Synthesis of catechol-functionalized polymer–based crosslinked thermoresponsive hydrogels for tissue-adhesive material

Injectable and temperature-sensitive hydrogels were synthesized for use as a tissue-adhesive material between dopamine end-capped Pluronic and CCDP-q-PDB (2-chloro-3′,4′-dihydroxyacetophenone-quaternized poly((dimethyl aminoethyl methacrylate)-co-(t-butylmethacrylate))). The mixture of dopamine end-capped Pluronic and CCDP-q-PDB exists in a viscous solution state at room temperature, but becomes a gel via in situ crosslinking at body temperature. The hydrogel structure was shown to be more stable than Pluronic F127 copolymers in aqueous solution. At a 14:8 wt% ratio of dopamine end-capped Pluronic to CCDP-q-PDB, the sol quickly transformed into a gel at body temperature and under physiological conditions (<10 s), showing excellent gel stability. To evaluate the tissue-adhesive properties, the temperature-sensitive crosslinked dopamine end-capped Pluronic CCDP-q-PDB hydrogels, which can be applied for drug delivery, tissue engineering, and for use as tissue adhesives, were tested using a universal testing machine.