Antimicrobial Coating for Medical Implants Offers Non-Drug Based Approach to Prevent Surgical Infections

Non-elective surgeries, which are increasingly frequent, often involve patients with pre-existing medical conditions that heighten their risk of post-surgical infections. One challenge in these scenarios is that patients may not immediately detect an infection stemming from their surgery. Current medical devices often utilize silver coatings as an infection deterrent. However, prolonged exposure to high levels of silver can lead to its accumulation in the body. Furthermore, silver coatings are unsuitable for certain load-bearing or supportive implanted devices. While drugs exist to combat infections, they are limited by their effective duration and potential side effects. Now, new research has led to the development of antibacterial material for internal medical devices that could help prevent infections.

A collaborative effort between Colorado State University (CSU, Fort Collins, CO, USA) and the University of St. Andrews (St. Andrews, Scotland) has resulted in an innovative and versatile antimicrobial material suitable for coating internal medical devices. This development combines prior research from both institutions on metal-organic frameworks. These are three-dimensional crystalline structures composed of metals and linkers, characterized by their porous nature and stability in water. The collaborative research successfully merged two distinct frameworks into a single, thin-film membrane capable of gradually emitting nitric oxide, a naturally occurring antimicrobial agent in the human body known for its prolonged and effective bacterial and fungal eradication capabilities.

For developing the thin-film material, the team experimented with three different membranes, each featuring varying combinations of metal-organic frameworks. Utilizing a novel cryogenic imaging technique, they were able to ascertain optimal ratios and methods for the sustained release of nitric oxide. Initial findings are encouraging, showing the material's effectiveness against common bacteria such as Staphylococcus and Escherichia coli. Impressively, even a minimal concentration of this material demonstrated significant antibacterial potency. This is a positive indicator of its practical application beyond laboratory settings. The research team is now focusing on refining the delivery mechanisms of this material and exploring its transition from thin-film form to a more universally applicable format. This advancement holds the potential to be effectively integrated into a wide range of medical devices, including pacemakers, enhancing patient safety and care in surgical and other medical contexts.

“Any implantable device is a candidate for this technology, and we think it will actually be inexpensive to manufacture,” said Chemistry Professor Melissa Reynolds, who led the work at CSU. “We haven’t found any limitations yet and are looking forward to working with companies to develop this approach.”

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Colorado State University
University of St. Andrews