To investigate the
tissue adhesive function of a
hydrogel composed of biocompatible amphiphilic
polymers,
polymers with various architectures were prepared from
2-methacryloyloxyethyl phosphorylcholine (MPC),
electrolyte monomers and hydrophobic n-
butyl methacrylate (BMA). A polyion complex (PIC)
hydrogel was formed within a few minutes after aqueous solutions containing the cationic and anionic MPC
polymers were mixed. Provided the electrical charge of the cationic and anionic MPC
polymers was approximately balanced, the PIC
hydrogel existed stably in a large amount of aqueous medium. The results of the fluorescence study of the MPC
polymers suggested that dissociation was suppressed and that the electrostatic interaction was enhanced in the block and graft
polymers compared to the random
polymers. This is due to the strategically designed architectures and the hydrophobic BMA units. Based on the results of the cytotoxicity test, the cytotoxicity of the MPC
polymers was lower than that of
glutaraldehyde, a cross-linker contained in
aldehyde-type
tissue adhesives. The cationic MPC
polymers demonstrated higher cytotoxicity compared to the anionic ones, which demonstrated no significant cytotoxicity at examined concentrations. The
tissue adhesion of the PIC
hydrogels was evaluated with a dura incision model. The results indicated that the
tissue adhesion strength of the PIC
hydrogel was lower than that of a commercially available
fibrin glue. However, the
tissue adhesion strength increased with an increase in the
polymer concentration and could be controlled by the water content of the
hydrogel. Although further investigation of the biocompatibility of the PIC
hydrogels and control of the water content is crucial, it can be concluded that the PIC
hydrogels formed by the amphiphilic MPC
polymers can be promising
tissue adhesives which demonstrate properties according to the architectures and chemical structures.