Biodegradable gellan gum hydrogels loaded with paclitaxel for HER2+ breast cancer local therapy

Hydrogels loaded with chemotherapeutics are promising tools for local tumor treatment. In this work, redox-responsive implantable hydrogels based on gellan gum were prepared as paclitaxel carriers for HER2-positive breast cancer therapy. To achieve different degrees of chemical crosslinking, hydrogels were synthesized in both acetate buffer and phosphate buffer and crosslinked with different concentrations of l-cysteine. It was shown that both, the type of buffer and the l-cysteine concentration used, conditioned the dynamic modulus, equilibrium swelling rate, porosity, and thermal stability of the hydrogels. Then, the biocompatibility of the hydrogels with the most suitable porosity for drug delivery applications was assessed. Once confirmed, these hydrogels were loaded with paclitaxel:β-cyclodextrin inclusion complexes, and they showed a glutathione-responsive controlled release of the taxane. Moreover, when tested in vitro, paclitaxel-loaded hydrogels exhibited great antitumor activity. Thus, they could act as excellent local tailored carriers of paclitaxel for future, post-surgical treatment of HER2-overexpressing breast tumors.