The toxicity of hydroxylated and carboxylated multi-walled carbon nanotubes to human endothelial cells was not exacerbated by ER stress inducer

Abstract Hydroxylated multi-walled carbon nanotubes (h-MWCNTs) and carboxylated MWCNTs (c-MWCNTs) have potential applications in biomedicine, but their toxicity to human endothelial cells under stressed conditions associated with chronic diseases was less studied in vitro . This study stressed human umbilical vein endothelial cells (HUVECs) with ER stress inducer thapsigargin (TG), and investigated the toxicity of h-MWCNTs and c-MWCNTs to normal and stressed HUVECs. h-MWCNTs and c-MWCNTs modestly reduced cellular viability, significantly promoted soluble ICAM-1 (sICAM-1), soluble VCAM-1 (sVCAM-1) as well as intracellular ROS, and decreased the expression of transcription factor KLF2 and KLF4 . Pre-treatment with TG significantly reduced cellular viability, promoted IL-6 and THP-1 monocyte adhesion, and increased the expression of a panel of ER stress genes. ANOVA indicated no interaction between MWCNTs and TG pre-treatment on most of the endpoints. It was concluded that the toxicity of h-MWCNTs and c-MWCNTs to HUVECs might not be exacerbated by ER stress inducer