In situ Crosslinkable Thiol-ene Hydrogels Based on PEGylated Chitosan and β-Cyclodextrin

Abstract

Novel β-Cyclodextrin incorporated injectable hydrogels employing PEGylated chitosan as biobasedhydrophilic matrix have been fabricated via thiol-ene reaction. As thiol bearing polymercounterpart of hydrogel precursors, native chitosan was firstly modified with polyethylene glycol groupsto increase its water solubility and bioinertness and then decorated with thiol groups to facilitate thiol-enecrosslinking with acryloyl-modified β-cyclodextrin. A series of hydrogels with varying amounts of acryloylβ-CD and PEGylated chitosan feed were synthesized with high efficiency under mild aqueous conditions.The resulting hydrogels were characterized by equilibrium swelling, structural morphology and rheology.These materials were investigated as controlled drug release platforms by employing a poorly watersoluble anti-inflammatory drug diclofenac as model compound. Benefiting from the inclusion complexformation of the drug with β-CD groups in gel interior, prolonged release profiles were maintained. Thetotal drug absorption and release of hydrogels were shown to be dependent on the amount of β-CD in gelmatrix. These hydrogels combined efficient crosslinking and β-CD incorporation into clinically importantchitosan scaffold and might have potential applications as injectable drug reservoirs such as inregenerative tissue engineering.