Metal-on-metal implants have been making headlines in publications such as The New York Times as a result of adverse events associated with them, which include bone and tissue damage. The debris produced by the implants is frequently linked to such problems.
Researchers at the University of Alabama at Birmingham are working to limit such wear by investigating the use of nanodiamond coatings on metal implants. In an early study published in the journal Acta Biomaterialia, the researchers found that the “[n]anostructured diamond coatings improve smoothness and wear characteristics of the metallic component of total hip replacements and increase their longevity.”
The scientists also observed some degree of debris from the nanodiamond coatings and noted the need for future studies to determine its effect on the body. Nevertheless, the researchers expect that the debris from the nanodiamonds to be well tolerated by the body. As the announcement explains:
Based on the way nanodiamonds interact with macrophages in a dish, the study authors suggest that the usual size and concentration of wear debris should cause neither inflammation nor toxicity. The macrophages that engulf smaller nanodiamonds release fewer inflammatory chemicals than those encountering larger particles shed by the metal and polymer surfaces of conventional implants.
“Our results add to the early evidence that nanodiamonds are indeed nontoxic in living cells,” said Vinoy Thomas, Ph.D., research associate in the Department of Physics within the UAB College of Arts & Sciences, and corresponding author of the study. “The next step will be to conduct experiments to confirm where nanodiamond particles of varying sizes and concentrations end up, and if buildup at those destinations is safe.
Press release: Early study suggests nanodiamonds safe for implants
Abstract in Acta Biomaterialia: In vitro studies on the effect of particle size on macrophage responses to nanodiamond wear debris