Platelet-Rich Plasma-Derived Exosome-Encapsulated Hydrogels Accelerate Diabetic Wound Healing by Inhibiting Fibroblast Ferroptosis

Platelet-rich plasma-derived exosomes (PRP-Exos) have recently been considered an optimized strategy for diabetic wound treatment, yet the potential role of PRP-Exos in diabetic wound healing is still unclear. This study aims to investigate the potential mechanisms of PRP-Exos in diabetic wound healing and to utilize the hydrogel Pluronic F127 as a carrier to maintain the sustained release of encapsulated PRP-Exos. PRP-Exos were isolated from the blood of healthy individuals and characterized, followed by co-culturing with isolated diabetic human skin fibroblasts (Diabetes HSF). RNA sequencing (RNA-seq) was used to analyze the effect of PRP-Exos on the transcriptome of normal and Diabetes HSF, screening and validating the crucial mechanism and target gene. Then, a hydrogel composed of Pluronic F127 and PRP-Exos (PRP-Exos/Gel) was constructed and applied in the diabetic mouse models to evaluate the effect and mechanism. RNA-seq analysis revealed that PRP-Exos significantly upregulated the expression of FosB in Diabetes HSF. Further intervention in the expression of FosB in Diabetes HSF showed that knocking down FosB induced ferroptosis in Diabetes HSF, characterized by decreased cell viability, increased oxidative stress, and increased iron ion levels, along with downregulation of GPX4 and SLC7A11 expression, while ACSL4 expression was increased; conversely, overexpression of FosB had the opposite effect. Subsequently, adding PRP-Exos to FosB-knocked down Diabetes HSF significantly weakened the inhibitory effect of PRP-Exos on ferroptosis in diabetic fibroblasts. The synthesized PRP-Exos/Gel exhibited significant thermosensitivity and sustained release of exosomes. In animal experiments, the PRP-Exos/Gel showed significant anti-inflammatory effects, evidenced by an increased proportion of M2 macrophages and a decreased proportion of central granule cells in wound tissue, and inhibited fibroblast ferroptosis, thereby accelerating wound healing. Overall, the constructed PRP-Exos/Gel displays a continuous release of exosomes and promotes diabetic wound healing by suppressing inflammatory responses and fibroblast ferroptosis, which provides new insights and methods for the treatment of diabetic wounds.