Pitaya stem polysaccharide promotes wound healing by modulating macrophage polarization via single-cell RNA...

Hyperactivation of M1 macrophages or delayed macrophage M2/M1 polarization during wound healing is a major obstacle to wound healing. Polysaccharide, as a biomaterial, has shown great potential and advantages in the field of wound dressings, but little is known about the role of polysaccharide (PSP) in wound healing. The aim of this study was to investigate the promotional effect of PSP on wound healing through its effect on macrophage M2/M1 polarization. The results showed that PSP treatment polarized the macrophage population toward an M2 phenotype, significantly accelerating wound closure in vivo, as evidenced by increased levels of collagen deposition, decreased levels of pro-inflammatory cytokines (INOS, IL-6, and IL-1β), and increased expression of CD31 (an angiogenic marker) and Ki67 (a cell proliferation marker). Functional changes in skin macrophages during wound healing were analyzed using single-cell RNA sequencing (scRNA-seq). The results highlighted a unique transcriptional signature associated with PSP-induced polarization of M2 macrophages. Moreover, PSP was found to upregulate the PI3K/Akt signaling pathway, which is crucial for cell survival, migration, and tissue repair. These results reveal that PSP can promote skin wound healing, emphasizing its potential as a natural product for treating skin wounds.