The aim of this study was to optimize the properties of a lubricious bioerodible
hydrogel barrier for the prevention of postoperative adhesions. Water-soluble macromers based on block copolymers of poly(
ethylene glycol) (PEG) and
poly(lactic acid) or poly(
glycolic acid) with terminal
acrylate groups were used, and these macromers were gelled in vivo by exposure to long wavelength ultraviolet light. The precursor was photopolymerized from buffered
saline solution while in contact with the tissues. This resulted in the conformal coating of the tissue with an adherent
hydrogel film, while forming a nonadhesive barrier at the free surface, on the treated
wound site. The
hydrogels were evaluated in two animal models of postsurgical adhesions, first in a rat cecum abrasion model and then in a rabbit uterine horn
ischemia model. In the rat cecum model, six of seven animals treated with a
hydrogel, with glycolide in the precursor as the comonomer, showed no adhesions; untreated animals and animals treated with precursor, but not gelled with light, showed consistent dense adhesions. In the rabbit uterine horn
ischemia model, using
hydrogels with
lactide in the precursor as the comonomer, and PEG of molecular weight from 6,000 to 18,500 Da, adhesions were dramatically reduced, with occurrence in none of seven animals treated with a gel containing PEG 10,000. By contrast, the seven animals in the control group demonstrated a mean of 35% involvement of the horn length in dense, fibrous adhesions. These materials, photopolymerized in vivo in direct contact with the tissues, appear to form an adherent
hydrogel barrier that is highly effective in reducing postoperative adhesions in the models used.(ABSTRACT TRUNCATED AT 250 WORDS)