Antimicrobial Titanium Surface via Click-Immobilization of Peptide and Its in Vitro/Vivo Activity

The use of antimicrobial peptides (AMPs)-functionalized titanium implants is an efficient method for preventing bacterial infection. However, the attachment of AMPs to the surface of titanium implants remains a challenge. In this study, a clickable titanium surface was developed by using a silane coupling agent with an alkynyl group. The antimicrobial titanium implant was then constructed through the reaction between the clickable surface and azido-AMPs (PEG-HHC36:N-3 -PEG(12)-KRVVWKVVWRR) via click chemistry of Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC). Such an antimicrobial titanium implant, with an AMP density of 897.4 +/- 67.3 ng/cm(2) (2.5 +/- 0.2 molecules per nm(2)) on the surface, exhibited good and stable antimicrobial activity, inhibited 90.2% of Staphylococcus aureus and 88.1% of Escherichia coli after 2.5 h of incubation, and even inhibited 69.5% of Staphylococcus aureus after 4 days of degradation. The CCK-8 assay indicated that the antimicrobial titanium implant exhibited negligible cytotoxicity to mouse bone mesenchymal stem cells. In vivo assay illustrated that this implant could kill 78.8% of Staphylococcus aureus after 7 days. This method has great potential for the preparation of antimicrobial titanium implants and the prevention of infections in the clinic.