Synthesis, characterization and anti-cancer applications of ytterbium doped gadolinium molybdate nanophosphor compound

Nanophosphor compounds with both diagnostic and therapeutic functions are potential for cancer diagnosis and treatment. Lanthanide complexes play a crucial role in cancer diagnosis and therapy. Gadolinium-complexes are commonly used as magnetic resonance imaging (MRI) contrast agents for cancer imaging. The role of a lanthanide, Ytterbium (Yb) in cancer treatment is not unknown. The present work focuses on finding the role of Yb when doped into Gadolinium complexes in cancer treatment. Our results demonstrate that Yb doped Gadolinium molybdate coated with biocompatible silica, effectively inhibited the viability of breast cancer cells after 24 and 48 h of treatment in in vitro, and in contrast the nanophosphor compounds did not affect the viability of healthy cells. Yb doped Gadolinium molybdate also up-regulated apoptotic genes in breast cancer cells. Hence we propose that Yb doped Gadolinium molybdate is a promising theranostic compound. To the best of our knowledge, this is the first report showing anti-cancer nature of Ytterbium-doped into Gadolinium nanophosphors.

Моделирование твердых растворов NaGd(MoO-=SUB=-4-=/SUB=-)-=SUB=-2-=/SUB=-- NaEu(MoO-=SUB=-4-=/SUB=-)-=SUB=-2-=/SUB=- и Na-=SUB=-2-=/SUB=-Gd-=SUB=-4-=/SUB=-(MoO-=SUB=-4-=/SUB=-)-=SUB=-7-=/SUB=--Na-=SUB=-2-=/SUB=-Eu-=SUB=-4-=/SUB=-(MoO-=SUB=-4-=/SUB=-)-=SUB=-7-=/SUB=- методом межатомных потенциалов

Simulation of the solid solutions in the system of double sodium–gadolinium and sodium–europium molybdates, which are promising matrices for solid state lasers and phosphors has been carried out by the method of interatomic potentials. Two types of solid solutions have been studied, one of which contains finite components corresponding to the stoichiometric NaGd(MoO_4)_2–NaEu(MoO_4)_2 compositions with statistical distribution of cations in the crystal lattice. Another object is a cation-deficient Na_2Gd_4(MoO_4)_7–Na_2Eu_4(MoO_4)_7 system, in which we have examined the variants of statistical distribution and partial ordering of cations over structural positions. Atomistic simulation has been performed using the GULP 4.0.1 software package (General Utility Lattice Program). It is shown that when we pass from sodium-gadolinium molybdate to sodium-europium molybdate, both of stoichiometric and cation-deficient compositions, an increase in the unit cell volume is observed, while the density of the crystal, the energy of interatomic interactions in the structure, the vibrational entropy and the heat capacity decrease along with increasing europium content. The energy of interatomic interactions in the structure for cation-deficient solid solutions is less than for stoichiometric ones. Other aforementioned characteristics for cation-deficient solid solutions have greater values than for stoichiometric ones. The role of cluster europium centers in concentration quenching in NaGd(MoO_4)_2–NaEu(MoO_4)_2 solid solutions has been examined.