Emerging investigator series: interactions of engineered nanomaterials with the cell plasma membrane; what have we learned from membrane models?

Abstract

With the increasing industrial and biomedical applications of engineered nanomaterials (ENMs), concerns have been raised regarding the increased risk of exposure. Exposure to ENMs can potentially lead to adverse health effects including cell toxicity. The plasma membrane, a lipid bilayer surrounding all cells, is the first cellular entity that comes into contact with foreign particles, and membrane damage by ENMs is one of the potential mechanisms through which ENMs induce cytotoxicity. In recent years, significant effort has been focused on elucidating the complex interactions at the particle–plasma membrane interface. Such studies have primarily relied on membrane models to tease out what particle physicochemical properties might perturb the structure and function of the cell plasma membrane. However, the diversity of membrane models has made it difficult to translate the results obtained from studies with one model to another and ultimately to live cells. This review summarizes the current knowledge on ENM–plasma membrane interactions based on studies in membrane models including lipid monolayers, supported lipid bilayers, and lipid vesicles. The mechanisms of membrane disruption by the ENMs in each model have been discussed in detail and the role of the membrane model itself in modulating the results has been described. In addition, results in membrane models have been compared with the current knowledge about cells. Finally, some of the challenges toward improving the current membrane models and enhancing the environmental relevance of studies are discussed.