Students embed stem cells in sutures to enhance healing

1^st on the web (August 10, 2009)

Johns Hopkins biomedical engineering students have demonstrated a practical way to embed a patient's own adult stem cells in the surgical thread that doctors use to repair serious orthopedic injuries such as ruptured tendons.

The students’ goal is to enhance healing and reduce the likelihood of re-injury without changing the surgical procedure itself.

The project team – 10 undergraduates sponsored by Bioactive Surgical Inc. – won first place in the recent Design Day 2009 competition conducted by the university's Department of Biomedical Engineering. In collaboration with orthopedic physicians, the students have begun testing the stem cell–bearing sutures in an animal model, paving the way for possible human trials within about five years.

"Using sutures that carry stems cells to the injury site would not change the way surgeons repair the injury," said Matt Rubashkin, the student team leader, in a release. “We believe the stem cells will significantly speed up and improve the healing process. And because the stem cells will come from the patient, there should be no rejection problems."

The corporate sponsor, Bioactive Surgical, developed the patent-pending concept for a new way to embed stem cells in sutures during the surgical process. The company then enlisted the student team to assemble and test a prototype to demonstrate that the concept was sound. The undergraduates performed this work during the yearlong Design Team course, required by the school's Biomedical Engineering Department.

As envisioned by the company and the students, a doctor would withdraw bone marrow containing stem cells from a patient's hip while the patient was under anesthesia. The stem cells would then be embedded in the novel suture through a quick and easily performed proprietary process. The surgeon would then stitch together the ruptured Achilles tendon or other injury in the conventional manner but using the sutures embedded with stem cells.

At the site of the injury, the stem cells are expected to reduce inflammation and release growth factor proteins that speed up the healing, enhancing the prospects for a full recovery and reducing the likelihood of re-injury. The team's preliminary experiments in an animal model have yielded promising results, indicating that the stem cells attached to the sutures can survive the surgical process and retain the ability to turn into replacement tissue, such as tendon or cartilage.

"These students have demonstrated an amazing amount of initiative and leadership in all aspects of this project, including actually producing the suture and designing the ensuing mechanical, cell-based and animal trials," said Lew C. Schon, MD, one of the inventors of the technology, in a release. “The students exceeded all expectations. They have probably cut at least a year off of the development time of this technology, and they are definitely advancing the science in this emerging area.”

For more information:

• Lew C. Schon, MD, is an assistant professor of orthopedic surgery in the Johns Hopkins School of Medicine. He can be reached at 3333 N. Calvert Street Johnston Prof. Building, Suite 400 Baltimore, MD 21218; (800)-571-9820; e-mail: lschon@gcoa.net.