Cytotoxicity induced by new spiral mesoporous silica nanorods via specific surface area and ROS accumulation in HeLa cells

Abstract

Mesoporous silica nanoparticles (MSNs), with good biological safety and drug carrying capacity, are being widely used for applications in biomedical research. In this study, three new spiral mesoporous silica nanorods (MSNRs) with different aspect ratios were synthesized through adjusting the dosage of NH₃·H₂O by the modified Stöber method. Furthermore, MSNRs were used to study their interactions with HeLa cells. The synthesized MSNRs had periodical thread and narrower aperture size distribution. As indicated by laser scanning confocal microscopy (LSCM) and biological transmission electron microscopy, MSNRs were found to be internalized by HeLa cells and were primarily localized in the cytoplasm, lysosomes and membranous vesicles. When the concentration of MSNRs reached 320 μg mL⁻¹, MSNRs had different degrees of cytotoxicity. The cytotoxicity was positively correlated with the size of the specific surface area of MSNRs. Reactive oxygen species (ROS) production was induced in the HeLa cells by the MSNRs, and reactive oxygen species generation might be the major factor causing cytotoxicity. The results of this study indicated that the effect of MSNRs on HeLa cell viability and cellular oxidative stress was related to specific surface area and has great potential in drug loading and delivery.