New Patent Recognizes Antibacterial Effects of Silicon Nitride

SINTX Technologies, Inc., a Salt Lake City, Utah-based maker of silicon nitride ceramics for industrial and biomedical applications, including medical devices has announced that it has been awarded a U.S. patent for antibacterial applications of the material. The company formed after Amedica sold its spine device business to CTL Medical (now CTL Amedica) in 2018 and changed the company’s name to SINTX Technologies, Inc. SINTX supplies the ceramic to CTL Amedica for use in its interbody spacers.

The patent issued by the United States Patent and Trademark Office covers “antibacterial biomedical implants and associated materials.” CTL Amedica markets its silicon nitride interbody spacers having bacteriostatic properties and biofilm inhibition, based on in vitro and in vivo mouse studies. To date, no studies examining infection rates in patients with silicon nitride implants have been published.

SINTX President and CEO Sonny Bal, M.D., Ph.D., J.D. told OTW that the company has “data showing a lower incidence of infection with silicon nitride implants when compared to infection rates cited in the literature, and we have cited that data in a number of our clinical publications… The in vitro and animal data along with studies related to the surface chemistry of silicon nitride are sufficient to make the claim that our material resists bacteria.” Neither SINTX, nor CTL Amedica claim that the silicon nitride-based ceramic devices reduce infection rates, as “to show a statistically meaningful decrease in infection risk, we would have to conduct a very large study,” said Bal.

The patent also covers the addition of silicon nitride to other biomaterials, such as PEEK (Polyether ether ketone) and titanium. Medical devices made using these combinations are not yet available, but SINTX expects to launch the composites early in 2021, starting with a silicon nitride and PEEK blend. The company also produces silicon nitride in forms that can be integrated into fabrics.

Earlier in October SINTX announced that it had developed a “catch-and-kill” mask that will inactivate respiratory viruses and bacteria. The masks are not yet available as the process of integrating the silicon nitride into the woven or non-woven mask fibers needs further optimization, reported the company. A study published in September has shown that the virus that causes COVID-19 can be inhibited by silicon nitride, though is not included in the current patent.