Life Science and Medical News from Around the Globe
Cancer Drug Paclitaxel Is 50X More Potent When Delivered Via Exosomes; Dye-Labeled Exosomes Also Mark Cancer Locations in Body
For the first time, scientists at the University of North Carolina at Chapel Hill (UNC-Chapel Hill) have packaged the cancer drug paclitaxel into exosomes — membrane-bounded vesicles derived from a patient’s own immune system — and thus made the drug 50 times more potent against mulit-drug-resistant (MDR) lung-cancer tumors. Elena Batrakova (photo) (https://pharmacy.unc.edu/directory/batrakov/), Ph.D., and her colleagues at the UNC Eshelman School of Pharmacy’s Center for Nanotechnology in Drug Delivery (CNDD) harvested exosomes from macrophages, phagocytic white blood cells that help protect the body against infection. Exosomes frequently carry chemical messages and are bound by the same material found in cell membranes. It is now believed that diseases like cancer and AIDS may propagate throughout the body, in part, by hijacking exosomes, but Dr. Batrakova is using these vesicles as a natural drug-delivery system. The exosomes can also deliver a dye that stains tumor cells and makes it easy to see how widespread a particular cancer is. Like the synthetic nanoparticles currently being used to deliver many chemotherapeutic agents, exosomes have a natural ability to home in on tumors. Unlike those man-made particles, however, which are often seen as foreign objects and swept up by the immune system, exosomes derived from white blood cells are ignored by the patient’s natural defenses because they are part of that defense system and they are allowed to deliver their payload unimpeded. The UNC team’s findings were published online on November 13, 2015 in Nanomedicine: Nanotechnology, Biology and Medicine. The article is titled “Development of Exosome-Encapsulated Paclitaxel to Overcome MDR in Cancer Cells.” “Exosomes are engineered by nature to be the perfect delivery vehicles,” said Dr.