Pioneering stem cell research discoveries are driving more research into the molecular mechanisms of cartilage regeneration and repair. New therapies are desperately needed to heal or replace damaged cartilage in joints ravaged by osteoarthritis (OA).
Articular cartilage develops as you develop in your mother’s womb to provide a smooth gliding surface for joint movement. Once lost to the devastating effects of osteoarthritis, the smooth layer of cartilage no longer cushions the ends of the bones where they come together to form joints. Damaged cells pile up in bony spurs and swollen joints, triggering constant, grinding pain. Today, total joint replacement surgery is the only treatment available for this painful and crippling disease, but that is about to change thanks to stem cell research.
In the near future, scientists hope to treat damaged cartilage with grafts of newly grown cartilage tissues derived from stem cells. At Boston Children’s Hospital, Arthritis National Research Foundation funded researcher April Craft, PhD, is working to harness the power of stem cells to generate a new layer of articular cartilage. “The challenge with cartilage repair and regeneration is that the articular cartilage lining our joints forms prenatally,” she explains. “Regeneration does not normally occur after birth.”
As an Assistant Professor in the Departments of Orthopaedic Surgery and Stem Cells and Regenerative Biology at Harvard Medical School, Dr. Craft is coaxing stem cells to grow into articular cartilage in a petri dish. Using pluripotent stem cells, cells that can generate into any cell type in the body, she has generated specialized cells called chondrocytes that develop during embryonic development. Chondrocytes are the cells that make up cartilage tissues, and part of their job is to make proteins that help distribute load and lubricate joints.
Ultimately, the goal of this stem cell research is to generate stable articular cartilage that can be successfully transplanted into a patient’s knee or other joints. “The challenge with using pluripotent stem cells is to reliably and efficiently generate large numbers of articular chondrocytes and cartilage tissues,” she explains. “We anticipate that knowledge we gain through these studies can be used to predict whether certain populations of cells from existing cartilage tissues are better suited than others to repair or regenerate cartilage tissues.“
The ability to create more effective implants for long-term cartilage repair will improve dramatically with increased knowledge of how these tissues develop normally in the body. “We were the first to demonstrate that human articular cartilage tissues generated in this manner are very similar to those found in our joints,” says Dr. Craft. “Now we have an opportunity to build on these findings to learn more about cartilage development, and define characteristics of cells that have the greatest ability to regenerate this tissue.”
No longer the stuff of science fiction, her Arthritis National Research Foundation funded stem cell research holds promise for nearly 27 million Americans who suffer the pain of osteoarthritis. Cartilage tissues grown in a lab setting offer a safe and non-invasive way to screen for new drugs that might protect against further damage.
“The field of regenerative medicine is exploding,” says Dr. Craft. “With Arthritis National Research Foundation support, we are moving step by step to identify the most promising cells to grow ‘cartilage in a dish’ so that we can achieve our goal of healing damaged joints.”
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