Paper-art-inspired Stents Help Deliver Drugs

New type of stent inspired by Japanese paper art – kirigami could be used to deliver drugs to the gastrointestinal tract, respiratory tract, or other tubular organs in the body, as designed by the engineers and their collaborators at the Massachusetts Institute of Technology (MIT), Cambridge, MA, published in the journal Nature Materials. The device has two key elements – a soft, stretchy tube made of silicone-based rubber, and a smooth layer of plastic coating etched with needles that pop up when the tube is stretched. This allows the needles to penetrate the localized tissue and deliver the drug-containing microparticles over an extended period even after the stent is removed.

"This kind of drug delivery could make it easier to treat inflammatory diseases affecting the GI tract such as inflammatory bowel disease or eosinophilic esophagitis. This technology could be applied in essentially any tubular organ. Having the ability to deliver drugs locally, on an infrequent basis, really maximizes the likelihood of helping to resolve patients’ conditions and could be transformative in how we think about patient care by enabling local, prolonged drug delivery following a single treatment," says Giovanni Traverso, an MIT assistant professor of mechanical engineering, a gastroenterologist at Brigham and Women’s Hospital, and the senior author of the study.

Paper Inspired Stent as Targeted Therapy

Since the lodging of the stent in the GI tract can be tricky as the digested food is continuously moving through it, temporary insertion of the stent endoscopically followed by drug delivery and then easy removal serves the purpose just right. The localized delivery of the drug to the affected tissue thereby helps in curbing out the side effects encountered on other organs in the body.

The team tested the effectiveness of the stents in the esophagus of pigs by imparting microparticles containing a drug called budesonide, a steroid that is used to treat IBD and eosinophilic esophagitis.

The whole process took only a couple of minutes, and it was seen that the microparticles then stayed in the tissue and gradually released budesonide for about one week.

"The novelty of our approach is that we used tools and concepts from mechanics, combined with bioinspiration from scaly-skinned animals, to develop a new class of drug-releasing systems with the capacity to deposit drug depots directly into luminal walls of tubular organs for extended-release. The kirigami stents were engineered to provide a reversible shape transformation: from flat to 3D, buckled-out needles for tissue engagement, and then to the original flat shape for easy and safe removal," says Sahab Babaee, an MIT research scientist, and the lead author of the paper.

The team had created kirigami needles of several different sizes and shapes along with the thickness of the plastic sheet. This helps in applying the technique to various sizes of the targeted tubular organs like blood vessels and the respiratory tract and their compartments. The team is now set to eventually test the stents in patients.

Source-Medindia