Researchers demonstrated single-molecule nanomachines that can target diseased cells and then kill them by drilling through the cell membrane. Developed by a team at Rice University, Durham University (UK), and North Carolina State University, the single-molecule nanomotors are about one-billionth of a meter wide and spin at 2 to 3 million rotations per second. They're activated by ultraviolet light and could also be used to deliver drug treatment into the cells. From Rice:
"These nanomachines are so small that we could park 50,000 of them across the diameter of a human hair, yet they have the targeting and actuating components combined in that diminutive package to make molecular machines a reality for treating disease," Tour said…
The researchers found it takes at least a minute for a motor to tunnel through a membrane. "It is highly unlikely that a cell could develop a resistance to molecular mechanical action," Tour said.
Pal expects nanomachines will help target cancers like breast tumors and melanomas that resist existing chemotherapy. "Once developed, this approach could provide a potential step change in noninvasive cancer treatment and greatly improve survival rates and patient welfare globally," he said…
The Pal lab at Durham tested motors on live cells, including human prostate cancer cells. Experiments showed that without an ultraviolet trigger, motors could locate specific cells of interest but stayed on the targeted cells' surface and were unable to drill into the cells. When triggered, however, the motors rapidly drilled through the membranes.
"Molecular machines open cell membranes" (Nature)
