Copper nanoparticles exert size and concentration dependent toxicity on somatosensory neurons of rat

Abstract

Metal nanoparticles, due to their unique properties and important applications in optical, magnetic, thermal, electrical, sensor devices and cosmetics, are beginning to be widely manufactured and used. This new and rapidly growing field of technology warrants a thorough examination of the material's bio-compatibility and safety. Ultra-small particles may adversely affect living cells and organisms since they can easily penetrate the body through skin contact, inhalation and ingestion. Retrograde transport of copper nanoparticles from nerve endings on the skin can reach the somatosensory neurons in dorsal root ganglion (DRG). Since copper nanoparticles have industrial and healthcare applications, we determined the concentration and size-dependant effects of their exposure on survival of DRG neurons of rat in cell culture. The neurons were exposed to copper nanoparticles of increasing concentrations (10-100 μM) and sizes (40, 60 and 80 nm) for 24 h. Light microscopy, histochemical staining for copper, lactate dehydrogenase (LDH) assay for cell death, and MTS [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay for cell viability were performed to measure the resultant toxicity and cell survival. DRG neurons exposed to copper nanoparticles displayed vacuoles and detachment of some neurons from the substratum. Neurons also exhibited disrupted neurite network. LDH and MTS assays revealed that exposure to copper nanoparticles had significant toxic effect with all the sizes tested when compared to unexposed control cultures. Further analysis of the results showed that copper nanoparticles of smaller size and higher concentration exerted the maximum toxic effects. Rubeanic acid staining showed intracellular deposition of copper. These results demonstrate that copper nanoparticles are toxic in a size-and concentration-dependent manner to DRG neurons.

Copper nanoparticle-induced ovarian injury, follicular atresia, apoptosis, and gene expression alterations in female rats

“…[8][9][10][11][12][13][14] Recently, a new type of nano-Cu IUD was invented by However, numerous studies have unequivocally indicated that exposure to Cu NPs can result in adverse effects in vivo and in vitro. [16][17][18][19][20] For instance, a previous study demonstrated that the exposure of mice to Cu NPs resulted in severe kidney, liver, and spleen impairment. 16 Another study further revealed that the nephrotoxicity of Cu NPs was highly correlated with significant alterations in the expression of many genes, such as those involved in oxidative phosphorylation, the cell cycle, the mitogen-activated protein kinase signaling pathway, and glutathione metabolism.…”

Nanoparticle growth and surface chemistry changes in cell-conditioned culture medium

“…Currently nanotoxicology studies often employ LDH as a simple cytotoxicity marker [10,30,31]. Elevated LDH levels have been detected in in vitro cell studies of NPs [32], but in the literature conclusions about mechanisms and impacts are mixed.…”

In vitro biocompatibility of calcined mesoporous silica particles and fetal blood cells

“…37 Size-dependent neurotoxicity of copper nanomaterials (40-80 nm) was demonstrated in murine somatosensory neurons, with smaller particles being more toxic than larger ones. 38 The cytotoxicity of nanosized and microsized CuO materials was studied in a human alveolar cell line. 39 The 42 nm particles were significantly more toxic to the mitochondria and DNA than were the 3 µm particles.…”