ATRP Synthesized Environmentally Responsive Micro- and Nanostructured Hydrogels Over Biomedical Devices

Surfaces that are spatially functionalized with intelligent hydrogels, especially at the micro- and nanoscale, are of high interest in the biomedical field. Though patterned brushes can be successfully employed for biodiagnostic applications, the advantages of a crosslinked polymer network such as mechanical robustness, material entrapment, and tunable transport properties make hydrogels useful for both sensing and therapeutic applications. Herein, microcontact printing (µCP) for XY control, followed by atom transfer radical polymerization (ATRP) for Z/thickness control was applied to synthesize a controlled array of environmentally responsive hydrogels (e.g., N-isopropylacrylamide) over material surfaces/devices. The nanoscale drug/particulate loading, response to external stimuli and release were characterized using atomic force microscopy (AFM), quartz crystal microbalance with dissipation (QCM-D) and scanning electron microscopy (SEM). Using such arrays of responsive hydrogels, it is possible to fabricate rapid point of care biomedical devices for diagnostic and therapeutic applications.