Selenium-incorporated mesoporous silica nanoparticles for osteosarcoma therapy

ABSTRACT

Selenium (Se) compounds are promising chemotherapeutics due to their ability to inhibit cancer cell
activity via the generation of reactive oxygen species (ROS). However, to circumvent adverse effects on
bone healthy cells, new methods are needed to allow intracellular Se delivery. Mesoporous silica nano-
particles (MSNs) are promising carriers for therapeutic ion delivery due to their biocompability, rapid
uptake via endocytosis, and ability to efficiently incorporate ions within their tunable structure. With the
aim of selectively inhibiting cancer cells, here we developed three types of MSNs and investigated their
ability to deliver Se. Specifically, MSNs containing SeO32− loaded on the surface and in the pores
(MSN-SeL ), SeO 32− doped in the silica matrix (Se-MSNs) and Se nanoparticles (SeNP) coated with meso-
porous silica (SeNP-MSNs), were successfully synthesized. All synthesized nanoparticles were stable in
neutral conditions but showed rapid Se release in the presence of glutathione (GSH) and nicotinamide
adenine dinucleotide phosphate (NADPH). Furthermore, all nanoparticles were cytotoxic towards SaoS-2
cells and showed significantly lower toxicity towards healthy osteoblasts, where Se doped MSNs showed
lowest toxicity towards osteoblasts. We further show that the nanoparticles could induce ROS and cell
apoptosis. Here we demonstrate MSNs as promising Se delivery carriers for osteosarcoma (OS) therapy.