Anti-cancer drugs are hazardous to cancers, but they are only slightly less so to healthy tissue. For example, the drug doxorubicin may efficiently jam the genetic machinery of rapidly dividing cancer cells, but it is also highly toxic to heart tissue. Such cardiac toxicity limits how much of the drug can be administered to patients.
"The unprecedented rapid release of such large amounts of drug directly into the cancers' blood vessels--triggered only by mild focused heating--seems to cause such drastic damage that the tumor just can't survive." David Needham
David Needham, a professor of mechanical engineering and materials sciences, invented a nanocapsule delivery technology in 1996 to get around that dilemma. Using his knowledge of lipid membranes, he engineered microscopic nanowax capsules, called liposomes, which can be packed with anticancer drugs. By heating a tumor from the outside with microwave energy, these drug-delivering capsules flow through the patient’s blood stream, melting only when they reach the warm blood vessels that feed the tumor to dump a virtual flood of drug.
The technology, licensed as Thermodox by Celsion Corporation, is now showing early promise in fighting recurrent breast cancer on the chest wall in an ongoing phase I clinical trial at Duke Medical Center. Several patients enrolled in the study--designed only to identify the maximal tolerated drug dose--have already begun to show signs that their disease may be stabilizing or regressing. The work is supported by the National Cancer Institute through a major center grant awarded to the Duke Hyperthermia Program, directed by Mark Dewhirst of Duke Medical Center.
David Needham Website: mems.duke.edu/faculty/david-needham
Mark Dewhirst Website: bme.duke.edu/faculty/mark-dewhirst