title: Experimental evaluation of photocrosslinkable chitosan hydrogel as injection solution for endoscopic resection.
abstract: OBJECTIVE
  Saline as an injection solution for endoscopic resection techniques has several disadvantages such as a short-lasting effect leading to a potentially higher risk of bleeding and perforation. The new substance of photocrosslinkable chitosan hydrogel in a DMEM/F12 medium (PCH) can be converted into an insoluble hydrogel by ultraviolet irradiation for 30 s, and was evaluated in two sets of animal experiments.
  
  
  METHODS
  18 pigs were used in the two parts of the study. First, mucosal resections were done with either PCH or hypertonic saline; the effects of both agents on wound healing were examined endoscopically and histologically. Second, in vivo degradation of PCH was examined using six pig stomachs.
  
  
  RESULTS
  PCH injection led to a longer-lasting elevation with clearer margins, compared with hypertonic saline, thus enabling precise endoscopic submucosal dissection (ESD) along the margins of the elevated mucosa. The endoscopic appearance after ESD was similar in both groups. PCH biodegradation was completed within 8 weeks according to endoscopic and histologic analyses.
  
  
  CONCLUSIONS
  PCH is a promising agent for submucosal injection prior to various techniques of endoresection. It should be evaluated in clinical trials after biocompatibility testing for PCH is completed.
authors.affiliation: Department of Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ishizuka
authors.forename: M
authors.initials: M
authors.lastname: Ishihara
authors.forename: S
authors.initials: S
authors.lastname: Aiko
authors.forename: Y
authors.initials: Y
authors.lastname: Nogami
authors.forename: S
authors.initials: S
authors.lastname: Nakamura
authors.forename: Y
authors.initials: Y
authors.lastname: Kanatani
authors.forename: S
authors.initials: S
authors.lastname: Kishimoto
authors.forename: H
authors.initials: H
authors.lastname: Hattori
authors.forename: T
authors.initials: T
authors.lastname: Horio
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Maehara
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000493:pharmacokinetics; D048271:Chitosan / Q000493:pharmacokinetics; D003432:Cross-Linking Reagents; D004210:Dissection; D004724:Endoscopy; D005240:Feasibility Studies; D020100:Hydrogels / Q000008:administration & dosage* / Q000493:pharmacokinetics; D007267:Injections; D007413:Intestinal Mucosa / Q000601:surgery*; D008297:Male; D023421:Models, Animal; D012965:Sodium Chloride / Q000008:administration & dosage; D013552:Swine; D016896:Treatment Outcome; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D020100:Hydrogels; D012965:Sodium Chloride; D048271:Chitosan