The yellow cast of an innovative new catheter design created by a 3D printer is shown on the left along with the finished prototype on the right. The markings indicate the urinary duct (U), the flexible inner wall (i.w.) between the urinary duct and the inflation channel (I) and the stiff exterior wall (e.w.). Pressurizing the narrow chamber deforms the main channel, dislodging biofilm so that it can be flushed from the tube.
Urinary catheters are notorious hosts for bacterial colonies, forming biofilms that resist easy removal. These biofilms also tend to welcome pathogenic bacteria to settle nearby, causing dangerous infections and plugging the catheter lumen. Now researchers at Duke University have created a new catheter that can be easily cleansed of biofilms formed on its interior with a bit of pressure.
Previously, preventing bacterial infection within urinary catheters was thought to require anti-microbial coatings, but those can lead the bacteria to evolve into antibiotic resistant strains, creating an even bigger problem. The catheter developed at Duke instead uses physical forces to dislodge bacterial biofilms which are then flushed out along with the urine.
The silicone catheter has an additional channel within it that can be expanded by pumping air or a liquid through it. The expansion makes biofilms experience considerable mechanical forces that cause biofilms to lose their grip and pop right off. A nice flush of the catheter ferries these biofilms out and keeps the urinary channel clear. The expansion of the inner pressure channel does not widen the catheter’s external caliber, preventing any discomfort to the patient. While the first prototype has shown the ability to remove 90% of biofilms grown in the catheter’s interior, the team has plans to modify the device’s design to help make sure everything is removed.
Here’s a video of the new catheter in action:
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