Researchers in the UK are exploring the possibility of 3D printing patient-specific silver-based implants to reduce infection and antimicrobial resistance.

3D printed silver
3D printed silver (Image: Wolverhampton University)

Despite advances in invasive surgery and aseptic techniques, the team from the from the Universities of Wolverhampton and Sussex said implant-related infection remains a common complication.

Anti-bacterial silver lining for implants and 3D printed prosthetics

The team reported that 3D printed silver implants and tissue engineering scaffolds provide antibacterial protection and feature complex porous architecture suitable for patient-specific tissue reconstruction.

Dr Arun Arjunan, Reader in Additive Manufacturing of Functional Materials at Wolverhampton University, said: “Millions of people across the world suffer from inflammatory and degenerative diseases associated with bone and joints requiring implants where infection is a serious complication resulting in pain, mortality, prolonged recovery, and antimicrobial resistance. Therefore, reducing the risk of infection associated with tissue implants requires imminent attention, where pure silver offers enormous potential.

“Although the idea of using silver as an antibacterial agent is not necessarily new, this research is the first step towards developing 3D printed silver-based infection resistant porous implants.

“3D printing patient-specific implants featuring silver is challenging due to the high laser energy dissipation, reflection and complex thermo-mechanical behaviour. Additionally, the printability, mechanical performance and microbial resistance of 3D printed silver have not yet been explored.”

In the study, the team fabricated 99.9 per cent pure silver through selective laser melting. The properties of the resulting silver and two fully porous bone scaffolds were investigated to assess the suitability for tissue engineering.

The antimicrobial efficacy of printed silver was tested against Staphylococcus aureus and led to 90 per cent kill in four hours and 99.9 per cent in 14 hours. According to the team, the study also shows that 3D printed silver scaffolds can be used as a cancellous bone replacement due to their comparable strength.

Dr Arjunan said: “While the 3D printed pure silver implants might not offer the required structural strength for replacing cortical bone, it can lend itself to the development of hybrid implants that offer antibacterial efficacy without secondary post-processing."

“This not only reduces the cost of developing fully porous antibacterial bone scaffolds but also accelerates the bench-to-bedside development of patient-specific antibacterial implants,” said Dr Chang Wang from Sussex University. “Though there are many remaining challenges, reducing the use of antibiotics through the development of multifunctional implants is the future of bone reconstruction."

According to Wolverhampton, this study will serve as the basis for developing new functional silver-based biomaterials and alloys that are suitable for infection-resistant total-bone replacement, reducing the reliance on antibiotics and improving patient recovery.

The team’s findings are published in Journal of the Mechanical Behavior of Biomedical Materials.