ITMO, ChelGU and SFU: A minimally invasive method for cleaning urethral catheters

The main articles are:

• Catheters
• Robots in medicine

2023: Building Magnetic Soft Robots

ITMO scientists, together with colleagues from Chelyabinsk State University and Southern Federal University, have proposed a minimally invasive and safe approach for cleaning urethral catheters. It is based on magnetic soft robots that remove biofilms with bacteria with almost 100% efficiency. Moreover, they can be controlled remotely - using a magnetic field. The use of soft robots will prevent the development of infections and avoid the frequent painful procedure for changing catheters. ITMO announced this on November 15, 2023.

People with problems with urination (for example, elderly people with incontinence), as well as patients on inpatient treatment after injuries, are forced to wear urethral catheters - they drain fluid from the bladder. Being in the human body, catheters after some time overgrow with biofilms from different bacteria, which increase the risks of urethritis and other urinary tract diseases. To prevent this from happening, catheters need to be replaced at least once a week. However, this is a rather painful procedure that makes the patient uncomfortable. If the infection does develop, patients are forced to take antibiotics, which can lead to antibiotic resistance.

Scientists from St. Petersburg, Chelyabinsk and Rostov-on-Don have developed a soft magnetic robot that is able to mechanically clean the catheter surface from biofilms, preventing the spread of bacteria. It is a composite consisting of magnetic nanoparticles and an elastomer (highly elastic polymer). Scientists tested seven types of robots - the most effective of them turned out to be in the form of an octogram (eight-pointed star). Due to his difficult form, he is better at his task.

It works like this: the robot is placed inside a product that is in a magnetic installation. Under the action of an alternating magnetic field, the robot begins to rotate and move around the catheter, removing the biofilm from its surface.

We tested the effectiveness of the robot in in vitro experiments: we grew biofilms with bacteria in higher concentrations on catheters than are found in real life. To do this, we used two types of bacteria: Gram-positive (Pseudomonas aeruginosa) and Gram-negative (Staphylococcus aureus). In about a minute, the robot destroyed a three-day culture of bacteria with almost 100% efficiency. We also evaluated the survival of bacteria after catheter cleaning. On average, we managed to achieve about 50-80% of bacterial mortality for all types of robots, - said the authors of the development, engineer of the chemical and biological cluster ITMO Daniil Kladko and ITMO graduate Polina Baburova.

The results of the study in the future will increase the time of wearing the catheter and reduce the risk of infections. The authors of the development suggest that it will be enough to use the robot catheter about once a week to clean. The next step of scientists is to improve the laboratory magnetic installation and conduct experiments on animals. In addition, scientists plan to adapt robots for cleaning and other types of catheterization: venous, stomach (in gastrostomy), tracheal intubation.