Optimized Cytocompatibility and Antimicrobial Activity of Octacalcium Phosphate/ε-Polylysine Composite Coating Electrochemically Codeposited on Medical Titanium.

Preventing bacterial infection of bone implants is a major challenge for developing functional biomedical materials at present. With more significant emergence of drug-resistant bacteria, exploration of antimicrobial materials has become increasingly important and urgent. More and more researchers have devoted their work to the study of a kind of antimicrobial material for improving inhibition of drug-resistant bacteria, and other bioproperties as well. In this work, we first introduced ε-polylysine (ε-PL), which possessed a broad antibacterial spectrum and negligible cytotoxicity to the human body, into an octacalcium phosphate (OCP) coating on a titanium surface by electrochemical codeposition (ED). The measurements of the structure and composition of the OCP/ε-PL composite coating demonstrated that ε-PL had succeeded in combining with OCP. The bioactivity assessment of all samples indicated that the OCP/ε-PL composite film had owned good biological mineralization capability. In vitro, it also had better ability to promote cell proliferation and differentiation when the concentration of ε-PL was 10 mg/mL compared with other concentrations. In the meanwhile, the antibacterial test indicated that the ε-PL introduced to OCP was able to markedly improve the antibacterial property against both Gram-positive and Gram-negative bacteria.