Silver Lining for Titanium Implants Reduces Infection Risk
A novel method of coating titanium implants for orthopaedic and trauma surgery promises to reduce infection complications, according to a paper published in Langmuir: The ACS Journal of Fundamental Interface Science.
Infection remains a major complication when implants such as screws and plates are embedded into people during procedures like joint replacement surgery and spinal fusion surgery. Most infections occur because the devices’ titanium implant surfaces have poor antibacterial and osteoinductive properties, despite titanium possessing the highest biocompatibility of all metals.
Assistant Professor Rahim Rahimi at Purdue University has developed a process which immobilises silver onto the implant surfaces of titanium orthopaedic devices to improve their antibacterial properties and cellular integration. The process can be implemented onto many currently utilised metal implant surfaces.
The antibacterial efficacy of laser-nanotextured titanium surfaces with laser-immobilised silver was tested against both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. The surfaces retained efficient and stable antimicrobial properties for more than six days. The laser-nanotextured titanium surfaces also provided a 2.5-fold increase in osseointegration properties compared with a pristine titanium implant surface.
“The first step of the two-step process creates a hierarchical nanostructure onto the titanium implant surface to enhance the bone cells’ attachment,” A/Prof Rahimi said. “The second step immobilises silver with antibacterial properties onto the titanium implant surface.
“The technology allows us to not only immobilise antibacterial silver compounds onto the surface of the titanium implants but also provide a unique surface nanotexturing that allows better settle attachment mineralisation.
“These unique characteristics will allow improving implant outcomes, including less risk of infection and fewer complications like device failure.”
A/Prof Rahimi said the traditional method to address infections caused by implanted orthopaedic devices often utilises antibiotics or other surface modifications that have their own associated complications.
“Long-term antibacterial protection is not possible with these traditional drug coatings because a large portion of the loaded drug is released in a short time,” Rahimi said. “There also is often a mixture of microbes that are found in implant-associated infection; it is essential to choose a bactericidal agent that covers a broad spectrum.”
Source: Purdue University
