ELISA analysis of wound tissue for concentration of NGF (A), SP (B), and CGRP (C). Comparison of the concentration of NGF (A), SP (B), and CGRP (C) between SKP-treated and control groups at different post-wound days. ##P < 0.01, comparison between SKP-treated and control groups; #P < 0.05, comparison between SKP-treated and control groups.