Reduction responsive BODIPY decorated mesoporous silica nanoscale platforms for photodynamic therapy

In this work, we decorated the surface hydroxyl of mesoporous silica nanoparticles (MSNs-OH) by using iodine BODIPY containing disulfide bond and carboxyl group (I2BDP–SS–COOH) for photodynamic therapy. To improve the water solubility, the MSNs were further PEGylated by PEG–SS–COOH to prepare MSNs-I2BDP-PEG. The particle size and stability of MSNs-I2BDP-PEG were characterized by the transmission electron microscopy (TEM) and dynamic light scattering (DLS). The confocal laser imaging and cells cytotoxicity experiments indicated that MSNs-I2BDP-PEG could be endocytosed well, and the intracellular higher concentrations of glutathione in tumor cells could stimulate the cleavage of disulfide bonds to release BODIPY for photodynamic therapy. This work highlights the great potential of post-modificating silica nanoparticles as multifunctional materials in biomedical fields.