Histological analysis in vivo. (a) H&E staining. (c) CD 45 IHC staining of leukocytes on day 3. (d, f) IHC staining of macrophages and CD163 positive macrophages on day 3. (b, e, g) Statistical analysis of inflammatory cells, macrophages, and CD163 positive macropahges on day 3. (h, i) H&E staining and epidermal thickness analysis on day 15. (j, k) Masson staining and statistical analysis of dermal collagen deposition on day 15. (l–w) IHC staining and statistical analysis of Col I, Col III, MMP1, TIMP1, VEGF, and ɑ-SMA on day 15. *P < 0.05; **P < 0.01; ***P < 0.001.