Biocompatible Eu doped mesoporous calcium silicate nanospheres for pH-responsive drug release

Abstract

Calcium silicate is a kind of inorganic biomaterial containing Si, Ca, O elements, they have been widely investigated and applied in a variety of medical applications in the past four decades. Herein, Europium (Eu) doped mesoporous calcium silicate nanoparticles (Eu-MCS) with sizes ranging from 60 nm to 110 nm were prepared via a simple hydrothermal synthesis method. The morphology, structure, texture and optical property were characterized by SEM, TEM, XRD, N2 adsorption/desorption and PL spectra, respectively. The prepared material emits strong red luminescence at 613 nm upon UV irradiation and is cytocompatible at a wide range of concentrations, exibiting promising application in bioimaging. The Eu-MCS has a high loading capacity of 356.67 μg/mg for the anticancer drug DOX, and the drug loaded material DOX@Eu-MCS showed pH-controlled drug release behaviour. Moreover, both of the biocompatibility tests on normal human cells HEK293 and human colon cancer cells HT29 indicate a low cytotoxicity of Eu-MCS. The cell cytotoxity assays of the DOX loaded nanomaterial (DOX@Eu-MCS) on Hela cancer cells prove a high cancer cell mortality. Therefore, the as-prepared red emissive nanocarrier Eu-MCS has great potential to be used as an integrated platform for cancer diagnosis and therapy.