New coating for implants, medical devices cuts infection risk

Infections after hip replacements and from orthopaedic device procedures can be complicated and lead to painful and repeat surgeries, with the chance of ‘superbugs’ leading to fatality.

Now researchers from Flinders University, Swinburne University of Technology and RMIT have developed a new surface coating to protect medical devices from antimicrobial resistance.

The research team created the coating by adding gallium liquid metal to hydroxyapatite for a novel compound with significant long-term antibacterial properties. “Even with sterilisation measures, opportunistic bacteria, including the rise of some resistant to antibacterial drugs, can form on biofilm build-up on contact surfaces of surgical and other devices,” said lead medical biotech researcher Dr Vi-Khanh (‘Khanh’) Truong from the Biomedical Nanoengineering Laboratory (BNL) at Flinders University.

“Even worse, with orthopaedic devices an infection could be almost impossible to treat, particularly if it involves complications with antibiotic resistance,” he said.

The new technique adds to the viability of regular hydroxyapatite-coated metallic implants, which have been known to fail and cause infection and even death in up to 2% of patients, said co-author Dr Andrew Ang, from Swinburne University of Technology, Melbourne.

“Up to half of these infections can lead to further surgery and removal of the device — and this new coating also shows promise in integrating to the patient’s bone.”

The global orthopaedic device market is forecast to rise from more than US$45 billion to $US64 billion by 2026, as the world’s population continues to age.

With further testing, researchers say the technique, which uses plasma spray fabrication, could scale up for commercial applications in the future. Regulatory approvals could be simplified with both hydroxyapatite and gallium derivatives already FDA-approved compounds.

Demand for such applications — including for new-era dental or other implants which attach to bone — should be strong, given no orthopaedic implants have antimicrobial surface modifications at present, Truong said.

“This novel coating is made using an environmentally friendly technology, with no harmful organic solvents used in the process,” he said.

Matthew Flinders Professor Krasimir Vasilev, Director of the Biomedical Nanoengineering Laboratory, said the research group aims to provide clinicians and the biomedical industry with urgently needed new technologies to improve patient wellbeing and save lives.

Image caption: Dr Vi-Khanh (‘Khanh’) Truong. Credit: Flinders University.