A team of Penn State University scientists has invented a new system that uses magnetism to purify hybrid nanoparticles -- structures that are composed of two or more kinds of materials in an extremely small particle that is visible only with an electron microscope. Team leaders Mary Beth Williams, an associate professor of chemistry, and Raymond Schaak, a professor of chemistry, explained that the never-before-tried method will not only help scientists to remove impurities from such particles, it also will help researchers to distinguish between hybrid nanoparticles that appear to be identical when viewed under an electron microscope, but that have different magnetism -- a great challenge in recent nanoparticle research. The system holds the promise of helping to improve drug-delivery systems, drug-targeting technologies, medical-imaging technologies, and electronic information-storage devices. The paper will be published in the journal Agewandte Chemie and is available on the journal's early-online website.
Schaak explained that purifying hybrid nanoparticles presents an enormous challenge, especially when nanoparticles are designed for human use -- for example, for drug delivery or as a contrast-dye alternative for patients undergoing MRI studies. "The problem is that although molecules are synthesized and purified using well-known methods, there have not been analogous methods for purifying nanoparticles," Schaak said. "Hybrid particles are especially challenging because the methods that are used to make them often leave impurities that are not easily detected or removed. Impurities can change the properties of a sample, for example, by making them toxic, so it is a major challenge to find ways to remove such impurities."
The team combined forces to figure out a way to purify hybrid nanoparticles. "We had to find a way to separate impurities from the target nanoparticles, even when these particles are similar in size and shape
|Contact: Barbara Kennedy|