Tricks for organic-capped Cu2-xS nanoparticles encapsulation into silica nanocomposites co-doped with red emitting luminophore for NIR activated-photothermal/chemodynamic therapy

The present work introduces the factors controlling the encapsulation of oleate-oleylamine-stabilized Cu(2−x)S nanoparticles (NPs) into silica nanocomposites (SNs) through the water-in-oil microemulsion method. The tendency of the Cu(2−x)S NPs to form negatively charged aggregates is highlighted as the factor restricting their loading into the SNs. The different preliminary treating of Cu(2−x)S NPs reveals that the recharging is rather than the de-aggregation facilitates their loading into the SNs. The treating of Cu(2−x)S NPs by [Ru(dipy)3]2+ complexes both facilitates their loading into the SNs and gain in their luminescence. The interfacial post-treating of the SNs by pluronic F-127 (F-127) is represented as the factor affecting both aggregation behavior and therapeutic function of the SNs. The electron spin resonance (ESR) spectroscopy results reveal the factors (heating, treating by F-127, addition of glutathione) that suppress and enhance the generation of reactive oxygen species (ROS) by the SNs. The luminescence of the SNs reveals the specificity in the intracellular trafficking of their treated and untreated counterparts. The cytotoxicity enhancement under the low power NIR-irradiation of the cancer cells incubated by the SNs is explained by the heating-induced increase in the level of ROS generation. The greater cytotoxicity of the treated by F-127 vs the untreated SNs both in “dark” and NIR-irradiated conditions is correlated with the difference in their ability to stand against the suppressive effect of glutathione.