Abstract
The neuropeptide substance P (SP) is known to stimulate wound healing by regulating the production of relevant cytokines as well as cell proliferation and migration. However, the therapeutic application of SP is limited by its low stability under biological conditions and oxidation during purification, formulation, and storage. To address this problem, we developed a novel formulation of SP as an SP gel, and investigated its wound healing activity both in vitro and in vivo. SP in SP gel was stable at various temperatures for up to 4 weeks. In vitro, SP gel exhibited more potential as a candidate wound-healing agent than SP alone, as evidenced by the observed increases in the proliferation and migration of human epidermal keratinocytes and human dermal fibroblasts. In vivo experiments showed that SP gel treatment enhanced the healing of full-thickness wounds in mice as compared to SP alone. These results demonstrate the benefits of SP gel as a promising topical agent for wound treatment.