Preparation of core-shell magnetic nano-upconversion materials and its targeting effect

In this paper, magnetic upconversion Fe3O4@SiO2@NaGdF4:Yb,Er (UCP) composite particles were prepared by Fe3O4@SiO2-NH2 nanoparticles reacting with NaGdF4:Yb, Er modified by alpha-bromoisobutyric acid for the first time. The products were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), EDS and fluorescence spectrum. The results show that UCP composite nanoparticles have upconversion fluorescence emission peaks as NaGdF4:Yb,Er but weaker emission intensity. In contrast to NaGdF4:Yb,Er@Fe3O4 particles, UCP composite nanoparticles have better fluorescence luminescence properties, but poor magnetic properties. Biological distribution and magnetic nano-uptake of radioactive in mouse show nanomagnetic UCP particles loaded with drugs can be accumulated in the tumor site of spleen and pancreas by magnetic controlled targeting, in order to achieve drug magnetic targeted therapy. (C) 2018 Elsevier B.V. All rights reserved.