FOR IMMEDIATE RELEASE

ACS News Service Weekly PressPac: January 12, 2022

An ice-inspired lubricant improves osteoarthritis symptoms in rats

“Ice-Inspired Lubricated Drug Delivery Particles from Microfluidic Electrospray for Osteoarthritis Treatment”
ACS Nano

With the Winter Olympics approaching, many people will soon be tuning in to watch events that take place on ice, such as figure skating, speed skating and ice hockey. An ultrathin, super-lubricating layer of water on the ice’s surface is essential for skaters’ graceful glides. Inspired by this surface, researchers reporting in ACS Nano have developed a treatment for osteoarthritis that enhances lubrication and reduces friction and inflammation in a rat model of the disease.

Osteoarthritis, a chronic disease common in middle-aged and older people, is characterized by persistent inflammation and degeneration of cartilage in the joints. Anti-inflammatory drugs can help relieve pain and inflammation, but long-term use can reduce their effectiveness or cause gastrointestinal problems. Corticosteroids injected directly into the joint provide temporary relief, but frequent treatments can sometimes damage the cartilage. Yuanjin Zhao and colleagues wanted to develop drug delivery particles that, when injected into a joint, could safely enhance lubrication and decrease inflammation.

The researchers based their particles on hyaluronic acid (HA), a natural polysaccharide already used as a lubricant to treat osteoarthritis, but this molecule degrades rapidly inside the body. So the researchers used a microfluidic device to make tiny methacrylate anhydride-HA gel particles, which they reasoned might be stronger and persist longer in the body than an HA solution. To enhance the lubrication of the particles, the team coated them with 2-methylacryloyloxyethyl phosphorylcholine (MPC), which has positively and negatively charged chemical groups that attract a thin layer of water, similar to ice. In addition, the particles’ pores were loaded with an anti-inflammatory drug, which could be slowly and continuously released. The researchers then injected drug-loaded HA-MPC particles into the knee joints of rats with early-stage osteoarthritis. The joints of treated rats were more lubricated and had less cartilage destruction, joint friction and inflammation compared with a control group. The treated rats also expressed higher levels of collagen II and aggrecan, two markers of healthy cartilage. The particles have great potential for clinical applications, but first they must undergo additional animal and biosafety tests, the researchers say.

The authors acknowledge funding from the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Natural Science Foundation of Jiangsu and the Shenzhen Fundamental Research Program.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive press releases from the American Chemical Society, contact newsroom@acs.org.

###

Note: ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies.

Close-up of ice skater's skates moving over a frozen sheet of ice
The thin layer of water that allows skaters to glide across the ice inspired a lubricating treatment for osteoarthritis.
Credit: l i g h t p o e t/Shutterstock.com