Inspired by paper cutouts, stents can deliver medicine to the gastrointestinal tract

MIT engineers and their collaborators are inspired by Japanese kirigami, which can be used to fold and cut paper to create three-dimensional structures and deliver medicine to the gastrointestinal tract, respiratory tract, and other tubular organs. .. Designed the type of stent. With the body.

When the tube is stretched, the stent is coated with a smooth layer of etched plastic with a small “needle” that allows the needle to penetrate. Organization Deliver the payload of medicine-Contains fine particles. These drugs are released over a long period of time after the stent is removed.

This kind of localization Drug delivery May be easy to handle Inflammatory disease It affects the gastrointestinal tract such as inflammatory bowel disease and eosinophilic esophagitis, said Giovanni, an assistant professor of mechanical engineering at MIT, a gastroenterologist at Brigham and Women’s Hospital, and the lead author of the study.・ Traverso said.

“This technique can be applied to essentially any tubular organ,” says Traverso. “In rare cases, being able to deliver the drug locally can maximize the potential to help resolve the patient’s condition and change their mindset. Patient care A single treatment enables topical and long-term drug delivery. “

Today’s MIT research scientist Sahab Babae Natural materials..

Elastic stent

Inflammatory bowel disease of the gastrointestinal tract, such as IBD, is often treated with drugs that weaken the body’s immune response. These drugs are usually injected, which can cause side effects elsewhere in the body. Traverso and his colleagues wanted to come up with a way to deliver such drugs directly to the affected tissue to reduce the potential for side effects.

Stents may provide a means of delivering drugs to the target area of ​​the gastrointestinal tract, but because digested food moves continuously through the gastrointestinal tract, what type of stent is inserted into the gastrointestinal tract It’s also difficult. Maybe so. To make this possibility more feasible, the MIT team came up with the idea of ​​creating a stent that would be temporarily inserted, stay firmly in the tissue to deliver the payload, and be easily removed.

The stents they designed have two important components. A soft, stretchy tube made of silicone-based rubber and a plastic coating etched with needles that pop out when stretched. This design was inspired by the paper cuts that Travelso’s lab had previously used to design non-slip coatings on soles. Others have used it to create bandages that adhere more tightly to the knees and other joints.

“The novelty of our approach is the ability to deposit drugstores directly on the luminal walls of tubular organs, using tools and concepts from mechanics, in combination with biostimulation from animals with scaly skin. We have developed a new class of drug release system with sustained release. “Kirigami stents go from flat needles for meshing with tissue to 3D buckling needles and back to their original flat shape. It now offers reversible shape transformations for easy and safe removal. “Designed.”

In this study, MIT’s team coated plastic needles with fine particles that could carry the drug. After inserting the stent with an endoscope, use the endoscope to inflate the balloon inside the tube and inflate the tube. When you stretch the tube, the plastic needle pops out and the luggage is released.

“This is a dynamic system that has a flat surface and can create these small needles to pop out and drive into tissue for drug delivery,” says Traverso.

For this study, researchers created several different sizes and shapes of kirigami needles. By varying these properties and the thickness of the plastic sheet, researchers can control how deep the needle pierces the tissue. “The benefits of our system apply to scales of various lengths. Gastrointestinal tract Or any tubular organ, “says Babaee.

Guy Drug Delivery

Researchers tested endoscopically by inserting a stent into the esophagus of a pig. When the stent was placed, researchers inflated a balloon inside the stent to allow the needle to pop out. The needle, which penetrated the tissue about 0.5 mm, was coated with fine particles containing a drug called budesonide, a steroid used to treat IBD. Eosinophilic esophagitis..

When the drug-containing particles were deposited on the tissue, the researchers contracted the balloon, flattened the needle, and allowed the stent to be removed endoscopically. This process took only a few minutes, the particles stayed in the tissue and gradually released budesonide over a period of about a week.

Depending on the composition of the particles, it can be adjusted to release the drug over a longer period of time, Traverso says. This eliminates the need for the patient to take the medication himself and allows the patient to receive the medication on a regular basis with a temporary stent insertion, making it easier for the patient to maintain the correct medication schedule. It also avoids side effects that can occur with systemic administration.

Researchers have also shown that stents can be delivered to blood vessels and blood vessels. AirwayThey are currently working on offering other types of drugs and scaling up the manufacturing process, eventually Stent In the patient.