Biological Effect of Silver-modified Nanostructured Titanium Dioxide in Cancer

BACKGROUND/AIM

Nanomedicine is a promising scientific field that exploits the unique properties of innovative nanomaterials, providing alternative solutions in diagnostics, prevention and therapeutics. Titanium dioxide nanoparticles (TiO₂ NPs) have a great spectrum of photocatalytic antibacterial and anticancer applications. The chemical modification of TiO₂ optimizes its bioactive performance. The aim of this study was the development of silver modified NPs (Ag/TiO₂ NPs) with anticancer potential.

MATERIALS AND METHODS

Ag/TiO₂ NPs were prepared through the sol-gel method, were fully characterized and were tested on cultured breast cancer epithelial cells (MCF-7 and MDA-MB-231). The MTT colorimetric assay was used to estimate cellular viability. Western blot analysis of protein expression along with a DNA-laddering assay were employed for apoptosis detection.

RESULTS AND CONCLUSION

We show that photo-activated Ag/TiO₂ NPs exhibited significant cytotoxicity on the highly malignant MDA-MB-231 cancer cells, inducing apoptosis, while MCF-7 cells that are characterized by low invasive properties were unaffected under the same conditions.

Fabrication of Ag-modified hollow titania spheres via controlled silver diffusion in Ag-TiO2 core-shell nanostructures

Inorganic hollow spheres find a growing number of applications in many fields, including catalysis and solar cells. Hence, a simple fabrication method with a low number of simple steps is desired, which would allow for good control over the structural features and physicochemical properties of titania hollow spheres modified with noble metal nanoparticles. A simple method employing sol-gel coating of nanoparticles with titania followed by controlled silver diffusion was developed and applied for the synthesis of Ag-modified hollow TiO₂ spheres. The morphology of the synthesized structures and their chemical composition was investigated using SEM and X-ray photoelectron spectroscopy, respectively. The optical properties of the synthesized structures were characterized using UV-vis spectroscopy. Ag-TiO₂ hollow nanostructures with different optical properties were prepared simply by a change of the annealing time in the last fabrication step. The synthesized nanostructures exhibit a broadband optical absorption in the UV-vis range.