Microneedles for portable devices

A team led by researchers from North Carolina State University has developed two approaches to incorporate antimicrobial properties into microneedles – vanishingly thin needles that hold great promise for use in portable medical devices.

Microneedles cause less pain, tissue damage and skin inflammation for patients, and could be a significant component of portable medical devices for patients with chronic conditions, such as Parkinson’s disease or diabetes. However, longstanding concerns regarding the possibility of infection associated with microneedles have been an obstacle to their widespread adoption – until now.

The first new technique could be used with microneedles destined for use in permanent or semi-permanent medical devices, such as glucose monitors for patients with diabetes.

The researchers’ modification of the surface of a microneedle with an antimicrobial coating prevented microbial growth and did not adversely affect skin-cell growth. They applied the coating using a laser-based vapour-deposition process that created a thin film of silver (which is antimicrobial) on the microneedle surface.

The second approach would be applicable to degradable microneedles, which are designed to dissolve on the skin’s surface and can be used for single-use drug-delivery situations such as vaccine delivery. Here, the researchers were able to incorporate an antimicrobial agent into the material used to make the microneedle itself. As the degradable microneedle dissolves, it releases the antimicrobial agent, guarding against infection.

’We expect these approaches to result in more widespread use of microneedles in outpatient treatments and technologies,’ said Dr Roger Narayan, a North Carolina State University researcher. ’For example, microneedles could be used as a relatively pain-free and user-friendly alternative to conventional needles in diabetes treatment.’