Localized Antiadhesive Hydrogel Barriers for Prevention of Postoperative Adhesion

Postoperative adhesions are frequent and serious complications that lead to longer operative times and high medical costs. Various types of antiadhesive materials, including films, solutions, and hydrogels, have been developed; however, they have limitations in providing localized antiadhesive properties, maintaining low volume change, and allowing for rapid preparation suitable for minimally invasive procedures. Here, we developed in situ-forming hydrogel barriers based on decanoyl group-modified Alaska pollock gelatin (C10-am-ApGltn) and a poly(ethylene glycol)-based crosslinker (4S-PEG). The resulting hydrogels adhered to the desired intestinal tissue surfaces and showed antiadhesive property within 60 s. The hydrogel barriers that adhered to the tissue were stable for at least 2 days in an aqueous environment. The hydrogel barrier prepared from 4 w/v% C10-ApGltn showed no volume changes after immersion in saline for 24 h. The gelation time of the hydrogel was within 4 s when the concentration of C10-ApGltn ranged from 4 to 15 w/v%; however, it slowed at 2 w/v%. The freeze-dried 4 w/v% C10-am-ApGltn sample rapidly dissolved in a buffer solution within a few min without heating. Furthermore, 4S-PEG for 4 w/v% C10-am-ApGltn sample dissolved within 3 s. An in vivo rat adhesion model revealed that the hydrogel barrier of 4 w/v% C10-ApGltn showed antiadhesive property, complete degradation behavior, and wound healing property within 2 weeks. With its antiadhesive effects, stable volume, and short preparation time, the hydrogel barrier developed from 4 w/v% C10-am-ApGltn has the potential to be used as a localized barrier for the prevention of postoperative adhesion.