A scanning electron micrograph shows an array of biodegradable polyethylene glycol-based microneedles with antimicrobial properties.

Microneedles are known to minimize pain, tissue damage, and skin inflammation, making them potentially suitable for future portable medical devices for the treatment of chronic diseases such as Parkinson’s and diabetes. However, the possibility of infection associated with microneedles has prevented their widespread adoption. Addressing this issue, researchers at North Carolina State University (NC State University; Raleigh) have developed two approaches for incorporating antimicrobial properties into microneedles that could prevent infection.

The first technique involves the incorporation of microneedles into permanent or semipermanent medical devices such as glucose monitors. In this case, the microneedles are coated with silver—an antimicrobial agent—using a laser-based vapor deposition process. By modifying the surface of the microneedles with the antimicrobial coating, the scientists found that they can prevent microbes without adversely affecting skin-cell growth.

The second technique involves degradable microneedles for single-use drug-delivery applications such as vaccine delivery. In this method, the antimicrobial agent is incorporated into the microneedle material itself. When the microneedle dissolves, the antimicrobial agent is released.

“We expect these findings to result in more-widespread use of microneedles in outpatient treatments and technologies,” remarks Roger Narayan, professor in the joint biomedical engineering department of NC State’s college of engineering and the University of North Carolina at Chapel Hill. “For example, microneedles could be used as a relatively pain-free and user-friendly alternative to conventional needles in diabetes treatment. They may also figure into new technologies pertaining to the delivery of anticancer drugs.” A paper focusing on this research, “Two Photon Polymerization of Microneedles for Transdermal Drug Delivery," will be presented May 24 at the First International Conference on Microneedles in Atlanta.

For more information on this project, see "New Microneedle Antimicrobial Techniques May Foster Medical Tech Innovation."