Evaluation of the in vitro and in vivo biocompatibility of carrageenan-based hydrogels

Carrageenans are highly sulphated galactans, well-known for their thermogelation properties which have been extensively exploited in food and cosmetics industry but poorly explored in the biomedicine field. In this study, we have assessed the in vitro and in vivo biocompatibility of kappa-carrageenan hydrogels that have been explored for regenerative medicine and tissue engineering applications. The in vitro cytotoxicity of the materials using a L929 mouse fibroblast cell line was evaluated, and the effect of kappa-carrageenan hydrogels on the activation of human polymorphonuclear neutrophils cells (hPMNs) was also evaluated by the quantification of reactive oxygen species by chemiluminescence. Subsequently, the inflammatory/ immune reaction to kappa-carrageenan hydrogels on subcutaneous implantation was studied in rats. Explants were retrieved after 1 and 2 weeks of implantation for histologial and RT-PCR analysis. The cytotoxicity screening revealed that kappa-carrageenan hydrogels did not significantly affect L929 metabolic activity. Moreover, hPMNs contact with kappa-carrageenan resulted in a reduced and a neglectable signal regarding the detection of superoxide and hydroxyl anions, respectively. The results from the in vivo experiments indicated that kappa-carrageenan induce a low inflammatory response. Overall, the data obtained suggest that kappa-carrageenan hydrogels are biocompatible and thus can be further studied for their use in target biomedical applications. (C) 2014 Wiley Periodicals, Inc.