Hydrogels from chitosan crosslinked with poly(ethylene glycol) diacid as bone regeneration materials

Abstract A simple method to covalently crosslink chitosan using poly(ethylene glycol) diacid as crosslinking agent is proposed. Networks net-chitosan-ι- PEG(COOH)2 were obtained by heating chitosan in aqueous PEG600(COOH)2 solutions at a temperature higher than 60°C. IR spectroscopy revealed the formation of amide bonds. It is shown that the obtained chemical networks are pH-sensitive hydrogels with enhanced hydrophilicity. The equilibrium degree of swelling of the hydrogels is determined by the conditions of their preparation - heating temperature and mole ratio between chitosan and the crosslinker. The ability of the polymer networks to facilitate bone regeneration processes was shown by in vivo implantation experiments.