Cell density-dependent accumulation of low polarity gold nanocluster in cultured vascular endothelial cells

Abstract

We have previously reported the cytotoxicity and various biological responses of organic-inorganic hybrid molecules. However, because all the molecules used were electrophilic, the effect of the hybrid molecule without electrophilicity remains unclear. The glutathione-protected gold nanocluster, Au 25 (SG) 18 , is an organic-inorganic hybrid molecule that shows a low intramolecular polarity and high stability. In this study, we examined the cytotoxicity and intracellular accumulation of Au 25 (SG) 18 in cultured vascular endothelial cells and compared these characteristics with those of negatively charged gold nanoparticles (AuNPs). Both Au 25 (SG) 18 and AuNPs accumulated in vascular endothelial cells in a dosedependent manner without cytotoxicity and more accumulation was observed at low cell densities. However, Au 25 (SG) 18 accumulated significantly less than AuNPs in the cells. These results suggest that the intramolecular polarity of organic-inorganic hybrid molecules could regulate intracellular accumulation.

Potential Environmental and Health Implications from the Scaled-Up Production and Disposal of Nanomaterials Used in Biosensors

“…Studies of aquatic organisms show nanoparticles accumulate in fish tissues (liver, intestine, gill, and muscles), urchin embryos, and algae [ 173 , 174 , 175 , 176 , 177 ]. Similarly, in human, animal, and cell line studies, nanoparticles were shown to accumulate in the cells of the brain, kidneys, liver, spleen, heart, and lungs [ 178 , 179 , 180 , 181 ]. Once nanoparticles accumulate in cells, they can cause apoptosis, histological changes, necrosis, lysis, atrophy, and DNA damage…”

Effects of Substitution on Cytotoxicity of Diphenyl Ditelluride in Cultured Vascular Endothelial Cells

“…Briefly, confluent vascular endothelial cells, vascular smooth muscle cells, fibroblastic IMR-90 cells, and epithelial LLC-PK1 cells grown in 24-well culture plates were treated with DPDTe, DPDSe, and DPDS for 24 h. After incubation, a portion of the treated medium was collected, and LDH activity was measured, as a marker for cell death, using the CytoTox 96 Non-Radioactive Cytotoxicity Assay kit. To analyze cell viability, mitochondrial activity was measured using a previously reported method with modification [22]. Confluent vascular endothelial cells grown in 24-well culture plates were treated with organotellurium compounds for 24 h. The conditioned media were discarded, and DMEM-AlamarBlue (10:1) solution was added to each well, and the cells were further incubated for 2 h. After incubation, DMEM-AlamarBlue was transferred from each well to a black bottom 96-well plate and fluorescence was measured (Ex = 544 nm, Em = 590 nm) using a multimodal plate reader (BMG LABTECH, Ortenberg, Germany).…”