In vitro effects of nanoparticles on renal cells.

backgroundThe ability of nanoparticles to cross the lung-blood barrier suggests that they may translocate to blood and to targets distant from their portal of entry. Nevertheless, nanotoxicity in organs has received little attention. The purpose of this study was to evaluate nanotoxicity in renal cells using in vitro models. Various carbon black (CB) (FW2-13 nm, Printex60-21 nm and LB101-95 nm) and titanium dioxide (TiO2-15 and TiO2-50 nm) nanoparticles were characterized on size by electron microscopy. We evaluated theirs effects on glomerular mesangial (IP15) and epithelial proximal tubular (LLC-PK1) renal cells, using light microscopy, WST-1 assay, immunofluorescence labeling and DCFH-DA for reactive oxygen species (ROS) assay.

resultsNanoparticles induced a variety of cell responses. On both IP15 and LLC-PK1 cells, the smallest FW2 NP was found to be the most cytotoxic with classic dose-behavior. For the other NPs tested, different cytotoxic profiles were found, with LLC-PK1 cells being more sensitive than IP15 cells. Exposure to FW2 NPs, evidenced in our experiments as the most cytotoxic particle type, significantly enhanced production of ROS in both IP15 and LLC-PK1 cells. Immunofluorescence microscopy using latex beads indicated that depending on their size, the cells internalized particles, which accumulated in the cell cytoplasm. Additionally using transmission electronic microscope micrographs show nanoparticles inside the cells and trapped in vesicles.

conclusionThe present data constitute the first step towards determining in vitro dose effect of manufactured CB and TiO2 NPs in renal cells. Cytotoxicological assays using epithelial tubular and glomerular mesangial cell lines rapidly provide information and demonstrated that NP materials exhibit varying degrees of cytotoxicity. It seems clear that in vitro cellular systems will need to be further developed, standardized and validated (relative to in vivo effects) in order to provide useful screening data about the relative toxicity of nanoparticles.