Researchers at MIT have developed a kirigami-style stent that can provide localized drug delivery through needle-like projections that pop out when the stent is extended. The ‘spines’ on the stent’s surface deliver drug-loaded microparticles into the surrounding tissue, allowing for sustained drug release for an extended period. The technology is well suited to administering drugs within tubular structures, such as those found in the GI tract, the respiratory system, and blood vasculature.
Treating inflammatory gastrointestinal conditions, such as inflammatory bowel disease, is frequently performed through the systemic administration of immunosuppressive drugs. However, this means that side-effects are possible in off-target tissues. Localized delivery would be better, but requires a method to introduce a drug precisely into the wall of the gut where it is needed.
This latest technology may provide an answer, both for gastrointestinal drug delivery and in other areas where a stent can be placed. “This technology could be applied in essentially any tubular organ,” said Giovanni Traverso, a researcher involved in the study, in an MIT press release. “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.”
The stents consist of a stretchy rubber tube covered with a plastic layer that contains spines. These pop out when the stent is extended by a small actuator. “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,” said Sahab Babaee, another researcher involved in the study. “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.”
The stent is intended to be delivered endoscopically, and then a balloon is used to expand and stretch it when it reaches the target tissue. So far, the researchers have tested the system within the guts of pigs, and used the stent to deliver budesonide, a steroid drug for inflammatory bowel disease. The researchers were able to deliver, deploy, and remove the stent within a few minutes. The microparticles left behind were able to release budesonide continuously for a week.
See a video about the technology:
Study in Nature Materials: Kirigami-inspired stents for sustained local delivery of therapeutics