Many of the nanoparticles you read about on this site that hold possibilities for drug delivery are actually hybrids of two or more particles that work together. So, a challenge, according to researchers, is to ensure the purity of the nanoparticles when they are fused together to form a drug-delivery device. A team of Penn State researchers has devised a system that uses magnetism to make sure we're only getting the pure stuff in our nano-delivery vehicles. Penn State release