Supplementary Material for: Effects of Sprayable, Highly Adhesive Hydrophobized Gelatin Microparticles on Endoscopic Submucosal Dissection: A Swine Model

Introduction: Sprayable wound dressings containing hydrophobized microparticles (hMPs) are characterized by strong adhesiveness. We examined the effect of hMPs derived from Alaska pollock gelatin on endoscopic submucosal dissection (ESD) ulcers. Methods: (1) In an in vivo model of miniature swine gastric ESD, gastric ulcers were created by ESD and then sprayed with hMPs or untreated followed by microscopic examination. (2) In an ex vivo ESD model of resected stomach, a pinhole-shaped perforation was created on the ESD ulcer of resected stomach; hMPs were then sprayed on the perforation; and air leakage and intragastric pressure were measured. (3) In an in vivo duodenal ESD model of miniature swine, duodenal artificial ESD ulcers with pinhole-shaped perforation were examined; ulcers were classified into hMPs-sprayed and nonsprayed groups, and inflammation in the intrinsic muscle layer and serosa were compared between the groups. Results: (1) Histological observation of submucosal tissues showed a decreased number of invading inflammatory cells in hMP-sprayed tissues compared with the control in miniature swine gastric ESD (p p p Conclusions: Sprayable, tissue-adhesive hMPs are a promising medical material for intraoperative and postoperative treatment of ESD-induced wound via anti-inflammation and strong adhesiveness.