Zn2+ driven H2S/Cu2+ sustained releasing nanofibers with immunoregulation for wound healing

Immunoregulation is one of the important factors in wound healing. Currently, wound dressings with immunoregulation is necessary to overcome the complicated interventions, high-cost treatments and uncontrolled release behaviors. In this study, a novel Cu and Zn loaded nanofiber dressing (FM-Cu-Zn) with immunoregulation and controllable release without external intervention was prepared by electrospinning. The dressing is composed of ZnCl2, CuS nano particles, poly-3-hydroxybutyrate-co-4-hydroxybutyrate (P34HB). Where Zn2+ is the "promoter" of immunotherapeutic activity by reducing the environmental pH to trigger H2S and Cu2+ releasing from CuS. Then, H2S and Cu2+ can regulate the inflammatory response and accelerate wound healing. The results in vivo indicated the FM-Cu-Zn nanofiber dressing showed better anti-inflammatory and wound healing ability, the wound healing rate was upto 95 % after 11 days treatment by the obtianed dressing, which was much higher compared to control groups. Notably, the dressing can promote macrophage polarization toward a pro-regenerative M2 phenotype without any external intervention. Therefore, the FM-Cu-Zn nanofiber with the immunomodulatory property can serve as a promising dressing in wound healing field.