A Novel Biofilm Disruptive Agent Influences the Wound Healing Process by Altering the Level of Cytokines and Chemokines Within the Wound

Wound healing occurs through specific overlapping steps involving different host cell types and mediated by cytokines and chemokines (C/C) with pleiotropic functions. We previously showed by H&E staining that treatment with the novel antimicrobial biofilm disruptive agent (BDA) decreased inflammation on day 1 post-injury (D1), increased angiogenesis and granulation tissue formation on D3, and enhanced keratinocyte hyperplasia on D7.

Currently, we examined the influence of BDA on the level of C/C affecting the stages of healing. We generated full-thickness skin wounds in mice and covered them with sterile gauze (NT), gauze plus polyethylene glycol base (PT), or gauze plus BDA (BDAT). At D1, D3, and D7, the wound bed and margins were excised. Proteins were extracted from portions of the tissues for analysis of C/C levels by U-PLEX biomarker assay.

Remaining tissues were formalin-fixed, sectioned, and stained specifically for M2 macrophages. On D1, levels of pro-inflammatory C/C CCL3, IL-1β, IL-6, IL-12p70, IL-17F, and CXCL1 were elevated with BDAT but lower than NT and PT; in contrast, the level of CXCL10 was increased. On D3, levels of the same C/C, now related to reepithelialization and angiogenesis, remained reduced in BDAT mice, while CXCL10 was elevated. On D7, levels of C/C responsible for keratinocyte hyperplasia were elevated by BDAT: GM-CSF, IL-17F, IL-6, and CXCL1. At D1, no M2 macrophages were observed; on D3, M2 macrophages were present in tissues of BDAT mice; while by D7, M2 macrophages were present in tissues from all treatments.

These results suggest that BDAT prevents over-exuberant inflammation in a clean wound by reducing the level of pro-inflammatory cytokines while promoting the appropriate formation of blood vessels by increasing CXCL10 on D1; accelerates wound healing by enhancing the numbers of M2 macrophages on D3; and advances reepithelialization on D7 by increasing levels of C/C involved in keratinocyte hyperplasia.