Antimicrobial and Antibiofilm Properties of Ag-Zn-Hydroxyapatite as Potential Bone Substitute

Bone periprosthetic infections are very frequent in surgical interventions in joint replacements with metallic, ceramic, or polymeric implants. The objective of this work was to evaluate the antimicrobial and antibiofilm properties of hydroxyapatite (HA) of natural origin functionalized with Zn and Ag ions as raw material for the preparation of bone substitutes. Their microbial inhibition capacity was tested by agar diffusion assays on cultures of Pseudomonas aeruginosa PA01, Escherichia coli DH5α, Micrococcus luteus S66, Bacillus subtilis ATCC 6633 and Pseudomonas extremaustralis 2E-UNGS. All microorganisms exhibited inhibition halos indicative of the antimicrobial activity of the Ag-Zn-HA, while different responses were obtained for Ag-HA or Zn-HA. A decrease in P. extremaustralis 2E-UNGS and P. aeruginosa PA01 biofilm development was observed in presence of Ag-Zn-HA. These results show that hydroxyapatite functionalized with silver and zinc ions is a promising material to prevent infections when used as a bone substitute.