SAN DIEGO — The California Institute for Regenerative Medicine has awarded Scripps Health more than $12.7 million to study the use of stem cells to repair certain types of knee injuries.
The funding will support laboratory-based tissue engineering and cartilage and bone repair surgeries in animals, led by investigators at the Shiley Center for Orthopaedic Research and Education at Scripps Clinic on Torrey Pines Mesa. Researchers aim to demonstrate that “surgically implanting the engineered, scaffold-free tissue to repair such injuries in animal models is safe and effective,” according to a Scripps statement.
At the end of the five-year grant period, researchers plan to submit an application to the Food and Drug Administration for a new drug or biological product. If approved, the process could lead to 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 focuses on larger knee injuries in which damage to cartilage and underlying bone exceeds 2 square centimeters.
One current treatment option is osteochondral allograft transplant surgery, in which surgeons remove a cylinder of damaged cartilage and bone and replace it with healthy tissue from a deceased donor, according to Scripps. Limitations include donor availability and tissue preservation.
Another option is a cell-based therapy using a patient’s own cartilage cells, which requires two surgeries and relies on cells that may not be ideal for regrowing cartilage due to slow growth and poor metabolism.
The CIRM funding — from a state agency established in 2004 after voters approved Proposition 71 — will build on earlier work at the research center.
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 samples effectively repaired defects and integrated with injured tissue, the organization 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 the medical journal Clinical Orthopaedics and Related Research, knee cartilage injuries affect about 900,000 people annually in the United States, resulting in more than 200,000 surgical procedures.
While the grant focuses on knee injuries, similar cartilage and bone damage can occur in joints, including the ankle, elbow, shoulder and hip, and may lead to osteoarthritis, Scripps researchers said.
