Polyurethane coatings are used in antibacterial catheters to help prevent infection

Researchers at Brown University have developed a new antibacterial coating for intravascular catheters that could one day help prevent catheter-related blood flow infections, the most common type of hospital infection.
infections are a major burden for hospitals, health care providers, and most patients," said Anita Shukla, an assistant professor of engineering at Brown University and author of a new paper describing the work. "We wanted to develop a coating that would both kill plankplank (free-floating) bacteria and prevent bacteria from being planted on the surface
the
. The preliminary data we have collected suggest that we have something very promising.
In this paper, researchers have shown that polyurethane coatings can be easily applied to a variety of medically relevant surfaces and gradually release a drug called kinofen, which can kill nearly a month of methicillin-resistant Staphylococcus aureus (MRSA) bacteria in laboratory tests. Tests have also shown that the coating prevents the formation of MRSA biofilms, and antibacterial treatment is particularly effective.
the study, published in Frontiers in Cell and Infectious Microbiology, Shukla collaborated with the Eleftherios Mylonakis and Beth Fuchs Laboratories in the Department of Infectious Diseases at Brown Warren Alpert School of Medicine.
"It's the perfect collaboration between medicine and engineering," Shukla said of the partnership. They (Mylonakis and Fuchs) asked us about the types of problems they often have in clinics. As an engineering laboratory focused on developing new drug delivery biomass, we can find engineering solutions to the problems they bring us. The
of this matter is very prominent. In the United States alone, more than 150 million people are implanted with intravascular catheters each year, and 250,000 people are infected with implant-induced infections each year. These infections can be fatal in up to 25 per cent of cases, adding millions of dollars to hospital stays even if successfully treated.
researchers say previous approaches to the problem have had limited success. Other antibacterial coatings tend to fail after up to two weeks, usually because they release the drug too quickly. Other coatings also tend to use traditional antibiotics, raising concerns about long-term antibiotic resistance.
shukla and colleagues used kinofen for their new coating. The drug was originally developed and approved by the U.S. Food and Drug Administration to treat arthritis, but studies by Mylonakis, Fuchs and others have shown that it is also very effective in killing methicillin-resistant Staphylococcus aureus and other dangerous microorganisms. In addition, the way it works makes it difficult for bacteria to form a natural resistance. Kinofen has never been used in coating technology before.
to make the coating, the researchers dissolved polyurethane and kinofen in a solution and placed it on a catheter. The solvent is then evaporated, leaving a stretchable but durable polymer coating. Mechanical tests have shown that the coating can be stretched up to 500% without breaking.
to test the effectiveness of the coating, the researchers placed the coating catheters on solutions and agar plates resistant to the growth of methicillin Staphylococcus aureus. Experiments have shown that the coating inhibits MRSA growth for up to 26 days, depending on the initial concentration of kinofen used in the coating. The researchers also used bioluminescence imaging to look for signs of biofilm formation. These experiments have shown that the coating can prevent traces of any biofilm. For comparison, the researchers also tested a catheter fitted with a more traditional antibiotic that is very effective against free-floating methicillin-resistant Staphylococcus aureus, but has not proven to prevent biofilm formation.
Shukla said: "Biofilms have an effective way of avoiding antibiotics, and the formation of bacterial biofilms makes drug treatment thousands of times more difficult than plankton. In fact, it is important that these coatings prevent the formation of biofilms in the first part.
Shukla said preliminary tests of toxicity in the lab showed no adverse effects on human blood or liver cells, but more tests were needed before the coating could be ready for use in patients. The fact that both coating components have been approved by the FDA for other uses should speed up the approval process for in vivo trials.