Biomedical research could someday look a lot like playing video games thanks to a new device that allows users to manipulate cells with the swerve of a joystick. A team of physicists and engineers at Ohio State University developed the device from a tiny piece of square-centimeter silicon inlaid with rows of zigzagging magnetic wires. At each corner, the wire behaves like two magnets pointed north to north or south to south. The fields of the two magnets create a point of strong attraction just above them. A nearby magnetic object, such as a magnetically-tagged cell, is attracted to the corner and gets stuck there. To get the particles moving, the researchers then place two magnetic fields around the chip — one in the plane of the chip and the other perpendicular to it. By flipping the direction of these fields, the researchers can guide tagged cells along the zigzagging wire and even make them jump from one wire to the next. The researchers computerized the magnetic field switching, allowing a user to steer the cells by simply handling a joystick. The OSU research team tested the device with magnetically tagged T-cells, the body’s guardians against infection. They snapped the cells to attention at one end of the chip, marched them down to the other end, and made them hop from one wire to another.

Jeffrey Chalmers, the chemical engineer who tagged the T-cells for the experiment, said the device would be ideal for examining tumor cells. To study biopsied tumors, researchers often treat them with enzymes, which break them down into their constituent cells. Researchers then separate cancerous cells they want to study from healthy cells like fat and blood. “Part of the problem with cancer … is that it’s our own cells going haywire, so it’s a heck of a lot harder to figure out what’s different,” Chalmers said. With this method, he said, researchers could magnetically tag the well-understood healthy cells and then remove them from a sample, leaving only the cancerous cells. Chalmers said this would be a boon to both a researcher studying a specific type of cancer or a clinician diagnosing a patient. “The more you can separate them out, [the more] you know what you’re looking at.”

The small magnetic fields are gentle on specimens; the device works on a flat surface, an improvement over other methods; and it’s also cost-effective. The project’s principal investigator, physics professor Ratnasingham Sooryakumar, said that the whole set up only costs about $200. He added that it could easily be scaled up to a square centimeter silicon platform, with about 10,000 tiny traps, or scaled down to manipulate organelles within a single cell. Sooryakumar said that scaling up would lead to a “lab on a chip,” where researchers could cheaply and easily look at distinctive behavior within large populations of cells, making it easier to draw firm conclusions. “You can look at each cell rather than averaging it out, and say, ‘the cell on vertex number 348 did this,’” Sooryakumar said. “When you actually have 10,000 of them to analyze the data, you can understand stat distributions that we normally would not have gotten in ensemble measurements, and that’s a huge thing.”

Source: Fox News

Posted September 23rd, 2009 under Tech Transfer

Write a comment