The effect of intradermal botulinum toxin type A injection on healing of porcine full-thickness wounds.

Botulinum toxin type A (BTX-A) has been proposed to improve wound healing quality beyond its neuromuscular effects; however, histopathologic evidence from translational skin models remains limited. This study evaluated the effects of intradermal BTX-A on cutaneous wound healing using a porcine full-thickness wound model. Ten standardized circular wounds were created and treated with intradermal BTX-A or saline as a control. Wound area and histopathological parameters-including inflammatory cell infiltration, differential inflammatory cell counts, blood vessel density, fibroblast proliferation, collagen density, and collagen fiber organization-were assessed at postoperative day 3, 7, 14, 21, and 28. Wound area decreased progressively in both groups, with no significant differences in wound closure kinetics. In contrast, BTX-A-treated wounds exhibited significantly reduced inflammatory cell infiltration during the early postoperative period, with decreased neutrophil, lymphocyte, and macrophage counts at selected time points (p < 0.05). Blood vessel density and fibroblast counts were significantly increased in BTX-A-treated wounds during the early proliferative phase (p < 0.05). Collagen density was consistently higher in BTX-A-treated wounds at all time points, and collagen fiber organization was significantly improved during the remodeling phase. These findings indicate that intradermal BTX-A improves wound healing quality by modulating inflammation, angiogenesis, fibroplasia, and collagen maturation without accelerating wound closure.