Engineering students at Johns Hopkins University have developed a way to embed a patient's own stem cells into the surgical threads that doctors use to repair damaged tissue. The technology is aimed at helping the healing process along, especially for serious orthopedic injuries to muscles, tendons, and ligaments. The students are currently collaborating with orthopedic surgeons to test the sutures in animal models.

Stem cells are the precursors to every cell and tissue in our body. They have the unique ability to develop into specific cell types through a process known as differentiation. There are two broad categories of stem cells: embryonic stem cells, which can differentiate into all embryonic tissue, and adult stem cells, which act to repair tissue while also maintaining the normal turnover of certain cell types, including blood and skin. Adult stem cells can be obtained from a variety of sources, including umbilical cord blood and bone marrow.

One of the many advantages of the new technology is that it would in no way change standard procedures while the use of stems cells would enhance tissue recovery. Furthermore, the stem cells come the patient, thereby eliminating the need for donor matching and thus, any chance of tissue rejection.

The synthesis of the surgical thread begins by obtaining bone marrow from the patients in question. Stem cells are then isolated and incorporated into the fibers of the thread, which are then used by surgeons to stitch together and repair damaged tissue using conventional surgical techniques.

At the site of the repair, the stem cells should theoretically speed up the healing process by releasing growth factors, reducing the inflammatory response of the body, and developing into replacement tissue, including ligaments or cartilage. The preliminary results have been promising. Along with the successful incorporation of the stem cells into the sutures, the cells are surviving the surgical procedure. Testing in humans could begin in as little as five years.

It has been estimated that every year up to 46,000 people in this country undergo surgery to repair their Achilles tendon, costing as much as $40,000 per person. The recovery process can take as long as a year, and 20% of the surgeries fail, requiring another operation. In this regard, this new development offers the promise of a treatment that is not only potentially more effective, but could possibly make a big difference in the long term costs. The technology is being studied as a possible therapy in other orthopedic procedures, including rotator cuff injuries, as well as cardiology and obstetrics.