The effect of PEGylation on the stimulation of IL-1β by gold (Au) nanoshell/silica core nanoparticles

Abstract

Au nanoshell/silica core (GNS) nanoparticles have been used for the photothermal ablation of tumors and imaging, and have recently reached clinical trials. In this study, we compared the ability of bare (GNS) and PEGylated Au nanoshell/silica core (PEG-GNS) nanoparticles to stimulate the production of IL-1β in the macrophage cell line. GNS particles formed large aggregates while PEG-GNS particles did not form in cell culture medium. Correspondingly, GNS particles induced the production of IL-1β while PEG-GNS did not induce in THP-1 macrophage cell lines. Corroborating with the in vitro results, GNS induced a significant level of neutrophil influx in the peritoneal cavity, and PEG-GNS reduced the level four times. The density of PEG on the particle surface has little effect on both the induction of IL-1β and neutrophil influx by PEG-GNS. The ability of GNS and PEG-GNS particles to induce and scavenge reactive oxygen species (ROS) was also assessed. We demonstrated that GNS was able to induce and scavenge ROS while PEG-GNS was not. The excess of ROS induced by GNS potentially caused the activation of inflammasomes, and thus the secretion of IL-1β. Our finding on the reduction of IL-1β production by the PEGylation of nanoparticles has implications in other particulates used for drug delivery, imaging and therapy.