By inserting a "memory" into a plastic material, researchers say they have created a surgical thread that can ties itself into a knot. The same substance may also be used for medial implants such as stents or bone screws.
The material, made of thermoplastic polymers that an be absorbed by the body, an be engineered to assume s string-like shape at room temperature and then transform into a medially useful shape when warmed by body temperature, said Robert Langer, o-author of a study in the journal Science.
Langer, a professor of chemistry at the Massachusetts Institute of Technology, said the plastic could be used to make implants or bone screws that are not much bigger than a piece of string when inserted into the body. One they warm up, the devices change to form the appropriate implant.
He said that sine the material has a memory, it could be threaded into an incision as a loose knot. When it warms o the body's temperature, the material remembers its designed shape and size and shrinks to tighten the wound. Later, after the wound is healed, the material dissolves and is harmlessly absorbed by the body.
"It is like a smart suture," said Langer. "That could be very important in losing an incision in a place that is hard to reach by surgeon."
The researcher said the material could be used to make vascular stents, devices that hold open blocked arteries to allow easy blood flow. Stents made of thermoplastic polymer material with a memory could be inserted as a small thread or string and would then spring to a designed shape and size one it is warmed by the body, said Langer.