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.