Introduction: Device-associated bacterial infections are a major and costly clinical challenge. This project aims to develop a smart new "biomaterial" for implants that helps to protects against infection and inflammation, promotes bone growth, and is biodegradable.
Methods: Pure Mg as a model biodegradable material was coated with gallium doped strontium-phosphate through a chemical conversion process. Gallium was distributed in a graduated manner throughout the strontium-phosphate coating, with a compact structure and a gallium-rich surface. The sample was exposed to Gram-positive Staphylococcus aureus and Gram-negative E. coli - two major strains causing clinical infections, for its effects of antibacterial and bone cells growth promotion.
Results: Ga was distributed in a gradient way throughout the entire strontium-phosphate coating with a compact structure and a gallium-rich surface. The Ga coating protected the underlying Mg from substantial degradation in minimal essential media at physiological conditions over 9 day. The liberated Ga ions from the coatings upon Mg specimens inhibited the growth of Gram-positive Staphylococcus aureus, and Gram-negative Escherichia coli – key strains causing infection and early failure of the surgical implantations in orthopaedics and trauma. More importantly, the gallium dopants displayed minimal interferences with the strontium-phosphate based coating, which boosted osteoblasts and undermined osteoclasts in in vitro co-cultures. This work provides a new strategy to prevent bacterial infection and control the degradation behaviour of Mg-based orthopaedic implants, while preserving osteogenic features of the devices.
Conclusion/Clinical Significance/Potential Commercialization: This work provides a new biocompatible strategy to prevent bacterial infection and control the degradation behaviour of Mg-based orthopaedic implants. The results provides great evidence for the great potential to attract biomaterial industry for further development of orthopaedic Implant.