Photoresponsive Bridged Silsesquioxane Nanoparticles with Tunable Morphology for Light-Triggered Plasmid DNA Delivery

Bridged silsesquioxane nanocomposites with tunable morphologies incorporating o-nitrophenylene-ammonium bridges are described. The systematic screening of the sol-gel parameters allowed the material to reach the nanoscale with controlled dense and hollow structures of 100-200 nm. The hybrid composition of silsesquioxanes with 50% organic content homogeneously distributed in the nanomaterials endowed them with photoresponsive properties. Light irradiation was performed to reverse the surface charge of nanoparticles from +46 to -39 mV via a photoreaction of the organic fragments within the particles, as confirmed by spectroscopic monitorings. Furthermore, such nanoparticles were applied for the first time for the on-demand delivery of plasmid DNA in HeLa cancer cells via light actuation.