Design and preparation of pH-responsive curdlan hydrogels as a novel protein delivery vector

New pH-responsive saccharide hydrogels were designed and prepared using curdlan derivatives (curdlan-Boc-histidine, CUR-HIS). The CUR-HIS hydrogels possessed highly porous structures. The swelling ratios of CUR-HIS hydrogels increased with the degree of substitution of Boc-histidine groups. And the addition of 0.5 mol/L NaCl provoked a sharp reduction of swelling ratio of CUR-HIS hydrogels. Bovine serum albumin (BSA) can be efficiently encapsulated into CUR-HIS hydrogels. Moreover, the release profiles of BSA at different pH values from CUR-HIS hydrogels were significantly different. These hydrogels showed good biocompatibility in the cytotoxicity assays. The CUR-HIS hydrogels are of great potential in biomedical applications such as protein delivery systems.