Luminescent GdVO4:Eu3+ functionalized mesoporous silicananoparticles for magnetic resonance imaging and drug delivery

Abstract

Luminescent GdVO₄:Eu³⁺ nanophosphor functionalized mesoporous silica nanoparticles (MSN) were prepared (denoted as GdVO₄:Eu³⁺@MSN). The in vitro cytotoxicity tests show that the sample has good biocompatibility, which indicates that the nanocomposite could be a promising candidate for drug delivery. Flow cytometry and confocal laser scanning microscopy (CLSM) confirm that the sample can be effectively taken up by SKOV3 ovarian cancer cells and A549 lung adenocarcinoma cells. It was also shown that the GdVO₄:Eu³⁺@MSN brightened the T₁-weighted images and enhanced the r₁ relaxivity of water protons, which suggested that they could act as T₁ contrast agents for magnetic resonance (MR) imaging. It was found that the carriers present a pH-dependent drug release behavior for doxorubicin (DOX). The composites show a red emission under UV irradiation due to the GdVO₄:Eu³⁺ nanophosphors. Furthermore, the PL intensity of the composite shows correlation with the cumulative release of DOX. These results suggest that the composite can potentially act as a multifunctional drug carrier system with luminescent tagging, MR imaging and pH-controlled release property for DOX.