Nanodiamonds may be an artificial joint's best friend

Compared to conventional metal and polymer implants, artificial joints coated with a nanodiamond material not only would offer a marked reduction in wear debris, but should prevent inflammation and toxicity that results when the body's immune system attacks the debris caused by wear, suggest researchers at the University of Alabama at Birmingham (UAB).

With conventional implants, joint wear generates particles of metal and polymer that are attacked by immmune cells called macrophages, which then work to eliminate the debris. As the macrophages do their job, however, the cells secrete chemicals that cause swelling and pain.

Based on research at UAB that studied how nanodiamonds would interact with macrophages, researchers concluded that nanodiamond debris, which consists of much smaller particles than debris from metal or polymer implants, would release less inflammatory chemicals when ungulfed by the immune cells. The researchers published the results of their study in the journal Acta Biomaterialia.

The next step for the researchers is to determine where the nanodiamond particles end up in the body, and to confirm that those destinations are safe, reported Vinoy Thomas, Ph.D., one of the authors of the study and a research associate in the physics department at UAB's College of Arts & Sciences.

A previous study showed that 60 percent of a nanodiamond material injected into mice wound up in the liver within 30 minutes. The rest went to the spleen and lungs.

For more on the research, visit "Early study suggests nanodiamonds safe for implants," on the UAB News Web site.