Preparation and characterization of a biodegradable hydrogel containing oligo(2,2-dimethyltrimethylene carbonate) moieties with tunable properties

A series of biodegradable hydrogels based on oligo(2,2-dimethyltrimethylene carbonate)-block-poly(ethylene glycol)-block-oligo(2,2-dimethyltrimethylene carbonate) diacrylate (DPD-DA) precursor with varied length of hydrophilic poly(ethylene glycol) (PEG) segment and hydrophobic oligo(2,2-dimethyltrimethylene carbonate) (ODTC) segment were prepared by photopolymerization. Hydrophobic interaction was found to affect the properties of the hydrogel. The elastic modulus and toughness of the hydrogel could be tuned by altering the lengths of the hydrophobic ODTC segment as well as the hydrophilic PEG segment. In a monolayer culture, the number of swine cartilage chondrocytes (SCCs) attached to the hydrogel surface increased along with an increase in the length of ODTC segment in the precursor. SCCs cultured on the surface of hydrogel and photo-encapsulated in the hydrogel demonstrated comparable cytocompatibility with the widely recognized PEG hydrogel.