A laser treatment method was developed that could potentially turn any metal surface into a rapid bacteria killer just by giving the metal’s surface a different texture. The technique allows the surface of copper to immediately kill off superbugs such as MRSA. Copper has been used as an antimicrobial material for centuries but it typically takes hours for native copper surfaces to kill off bacteria. The new one-step laser-texturing technique effectively enhances the bacteria-killing properties of copper’s surface.
The researchers have begun testing the technology on the surfaces of other metals and polymers that are used to reduce risks of bacterial growth and biofilm formation on devices such as orthopedic implants or wearable patches for chronic wounds. Giving implants an antimicrobial surface would prevent the spread of infection and antibiotic resistance because there wouldn’t be a need for antibiotics to kill off bacteria from an implant’s surface.
The technique might apply to metallic alloys that also are known to have antimicrobial properties. Metals such as copper normally have a very smooth surface, which makes it difficult for the metal to kill bacteria by contact. The technique uses a laser to create nanoscale patterns on the metal’s surface. The patterns produce a rugged texture that increases surface area, allowing more opportunity for bacteria to hit the surface and rupture on the spot.
Researchers in the past have used various nanomaterial coatings to enhance the antimicrobial properties of metal surfaces but these coatings are prone to leach off and can be toxic to the environment. The new process selectively generates micron and nanoscale patterns directly onto the targeted surface without altering the bulk of the copper material.
The laser-texturing has a dual effect: The technique not only improves direct contact but also makes a surface more hydrophilic. For orthopedic implants, such a surface allows bone cells to more strongly attach, improving how well the implant integrates with bone.