Researchers from North Carolina State University and the University of North Carolina at Chapel Hill have developed a drug delivery technology that consists of an elastic patch that can be applied to the skin and will release drugs whenever the patch is stretched. For example, if applied to the elbow, the patch would release a drug when the elbow bends and stretches the patch. “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,” says 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. 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. Here’s how it works: 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.
The paper, “Stretch-Triggered Drug Delivery from Wearable Elastomers Containing Therapeutic Depots,” is published online in the journal ACS Nano. Co-authors include Yanqi Ye and Jicheng Yu of the joint biomedical engineering program, and Zheng Cui and Tushar Ghosh of NC State. The work was supported by the American Diabetes Association, a pilot grant from UNC Chapel Hill’s NC TraCS Institute, and by the National Science Foundation through the ASSIST Engineering Research Center at NC State. (Also see full Article by Matthew Shipman)