title: Comparison of covalently and physically cross-linked polyethylene glycol-based hydrogels for the prevention of postoperative adhesions in a rat model.
abstract: A covalently and a physicochemically cross-linked hydrogel, both based primarily on polyethylene glycol and both formed in situ, were compared side by side in a rat uterine horn devascularization and serosal injury model for efficacy in adhesion prevention. The primary difference between the two materials was the nature of their cross-linking. The covalently cross-linked hydrogel was a photopolymerized polyethylene glycol-co-lactic acid diacrylate, and the physically cross-linked hydrogel was a polyethylene glycol-co-polypropylene glycol, Poloxamer 407. In the surgical model employed, application of the covalently cross-linked hydrogel reduced the extent of adhesion formation from 75 +/- 10% in the control group to 16 +/- 6% (mean +/- s.d., P < 0.001). Application of the physically cross-linked hydrogel reduced adhesion formation to 38 +/- 19% (P < 0.01). Retention of the two hydrogels upon the site of application was also evaluated. The covalently cross-linked hydrogel formed a continuous barrier upon the uterine horns for more than 4 d, while the physicochemically cross-linked hydrogel was present upon the uterine horns for less than 2 d. This difference in retention was probably the cause of the difference in efficacy and may be attributed to the nature of the cross-linking.
authors.affiliation: Department of Biomedical Engineering, University of Texas, Austin 78712, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: West
authors.forename: J A
authors.initials: JA
authors.lastname: Hubbell
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000378:metabolism; D005260:Female; D005782:Gels; D011060:Poloxalene / Q000737:chemistry / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000737:chemistry / Q000378:metabolism*; D011183:Postoperative Complications / Q000517:prevention & control*; D019736:Prostheses and Implants; D051381:Rats; D017207:Rats, Sprague-Dawley; D000267:Tissue Adhesions / Q000517:prevention & control*; D014599:Uterus / Q000601:surgery
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D005782:Gels; D011092:Polyethylene Glycols; D011060:Poloxalene