Nocardia rubra cell wall skeleton accelerates cutaneous wound healing by enhancing macrophage activation and angiogenesis.

Objective This study was performed to investigate the effect of Nocardia rubra cell wall skeleton (N-CWS) on wound healing of full-thickness skin defects. Methods Two 2- × 2-cm full-thickness wounds, one on each side of the midline, were made on the back of 12 rats. One wound was covered with Vaseline gauze soaked in normal saline, whereas the other was covered with Vaseline gauze and N-CWS. Wound dressings were changed every other day from day 0 (wound creation) to day 11. Four of the 12 rats were killed on day 7, and biopsy samples were obtained for biochemical and histopathological analyses. The expression levels of CD31, CD68, and F4/80 in the tissues were examined immunohistologically. The expression of transforming growth factor (TGF)-β1 in the wound was determined by western blot. Results N-CWS increased the wound healing rate, reduced the complete wound healing time, and increased the expression levels of CD31, CD68, and F4/80 on day 7. The TGF-β1 expression level in the wound was significantly higher in the N-CWS group than in the control group on day 7. Conclusions N-CWS can activate macrophages, increase TGF-β1 expression, and enhance angiogenesis and thus accelerate cutaneous wound healing.