[Editors] MIT: Natural polyester makes new sutures stronger, safer

[Elizabeth Thomson]

MIT News Office
Massachusetts Institute of Technology
Room 11-400
77 Massachusetts Avenue
Cambridge, MA  02139-4307
Phone: 617-253-2700
http://web.mit.edu/newsoffice/www

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MIT: Natural polyester makes new sutures stronger, safer
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For Immediate Release
THURSDAY, MAR. 22, 2007
Contact: Elizabeth A. Thomson, MIT News Office
Phone: 617-258-5402
Email: thomson at mit.edu

PHOTO AVAILABLE

CAMBRIDGE, Mass.--With the help of a new type of suture based on MIT 
research, patients who get stitches may never need to have them 
removed.

A biopolymer suture cleared last month by the FDA is made of 
materials that the human body produces naturally, so they can be 
safely absorbed once the wound is healed. They are also 30 percent 
stronger than sutures now used and very flexible, making them easier 
for surgeons to work with.

The sutures were developed by Tepha, Inc., a Cambridge company that 
hopes to use the same material to produce an array of absorbable 
medical devices, including stents, surgical meshes and possibly a 
heart valve scaffold, says Simon Williams, CEO of Tepha and a former 
MIT postdoctoral associate.

Williams said he envisions that the new sutures will be used for 
abdominal closures, which are prone to re-opening, and to stitch 
tendons and ligaments.

Developed using a method created at MIT, the absorbable sutures are 
the first made from material produced by genetically modified 
bacteria.

About 20 years ago, researchers in the laboratory of MIT biology 
professor Anthony Sinskey started swapping genes between different 
bacteria, hoping to achieve industrial production of desirable 
natural compounds synthesized by those bacteria.

The researchers focused their "biopolymer engineering" efforts on a 
group of genes that code for enzymes in a pathway that produces 
polyesters. Those polyesters can be broken down into metabolites 
naturally produced by humans, so they cause no harm when absorbed.

Once the genes were identified, they could be transferred into a 
strain of industrial E. coli that can produce large quantities of the 
strong, flexible polymer.

The FDA cleared the biopolymer sutures on Feb. 8, and Williams said 
Tepha plans to start marketing them soon, in partnership with another 
company.

"Not only is it technically and in an engineering sense a tremendous 
victory, but it's also a victory for society because this leads to 
new medical devices that can help people in new and novel ways," said 
Sinskey, who is one of the founders of Tepha and sits on its board of 
directors.

The new suture is the first of what the researchers hope will be many 
medical devices made from the natural polyesters.

"What we've found is that this one material seems to be finding a lot 
of use in different applications," because of its wide range of 
desirable properties, Williams said.

Tepha is now working on developing other medical devices, such as 
surgical meshes, multifilament fibers and stents. Ultimately, the 
researchers hope to develop an artificial scaffold that could be used 
to grow heart valves after being implanted in a patient, which would 
spare children with heart valve defects from undergoing repeated 
surgeries. Tests of the device in animals have shown promise.

"We've been able to show we can produce a valve scaffold that 
functions better and can grow with the animal," Williams said. "If 
the valve can grow with the patient, you don't need the repeated 
surgeries."

Tepha, founded six years ago, is a spinoff of Metabolix, a company 
the researchers founded in 1992 to market bioplastics and biopolymer 
packaging materials.

Other current and former MIT researchers who helped develop the 
recombinant DNA methods used to create the biopolymer are JoAnne 
Stubbe, Novartis Professor of Chemistry and professor of biology, 
former postdoctoral associate Oliver Peoples and the late Professor 
Emeritus Satoru Masamune.

Original work at MIT on this technique was funded by the National 
Institutes of Health.

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Written by Anne Trafton, MIT News Office