Scientists from the University of North Carolina at Chapel Hill and the North Carolina State University have developed an ingenious drug delivery technology that release drugs through the skin whenever an elastic patch is stretched. For instance, if the elastic patch is applied to the elbow, the patch would release a drug anytime when the patch is stretched by if the elbow bends. The study paper was published in the scientific journal ACS Nano.
According to Zhen Gu, an assistant professor in the joint biomedical engineering program at NC State and UNC-Chapel Hill and co-senior author of the paper describing the research project, this new drug release method could be used to release an antibacterial gradually as people move around or a painkiller when an arthritic patient goes for a walk.
The technology makes use of an elastic film that featuring biocompatible microcapsules packed with nanoparticles filled with drugs. The microcapsules stick on the side of the film that touches the patient's skin, halfway out of the film. The drugs will slowly leak out of the nanoparticles and remain stored in the microcapsules. When the patient moves the elastic film is stretched and the microcapsules are stretched as well. The surface area of the microcapsule is enlarged and the stored drug is effectively squeezed out onto the patient's skin, where it is absorbed.
Yong Zhu, associate professor of mechanical and aerospace engineering at NC State and co-senior author of the paper, explains that the microcapsules are not only stretched from left to right, but they are also compressed from bottom to top, pushing the drug out of the microcapsule. After the microcapsule is being stretched, it will be "recharged" by the drugs that keep leaking out of the nanoparticles.
Jin Di, co-lead author and a Ph.D student in Gu's lab, declared that this technique can be used to apply drugs directly such as antibiotics for wound healing, grow factors, or medication for melanomas directly to the skin.
The drugs delivery system alternately could incorporate microneedles on top of the microcapsules. If this configuration is used then the drugs can be squeezed through the microneedles. Being very small, the microneedles are painless, yet they are large enough to allow drugs to diffuse into the bloodstream.
