Imagine a mini assembly line along which doctors could tweak, modify or correct malfunctions within millions of individual cells in minutes. Such an invention would vastly expand the current multibillion-dollar microfluidic device industry, which currently produces instruments that can analyze individual cells but not alter them. Now researchers at Sandia National Laboratories have taken an important step toward this dream. Murat Okandan, working with Paul Galambos, Sita Mani and Jay Jakubszak, has developed a mechanized microgizmo that can grip individual red blood cells between two rows of tiny silicon teeth and temporarily deform their shape. The microjaw snaps open and shut rapidly, clamping down on roughly 10 cells a second as they flow through a channel 20 microns wide.
For now, the researchers are hoping to discover if their prototype devicefor which they have applied for a patentactually disrupts the blood cells' membranes. To do so, they will test whether cells chewed by the microjaw can absorb a fluorescent material. But in the near future, they also plan to replace the microjaw with a hollow silicon needle, which could introduce DNA, RNA, drug molecules or proteins into living cells. In this way, the device might be used to treat or reverse the effects of gene imbalances, chemical attacks, and bacterial or viral infection within single cells, they say. "We've shown that we can create a micromachine that interacts at the scale of cells," Okandan comments. "We've created a demonstration tool with very flexible technology that we believe will enable many designs and concepts. This device itself may generate considerable interest from the agriculture or genetic engineering marketplaces."