RESUMO
OBJECTIVE: Scar tissue formation, as a normal part of wound healing, initiates in the proliferation phase, continues after the remodelling phase, and may cause an unpleasant appearance or disruption in normal functioning. This study investigated the effects of a topical gel on acute wound healing and reducing scars in a rat model. METHOD: ChitoScar (ChitoTech Company, Iran), a commercial scar-reducing gel based on chitosan, was analysed for antibacterial and antiviral activity through a quantitative suspension test. Its cytotoxic effect was investigated, and then irritation and delayed-type hypersensitivity tests were carried out on rabbits through direct application of the gel. Furthermore, the effect of the chitosan-based gel on wound healing and scar tissue formation was studied in rats with an acute wound in two groups: the treatment group (topical application of the chitosan-based gel); and the control group (without treatment). Histopathological examination was carried out based on the inflammatory cells, collagen fibre, keratinocytes and fibroblasts. RESULTS: Analysis revealed that the chitosan-based gel had no cytotoxicity and caused no erythema, oedema, local or other systemic adverse response. Wound healing occurred earlier in the treatment group, which was a result of a significant increase in re-epithelialisation, angiogenesis, fibroblast population and collagen fibre thickness (p<0.05). In the treatment group, wounds healed completely after 21 days and scars totally disappeared after 28 days, while in the control group, wound healing remained incomplete with distinct scar tissue. CONCLUSION: The results demonstrated the positive effect of the chitosan-based gel on the duration and quality of the wound healing process, as well as minimising the scar tissue formation in this in vivo study.
