Regenerative Medicine for Osteoarthritis
McGowan Institute for Regenerative Medicine associate director Rocky Tuan, PhD, is the director of the Center for Cellular and Molecular Engineering, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, and the executive vice chairman for orthopaedic research at the University of Pittsburgh. Dr. Tuan’s research focuses on the development, growth, function, and health of the musculoskeletal system, the biology of adult stem cells, and the utilization of this knowledge to develop technologies that will regenerate and/or restore function to diseased and damaged musculoskeletal tissues. Recently, Dr. Tuan was part of a group of researchers interviewed by Dorothy Foltz-Gray, Lifescript. Ms. Foltz-Gray’s article, “Stem Cell Treatments for Joint Cartilage,” summarized the insights of Dr. Tuan as well as scientists from Weill Cornell Medical College, Duke University Medical Center, and Columbia University Medical Center’s College of Dental Medicine.
Osteoarthritis (OA) is the most common joint disorder, which is due to aging and wear and tear on a joint. Cartilage is the firm, rubbery tissue that cushions your bones at the joints, and allows bones to glide over one another. If the cartilage breaks down and wears away, the bones rub together. This causes pain, swelling, and stiffness. Bony spurs or extra bone may form around the joint. The ligaments and muscles around the joint become weaker and stiffer.
Ms. Foltz-Gray writes that scientists are making progress in adult stem cell therapies for osteoarthritis, and some plan to start clinical trials within the next decade. She asks, “What are the future osteoarthritis treatments, and how might they work?” She learned of today’s most promising research approaches involving adult stem cell-based therapies:
- Laboratory-grown cartilage
- Stem cell insertion
- Stem cell recruitment
- Anti-inflammatory stem cell injection
Laboratory-grown cartilage would be used for patients with early-stage osteoarthritis, where the cartilage defects are defined but not large—“perhaps 2 centimeters,” Dr. Tuan explained. Surgeons measure the area of damaged joint cartilage to be replaced. Then they remove stem cells from the body and place them in a gel or material made of tiny fibers, so that they can grow into a three-dimensional structure. In about 2 months, the stem cells turn into cartilage, which surgeons then implant into the joint. This process eventually could be performed with only a small incision, just large enough to insert the new cartilage structure and unfurl it over the once-damaged cartilage, Dr. Tuan predicted.
Stem cell insertion might be used with people with early joint damage, but also those with advanced osteoarthritis who have little joint cartilage left, Dr. Tuan said. In this process, researchers must first harvest cells and then purify them to get usable cells, Dr. Tuan said. The purified stem cells are inserted into the joint, along with a material that encourages stem cells to turn into new cartilage in several months, Dr. Tuan said.
A benefit for all osteoarthritis patients is stem cell recruitment. It provides a natural supply of cells without invading the body. It also allows the body to heal damaged joints with the patient’s own stem cells, reducing the risk of rejection. A protein is used to attract the necessary stem cells to the joint and regenerate cartilage. This method has only been performed in pre-clinical studies.
Anti-inflammatory stem cell injections might benefit people at risk of developing osteoarthritis, as well as those that have the disease. In pre-clinical studies, the injections reduced the degenerative process and inflammation.
Adult stem cell research could provide amazing new treatments for osteoarthritis. Experts hope to apply these therapies and alleviate or prevent arthritis in people, as well as postpone or reduce the need for joint replacement surgery, however at this time these approaches are only research studies and are not available for clinical use.