Polyacrylate nanoparticles: toxicity or new nanomedicine?

Abstract

To the Editors: Nanotoxicology is now becoming a very important field in view of the unique physicochemical properties of nanomaterials that may lead to adverse biological effects on occupational, environmental and consumer matters. However, a conclusion on the toxicity of nanomaterials should be carefully drawn taking into account the complexity of determining the toxicity of nanoscale materials. Until now, studies on the adverse outcomes of nanomaterials, such as carbon nanotubes and nanoparticles, were limited to the experimental stage. Although there were some reports on human cell lines, the research was limited to in vitro studies; in vivo studies were completely limited to animals. Very recently, researchers from Beijing Chaoyang Hospital, Beijing, China, have reported the first case of the clinical toxicity of polyacrylate nanoparticles in humans 1. The main evidence involves pathological examination of patients’ lung tissue and observations by transmission electron microscopy. Nonspecific pulmonary inflammation, pulmonary fibrosis and foreign-body granulomas of pleura were displayed. Round nanoparticles ∼30 nm in diameter were observed to lodge in the cytoplasm and karyoplasm of pulmonary epithelial and mesothelial cells and also in chest fluid. Based on these clinical observations and analysis, the authors conclude that long-term exposure to polyacrylate nanoparticles could result in serious damage to human lungs. Here, we note that their work may provide important evidence for concerns about the toxicity of nanoparticles in humans and may afford promising opportunities to develop a new clinical therapeutic treatment for such nanoparticle-based diseases. However, we would like to point out that there are not enough data to strongly suggest that the clinical symptoms of the patients result from the toxicity of polyacrylate nanoparticles themselves. Therefore, adequate experimental evidence is very necessary for supporting the claimed toxicity, such as in vivo and in vitro toxicological assessments of polyacrylate nanoparticles, control experiments using animals …