Fabrication of thiol reactive polymeric microstructures

Abstract

PEG-based 3D hydrogel patterns containing thiol reactive maleimide functional groups have been prepared using a novel Diels-Alder/retro Diels-Alder strategy. Bulk-hydrogels and hydrogel patterns containing various amount of thiol reactive maleimide were synthesized by photo-polymerization in presence of photoinitiator and PEG-DA cross linker. The thiol reactive maleimide group was protected with furan during gelation of bulk-hydrogel and patterning of hydrogels and then was deprotected by retro-Diels-Alder reaction. After activation of maleimide in the hydrogel structure, the reactive maleimide group embedded hydrogels can be efficiently derivatized with thiol containing molecules such as a fluorescent dye, BodipyC10SH. Thiol containing biotin derivatives were covalently attached to the thiol reactive maleimide in bulk-hydrogel and hydrogel patterns under mild condition. Immobilization of FITC-streptavidin onto biotinylated hydrogel patterns were performed and investigated by fluorescence microscope. In order to detect amount of accessible biotin in the hydrogel, HABA-assay was carried out with biotinylated bulk-hydrogels.