In their study, published in the scientific journal ACS Nano, the team showed that by using a laser to heat a thin sheet of carbon atoms — called graphene — placed on the surface of an implant, they could kill more than 98 percent of methicillin-resistant Staphylococcus aureus (MRSA) bacteria, which are a major cause of hospital-acquired infections.
What’s more, by finely controlling the intensity of the laser, they were able to kill the bacteria without damaging the underlying tissue, making it a promising approach for preventing infections in implants such as artificial joints, heart valves, stents, and catheters.
Graphene is a material made up of a single layer of carbon atoms arranged in a hexagonal lattice and has exceptional properties, such as being extremely strong, flexible, lightweight, and conductive of heat and electricity. For these reasons, graphene has been extensively studied for a wide range of applications, including electronics, energy storage, and biomedical devices.
The NTU Singapore team, led by Associate Professor Javier García de Abajo, used graphene because of its excellent thermal properties and its ability to convert light energy into heat, which allows it to rapidly kill bacteria.
When a laser is shone onto graphene, the material rapidly heats up, creating a localized zone of high temperature that is lethal to bacteria. In their experiments, the researchers found that the laser-induced graphene could kill MRSA bacteria in just a few seconds.
In addition to killing bacteria, the laser-induced graphene also prevented the bacteria from forming a biofilm, which is a thin, slimy layer of bacteria, yeast, and other microorganisms that can grow on surfaces in contact with water.
Laser-induced graphene is a promising approach for preventing infections in implants. It is effective in killing bacteria and preventing the formation of biofilm without damaging the underlying tissue.
Biofilms are a major problem in healthcare, as they can make it much harder to treat infections and can lead to chronic conditions. They are also a major cause of device-associated infections, which are infections that occur in patients who have medical devices implanted in their bodies.
"Device-associated infections are a serious concern, as they can lead to sepsis and other life-threatening conditions," explains García de Abajo. "It is essential to develop new strategies to prevent these infections, and we believe that laser-induced graphene could be a promising solution."
The researchers plan to further develop their technology and to work towards bringing it to the market. They also believe that laser-induced graphene could have applications beyond healthcare, such as in the food industry or in water purification systems.
