Biocompatibility Study of Gold Nanoparticles to Human Cells

Abstract

Gold nanoparticle (GNP) is one of the most stable and popular nanoparticles, which receives considerable attention due to their applications in biomedical imaging and diagnostic tests. However, its cytotoxicity has not been fully investigated. Here we report the effects on biocompatibility of water-soluble GNPs with different sizes and concentrations to human bone marrow mesenchymal stem cells (hBMSCs) and human hepatoma carcinoma cells (HuH-7). Cytotoxicity was analyzed at different time points using MTT assay after coculturing with different concentrations of GNPs. Both cells incubated with 71.1 µg/mL 15- and 30-nm GNPs exhibited more than 80 % cell survival. However, cell viability decreased to less than 60% after incubated with 31.6 µg/mL 5-nm GNPs for 5 days. GNP 15 nm in size was chosen for the following experiments. According to Annexin V and propidium iodide (PI) analysis, the percentage of necrotic cells increased gradually with the concentration of GNPs increased. Approximately 1.5 fold increase in the level of reactive oxygen species (ROS) was found, suggesting that necrosis might be triggered by ROS production after GNPs were endocytosed by cells. Alkaline phosphatase activity and calcium deposition of hBMSCs during osteogenic differentiation were inhibited slightly by coculturing with GNPs. A similar observation was made in adipogenic hBMSCs, in which the accumulation of triacylglycerides was repressed by the addition of GNPs. In conclusion, despite 15- and 30-nm GNPs had little toxicity to hBMSCs and HuH-7 cells, they still had some influence on both osteogenic and adipogenic capabilities of hBMSCs.