COLLEGE STATION - Engineers in the Texas Engineering Experiment Station’s (TEES) Center for Space Power are using the final frontier - space - to fight the war against cancer. Researchers from the Center for Space Power and the Center for Microencapsulation and Drug Delivery (CMDD) at Texas A&M and NASA Johnson Space Center are working with a Microencapsulation Electrostatic Processing System (MEPS) in which tiny, multilayer capsules resembling liquid-filled balloons are formed to deliver drugs directly to tumors for improved cancer treatments and other medical uses. In today’s (May 30) launch of NASA’s space shuttle STS-111, the scientists are sending a self-contained experiment to the International Space Station. In the experiment, fluids are loaded into a soft fluid container and then pumped into a reaction chamber, where capsules will hopefully form. A microscope focuses on the liquid-liquid interface where the capsules form so that the researchers can watch the formation to learn about the fluid dynamics of the process. Suitable multilayer microcapsules can only be made reliably in space, where the lack of gravity allows the capsules to achieve useful size. So, the Texas A&M researchers are working with NASA to study microcapsule formation in space in hopes of eventually making the capsules commercially on Earth. "The microgravity and vacuum in space make for perfect lab conditions that can’t be replicated here on Earth," said Frank Little, assistant director of the Center for Space Power, a division of TEES and part of a NASA program for the commercial development of space. "There are some alloys that, because of the different properties of the materials involved, can only be made in space, where those properties are not an issue. It’s the same with microcapsules. But if we have the knowledge of how microcapsules form in space, we can eventually make them here." In treating tumors with conventional drugs, doctors block the tumor’s blood supply, which in turn causes the tumor to shrink and eventually go away - a process called embolization. With chemotherapy, a drug is injected into the tumor and followed with an embolizing foam, stopping the blood flow so that the chemical stays in the tumor. Microcapsules accomplish this chemo-embolization process in one step. The capsules, just larger than blood cells, block small capillaries, choking off its blood supply so that the drugs diffuse through capillary walls and into the tumor, killing the tumor. Because the treatment is targeted, and because the capsules carry about 5 percent of the usual dose of the drug, microcapsules avoid most of the unpleasant side effects usually associated with chemotherapy treatments. Microcapsules form at the interface of two fluids that don’t mix together well, such as oil and water. The liquids slide past each other slowly, causing a slight disruption in the fluids. As they slide past each other, the liquids form droplets composed of a mixture of the two liquids. A thin polymer wall forms around the droplet, which can be electrostatically coated to modify the capsule surface. This is the second MEP experiment to be flown in space. The first MEP experiment went up on STS-95, the headline-making flight with former astronaut and U.S. Senator John Glenn. Last week, The Texas A&M University System Board of Regents approved the Center for Microencapsulation and Drug Delivery (CMDD), a collaborative effort between Texas A&M University, the Texas A&M System Health Science Center, the Texas Agricultural Experiment Station and TEES.
