Evaluation of chitosan–gelatin films for use as postoperative adhesion barrier in rat cecum model

Postoperative adhesions remain a significant complication of abdominal surgery and can result in pain, infertility and potentially lethal bowel obstruction. Pharmacotherapy and barrier devices have reduced adhesion formation to varying degrees in preclinical studies or clinical trials. In this study, we produced blends between chitosan (Ch) and gelatin (G) with various compositions (Ch/G 100/0, 75/25, 50/50, 25/75 w/w) as candidate materials for prevention of postoperative abdominal adhesion. For in vivo analysis, 30 female rats weighing 200–250 g were divided into 5 groups (One control and 4 treatment groups). Under general anesthesia, the anterior surface of serous membrane in rat was scraped slightly with sterile gauze until obvious congestion and small bleeding drops appeared, then sample films set on the cecum in treatment groups and the intestine was put back into the abdominal cavity, which were then closed. After 4 weeks, the abdominal cavity was reopened and the grades of peritoneal adhesion were studied by macroscopic and pathologic assessments. Our results showed Ch1/G3 films had an insignificant reduction effect on postoperative adhesion, but surprisingly, the sample with more than 25% by weight of chitosan did not have any effect on reducing adhesion formation but also increased inflammation near the cecum. Administration of chitosan–gelatin films with higher than 25% weight of chitosan had no effect on reduction of adhesion formation in the rat cecum model.