Osteoarthritis is a joint disease that occurs when the cartilage (the flexible and slippery tissue that protects the ends of bones in the joints) wears away, causing bones to rub against each other. Common causes of osteoarthritis include aging, sports injuries, and excess body weight. Scientists from Tsinghua University and Shanghai Jiao Tong University have developed nanoparticles that can be injected as lubricant into the knee joint to inhibit the development of osteoarthritis.

The nanoparticles are made of silica coated with a layer of very soft polymer material that can absorb water, becoming slippery. This polymer coating is also loaded with diclofenac sodium, a widely used anti-inflammatory drug that can ease the osteoarthritis symptoms. To demonstrate their therapeutic effect, the nanoparticles were injected into the knees of rats that had their cartilage surgically removed. The rats treated with nanoparticle injection showed less severe tissue damage and better walking ability, compared to untreated rats.

Although this study showed promising results of osteoarthritis treatment, it didn’t compare the nanoparticle injection with knee injections currently used in clinics, such as hyaluronic acid. In addition, the injection had to be performed repetitively, as the nanoparticles can diffuse in several days. One possible future direction is to fabricate artificial cartilage implants with the lubricated polymer coating as a long-term treatment of severe osteoarthritis.

Managing Correspondent: Anqi Zhang

Original journal article: Euryale Ferox Seed‐Inspired Superlubricated Nanoparticles for Treatment of Osteoarthritis. Advanced Functional Materials.

Image Credit: MyArthritisRx