Curcumin-silica nanocomplex preparation, hemoglobin and DNA interaction and photocytotoxicity against melanoma cancer cells.

Melanoma is a malignant cancer of the skin associated with a high mortality. Early medical diagnosis and surgical intervention are essential for the treatment of melanoma. The use of plant-based compounds is an important strategy for the prevention and treatment of different types of cancers. Curcumin is a promising natural anticancer compound used towards treatment for various kinds of cancers. Studies have shown that curcumin could be applied as a photosensitizer in cancer photodynamic therapy (PDT). PDT uses light and a photosensitizing agent which produce reactive oxygen species leading to cancer cell death. The main obstacle for using curcumin as photosensitizer is its low solubilization ability in an aqueous environment. To improve its application in cancer treatment, we synthetized curcumin-silica nanoparticles as photosensitizer for photodynamic treatment of human melanoma cancer cells. Scanning electron microscopy, Transmission electron microscopy, Powder X-ray diffraction and Thermo geometric analysis indicated that curcumin was loaded on silica. The solubility of curcumin in water increased by using silica nanoparticles which wasconfirmed by spectroscopy results. The spectroscopy study confirmed the interaction of curcumin-silica nanocomplex with double strand DNA and no interaction with hemoglobin. The curcumin-silica nanocomplex and curcumin photodynamic effect was investigated on human melanoma cancer cells (A375) and also human fibroblast cells. The cell toxicity experiments showed that the curcumin-silica nanocomplex had greater photodynamic effects on cancer cell death as compared to free curcumin. The apoptotic assay by acridine orange/ethidium bromide (AO/EB) dual staining and colony forming ability confirmed the MTT results. Therefore, these results suggest that the curcumin-silica nanocomplex has great potential to be employed in photodynamic treatment of melanoma cancer.