Scientists have developed a new drug delivery method that consists of an elastic patch that can be applied to the skin and will release drugs whenever the patch is stretched.
The technique was developed by scientists from North Carolina State University and the University of North Carolina at Chapel Hill.
Researchers in the journal ACS Nano explains that if applied to the elbow, the patch would release a drug when the elbow bends and stretches the patch.
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, says, "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."
The technology comes with an elastic film studded with biocompatible microcapsules. These microcapsules contain nanoparticles that can be filled with drugs.
The microcapsules stick halfway out of the film, on the side of the film that touches a patient's skin. The drugs leak slowly out of 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.
Yong Zhu, co-senior author of the paper and an associate professor of mechanical and aerospace engineering at NC State, says, "When the microcapsule is stretched from left to right, it is also compressed from bottom to top. That compression helps push the drug out of the microcapsule."
After being stretched, the microcapsule is 're-charged' by the drugs that continue to leak out of the nanoparticles.
Jin Di, co-lead author and a Ph.D student in Gu's lab, "This can be used to apply drugs directly to sites on the skin, such as applying anti-cancer medications to melanomas or applying growth factors and antibiotics for wound healing."