The DOPA-Functionalized Bioadhesive with Properties of Photocrosslinked and Thermoresponsive

The unusual amino acid L-3,4-dihydroxyphenylalanine (DOPA), which was found in mussel adhesive protein, was recognized as crucial element for the adhesive of mussel. In this work, the synthesis of thermoresponsive and photocrosslinkable bioadhesive with ternary networks prepared by incorporating dopamine acrylamide (DAM) and N-isopropylacrylamide (NIPAAm) into a crosslinked network based on poly(ethylene glycol)-triacrylate (PEG-TA) was reported. The effects of DAM and NIPAAm on polymerization kinetics, swelling kinetics, adhesion strength, thermomechanical properties, and cytotoxicity assays were systematically evaluated. The results showed that DAM could affect photopolymerization kinetics of terpolymer due to inhibitory effects of the catechol. The terpolymer has not only strong adhesion strength which was better than that of the commercial fibrin adhesives (0.05 MPa), but also the good humid-resistant property. The thermoresponsive properties of the system were investigated by the measurement of swelling kinetics. The equilibrium swelling ratio of gels was obviously higher at 25 degrees C than at 37 degrees C. The thermomechanical properties of terpolymer indicated that the presence of the catechol moiety increased significantly the glass transition temperature (T-g) and crosslink density of ternary network. The results of cytotoxicity of gels indicated that terpolymer were biocompatible and less cytotoxicity towards the growth of mouse fibroblast cells (L929 cells). The obtained products could have the potential to serve as the bioadhesive in the future. (C) 2014 Wiley Periodicals, Inc.