Organically modified silica nanoparticles with intraparticle heavy-atom effect on the encapsulated photosensitizer for enhanced efficacy of photodynamic therapy

We report a novel nanoassembly formulation for photodynamic therapy, which is composed of covalently iodine-concentrated organically modified silica (ORMOSIL) nanoparticles (diameter < 30 nm) and a hydrophobic photosensitizer embedded therein. Comparative studies with iodinated and noniodinated nanoparticles have demonstrated that the intraparticle external heavy-atom effect on the encapsulated photosensitizer molecules significantly enhances the efficiency of ¹O ₂ generation and, thereby, the in vitro PDT efficacy.