Orthopaedics researchers in the United States have developed an injectable gel that encourages self-healing of knee injuries.
The research team at the University of Iowa said this week that the new treatment could offer a minimally invasive, practical and inexpensive approach for repairing cartilage and preventing osteoarthritis.
“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,” explained Yin Yu, first author of a study published in the May issue of the journal Arthritis and Rheumatology.
The researchers had previously identified precursor cells within normal cartilage that can mature into new cartilage tissue, indicating a potential approach for cartilage repair.
They also identified molecular signalling factors that attract these precursor cells, known as chondrogenic progenitor cells (CPC), 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, the University of Iowa said.
In the new study, which used an experimental model of cartilage injury, 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.
“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,” commented James Martin, PhD, University of Iowa assistant professor of orthopaedics and rehabilitation. “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.”
Further research is needed, but the team´s long-term goal is to commercialise the gel as a treatment that can be used in humans.