A groundbreaking innovation is on the horizon for patients with urinary stents and catheters, as researchers unveil a revolutionary stent coated with antimicrobial fibers that could combat infections and reduce the need for frequent replacements.
Lining medical stents and catheters with hair-like structures called cilia may help keep the implanted medical tubes clean, preventing infection. Researchers have designed a prototype stent lined with these cilia, which can move fluid at speeds of up to 10 millimeters per second when exposed to ultrasound waves.
A stent is a small, mesh-like tube made of metal or plastic used to keep blood vessels open.
It's often implanted during angioplasty procedures to treat blocked or narrowed arteries.
Stents can be balloon-expandable or self-expanding and come in various materials, including stainless steel and cobalt chromium.
They help reduce the risk of further blockages and improve blood flow to the heart or other vital organs.
Urinary stents and catheters are prone to bacterial buildup, which can cause infection and blockages inside the tubes. These microorganisms thrive in the warm, moist environment of the body’s urinary system, making it an ideal breeding ground for bacteria. As a result, experts recommend replacing these devices every three to six months.
Biomedical engineer Francesco Clavica and his colleagues have developed a cleanable stent made of a silicon-based polymer, featuring slanted cilia covering the inner walls of the device. When exposed to ultrasound waves, the cilia vibrate and generate fluid vortices that rotate in opposite directions on either side of each cilium tip. This motion pushes urine and debris towards the bladder.
The design of the cilia-lined stent is inspired by the hair-like structures found in nature, such as those used by baby sea stars to create whorls in the water that pull food in. The researchers have successfully tested their prototype in a laboratory setting, where it cleared crystal clusters and bacteria from the device.
Baby sea stars, also known as juveniles, go through a crucial development stage after hatching from eggs.
During this period, they undergo metamorphosis, transforming into miniature versions of adult sea stars.
They attach themselves to rocks or other surfaces using their tiny tube feet and begin feeding on small prey.
Baby sea stars can regrow lost arms and have a unique ability to regenerate their entire body from a single arm.
This remarkable adaptation allows them to quickly recover from predators or injuries.
While the cilia-lined stents are still in the experimental phase, the technology has great potential for reducing the need for frequent replacements. In the future, these devices may be able to be cleaned at home, making them more accessible to patients worldwide. The researchers plan to test their stents in pigs next and hope that one day they will become a reality.
The development of cilia-lined stents has the potential to significantly reduce the number of urinary stents and catheters that need to be replaced each year. With over 1.5 million devices inserted annually, this could have a major impact on public health. The ability to clean these devices at home without replacing them entirely could also help alleviate the burden on healthcare systems.
The research was published in Ultrasound-activated cilia for biofilm control in indwelling medical devices Proceedings of the National Academies of Sciences Vol. 122, April 28, 2025. doi: 10.1073/pnas.2418938122. The researchers also drew inspiration from a study on starfish larvae published in Nature Physics Vol. 13, April 2017, p. 380. doi: 10.1038/nphys3981.
- sciencenews.org | Lining medical stents with hairlike fuzz could fend off infections
