Graphene spike mat uses ordinary fridge magnet technology to fight antibiotic resistance

Graphene’s powerful antibacterial properties make it a potential breakthrough in the fight against antibiotic-resistant bacteria. However, until now there has been no efficient way to control these properties and therefore no way to harness its potential in the medical field.

Now researchers at Chalmers University of Technology in Sweden have solved this problem using the same technology used in common refrigerator magnets, resulting in an ultra-thin, acupuncture-like surface that can act as a coating for catheters and implants, killing 99.99% of bacteria on the surface.

Healthcare-associated infections are a widespread problem worldwide, causing great suffering, rising healthcare costs and an increasing risk of growing antibiotic resistance. Most infections occur in association with the use of a variety of medical technology products, such as catheters, artificial hips and knees, and dental implants, where bacteria can enter the body through foreign surfaces.

Researchers at Chalmers University of Technology have been investigating how graphene, an atomically thin, two-dimensional graphitic material, can contribute to the fight against antibiotic resistance and infections in medicine.

The team previously showed how vertical graphene flakes prevent bacteria from adhering to substrates – instead, the bacteria are chopped up and killed on the sharp flakes.

“We are developing ultra-thin graphene-based antibacterial materials that can be applied to any surface, including biomedical devices, surgical surfaces and implants, to eliminate bacteria.

“Graphene prevents bacteria from physically attaching to surfaces, so an added benefit is that there is no risk of increased antibiotic resistance, unlike other chemical alternatives such as antibiotics,” said Ivan Mijakovic, professor of systems biology at Chalmers University of Technology and one of the authors of the recently published study.

Kills 99.99% of bacteria on surfaces

But the researchers face a challenge: although they can demonstrate its germicidal properties in the lab, they have not yet been able to control the orientation of the graphene flakes, and as a result, have not been able to apply the material to the surfaces of medical devices for clinical use.

Until now, graphene’s germicidal properties could only be controlled in one specific direction – the flow direction in manufacturing processes – but researchers at Chalmers University have made a promising breakthrough that could lead to practical applications in medicine and beyond.

“We’ve found a way to control the effect of graphene in several different directions, and with a very high level of uniformity. This new orientation method allows us to integrate graphene nanoplates onto the surface of medical plastics, creating an antibacterial surface that kills 99.99% of bacteria that try to attach to it.”

“This allows for much greater flexibility when using graphene to make bacteria-killing medical devices,” said Roland Kadar, professor of rheology at Chalmers University of Technology.

Controlling the magnetic field delivers unprecedented efficiency

By arranging the geomagnets in a circular configuration and aligning the magnetic field within the array in a straight line, the researchers were able to induce uniform orientation of the graphene, achieving extremely high bactericidal effects on surfaces of any shape.

The method, described in the journal Advanced Functional Materials, is called “Halbach array” and allows graphene to align in a strong, unidirectional manner by strengthening and homogenizing the magnetic field inside the magnet array while weakening the magnetic field on the opposite side – a technique similar to that found in refrigerator magnets.

“This is the first time that the Halbach alignment method has been used to orient graphene in a polymer nanocomposite. Now that we have results, of course we want to introduce these graphene plates into the medical sector to reduce the number of healthcare-associated infections, alleviate patient suffering and combat antibiotic resistance,” says Vinny Guy, researcher in rheology and soft matter processing at Chalmers University of Technology.

This new orientation technique also shows great potential in other areas, such as batteries, supercapacitors, sensors and durable, water-resistant packaging materials.

“Given the broad implications for these fields, this method truly opens new horizons in materials configuration and provides a powerful tool for successfully designing and customizing nanostructures that mimic the complex structures found in natural systems,” Kadar said.