Electric fields direct drugs to tumors

Science : Chemotherapy targets cells that rapidly divide. In an adult cancer patient, those cells include the ones that make up tumors, but also ones in hair, bone marrow, the digestive tract, and the immune system. Given that most chemotherapy drugs are delivered intravenously, side effects are unavoidable and can be severe. To ensure that a higher fraction of a drug reaches its intended target, the tumor, Joseph DeSimone of the University of North Carolina, Chapel Hill, and his collaborators have been exploring the use of electric fields. The technique, which relies on the electrical polarity of most drug molecules, has been applied before to drive drugs to the eye and bladder. DeSimone set out to test whether it could also work with solid tumors. He and his team created small reservoirs of drugs, equipped them with an electrode, and then implanted them next to tumors (the team used mice and dogs in their experiments). Oppositely charged electrodes were placed on the other side of the tumors. The results are promising. Compared with delivering the drug intravenously, the use of electric fields not only significantly boosted the concentration of the drug in the tumor, but also shrank the tumor faster. Whether the technique could work with humans remains to be seen.