UCLA researchers have created a new surface treatment that prevents bacteria from sticking to medical devices such as catheters and stents.
A hospital or medical clinic may seem like the last place you’d expect to get a bad infection, but nearly 1.7 million Americans do it each year, resulting in nearly 100,000 deaths from infection-related complications and $ 30 billion. direct medical expenses.
According to experts, the main culprit is medical equipment such as catheters, stents, heart valves and pacemakers, which account for two-thirds of all infections. Their surfaces are often covered with dangerous bacterial films. However, a unique surface treatment developed by a team led by scientists from the University of California, Los Angeles (UCLA) can help improve the safety of these devices while reducing financial strain on the healthcare system.
The new technique, which has been tested in both laboratory and clinical conditions, involves applying a thin coating of zwitterionic material to the surface of the device and permanently bonding this layer to the base substrate using ultraviolet radiation. The resulting barrier prevents microbes and other potentially hazardous organic materials from adhering to the surface and infecting humans.
The results of the team were published in the magazine Advanced materials on May 19, 2022
In the laboratory, the researchers applied the surface treatment of several commonly used materials for medical devices, and then tested the resistance of the modified materials to various types of bacteria, fungi and proteins. They found that the treatment reduced biofilm growth by more than 80% – and in some cases up to 93%, depending on the microbial strain.
“The modified surfaces have shown stable resistance to microorganisms and proteins, which is exactly what we were trying to achieve,” said Richard Kanner, Dr. Mung Ki Hong of UCLA, Professor of Materials Innovation and senior author of the study. “Surfaces significantly reduce or even prevent the formation of biofilm.
“And our early clinical results are outstanding,” Kanner added.
The clinical trial included 16 long-term users of urinary catheters who switched to silicone catheters with the new zwitterionic surface treatment. This modified catheter is the first product manufactured by Kaner, a company founded by its laboratory called SILQ Technologies Corp., and approved for use in patients by the Food and Drug Administration.
Ten patients described their urinary tract condition using a surface-treated catheter as “much better” or “much better,” and 13 chose to continue using the new catheter over conventional latex and silicone options after the end of the period. of the study.
“A patient came to UCLA a few weeks ago to thank us for changing her life – something I never thought possible as a materials scientist,” Kanner said. “Her previous catheters would be blocked in about four days. She was in pain and needed repeated medical procedures to replace them. With our surface treatment, it now comes every three weeks and its catheters work perfectly without inlay or clogging – a common occurrence with previous ones. ”
Such catheter-related urinary tract problems are illustrative of problems affecting other medical devices that, once placed or implanted, can become a breeding ground for bacteria and harmful biofilm growth, said Kanner, a member of the California Institute. for nanosystems at UCLA, who is also a distinguished professor of chemistry and biochemistry, as well as materials science and engineering. Pathogenic cells pumped by these highly resistant biofilms then cause recurrent infections in the body.
In response, medical staff routinely give strong antibiotics to patients using these devices, a short-term solution that poses a long-term risk of developing life-threatening, antibiotic-resistant “superbacterial” infections. The more widely and often antibiotics are prescribed, Kanner said, the more likely bacteria are to develop resistance to them. A landmark 2014 report by the World Health Organization recognizes the overuse of antibiotics as an immediate threat to public health, with officials calling for an aggressive response to prevent a “post-antibiotic era in which common infections and minor injuries that were treatable by decades, I can kill again. “
“The beauty of this technology,” Kanner said, “is that it can prevent or minimize biofilm growth without the use of antibiotics.” It protects patients using medical devices – and therefore protects us all – against microbial resistance and the spread of superbugs.
Zwitterionic surface treatment polymers are known to be extremely biocompatible and absorb water very tightly, forming a thin hydration barrier that prevents bacteria, fungi and other organic materials from sticking to surfaces, Kanner said. And, he noted, the technology is highly efficient, non-toxic and relatively low cost compared to other current surface treatments for medical devices, such as antibiotic or silver coatings.
In addition to its use in medical devices, surface treatment techniques can have non-medical applications, Kanner said, potentially extending the life of water purification devices and improving lithium-ion battery performance.
Funding sources for the study include the National Institutes of Health, the National Science Foundation, the Canadian Institutes of Health Research, SILQ Technologies Corp. and the UCLA Sustainability Grand Challenge.
Reference: “Easily Scalable, Clinically Demonstrated, Antibiotic Zwitterionic Surface Treatment for Implantable Medical Devices” by Brian McVerry, Alexandra Polasco, Ethan Rao, Reyhane Hagniaz, Dayong Chen, Na He, Pia Ramos, Joel Hayashi Pye , Mackenzie Anderson, Brandon Bui, Aref Sayeh, Sheila Mahendra, Dino Di Carlo, Eugene Kreidin, Ali Hademhoseyni, Amir Sheikh and Richard B. Kanner, March 22, 2022, Advanced materials.
DOI: 10.1002 / adma.202200254