The Effectiveness of Chitosan Wound Dressing in the Form of a Film Compared to Its Hydrogel on Burn Wound Healing in the Male Wistar Rat Model

Modern wound dressings are made and used in the form of foam, film, hydrocolloid, and hydrogel. This research aimed to compare the effectiveness of chitosan in the form of film and hydrogel on burn wounds in an animal model.

The present study is an experimental intervention type among the Wistar male rat model, which was conducted in the Islamic Azad University of Karaj, Iran in the winter of 2020. The dressing was prepared in the form of film and hydrogel based on chitosan. 36 rats were divided into three groups: negative control, hydrogel, and film. After wound formation on days 3, 7, 14, and 21, healing was investigated by histological and molecular methods. The results were analyzed using SPSS21 as well as non-parametric tests .

36 male Wistar rats weighing 200 to 250 grams were tested and the results showed that the percentage of wound healing was the same in the groups until the third day, and on the 7th and 14th days in the film group respectively, 56.55±3.16 and 76.66±4.04 percent and in the hydrogel group it was 60.66±2.51 and 88.33±2.08 percent which showed a significant difference (p-value =0.002) compared to the negative control group (20.55±2.81 and 50.33±5.85 percent). In the histological examination, 100% of the film group and 66.7% of the hydrogel group had moderate and complete epithelium on the fourteenth day; the healing process by examining the collagen matrix and angiogenesis also showed a better effect of chitosan in both forms of intervention. Better control of inflammation in the film group compared to other groups was evident in the examination of inflammatory cells. In the molecular study, an increase in IL-8 gene expression as a factor involved in causing inflammation was observed in both film and hydrogel groups until the third day, and a decrease on other days; there was no significant difference in the expression of IL-10 gene, which inhibits inflammation, between the two forms of film and hydrogel (p-value=0.07), although there was a significant difference with the negative control.

Considering the ease of application and maintenance of the film form and better control of inflammation, it seems that the film form is preferable to the hydrogel.