@PG nanocomplexes were prepared by hybridisation of nitroprusside (SNP) with Prussian blue (SN-PB NPs) and loaded with prodigiosin (PG). Under near-infrared (NIR) irradiation, SN-PB NPs generated mild hyperthermia, facilitating the release of nitric oxide (NO) and PG to combat bacterial biofilms and multidrug-resistant pathogens. The in vivo assay using diabetic infected wounds demonstrated that SN-PB@PG NPs with NIR reduced the wound area to 10.6% by the 11th day, which is superior to that of control group (29.6%). In the flap transplantation experiments, the data showed SN-PB@PG NPs with NIR group only have a necrobiosis of 3.8% of flaps on the 8th day, which is superior to 31.3% of the control group. Additionally, the release of NO promoted vascular regeneration by up-regulating vascular endothelial growth factor (VEGF) and platelet endothelial cell adhesion molecule-1 (CD31), and regenerated sarcomeric tissue by down-regulating MMP-9. The results indicated that the combination of SN-PB@PG NPs with gas and photothermal therapy exerted a combined antibacterial and wound healing effect. Compared to traditional clinical methods such as surgical debridement and hyperbaric oxygen therapy, this new strategy efficiently addresses issues of infection and healing, which is convenient for clinical application.