Coronavirus Infection Danger Concept

Scientists have developed a method to prevent deadly infections without antibiotics

Coronavirus Infection Danger Concept

The newly developed method involves applying a layer of zwitterionic material to a device and bonding it to the underlying substrate with UV light. The resulting barrier prevents bacteria and other harmful organic materials from attaching and causing infections.

UCLA researchers have developed 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 get a serious infection, yet nearly 1.7 million Americans do each year, resulting in nearly 100,000 deaths from infection-related complications and $30 billion in direct medical expenses.

According to specialists, medical devices such as catheters, stents, heart valves and pacemakers are the main culprits, accounting 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 the University of California, Los Angeles (UCLA) scientists could help improve the security of these devices while reducing the financial strain on the healthcare system.

The new technique, which has been tested in both laboratory and clinical settings, involves depositing a thin layer of zwitterionic material on the surface of a device and permanently bonding that layer to the underlying substrate using ultraviolet light irradiation. The resulting barrier prevents germs and other potentially hazardous organic materials from adhering to the surface and contaminating humans.

The team’s results have been published in the magazine Advanced materials on May 19, 2022.

Harmful medical devices for microbes

Harmful microbes grow freely on implanted medical devices. A new method of applying a surface coating to medical devices is likely to improve their safety, reducing complications and deaths for patients. Credit: Amir Sheikhi/Penn State

In the lab, researchers applied the surface treatment to several commonly used medical device materials and then tested the modified materials’ resistance 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 showed robust resistance to microorganisms and proteins, which is exactly what we wanted to achieve,” said Richard Kaner, UCLA’s Dr. Myung Ki Hong Professor of Materials Innovation and senior author of the study. “The surfaces have greatly reduced or even prevented the formation of biofilm.

Richard Kaner

Senior author of the study, Richard Kaner. Credit: Reed Hutchinson/UCLA

“And our early clinical results were excellent,” Kaner added.

The clinical study involved 16 long-term urinary catheter users who switched to silicone catheters with the new zwitterionic surface treatment. This modified catheter is the first product made by a company Kaner founded from his lab called SILQ Technologies Corp. and has been approved for use on patients by the Food and Drug Administration.

Ten of the patients described their urinary tract disease using the surface-treated catheter as “much better” or “very much better,” and 13 chose to continue using the new catheter over conventional latex and silicone options after the study period ended.

“A few weeks ago, a patient came to UCLA to thank us for changing her life — something I never thought possible as a materials scientist,” Kaner said. “Her previous catheters would clog after about four days. She was in pain and required repeated medical procedures to replace them. With our surface treatment she now comes every three weeks and her catheters are working perfectly with no crusting or occlusion – a common occurrence with her previous one.”

Such catheter-related urinary tract problems are illustrative of the problems that plague other medical devices, which, once inserted or implanted, can become breeding grounds for bacteria and harmful biofilm growth, said Kaner, a member of the California NanoSystems Institute at UCLA who is also a distinguished professor. chemistry and biochemistry, and materials science and engineering. The pathogenic cells pumped out by these highly resilient biofilms then cause recurrent infections in the body.

In response, medical personnel routinely give strong antibiotics to patients using these devices, a short-term solution that poses a longer-term risk of creating life-threatening, antibiotic-resistant ‘superbug’ infections. The more widely and more frequently antibiotics are prescribed, Kaner said, the more likely bacteria are to develop resistance to them. A landmark 2014 World Health Organization report recognized this 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 have been treatable for decades.” be, kill once again.”

“The great thing about this technology,” Kaner said, “is that it can prevent or minimize the growth of biofilm without the use of antibiotics. It protects patients using medical devices — and thus protects us all — from microbial resistance and the spread of bacteria.” super bacteria.”

The surface treatment’s zwitterion polymers are known to be extremely biocompatible, and they absorb water very well, forming a thin hydration barrier that prevents bacteria, fungi and other organic materials from adhering to surfaces, Kaner said. And, he noted, the technology is highly effective, non-toxic and relatively inexpensive compared to other current surface treatments for medical devices, such as antibiotic or silver coatings.

In addition to its use in medical devices, the surface treatment technique could also have nonmedical applications, Kaner said, potentially extending the life of water treatment devices and improving the performance of lithium-ion batteries.

Funding sources for the study included 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: “An easily scalable, clinically proven antibiofouling zwitterionic surface treatment for implantable medical devices” by Brian McVerry, Alexandra Polasko, Ethan Rao, Reihaneh Haghniaz, Dayong Chen, Na He, Pia Ramos, Joel Hayashi, Paige Curson, Chueh-Yu Wu, Praveen Bandaru, Mackenzie Anderson, Brandon Bui, Aref Sayegh, Shaily Mahendra, Dino Di Carlo, Evgeniy Kreydin, Ali Khademhosseini, Amir Sheikhi and Richard B. Kaner, March 22, 2022, Advanced materials.
DOI: 10.1002/adma.202200254

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