In a breakthrough study regarding how cells interact with carbon nanotubes and gold nanowires, researchers at Brown University have determined that these and other nanomaterials with a long aspect-ratio and rounded tips, can cause an inflammatory response in Mouse liver cells and Human mesothelial cells. Through molecular simulations and other invitro experiments, the researchers found that the rounded tips of certain commercially-available carbon nanotubes and gold nanowires can fool a cell into believing that it is (through endocytosis) engulfing a sphere, instead of the rounded tip of the larger nanotube or nanowire. Once the cell realizes that the cylindrical tip of the nanotube or nanowire is actually too large to ingest, it is too late to expel it, and an immune response is triggered which can cause repeated inflammation. The researchers would like to perform further studies to determine whether nanotubes without rounded tips, or less rigid materials, such as nanoribbons, cause the same reaction in cells.
The results of this research should be of great interest to scientists that are currently studying the use of nanomaterials to transport medicines to diseased cells within the body. The ability to design nanomaterials with a predictable nanomaterial-cell dynamic would be of great value in advancing key aspects of nanomedicine, including nano drug delivery. Further, the ability to re-design nanomaterials which could avoid endocytosis and any corresponding inflammatory process, could vastly improve the nanomaterial safety and health risks associated with the use of these materials.