Subra Suresh fleshes out the promise of nanotechnology, at least in regard to our understanding of disease. His talk, which focuses on malaria and its impact on red blood cells, demonstrates how the fields of engineering, biology and medicine are converging.To function properly, he explains, a red blood cell -- eight micrometers in diameter or 1/10th the thickness of a human hair -- must be able to squeeze through three micrometer openings in blood vessels. Working with a “laser tweezer” and two tiny (nano-sized) glass beads, Suresh can apply pressure to stretch single cells so that they become thin enough to fit through small openings. He uses a computer to simulate in three dimensions how red blood cells might fold and lengthen under normal conditions in the human body.
With malaria, infected red blood cells lose their ability to stretch, and Suresh can measure precisely the degree of deformation. The parasite changes the molecular structure of the cell, which “becomes stiff and sticky,” unable to move through small blood vessels. So the spleen, which normally clears impurities from the body, can’t do its job, and the disease progresses.
With a global group of collaborators, Suresh is working on genetic manipulation of the malaria parasite to see how knocking out individual proteins might impact the structure of the infected cell. This kind of biomolecular measurement and manipulation may some day lead to new therapies for a disease that infects more than 400 million people per year.
Suresh is also applying nanotech approaches to other diseases. He is looking into how cancer cells “become less stiff, move more easily, leading to metastatic invasions.” This may ultimately prove useful in studying breast cancer, he says.