When you receive an implant, such as a hip replacement, there is a real risk of developing an infection at the implant site. But new research suggests that covering them with gold nanorods, which bacteria fry, can prevent that from happening.
Bacterial infections at the site of recently placed implants can be very serious and can lead to complications such as weakening of the bond between the implant and the bone. If this occurs, subsequent surgery is often required to prevent premature failure of the implant.
Many research institutions are working to develop antibiotic coatings for implants to help remove them from their initial susceptibility to infection, but some of these materials may Some release a material payload continuously. This indiscriminate use of drugs can cause bacteria to develop resistance to the drugs, making antibiotics less effective.
That’s where gold nanorods come in.
Developed by scientists at Chalmers University of Technology in Sweden, this tiny object can be easily applied to the surface of an implant and has already been laboratory tested on glass surfaces. The rods, when applied, are very widely spaced from each other and only cover about 11% of the total underlying material in total.
Nanorods remain inert unless exposed to near-infrared radiation. But when exposed to it, the electrons in the outer layer start moving. This reaction generates heat, which kills microorganisms on the surface. For implants, the light is emitted from the outside and passes through the skin and tissue until it reaches the surface of the implant.
Importantly, the heating effect is sufficiently localized that it has little effect on surrounding tissue. That being said, some tissue cells immediately adjacent to the rod may be destroyed. But scientists believe this is not a problem because the small number of affected cells are quickly regenerated in the body.
“The trick is to adjust the size of the rods,” says Professor Martin Anderson, who led the study with PhD student Maya Usitaro. “If you make it any smaller or any larger, you’ll absorb light at the wrong wavelength. We want the absorbed light to penetrate better into the skin and tissue.”
Furthermore, it is also important to control the intensity of near-infrared rays, which corresponds to the amount of heat generated. When the temperature of the nanorods exceeds 120 °C (248 °F), the objects permanently transform into spheres that do not absorb light.
If the technology is further developed, it is hoped that regular near-infrared radiation could be used to prevent infections in the weeks following surgery. The research is described in a paper recently published in the journal Nano Letters.
Source: Chalmers University of Technology
