文摘
We report results of our investigations on relative uptake efficacy and phototoxic potential of curcumin organically modified silica nanoparticle (SiNp) (cur-SiNp) complexes and free curcumin in multicellular spheroids of human oral cancer cells. Uptake of free and nanoparticle-bound curcumin by cells was studied by spectroscopy. Results showed that compared to free curcumin, accumulation of curcumin in nanoformulation was higher by ?.7 and ?.4 times in spheroids of size ?95 and ?65?μm, respectively. Compared to free curcumin, for spheroids irradiated with blue light (20?J/cm2), cell death increased by ?.7 and ?.2 times, respectively, for spheroids of size ?95 and ?65?μm. Further, spheroids treated with cur-SiNp complex and light showed larger inhibition in growth and migration of cells and enhanced reactive oxygen species (ROS) generation as compared to spheroids treated with free curcumin under similar conditions. Experiments carried out in presence of a ROS scavenger, glutathione (GSH), confirmed the involvement of ROS in cur-SiNp-induced phototoxicity. The results suggest that nanoformulated curcumin is able to improve the phototoxic effects of curcumin in spheroids.