How this tech could transform joint replacements forever

More than 85,000 hip and knee replacements occur every year in Australia and implant-associated infections remain a critical challenge in orthopaedics. Now a new pioneering material could change everything.

An ageing population and rising rates of joint replacement surgery see more than 85,000 hip and knee replacements occur annually in Australia. This number means the need for durable, infection-resistant implants has never been greater. 

Implant-associated infections remain a critical challenge in orthopaedics. Systemic antibiotics are increasingly ineffective due to resistance, and antibiotic-loaded cements often provide only short-lived protection. Current solutions often rely on antibiotic-loaded materials, which can fail over time and contribute to antimicrobial resistance.

Now, a pioneering material developed at Flinders University is set to transform orthopaedic surgery by tackling two major challenges: infection and implant longevity. The innovation combines silver-gallium (Ag-Ga) liquid metal nanoparticles with a 3D bioceramic scaffold, creating a dual-function platform that promotes bone regeneration while providing sustained antimicrobial protection.

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“This new scaffold significantly reduces bacterial colonisation at implant sites and promotes healthy bone integration,” says Associate Professor Vi-Khanh Truong, lead author of the study published in Advanced Functional Materials.

“We’ve confirmed both antibacterial efficacy and regenerative capability in a physiologically relevant setting.”

The science behind the innovation

This is the first reported instance of integrating liquid metal-based nanomaterials into a load-bearing, bioactive ceramic scaffold. By embedding Ag-Ga nanoparticles into hydroxyapatite - a material already widely used in implants - the team achieved a seamless combination of antimicrobial activity and bone-regenerative function.

“This innovation helps create a new generation of bone repair materials that can prevent infection without relying on antibiotics, while also enhancing tissue integration and healing,” says Professor Krasimir Vasilev, Matthew Flinders Professor of Biomedical Nanoengineering.

The technology has demonstrated effectiveness against clinically significant pathogens, including Staphylococcus aureus, MRSA, and Pseudomonas aeruginosa, which are notoriously difficult to eliminate using conventional antibiotics.

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Expanding possibilities for safer bone repair

The Flinders team sees broad potential for this technology, ranging from antimicrobial bone void fillers that can treat infected fractures and spinal fusions, to next-generation bone cements offering ion-mediated antimicrobial protection. It could also enable patient-specific, 3D-printed scaffolds for complex craniofacial and long bone defects, as well as standalone implantable devices designed for infection-prone environments such as diabetic foot complications and oncology-related bone loss.

“Our technology offers a non-antibiotic, dual-function solution that can dramatically improve surgical outcomes - particularly for high-risk and compromised patients,” adds Associate Professor Truong.

By integrating antimicrobial and regenerative properties into a single material, this Flinders-led innovation offers a promising solution that could redefine standards for orthopaedic implants worldwide.

Acknowledgements:  This research at Flinders University was conducted with experts from Shandong University and partner institutions. Professor Vasilev is funded by a NHMRC Fellowship GNT1194466 and ARC grants DP220103543 and DP250101028.