Uptake and biological effects of chitosan-capped gold nanoparticles on Chinese Hamster Ovary cells

In this study we examine the cytotoxic effect of chitosan capped-gold nanoparticles on Chinese Hamster Ovary (CHO) cells in vitro. The particles were synthesized through a low cost and rapid method by the aqueous reduction of chloroauric acid (HAuCl4) with ascorbic acid (C6H8O6) at ambient temperature. High molecular weight chitosan biopolymer was used to stabilize the particles against aggregation. The conjugated particles were able to traverse the cell membrane and enter the cells by endocytic pathway, their intracellular presence being clearly revealed by dark field microscopy imaging and light scattering spectra. Gold nanoparticles cytotoxicity was measured and cells were found to be viable more than 85%, even after long time exposure. Our results suggest that chitosan-conjugated gold nanoparticles have minimal impact on cells viability and morphology during 19 h demonstrating great potential to be used in biomedical applications such as cellular imaging or photothermal therapy.