Plastic Material Developed to Repel Bacteria

A new wrap material repels everything that comes into contact with it, including liquids and bacteria. (Georgia Kirkos, McMaster University)

13 Dec. 2019. A Canadian engineering team developed a treated form of common plastic that in lab tests repels liquids and stubborn bacterial films. Researchers from McMaster University in Hamilton, Ontario describe their discovery they call Repel Wrap in today’s issue of the journal ACS Nano (paid subscription required).

The team led by McMaster engineering physicist Leyla Soleymani and mechanical engineering professor Tohid Didar is seeking feasible solutions for health care facilities and homes to prevent the spread of bacteria becoming increasingly resistant to antibiotics. The problem of antimicrobial resistance, notes World Health Organization is global and growing. The organization says new mechanisms of resistance to antibiotics are emerging that threaten our ability to combat infections from pneumonia, tuberculosis, blood poisoning, gonorrhea, and foodborne diseases, particularly those contracted in health care facilities.

The Soleymani and Didar labs study materials for biomedical applications, and in this case are seeking solutions that can be implemented quickly and easily by health care facilities. The researchers based their solutions on common polymer plastics, like those found everyday household and health care uses, such as polyolefins and polystyrene. The team altered the chemical and physical structure of the polymers to create nanoscale ridges in the material’s surface.

The tiny ridges in the Repel Wrap’s surface makes the material hydrophobic so it repels water, blood, and other liquids. “We’re structurally tuning that plastic,” says Soleymani in a university statement released through EurekAlert. “This material gives us something that can be applied to all kinds of things.” Chemical modifications, say the authors, help keep the material flexible, durable, and inexpensive to produce.

The nanoscale ridges in the surface also enable the polymer to repel bacteria, including microbes that form into biofilms, or stubborn bacterial communities, by preventing the bacteria to anchor to the material’s surface. Biofilms are bacteria that connect and expand through a matrix of organic matter. These colonies also stick tightly to surfaces, including medical devices and implants as well as human skin and teeth, making them difficult to treat, because of their persistence and ability to resist conventional antibiotics.

The researchers tested Repel Wrap with two kinds of bacteria known for resistance to antibiotics and that form into biofilms: methicillin-resistant Staphylococcus aureus, or MRSA, and Pseudomonas aeruginosa. MRSA is a gram-poistive bacterium, while Pseudomonas aeruginosa is gram-negative. “Gram” refers to a classification for bacteria where the microbes either retain (gram-positive) or shed (gram-negative) a test stain on their protective cell coatings.

Tests in the lab show Repel Wrap sharply reduces biofilm formation with these bacteria, reducing MRSA biofilms by 87 percent and Pseudomonas aeruginosa colonies by 84 percent. Other tests show samples of the material touched by surfaces contaminated by E. coli bacteria, repel these microbes and remain bacteria-free.

“We can see this technology being used in all kinds of institutional and domestic settings,” notes Didar. “As the world confronts the crisis of anti-microbial resistance, we hope it will become an important part of the anti-bacterial tool box.”

The authors are seeking industry partners to develop commercial applications of the material. Soleymani and Didar tell more about and demonstrate Repel Wrap in this McMaster video.

More from Science & Enterprise:

• Fine Fibers Spun to Deliver Brain Tumor Treatments
• Spray Fiber Process Designed for Wound Bandages
• FDA Tags Biofilm Disruption Device as Breakthrough
• Hydrogel Shown Safe to Repair Heart Damage
• Crispr Deployed for Programmable Smart Hydrogels

*     *     *