Fabrication and Stimuli-responsiveness of Phenylboronic Acid-containing Polymer Brush Micropattern

The smart biointerface with the capability to dynamically control the interaction between the biomolecules and material interface has attracted much attention. Here, a responsive smart biointerface was created based on the boronic acid-containing polymer brush micropattern. With 3-methacrylamidophenylboronic acid as monomer, micropatterned poly(3-methacrylamidophenylboronic acid) (PMAPBA) brushes were fabricated through combining the digital mirror device (DMD)-based light modulation technique and surface-initiated photoinduced atom transfer radical polymerization (Photo-ATRP). A series of methods such as optical microscopy, X-ray photoelectron spectroscopy, and time of flight-secondary ion mass spectrometry were applied to characterize the geometric shape, chemical composition and distribution of the resulting brush structure. The pH-responsiveness of micropatterned PMAPBA brushes was investigated with fluorescein isothiocyanate stained immunoglobulin G (IgG), and the result from laser confocal microscope revealed that the increase in the pH of the solution will hinder the immobilization of IgG protein on the PMAPBA brushes, which was attributable to the negatively charged hydrophilic ions produced by the ionization of phenylboronic acid. Besides, the catechol-boronate interaction between phenylboronic acid moieties and the secondary hydroxyls on the dextran could promote the immobilization of dextran on the PMAPBA brushes under neutral and alkaline conditions. In addition, the sugar-responsiveness of PMAPBA brushes enabled dynamic modulation of IgG adsorption behavior. The PMAPBA brushes micropatterned surface with dual stimuli-responsive could provide a novel route for the preparation of dynamic bioactive surfaces and controlled drug release systems. [GRAPHICS] .