A versatile new foam developed by researchers at the University of Georgia could significantly reduce healthcare-associated infections caused by implanted medical devices or drastically improve clean-up efforts after environmental disasters such as an oil spill.

The research, titled “Superhydrophobic and Conductive Foams with Antifouling and Water-Removing Properties,” was published in the January issue of the journal Science. ACS Applied Materials and Interfaces.

Like a spongy Swiss army knife, the porous 3D foam is water-repellent, meaning it’s resistant to blood, microbes and proteins, and exhibits antimicrobial and oil-water-separating properties. Its versatility, functionality and relatively inexpensive manufacturing costs can make it a valuable resource for future clinicians and environmental remediation professionals alike.

“Creating a multifunctional and versatile surface is an extremely challenging task,” said Hitesh Handa, associate professor in the UGA School of Chemical, Materials and Biomedical Engineering. “You may find a surface that is only antimicrobial, or you may find a surface that can only prevent blood from clotting. The ability to produce materials that are agglomerated, microbial and contamination resistant is a significant improvement over current standards.”

The material is a coarse foam with several fillers added: hydrophobic electrically conductive graphene nanoplates and hydrophobic bactericidal copper microparticles. In addition to water repellency, their inclusion created a rough surface that contributed to its high oil holding capacity, and copper, a known toxin to bacterial cells, added antimicrobial properties to the surface itself.

Research on its effectiveness has yielded positive results.

Using E. coli as the test bacteria, the researchers found that the material led to a 99.9% reduction in bacteria compared to a simple polymer. While this does not mean that all bacteria in the solution have been eliminated, it is a significant advance that Handa believes could improve the health outcomes of the more than 500,000 patients who get medical infections from medical implants each year.

“Current medical devices are prone to contamination,” said Handa. “When you insert any medical device into the body, the first thing that sticks to the surface is the proteins, and they act as an adhesive that keeps the blood or bacteria attached. So if we can stop the protein adsorption, half the battle is won.”

In addition, a series of tests demonstrated the material’s high ability to separate water and other oil-based contaminants. By placing a three-dimensional sponge made of this surface into various aqueous mixtures (chloroform, hydrochloric acid, and other organic particles), the researchers were able to demonstrate the sponge’s ability to absorb and remove organic pollutants from the water, as well as kill bacteria. in the water. itself.

On a large scale, the material can be effective in cleaning the environment from oil spills or other similar scenarios.

This idea is based on a phenomenon called the “lotus effect”, which refers to the self-cleaning properties that result from the ultrahydrophobicity exhibited by the lotus flower. It has long been the model for making superhydrophobic surfaces that have proven effective in cleaning, fogging and preventing contamination. However, past design strategies have failed due to a lack of functionality and scalability.

“Versatility is key here,” said Mark Garren, one of the paper’s co-authors and a postdoctoral fellow in Handa’s lab. “It is the multifunctional features that inspire it and then develop it and show all its possibilities.”

In the future, the researchers’ main goal is to apply the surface to medical devices and demonstrate its effectiveness before moving on to animal testing and ultimately human trials, rather than humans. Given less stringent safety standards, the surface may be easier to use in environmental cleaning applications.