Lab-grown cartilage may soon help ease the pain of millions of Americans who suffer from conditions like osteoarthritis.
In a study that holds implications for sports-injury sufferers and aging adults alike, researchers from the University of California, Davis created a type of artificial cartilage that, in animal studies, has shown to stand up to the rigors of physical movement and exercise.
With a cellular structure similar to that of natural cartilage, the bioengineered material features exceptional durability for lab-grown tissue. The artificial cartilage is composed of “a mix of glycoproteins and collagen,” which are also found in the cartilage in a person’s body.
“The artificial cartilage that we engineer is fully biological with a structure akin to real cartilage,” said Kyriacos Athanasiou, professor in the Department of Biomedical Engineering at the UC Davis.
“Most importantly, we believe that we have solved the complex problem of making tissues in the laboratory that are strong and stiff enough to take the extremely high loads encountered in joints such as the knee and hip,” added Athanasiou.
Breaking Free of Scaffolds
Most previous research into artificial cartilage has used a scaffolding system on which cells can grow. But recently, bioengineers have pivoted to a “scaffold-free” system that may allow cells — and the resulting cartilage — to more adequately mirror the naturally forming cartilage in the human body.
For the current study, the UC Davis researchers engineered human chondrocytes, which are the building blocks of natural cartilage, on a scaffold-less system. Without the scaffold, the chondrocytes were able to “self-assemble and stick together,” creating a cartilage-like formation, according to the study authors.
Then the researchers gave the artificial cartilage a boost — they stretched out the cells.
“As they were stretched, they became stiffer,” reported study ao-author Jerry Hu, a research engineer at UC Davis. “We think of cartilage as being strong in compression, but putting it under tension has dramatic effects.”
Notably, stretching out the cartilage led to a six-fold increase in durability characteristics and the ability to withstand stress, according to the study. In experiments on mice, the researchers found that the artificial cartilage can hold up to the demands of movement.
According to Hu, the next move will be to test the artificial cartilage in a “load-bearing joint” to further assess the material’s durability in a real-life environment.
Should it prove successful, the applications for human treatment are tremendous. More than 30 million Americans suffer from osteoarthritis, which results from a breakdown in one’s cartilage, according to statistics from the Centers for Disease Control and Prevention (CDC). Other issues, such as sports injuries, also lead to cartilage-related problems.
As they move ahead with further analysis, the researchers believe they’re on the precipice of an important leap forward in lab-grown tissues.
“In this comprehensive study, we showed that we can finally engineer tissue that has the tensile and compressive characteristics of native tissue,” said Athanasiou.