Stretched cavity-assisted molding of micrometer and submicrometer photopolymerized hydrogel particles

A novel top-down micromolding and nanomolding method, stretched cavity-assisted molding of particles (SCAMP), was designed to achieve monodisperse submicrometer size photopolymerized hydrogel particles. The mold was stretched and, while stretched, its cavities were filled with ultraviolet (UV)-curable precursor solution. Excess precursor solution on the mold was removed by discontinuous dewetting by tilting the mold so that the remaining liquid droplets inside the cavities were cured with 365-nm UV irradiation. Green fluorescent protein (GFP) and fluorescein isothiocyanate-conjugated bovine serum albumin were added to some particle precursor solutions to make fluorescent hydrogel formulations. The discontinuous dewetting and curing process was performed in a high-pressure and humid atmosphere inside the environmental chamber. Results show that protein-loaded particles are monodisperse, submicrometer-sized, and have high water content for high biomacromolecular drug loading.