Synthetic Lubricant Shows Promise Against Osteoarthritis

Researchers from Cornell University have patented a method to produce the required lubricating glycoprotein called lubricin in the knee joint that is absent in the elderly and people with osteoarthritis. Lubricin is produced naturally by the body, and it reduces the risk of injury in the knee joint during intense physical activity.

The manufacture of lubricin is not easy. This is the reason why a synthetic polymer resembling lubricin’s structure and functional composition was developed, said the paper published in the Proceedings of the National Academy of Sciences. Lead author Zhexun Sun, a postdoctoral researcher at the College of Engineering, worked on the study under professor David Putnam.

They are currently conducting clinical trials on dogs with osteoarthritic knees by injecting this experimental drug into the arteries with the help of professors from Cornell’s College of Veterinary Medicine. A force plate is used to measure the force exerted by each paw. Ultimately, this parameter is something their counting on to decide the synthetic polymer’s success.

“Once we finalise the efficacy study in dogs, we will be in a very good position to market the material for verterninary osteoarthritis treatment,” Putnam said in a press release. While the process is still ongoing, the final goal is to market the product for human use after further research and testing is complete. “The synthetic lubricin is patented through Cornell Technology Licensing; an Ithaca company, iFyber, is working with researchers to develop the synthetic lubricin therapeutic for humans,” the researchers said.

Lubrication produced in hydrodynamic mode when the knee is moving fast without force is easily available in the pharmaceutical market. Hyaluronic acid (HA), a compound producing the lubricant, is approved by the Food and Drugs Administration (FDA).

However, HA cannot be used in boundary mode, this refers to a state when there is force weighing down on the joint creating friction while running, skipping, kicking and jumping. Lubricin is the lubricant cushioning the knee against force and fastens around the cartilage to protect the knee from any injury in the ''danger'' mode.

The diblock copolymer with the same molecular composition was compared to a random polymer in the study. It was found that random polymers without this specific composition did not lubricate and bind to the cartilage. On the other hand, the diblock copolymer was found to reduce friction around the cartilage in boundary mode, equivalent to the natural lubricin.

“This diblock copolymer is an example of a synthetic polymer with lubrication properties equal to lubricin under boundary mode conditions, suggesting its potential utility as a therapy for joint pathologies like osteoarthritis,’’ the study confirmed.

Knee Injuries When the body stops producing the natural lubricant to protect the knee joints cartilages, it results in injury. Researchers at Cornell University have developed a way to produce lubricin, an important glycoprotein, using a synthetic polymer. Photo courtesy of Shutterstock