George Mason University

News at Mason

Professor hopes to get a leg up on research to halt knee pain

September 18, 2019   /   by Nanci Hellmich

“My long-term goal is to restore pain-free knees to patients and reduce their need for knee replacement. It would give them back their lives."

— Caroline Hoemann, a professor of bioengineering

Bioengineering professor Caroline Hoemann is developing biomaterials to help repair damaged knee cartilage.

Bioengineering professor Caroline Hoemann is developing biomaterials to help repair damaged knee cartilage. Photo by Ron Aira/Creative Services

Mason bioengineering professor Caroline Hoemann is making significant strides in developing treatments for chronic knee pain.

She is creating new biomaterials that might one day be used to treat damaged cartilage, a tissue that acts as a shock absorber for the bones.  

“My long-term goal is to restore pain-free knees to patients and reduce their need for knee replacement. It would give them back their lives,” says Hoemann, director of the Laboratory of Biomaterials and Nanomedicine on Mason’s Science and Technology Campus.

Athletes, physically active adults, people with osteoarthritis, and others sometimes have significant pain and limited movement in their knees from damaged cartilage, she says.

To repair the tissue, surgeons use a procedure called microfracture, in which they make multiple small holes in the bone exposed at the surface of the joint to stimulate a healing response.  “They have a good success rate in younger patients, but the repair tissues regenerate in an unpredictable manner,” she says.

That’s where biomaterials come in. “Our approach is to prompt the immune system to cooperate with the bone marrow to regrow damaged cartilage. Some biomaterials have a unique potential to stimulate the patients’ own cells to preserve and regenerate cartilage," Hoemann says.

In a recent test, researchers injected different biomaterials into the knees of rabbits during the healing phase after cartilage repair surgery. Then they used 3D ultrasound scans to see if more cartilage tissue grew back.  “In some cases, it grows back. In others, it doesn’t.” 

Parag Chitnis, an assistant professor in the Department of Bioengineering, says, “Dr. Hoemann has discovered an innovative application of ultrasound bio-microscopy for assessing cartilage health and tissue repair. Her efforts to develop novel biomaterials and noninvasive imaging techniques offer new technological solutions for alleviating chronic pain, and provides our students with exciting new training opportunities.” 

Hoemann has worked on this problem for more than two decades including as a professor at the École Polytechnique in Montreal.

She also served as a research director at a Montreal-based biomedical device company, where she invented and developed a biomaterial-based medical device for articular cartilage repair that achieved regulatory approval for use in more than 17 countries. The device has been acquired by Smith & Nephew, a medical technology company. It’s currently used by orthopedic surgeons outside the United States.

This type of research takes years. “We’ve been looking at the whole knee, which is why the research is drawn out. It’s a multifactorial problem because the knee is so complex,” Hoemann says.

She once saw a postcard of a person sitting on a lawn cutting grass with scissors, and sometimes her work feels the same way. That said, “it’s really rewarding when you finally start connecting everything, and it’s even more rewarding when you realize you’ve made an important advance that can help people."