Researchers from North Carolina State University and the University of North Carolina at Chapel Hill have developed an elastic patch that, when applied to the skin and stretched, delivers medicine. The patch releases the drugs as the elbow bends.
The device could be used to provide painkillers when patients with arthritic knees go for a walk, or to deliver antibacterial drugs gradually as users move around over the course of a day.
To operate, the technology uses an elastic film studded with biocompatible microcapsules. The microcapsules, in turn, are packed with nanoparticles that can be filled with drugs.
The microcapsules stick halfway out of the skin side of the film. The drugs, stored in the capsules, leak slowly out of the nanoparticles. When the elastic film is stretched, the microcapsules are stretched as well – enlarging the surface area and effectively squeezing some of the stored drug out onto the patient’s skin, where it can be absorbed.
The researchers also incorporated microneedles into the system, applying them on top of the microcapsules. In this configuration, the drugs can be squeezed through the microneedles. The microneedles are small enough to be painless, but large enough to allow drugs to diffuse into the bloodstream through tiny capillaries underneath the skin.
