Smart Coating Delivers Drugs

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Because these films are potentially compatible with most medical devices, there are many possible uses. Kris Wood, a postdoc at the Broad Institute, in Cambridge, MA, who has worked with Hammond on the film, says that the first application they're pursuing is cancer treatment. During surgery, doctors can't always remove all traces of a tumor. When cancer tissues are left behind, the disease can recur. After a tumor has been removed, says Wood, doctors could line the tissue that bordered it with a biodegradable polymer coated with a thin film containing anticancer drugs. "You could then administer the drug in a highly localized way," says Wood.

An important unanswered question, says Kotov, is whether or not there is a limit to how much drug can be loaded into Hammond's films. Devices coated with the films could deliver relatively low doses of therapeutic compounds because their release would be highly localized. However, if such implants could provide only a limited number of doses and had to be replaced, this would increase the risk of complications. But because Hammond's films are constructed layer by layer, Kotov says, "I suspect the maximum amount of drug that can be accumulated can be quite high."

Hammond is currently making films that incorporate paclitaxel, a drug commonly used to treat breast and lung cancer. If she can demonstrate that such films are stable, Hammond hopes to then test them in animals.