Cutaneous wound healing functions of novel milk-derived antimicrobial peptides, hLFT-68 and hLFT-309 from human lactotransferrin, and bLGB-111 from bovine β-lactoglobulin

The absence of multi-functional antimicrobial agents in clinical settings hinders cutaneous wound healing. Milk-derived antimicrobial peptides (MAPs) may be the imperative solution to wound repair, combining the dermatic curative properties of antimicrobial peptides with the biological activity of milk. Three novel MAPs, which were hLFT-68 (IAENRADAV) and hLFT-309 (GSPSGQKDLLF) identified in human milk and bLGB-111 (LDTDYKKY) identified in bovine milk in our previous work, were initially investigated for their function in wound healing. In vitro, the antibacterial activity and cellular mechanism of the MAPs were examined. It was found that they presented inhibition for Staphylococcus aureus and Escherichia coli, decreased the secretion of inflammatory factors (IL-1β, IL-6, and TNF-α), and promoted fibroblast and keratinocyte proliferation. An infected wound model was established to evaluate the in vivo anti-inflammatory and regeneration properties of the MAPs. The wound area shrank more rapidly, and the wound inflammation was reduced by MAP treatment. Especially on days 3-5 after mouse modeling, the wound repair rate increased by up to 35%. Furthermore, it was suggested that they encouraged collagen synthesis and deposition, and tissue regeneration. The presented results indicated that MAPs accelerated the recovery of infected wounds, possessing the potential for developing wound-healing therapy.