Scripps Health awarded more than $12m for knee injury research

Knee injuries can be debilitating, but new hope may be on the horizon.

The California Institute for Regenerative Medicine has granted Scripps Health more than $12.7 million to conduct studies on the use of stem cells to repair some types of knee injuries.

The funding will be used for laboratory-based tissue engineering and cartilage and bone injury repair surgeries in animals, led by investigators at the Shiley Center for Orthopaedic Research and Education at Scripps Clinic on Torrey Pines Mesa. SCORE researchers aim to demonstrate that “surgically implanting the engineered, scaffold-free tissue to repair such injuries in animal models is safe and effective,” said a statement from Scripps.

At the end of the five-year grant period, researchers plan to submit a new drug or biological product application with the Food and Drug Administration, which, if approved, could lead Scripps to begin clinical trials in humans.

“A biological implant that can successfully treat cartilage and bone defects of the knee would resolve the limited availability of donor graft tissue and has the potential to delay and eventually eliminate the need for joint replacement,” said Dr. Darryl D’Lima, director of orthopedic research at Scripps Health and the study’s lead investigator.

The approach being studied at Scripps is for larger knee injuries, where the damage to the cartilage and underlying bone are larger than 2 square centimeters.

A current treatment option is osteochondral allograft transplant surgery, in which the surgeon removes a coin-shaped cylinder of damaged cartilage and underlying bone and replaces it with a section of healthy cartilage and bone from a deceased donor, Scripps officials said. Drawbacks include availability of tissue from cadavers and preserving said tissue.

Another option for the aforementioned injuries is a cell-based therapy that uses the patient’s own cartilage cells. This approach requires two separate surgeries and uses cells not ideal for re-growing cartilage, due to slow growth and poor metabolism.

The grant funding from CIRM — a state-funded organization established in 2004 when California voters approved Proposition 71, which provides grants to stem cell research — will build on earlier work at SCORE.

According to Scripps, senior staff scientist Shawn Grogan “developed the technology to generate scaffold-free cartilage and bone tissue in the lab by producing cellular spheroids (3D clusters of cells) from a specific stem cell source (mesenchymal stem cells), which fused together to form tissue.” Implanting these lab-grown tissues into osteoarthritic tissue samples effectively repaired the defects and structurally integrated with the injured tissues, Scripps said.

“Scaffold-free tissue engineering differs from the more conventional method, in which transformed stem cells are embedded into a scaffold of fibers and grown into tissue,” a Scripps statement said. “The new technique avoids limitations associated with scaffolds, such as poor integration and compatibility with host tissue. Scaffold-free tissue closely mimics cells in developing native tissue and have high potential for healing.”

According to a report in the medical journal Clinical Orthopaedics and Related Research, cartilage injuries of the knee affect around 900,000 people annually in the United States, resulting in more than 200,000 surgical procedures.

While the CIRM grant funding is focused on treating cartilage and bone damage in the knee, the injuries can also occur in joints such as the ankle, elbow, shoulder and hip. These conditions can be precursors to the more widespread joint disease osteoarthritis, Scripps researchers said.