Iowa Research Focused on Cartilage Repair

Injuring a knee and damaging the cartilage is the nightmare of every young athlete. The reason? Present techniques for repairing damaged cartilage are generally not successful in the long run. The message most injured athletes receive is that cartilage in the joints, once damaged, does not repair itself. Instead it often gets worse.

A group of researchers at the University of Iowa is working to change that bleak picture. They have reason to believe that their solution will result in a minimally invasive, practical, and inexpensive approach for repairing cartilage and preventing osteoarthritis.

Yin Yu, a graduate student in the lab of James Martin, M.D., University of Iowa assistant professor of orthopaedics and rehabilitation, is first author of the study featured on the cover of the May issue of the journal Arthritis and Rheumatology.

Yu said, ” We are creating an [injectable, bioactive] hydrogel that can repair cartilage damage, regenerate stronger cartilage, and hopefully delay or eliminate the development of osteoarthritis and eliminate the need for total knee replacement.”

How he expects to accomplish this feat is explained in a press release from the University of Iowa Health Care. According to the release, Martin’s team had previously identified precursor cells within normal cartilage that can mature into new cartilage tissue. They also identified molecular signalling factors that attract these precursor cells, known as chondrogenic progenitor cells out of the surrounding healthy tissue into the damaged area and cause them to develop into new, normal cartilage. One of the signals, called stromal cell-derived factor 1, (SDF1) acts like a homing beacon for the precursor cells.

Yu loaded the custom-made hydrogel with SDF1 and injected it into holes punched into the model cartilage. The precursor cells migrated toward the SDF1 signal and filled in the injury site. Subsequent application of a growth factor caused the cells to mature into normal cartilage that repaired the injury.

The news release quoted Martin as saying, “There’s really no cure for osteoarthritis except for total joint replacement, which is not particularly suitable for younger patients because the artificial joints wear out and need to be replaced multiple times, Our approach aims to leverage the body’s own capacity for repair, and what we’ve shown is that cartilage does have regenerative potential; you just have to manipulate it just right.”