Gold nanoparticles: uptake in human mast cells and effect on cell viability, inflammatory mediators, and proliferation

Background: Gold nanoparticles (AuNPs) have potential for a wide range of applications as therapeutic and diagnostic agents. Since they have a high probability of interacting with human immune cells, cytotoxicity studies must be conducted. The investigation of AuNP/immune cell interaction has mainly focused on macrophages and dendritic cells, along with some other cell lineages. Scarce information is available regarding the effect of AuNPs on mast cells, which are abundant in the skin, mucosa, and perivascular space. Objective: To examine the uptake of AuNPs by HMC-1 human mast cells and the resulting effect on cell viability, pro-inflammatory mediators production, and proliferation. Results: With AuNPs treatment, the viability of HMC-1 cells decreased slightly (never less than 95%) during the first 4 h, but no changes were detected in the proliferation rate at any time. Increasing concentrations of AuNPs produced greater cell granularity (uptake). CLSM images exhibited AuNPs clusters in the cell cytoplasm. TNF-α and ROS production was not stimulated by AuNPs treatment at any concentration/time. Conclusion: Internalization of AuNPs into HMC-1 cells was demonstrated in an in vitro model, without showing cytotoxic effects or induction of pro-inflammatory mediators at any concentration tested.