Anti-tumor activity of self-charged (Eu,Ca):WO3 and Eu:CaWO4 nanoparticles

Non-stoichiometric (Eu,Ca):WO3 and Eu:CaWO4 nanoparticles with anti-tumor activity are synthesized in a sol–gel method by adding excessive Eu3 + and Ca2 + ions to tungsten oxide crystal structure. Colorimetric assay shows that 10 nm (Eu,Ca):WO3 and Eu:CaWO4 nanoparticles can effectively inhibit growth of mammary cancer cells without any harm to normal cells. Nanoparticles are characterized by X-ray diffraction, high resolution transmission electron microscopy and fluorescence optical spectrometry. Nanomaterials, insoluble in synthesized water, have complicated self-charging surfaces that trap mammary cancer cells. Surface self-charging effect is suggested as the inhibition mechanism.