Bioinspired Synthesis of Cross-linking of Dopamine-Containing Block Copolymers to Form Thermosensitive Covalent Hydrogels

摘要

Marine mussels secrete remarkable mussel adhesive proteins (MAPs) for adherence to the substrates upon which they reside. Inspired by the intermolecular cross-linking characteristics of MAPs, we report the synthesis of thermosensitive dopamine modified Pluronic copolymer (PluF127-Dopa) with high coupling efficiency. Under certain temperature and concentration, PluF127-Dopa copolymers in aqueous solution self-assemble into micelles and are able to rapidly form a more stable hydrogels upon addition of oxidizing reagents such as NaIO_4, resulting from oxidative cross-linking of dopamine. UV-vis spectroscopy was utilized to identify the reaction intermediates. The sol-gel transition curves of cross-linked PluF127-Dopa hydrogels (CL-PluF127-Dopa) were determined by a vial inversion method. The critical gelation concentration of CL-PluF127-Dopa hydrogels was significantly lower than those for PluF127-Dopa and unmodified Pluronic F127. The apparent mechanical strength of CL-PluF127-Dopa hydrogels was dramatically enhanced compared to those unmodified Pluronic copolymer hydrogels, suitable for sustained drug delivery. These new biomimetic materials are expected to have potential uses in biomedical applications.