The prevention of peritoneal adhesions by in situ cross-linking hydrogels of hyaluronic acid and cellulose derivatives.

Post-operative peritoneal adhesions can cause pelvic pain, infertility, and potentially lethal bowel obstruction. We have designed and synthesized injectable hydrogels that are formed by mixing hydrazide-modified hyaluronic acid (HA) with aldehyde-modified versions of cellulose derivatives such as carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC), and methylcellulose (MC). Gelation of these hydrogels occurred in less than 1 min, and had higher shear moduli than that of HA-HA gel (HAX). Hydrogels degraded in the presence of hyaluronidase in vitro, with HA-MC and HA-HPMC degrading more slowly than HAX and HA-CMC. The aldehyde-modified cellulose derivatives showed dose-dependent mild-to-moderate cytotoxicity to mesothelial cells and macrophages in vitro, but all were biocompatible in the murine peritoneum, causing no adhesions for 3 weeks. All the cellulose-derived gels showed efficacy in reducing the area of adhesion formation in a rabbit sidewall defect-bowel abrasion model.