Skin patch material releases drugs when it stretches

The wearable, tensile strain-triggered drug delivery device has been developed by researchers at North Carolina State University and the University of North Carolina at Chapel Hill.

“This could be used to release painkillers whenever a patient with arthritic knees goes for a walk, or to release antibacterial drugs gradually as people move around over the course of a day,” said Zhen Gu, co-senior author of a paper describing the work and an assistant professor in the joint biomedical engineering program at NC State and UNC-Chapel Hill.

According to NC State, the technology consists of an elastic film that is studded with biocompatible microcapsules. These microcapsules, in turn, are packed with nanoparticles that can be filled with drugs.

The university said in a statement that the microcapsules stick halfway out of the film, on the side of the film that touches a patient’s skin. The drugs release slowly from the nanoparticles and are stored in the microcapsules. When the elastic film is stretched, it also stretches the microcapsules – enlarging the surface area of the microcapsule and effectively squeezing some of the stored drug out onto the patient’s skin, where it can be absorbed.