A team of researchers from MIT, the Sanford-Burnham Medical Research Institute, and the University of California at San Diego (UCSD) has designed a new type of delivery system in which a first wave of nanoparticles hones in on the tumor, then calls in a much larger second wave that dispenses the cancer drug. This communication between nanoparticles, enabled by the body's own biochemistry, boosted drug delivery to tumors by more than 40-fold in a mouse study.