Study on Controllable Preparation of Silica Nanoparticles with Multi-sizes and Their Size-dependent Cytotoxicity in Pheochromocytoma Cells and Human Embryonic Kidney Cells

Abstract

High-tech products made by nano-materials are tightly connected to people's life. However environmental impacts and health effects of nanoparticles are widely getting attention. In this paper, we focused on the potential size-dependent cytotoxicity of nanomaterials. Silica (SiO 2 ) nanoparticles were used as model material. The ion exchange method and modified StÖber method were used to controllably prepare monodisperse uniform silica nanoparticles with six types of size (20, 50, 80, 140, 280 and 760 nm). And the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cellular morphology were introduced to evaluate the effect of the six sizes SiO 2 nanoparticles on pheochromocytoma (PC12) and human embryonic kidney (HEK293) cells viability. The results indicated that nanosized-SiO 2 (20, 50 and 80 nm) caused more cell damage when compared with microsized-SiO 2 (140, 280 and 800 nm). IC 50 of 24 hr exposure in PC12 cells were 118.2 ± 7.3, 320.4 ± 9.8, and 380.7 ± 10.5 µg/ml, and in HEK293 cells were 80.2 ± 6.4, 140.3 ± 9.6 and 309.2 ± 11.3 µg/ml for 20, 50-and 80-nm SiO 2 particles, respectively. Additionally, the SiO 2 particles of the other three sizes over 80-nm had little influence on the cell viability at the concentrations below 2000 µg/ml for two cultured cells. The results suggested that the exposure of SiO 2 nanoparticles with different sizes leaded to cellular morphological modifications and apoptosis in a size-dependent manner. Further studies on the molecular mechanisms of apoptosis and the toxicity in vivo are necessary.

Evaluation of the toxicity of food additive silica nanoparticles on gastrointestinal cells

“…As for cell lines, both cells made a similar response to silica NPs; however, GES‐1 cells were more sensitive than Caco‐2 cells. The cell‐line effect on the NP toxicity often happened (Yuan et al ., ).…”

<p>The Size-dependent Cytotoxicity of Amorphous Silica Nanoparticles: A Systematic Review of in vitro Studies</p>

“…The LD 50 values obtained after 24 h exposure were 120±8 µg/mL for the 20 nm aSiNPs and 320±10 µg/mL for the 50 nm aSiNPs. 63 Yuan et al 64 studied the toxic effects of six sizes aSiNPs (20,50,80,140,280, and 760 nm) also using HEK293 cells and PC12 cells. Compared with microsized-SiO 2 (140, 280, and 800 nm), nanosized-SiO 2 (20,50, and 80 nm) caused more severe cell damage, and it was obvious that the IC 50 values of aSiNPs increased with the particle size.…”

Biocompatibility assessment of Si-based nano- and micro-particles

“…Cells also presented with apoptosis after incubation with 20 nm SiO particles. [122] Furthermore, most of the in vitro studies presented used the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test to measure the cell viability. Fisichella et al , however, investigated that Si based particles can promote exocytosis of the formazan crystals from the MTT assay and can falsely estimate the cell viability.…”