Medical implants can be vastly improved by coating them with substances that release drugs over a period of time. For example, coating the stents used for keeping veins and arteries open with a substance that releases an anti-inflammatory drug over a period of months can help the body accept the stent more easily.
But creating an even coating on the stent that contains a specific dose of drug is not easy. When the coating is applied by dipping or spraying, some surfaces get a thicker coating and hence a higher dose than others. And drugs that don't end up on the stent are often wasted.
Now Robert Hoerr and colleagues at the University of Minnesota have come up with a way of delivering an even coating that contains a specific dose. The idea is to mix the drug with a dielectric solvent and then atomise the mixture to create an aerosol in which the droplets are charged. Then, by generating the opposite charge on stent, the droplets are attracted to its surface forming an even coating. Hoerr has formed a start up called Nanocopaeia to commercialise the idea.
Drug coated stents have shown themselves to be vastly superior to the uncoated variety. As a result they have become a hugely popular way of opening partially blocked blood vesssle. Hoerr's idea offers a way to reduce the cost of these implants, something that could benefit many people.
Read the full electrospraying patent application.
Justin Mullins, New Scientist contributor