Selective Release of Hydrophobic and Hydrophilic Cargos from Multi-Stimuli-Responsive Nanogels.

Highly stable multi-stimuli-responsive nanogels for selective release of simultaneously encapsulated hydrophobic and hydrophilic cargos in a spatiotemporally controlled manner are demonstrated here. The nanogel is composed of hydrophilic pH- and thermoresponsive poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and hydrophobic photocleavable o-nitrobenzyl (ONB) linkage. The hydrophobic cargos were noncovalently encapsulated into lipophilic interiors of the nanogels, while the hydrophilic cargos were chemically linked to the nanogel precursor polymer PDMAEMA through a redox-cleavable disulfide junction. For these dual-loaded nanogels, hydrophobic cargos can be released in response to temperature, pH, and UV light, while the hydrophilic cargos can be released in response to redox reagent. The stimuli-selective release of hydrophobic and hydrophilic cargos affords the system with great potential applications in combination chemotherapy, tissue engineering, anticorrosion, and smart nanoreactors.