Abstract
The suitability of chitosan and UVβcrossβlinkable chitosan for intraperitoneal use, for example as a barrier device for preventing peritoneal adhesions or for drug delivery, was examined. In vitro experiments using two major cell types present in the peritoneal cavity (mesothelial cells and peritoneal macrophages) revealed neither attractive interactions between crossβlinked chitosan gels and the cells nor a proliferative effect. However, the same UVβcrossβlinked chitosan applied in the peritoneal cavity of rabbits caused a granulomatous reaction with adhesion formation within two weeks in all animals, which persisted up to 4 weeks after exposure. Unmodified chitosan also caused adhesions, while UV irradiation did not. UVβcrossβlinkable chitosan induced significant elevations in MIPβ2 and TNFβΞ± from peritoneal macrophages, suggesting that soluble mediators could play a role in inducing adhesion formation. These results reinforce the view that the predictive value of in vitro cytotoxicity assays in matters of biocompatibility may not be sufficient, and suggest that other assays such as cytokine levels may be of value in predicting outcomes in situations involving multiple cell types (i.e. in vivo). Β© 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006