Abstract:A mouse full-thickness skin defect model was established to analyze the healing effect of a composite peptide comprising wheat oligopeptide and marine fish skin collagen oligopeptide. On the 4th and 14th days after the intervention, pathological changes in the wound were assessed by subjecting the skin taken from the back of mice to H&E staining; the extent of angiogenesis was determined based on CD34 expression (estimated by immunofluorescence). Serum metabolomic profiles were obtained using ultra-high-performance liquid chromatography and mass spectrometry to screen for differential metabolites whose expression was significantly altered. Metabolic profile analysis, OPLS-DA analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed. On the 4th, 6th, and 8th days after the injury, the wound healing rates in the composite-peptide group reached 59%, 74.1%, and 80.9% respectively, which were significantly higher than those observed in the model group. Furthermore, the granulation tissue continued to mature, and higher counts of CD34-positive cells were observed in the composite-peptide group. Metabolomic analysis showed that among differentially expressed metabolites in the composite-peptide group, 14 were upregulated and 20 were downregulated. KEGG pathway analysis showed that the composite peptides were significantly enriched for six pathways, i.e., taurine and hypotaurine metabolism, arginine and proline metabolism, and primary bile acid biosynthesis (compared to the model group). Thus, composite peptides can reduce the repair time of full-thickness skin defects in mice, possibly by promoting capillary formation and protein biosynthesis to accelerate wound healing.
