February 26, 2024

Healing Innovation: MIT Engineers Create “Smart Sutures” That Can Deliver Drugs or Sense Inflammation

” What we have is a stitch that is bioderived and modified with a hydrogel coating capable of being a tank for sensing units for inflammation, or for drugs such as monoclonal antibodies to deal with swelling. Remarkably, the coating likewise has the capability to retain cells that are feasible for a prolonged duration,” says Giovanni Traverso, an associate professor of mechanical engineering at MIT, a gastroenterologist at Brigham and Womens Hospital, and the senior author of the study.
The researchers imagine that these sutures might help clients with Crohns disease heal after surgical treatment to remove part of the intestinal tract. The stitches might also be adjusted for use to heal wounds or surgical cuts elsewhere in the body, the scientists say.
Previous MIT postdocs Jung Seung Lee and Hyunjoon Kim are the lead authors of the paper, which was just recently published in the journal Matter.
Influenced by catgut
Catgut stitches– which are made from strands of cleansed collagen from cows, sheep, or goats (but not felines)– type strong knots that naturally dissolve within about 90 days. Synthetic absorbable sutures are also readily available, catgut is still used in lots of types of surgery.
Traverso and his associates wished to see if they might build on this kind of tissue-derived suture to create a product that would be absorbable and hard, and have advanced functions such as sensing and drug delivery.
Such sutures could be particularly useful for Crohns illness patients who require to have a part of the intestinal tract got rid of due to blockage from extreme scarring or swelling. This procedure needs resealing the two ends left behind after one area of the intestinal tract is eliminated. It can lead to leakages that are hazardous for the patient if that seal doesnt hold tightly.
To help in reducing this risk, the MIT group wished to create a suture that might not just hold the tissue in location however also identify inflammation, an early caution sign that the resealed intestines are not recovery effectively.
The scientists developed their new sutures from pig tissue, which they “decellularized” utilizing detergents, to minimize the chances of inducing swelling in the host tissue. This process leaves a cell-free product that the scientists call “De-gut,” which includes structural proteins such as collagen, as well as other biomolecules discovered in the extracellular matrix that surrounds cells.
After dehydrating the tissue and twisting it into hairs, the researchers evaluated its tensile strength– a measure of just how much extending it can stand up to before breaking– and discovered that it was similar to commercially available catgut sutures. They likewise discovered that the De-gut stitches cause much less of an immune response from surrounding tissue than traditional catgut.
” Decellularized tissues have been thoroughly used in regenerative medication with their exceptional biofunctionality,” Lee says. “We now recommend a novel platform for carrying out sensing and delivery utilizing decellularized tissue, which will open up brand-new applications of tissue-derived products.”
Smart applications
Next, the scientists set out to enhance the suture material with additional functions. To do that, they coated the stitches with a layer of hydrogel. Within the hydrogel, they can embed several types of cargo– microparticles that can sense swelling, different drug molecules, or living cells.
For the sensing unit application, the researchers developed microparticles covered with peptides that are launched when inflammation-associated enzymes called MMPs exist in the tissue. Those peptides can be detected utilizing a simple urine test.
The researchers likewise showed that they could use the hydrogel finishing to carry drugs that are used to deal with inflammatory bowel disease, including a steroid called dexamethasone and a monoclonal antibody called adalimumab. These drugs were brought by microparticles made from FDA-approved polymers such as PLGA and PLA, which are utilized to control the release rate of drugs. This method could likewise be adapted to deliver other type of drugs such as antibiotics or chemotherapy drugs, the researchers state.
These clever sutures might also be utilized to provide healing cells such as stem cells. To check out that possibility, the researchers embedded the stitches with stem cells crafted to express a fluorescent marker, and found that the cells remained viable for at least 7 days when implanted in mice. The cells were likewise able to produce vascular endothelial growth element (VEGF), a development factor that stimulates blood cell growth.
The researchers are now working on more testing each of these possible applications, and on scaling up the manufacturing procedure for the sutures. They likewise wish to check out the possibility of using the stitches in parts of the body aside from the gastrointestinal tract.
” The decellularized gut suture established by the MIT group is an interesting platform for noticing and delivering a wide variety of therapies, consisting of small molecules, biologics, and living cells. The group has done a great job robustly showing the flexibility of this platform,” states Omid Veiseh, an associate professor of bioengineering at Rice University, who was not involved in the research study.
Recommendation: “A multifunctional decellularized gut suture platform” by Jung Seung Lee, Hyunjoon Kim, Gwennyth Carroll, Gary W. Liu, Ameya R. Kirtane, Alison Hayward, Adam Wentworth, Aaron Lopes, Joy Collins, Siid Tamang, Keiko Ishida, Kaitlyn Hess, Junwei Li, Sufeng Zhang and Giovanni Traverso, 16 May 2023, Matter.DOI: 10.1016/ j.matt.2023.04.015.
Other authors of the paper are Gwennyth Carroll, Gary Liu, Ameya Kirtane, Alison Hayward, Adam Wentworth, Aaron Lopes, Joy Collins, Siid Tamang, Keiko Ishida, Kaitlyn Hess, Junwei Li, and Sufeng Zhang.
The research was moneyed by the Leona M. and Harry B. Helmsley Charitable Trust, the MIT Department of Mechanical Engineering, the National Research Foundation of Korea, and a National Institute of Diabetes and Digestive and Kidney Disease Ruth L. Kirschstein NRSA Fellowship.

MIT engineers have designed tissue-derived “wise” sutures, pictured here, that can not just hold tissue in location, however likewise detect inflammation and release drugs. The stitches are covered with hydrogels that can be embedded with sensing units, drugs, or cells that release healing particles. Next, the researchers set out to improve the stitch product with additional functions. These wise sutures might likewise be used to deliver restorative cells such as stem cells. To explore that possibility, the scientists embedded the sutures with stem cells crafted to express a fluorescent marker, and found that the cells remained feasible for at least seven days when implanted in mice.

MIT engineers have developed tissue-derived “wise” sutures, imagined here, that can not just hold tissue in place, but also identify inflammation and release drugs. The sutures are coated with hydrogels that can be embedded with sensors, drugs, or cells that release therapeutic molecules. Credit: Courtesy of the researchers
The bioderived “wise sutures” might help clients heal after bowel resection or other kinds of surgery.
Inspired by stitches established thousands of years ago, MIT engineers have actually developed “smart” stitches that can not only hold tissue in place, but likewise discover inflammation and release drugs.
The brand-new stitches are stemmed from animal tissue, comparable to the “catgut” stitches first used by the ancient Romans. In a modern-day twist, the MIT team coated the stitches with hydrogels that can be embedded with sensing units, drugs, or even cells that release therapeutic molecules.