Pathogens and other viruses are proven to live longer on metal surfaces. But what if doorknobs and other metal surfaces can instantly kill them?
Engineers from Purdue University have developed a laser treatment method that can possibly turn metal surfaces into an instant bacteria killer just by giving an altered texture than the usual metal surface.
They published their study in the journal Advanced Materials Interfaces in April 2020. This discovery could help break transmission chains of superbugs and infections that result from indirect spread through metal surfaces.
Importance of metal surface disinfection
Bacteria are responsible for diseases such as salmonella, boils, and syphilis that can cause harm to our bodies. Most bacteria can survive long periods on metal surfaces that we usually touch like doorknobs, bathroom fixtures, car keys, etc.
But with the discovery of turning metals from friendly zones to killing fields for bacteria, this could change the transmission of diseases. Using the laser treatment by Purdue University to alter the surface texture of the metal such as copper, the number of bacteria that come in contact and die speeds up dramatically, making it useful for clinical practices.
Copper is often used as a naturally antimicrobial material because of the smooth surface. Scientists before have used nanomaterial coatings to enhance its surface area, however, the coating comes off very easily and were often toxic.
"Copper has been used as an antimicrobial material for centuries. But it typically takes hours for native copper surfaces to kill off bacteria. We developed a one-step laser-texturing technique that effectively enhances the bacteria-killing properties of copper's surface," said Rahim Rahimi, an assistant professor of materials engineering at Purdue.
However, the laser technique is not yet tailored to killing viruses such as the coronavirus because they are much smaller than bacteria.
How laser etching kills bacteria
Purdue engineers use a laser to etch nanoscale grooves into the metal to increase its surface area and enhance the antibiotic properties of the metal. Using this technology does not rub off or hurt the environment as this makes this much sturdier than existing technologies.
Rahimi said that they are not adding anything to the metal-no antibiotics, no spray coating. They created a robust process that selectively generated micron and nanoscale patterns directly onto the targeted surface without changing the material. They are now researching the alloy that is found to have antimicrobial properties.
It is proven that the treated surface has enhanced germ-killing properties that are even resistant to conventional antibiotics such as MRSA.
Making medical implants safer
As medical implants are a vulnerable spot to our body's immune system because they are considered foreigners, an extra measure must be taken to protect these infection-prone areas. Antibiotics are usually used to prevent biofilm formation but it could also make the bacteria antibiotic-resistant overtime.
Luckily, the new laser technique prevents this because of the boost it gives to the antimicrobial nature of the implant surface without the use of antibiotics to slow down the integration of the implant in the body.
Aside from that, etching the surface of the metals with nanoscopic patterns can also render the material hydrophilic which aids healing. It controls inflammation and helps bone cells to reattach more strongly, improve the integration of the implant to the body, and contribute to bone regeneration.
