MIT engineers have designed tissue-derived “smart” sutures, pictured here, that can not only hold tissue in place, but also detect 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/MIT
Key points:
- Engineers have developed smart sutures that can deliver drugs.
- The sutures are coated in a hydrogel that can embed several types of cargo.
- The team says the sutures can be adapted to deliver other solutions, like antibiotics, chemotherapy drugs and stem cells.
Inspired by the techniques of the Ancient Roman Empire, researchers have designed “smart” sutures that can not only hold tissue in place, but also detect inflammation and release drugs.
The new sutures are derived from animal tissue, similar to the “catgut” sutures first used by the ancient Romans. Catgut sutures—which are made from strands of purified collagen from cows, sheep, or goats (not cats)—form strong knots that naturally dissolve within about 90 days. Although synthetic absorbable sutures are also available, catgut is still used in many types of surgery.
In a modern twist, MIT researchers created a version coated with hydrogels that can be embedded with sensors, drugs, or even cells that release therapeutic molecules.
The new sutures are made from pig tissue, which the researchers “decellularized” using detergents, to reduce the chances of inducing inflammation in the host tissue. The researchers then coated the sutures with a layer of hydrogel in which they could embed several types of cargo, including microparticles that can sense inflammation, various drug molecules, and living cells.
For the sensor application, the team designed microparticles coated with peptides that are released when inflammation-associated enzymes, called MMPs, are present in the tissue. Those peptides can be detected using a simple urine test.
In experiments, the scientists showed they could use the hydrogel coating to carry drugs that are used to treat inflammatory bowel disease, including a steroid called dexamethasone and a monoclonal antibody called adalimumab. These drugs were carried by microparticles made from FDA-approved polymers such as PLGA and PLA, which are used to control the release rate of drugs.
As it stands now, the sutures could help patients heal wounds or surgical incisions, especially patients with Crohn’s disease who have surgery to remove part of their intestine. But, the team is already working on testing other applications and scaling up the manufacturing process. The researchers say this smart suture approach could be adapted to deliver antibiotics, chemotherapy drugs, and even stem cells.