"Preventing Bacterial Adhesion on Medical Devices"... GIST-KIST Develops Antibacterial Hydrogel [Science Insight]

Up to 60% Inhibition of Antibiotic-Resistant Bacterial Biofilms
Published in the International Journal Nano Letters

A new antibacterial material technology has been developed to prevent infections caused by bacterial adhesion on the surfaces of medical devices, such as catheters and artificial joints used in hospitals. This surface coating technology not only inhibits biofilm formation by bacteria with high antibiotic resistance but is also safe for human cells.

A joint research team led by Professor Ji-won Seo of the Department of Chemistry at Gwangju Institute of Science and Technology (GIST) and Dr. Jaehong Kim of Korea Institute of Science and Technology (KIST) announced on March 12 that they have developed a multifunctional antibacterial hydrogel that effectively inhibits biofilm formation by antibiotic-resistant bacteria on the surfaces of medical devices. The research findings were published in the international journal Nano Letters.

Schematic of nanostructure and functional changes according to peptoid ratio adjustment. In gelatin hydrogel, the self-assembled structure varies depending on the antimicrobial peptoid conjugation ratio, demonstrating a process where bacterial adhesion and biofilm formation are inhibited and cytotoxicity is minimized under optimal conditions. Provided by the research team

Biofilms: The Key Cause of Medical Device Infections

The surfaces of medical devices used in hospitals, such as catheters, stents, and artificial joints, are highly prone to bacterial adhesion and subsequent biofilm formation. Biofilms are structures where bacteria form communities within self-produced protective barriers, making it difficult for antibiotics to penetrate, and have thus been identified as a major cause of hospital-acquired infections. Once formed, biofilms are challenging to treat, delay patient recovery, and increase the risk of infection spreading within hospitals.

To address these challenges, the research team utilized an artificial protein-like substance called peptoid. Peptoids, which mimic the structure of natural proteins, can be designed to kill bacteria or prevent their attachment to surfaces. The team conjugated peptoids with a gelatin-based hydrogel, employing a self-assembly method that enables the formation of nanostructures within the gel, thereby achieving both antibacterial functionality and safety.

In particular, rather than simply increasing the amount of antibacterial substance, the team optimized the conjugation ratio between gelatin and peptoid to precisely control the distribution structure. As a result, when peptoids were evenly distributed within the gel, bacterial adhesion was significantly reduced while maintaining bactericidal effects, with minimal impact on human cells.

The antibacterial performance was validated through experiments in which Staphylococcus aureus and Pseudomonas aeruginosa were allowed to adhere to glass, silicon, and stainless steel surfaces. Under optimal conditions, the hydrogel reduced biofilm formation by approximately 60 percent for both bacteria compared to conventional methods.

Additionally, the hydrogel was designed so that the antibacterial effect is exerted through direct contact between the hydrogel surface and bacteria, rather than by releasing antimicrobial agents externally. This structural approach further enhances safety for human use.

Research team photo. From left: Professor Ji-won Seo, Department of Chemistry, GIST; Dr. Jaehong Kim and Dr. Ilsu Park, KIST; Master Jaewon Yoon; and PhD student Hee-ung Yoon, Department of Chemistry, GIST. Provided by GIST

The research team explained that this technology can be stably coated onto medical device surfaces, indicating a high potential for practical application in hospital settings. It is expected to help reduce the risk of infection in various medical devices such as catheters and artificial joints, while minimizing the use of antibiotics.

Dr. Jaehong Kim of KIST stated, "This study demonstrates that surface properties can be actively modified simply by adjusting the molecular conjugation ratio. Beyond antibacterial functions, this material platform has the potential to be expanded for various biomaterial surface designs."

Professor Ji-won Seo of GIST remarked, "Developing materials that can suppress the spread of antibiotic-resistant bacteria and biofilms is a critical challenge in clinical practice. This study is significant in that it presents a new surface material strategy that inhibits biofilm formation by combining antibacterial peptoids with hydrogel."

This research was supported by the Ministry of Science and ICT's GIST-InnoCORE (InnoCORE) program, National Research Foundation of Korea's Sejong Fellowship, Regional Innovation Leading Research Center, and Bio-Medical Technology Development Program, among others.

This content was produced with the assistance of AI translation services.