Size-Specific Copper Nanoparticle Cytotoxicity Varies between Human Cell Lines.

Ina Na,David C Kennedy

doi:10.3390/ijms22041548

Abstract

Commercially available copper nanoparticles of three different sizes were tested for cytotoxicity against three human cell lines using four different cytotoxicity assays. This array of data was designed to elucidate trends in particle stability, uptake, and cytotoxicity. The copper nanoparticles are not stable in cell culture media, and rapid changes over the time course of the assays play a critical role in the measured endpoints. Typically, the 40–60 nm particles tested were more cytotoxic than either smaller or larger particles. These particles were also taken up more readily by cells and exhibited different stability dynamics in cell culture media. This provides a good correlation between total cellular uptake of copper and cytotoxicity that may be directly linked to particle stability, though it is unclear why the intermediate-sized particles exhibited these unique properties when compared with both larger and smaller particles.

Highlights

Copper is an important trace element in humans and is tightly regulated in the body
We examine the cytotoxic behavior of three sizes of copper nanoparticles against three human cell lines using four different assays to build up an array of biological data correlated with the physical characterization of the particles to examine whether there is a significant risk posed by such particles in the cell lines examined, and, more broadly, whether these in vitro assays suggest that further study in more complex model systems related to exposure through food-based or medical products is needed
Sonication can damage proteins in serum, and so we decided to test if the presence of serum affected the dispersability of the particles in a cell culture medium or whether the serum could be added after the particles were dispersed

Summary

Introduction

Copper is an important trace element in humans and is tightly regulated in the body. High levels of copper are maintained in the brain for neurotransmitter production, and in the body, copper is involved in metabolic activity and immune response [1,2]. Nano-copper is used in large quantities in pesticides [20,21] and as a nutritional supplement in both cattle and poultry feed [22,23] This intersection with the food chain poses a potential exposure hazard to humans, and direct medical intervention using nano-copper can deliver copper nanoparticles directly into the blood, circumventing defence barriers through other traditional exposure routes such as ingestion and inhalation. We examine the cytotoxic behavior of three sizes of copper nanoparticles against three human cell lines using four different assays to build up an array of biological data correlated with the physical characterization of the particles to examine whether there is a significant risk posed by such particles in the cell lines examined, and, more broadly, whether these in vitro assays suggest that further study in more complex model systems related to exposure through food-based or medical products is needed

Methods

Results

Conclusion