Photodegradable polymer nanocapsules fabricated from dimethyldiethoxysilane emulsion templates for controlled release

Novel photodegradable polymer nanocapsules were prepared from hydrophilic monomers N-isopropylacrylamide (NIPAM) and methacrylic acid (MAA), and the hydrophobic cross-linker 5-(methacryloyloxy)-2-nitrobenzyl methacrylate (ONB) by the interfacial polymerization-emulsion templating approach, in which polymeric chains in the nanocapsule shell were cross-linked during the one-pot free radical polymerization by the photocleavable cross-linker ONB predissolved in dimethyldiethoxysilane (DMDES) emulsion templates. These prepared polymer nanocapsules possess a uniform morphology with a size around 550 nm. Upon UV light irradiation, the monodisperse polymer nanocapsules undergo light-induced degradation due to the photocleavage reaction of o-nitrobenzyl ester-based linkers in the nanocapsule shell. Furthermore, hydrophobic cargo molecules can be encapsulated into the polymer nanocapsules. Either burst release of the encapsulated hydrophobic cargo molecules by UV light irradiation, or slow release by pH, or synergistic release by these two stimuli can be realized. The prepared photodegradable polymer nanocapsules could be widely applied in the field of smart nanocarriers for controlled cargo delivery.