UA's John Szivek Awarded Major Grant to Develop Technology to Repair, Monitor Cartilage in Arthritic Joints
TUCSON, Ariz., -- A researcher at the University of Arizona Health Sciences Center (AHSC) has been awarded a major grant to conduct a first-of-its-kind study that will employ high-tech plastic carriers -- containing load-sensing devices and a micro-miniature radio transmitter -- to grow tissue-engineered cartilage to repair arthritic joints. The sensors and transmitters will allow researchers to monitor how well the new tissue responds to stress and physical rehabilitation.
Researchers believe this technology eventually could replace the use of artificial joints in most patients who currently require total joint replacement. Arthritis patients and athletes who damage their cartilage during sports activities will be the first to benefit from this medical advance. In addition, the technology should improve rehabilitation care for patients: The sensors and transmitter system would allow physical therapists to monitor patients during rehabilitation. Eventually, this will provide the information needed to speed up the rehabilitation process and increase the rate of effectiveness of this procedure. "Our research seeks to develop a product that can be used to re-grow damaged cartilage and also design better rehabilitation procedures for patients," explains John A. Szivek, PhD, principal investigator for the $1.1 million grant from the National Institutes of Health (NIH) and a research professor in the UA Department of Orthopaedic Surgery and senior scientist at the Arizona Arthritis Center. He cautions, however, that this technology likely will not be ready for clinical applications for several years.
Until now, most tissue cultures have created cartilage cell layers that did not have the same structure or mechanical properties as "human hyaline cartilage," Dr. Szivek says. (Human hyaline cartilage, the type found in joints, has a highly organized structure that makes it well suited to provide smooth, pain-free motion of the joints. This structure makes it strong enough to endure the enormous loads acting on our joints. For example, the cartilage on the kneecap is exposed to loads as large as six times the person's body weight.)
The sensing device in the scaffold that will carry the engineered tissues will measure how much the scaffold deforms when the patient uses their joint. This sensor will be calibrated before it is placed into patients and will be connected to a radio transmitter that will send the signal to a hand-held computer that can alert the patient if they are doing activities that may damage their tissue-engineered cartilage, he says.
Scientists believe the highly organized structure of cartilage, the basis of its strength, can be reproduced if cartilage cells are grown in culture while they are "loaded in the ways they are loaded in the patient," Dr. Szviek says. "One of the challenges of the research is to load them while they are growing on plastic scaffolding, which can be implanted into a patient, but eventually will dissolve. It seems unlikely that tissues grown in culture will adapt their structure once they are placed in the patient. As such, it may be essential to grow them with the right structure prior to placing them in the patient," he adds.
Dr. Szivek has been working on similar devices for other applications for the past decade. To develop the sensor and transmitter system for this application, methods of bonding and calibrating the sensors to the scaffolds must be developed. In addition, the transmitter system will be modified and its size reduced substantially to allow it to fit onto the scaffold and into the tissues in the region of the scaffolds.
The study will be carried out collaboratively with a team from the UA Department of Orthopaedic Surgery, the UA Biomedical Engineering Interdisciplinary Program and the Arizona Arthritis Center. Collaborators include William A. Grana, MD, and James B. Benjamin, MD, Department of Orthopaedic Surgery (and the Arizona Arthritis Center); Stuart Williams, PhD, and James Hoying, PhD, UA Biomedical Engineering; and Paul Calvert, PhD, UA Department of Materials Science and Engineering.