New research from the Queensland University of Technology (QUT) has uncovered a promising new technique in preventing persistent infections after hip-replacement surgery.
QUT researchers Dr Phong Tran and Dr Hien Tran developed a unique, anti-microbial coating through combining polydopamine, an adhesive polymer derived from the neurotransmitter dopamine, with the anti-bacterial agent silver and a biofilm rupturing agent.
Dr Phong Tran told Aged Care News that the unique end product was shown by their research to disrupt the ability of common infections to proliferate around titanium structures commonly used in prosthetic hips.
“Our results showed that the treatment was effective in eradicating the bacteria, Staphylococcus aureus (‘golden staph’) biofilms grown on a titanium substrate,” he said.
“During the process of lysing (breaking down the outer coating of the cell) the biofilm, the soluble silver was reduced to non-soluble silver nanoparticles which, with the self-adhering polydopamine, formed an antimicrobial coating attached to the treated surface.
“The antimicrobial coating then would protect the implant from being re-infected.”
The finding of this research may help future hip-replacement recipients avoid repeat surgeries and excessive use of antibiotic medications.
“A small percentage of the more than 50,000 hip replacement surgeries in Australia each year become infected and, while some implants can be retained by implant-retention surgery, they can easily get reinfected and need to be replaced,” Tran said.
“Implant-retention surgery aims to eradicate the bacterial biofilms on the implants and on surrounding tissues. This is often associated with extensive debridement and long-term antibiotic therapy.”
However, researchers are still some time away from implementing such technology in live research subjects.
Although the study provided promising results, Tran noted that the coating proved to be less than perfect in more complex assays.
“When we tested our treated surfaces in complex environments having both mammalian and bacterial cells present, they were not as effective in killing bacteria,” Tran said.
“Our work also indicates the importance of using a relevant testing environment in future antimicrobial biomaterials research to optimise antimicrobial performance.”
Biofilms are communities of bacteria that protect themselves with a sticky outer layer that adheres to a surface, such as a prosthetic hip.
Around 1 per cent of hip replacement surgeries are said to result in infection, with such infections a major contributor to the need for replacement surgeries.
Research contributing to a reduced need for revision surgery is welcomed as repeat exposure to general anaesthesic presents greater risks in the over-65 cohort.
Common co-morbities present in the older population, including increased blood pressure, clogged arteries, and heart or lung disease, make complications during surgeries involving general anaesthesia more common.
Those living with a cognitive condition, such as dementia, may be at a higher risk of developing a condition called ‘post-operative cognitive dysfunction’ (POCD) after surgery.
POCD describes instances of reduced cognitive dysfunction after a surgery involving general anaesthesia.
Whilst it is rare in patients under 40, it is estimated to be present in up to 10 per cent of Australian patients aged over 65 at the three month mark post any surgery.