Inhibiting dipeptidyl peptidase 4 positive fibroblasts using zinc sulfide cellulose nanofiber scaffolds to achieve scarless healing.

Wound regeneration with integral function and cutaneous appendages remains challenging in wound dressing applications. Cellulose nanofibers (CNF) exhibit remarkable characteristics in wound dressing applications; however, their utility in the wound healing process is limited by insufficient scar inhibition and regenerative healing. Herein, inspired by fibroblast heterogeneity mediating wound healing and skin regeneration, we developed a CNF scaffold designed to block Dipeptidyl Peptidase 4 positive (DPP4+) fibroblasts for regenerative healing. CNF encapsulated sitagliptin (SITA) and zinc sulfide nanoparticles (NZnS), namely CNF@SITA@NZnS, to fabricate a novel biomaterial for scar reduction and regenerative healing. The scaffold promoted scarless healing and hair follicle regeneration in rats. In vivo experiments, the wounds in the scaffold showed less skin fibrosis, a better collagen ratio and more new hair follicles. In vitro experiments showed that the scaffold material promoted scarless healing, possibly by inhibiting the secretion of extracellular matrix and fibroblast-to-myofibroblast conversion. The promotion of hair follicle regeneration by the scaffold material may be due to promotion of the migration and proliferation of human hair follicle papilla cells. RNA sequencing is performed to explore the underlying mechanisms, which can activate ECM-receptor interaction pathway in favor of the wound healing process. The inhibiting effect of CNF@SITA@NZnS scaffold on DPP4+ fibroblasts can be a potential target to reduce scarring and promote skin regeneration.