It is very important to prevent bacterial colonization at the early postoperative stages. There are four major strategies and their corresponding types of antibacterial surfaces specifically designed to fight infection: bactericide release, anti-adhesion, pH-sensitive, and contact-killing. Herein, we aimed at determining the antibacterial efficiency of different types of bactericidal ions and revealing the possible contribution of surface microgalvanic effects arising from a potential difference on heterogeneous surfaces. We considered five types of TiCaPCON films, with Ag, Zn, Pt, Ag + Zn, and Pt + Zn nanoparticles (NPs) on their surface. The Ag-modified film demonstrated a pronounced antibacterial effect at a very low Ag ion concentration of 0.11 ppb in physiological solution that was achieved already after 3 h of immersion in Escherichia coli ( E. coli) bacterial culture. The Zn-containing sample also showed a noticeable antibacterial effect against E. coli and Staphylococcus aureus ( S. aureus) strains, wherein the concentration of Zn ions was 2 orders of magnitude higher (15 ppb) compared with the Ag ions. The presence of Ag NPs accelerated the leaching of Zn ion out of the TiCaPCON-Ag-Zn film, but no synergistic effect of the simultaneous presence of the two bactericidal components was observed. After the incubation of the samples with Ag, Zn, and Ag + Zn NPs in E. coli and S. aureus suspensions for 24 and 8 h, respectively, all bacterial cells were completely inactivated. The Pt-containing film showed a very low Pt ion release, and therefore the contribution of this type of ions to the total bactericidal effect could be neglected. The results of the electrochemical studies and Kelvin probe force microscopy indicated that microgalvanic couples were formed between the Pt NPs and the TiCaPCON film, but no noticeable antibacterial effect against either E. coli or S. aureus strains was observed. All ion-modified samples provided good osteoblastic cell attachment, spreading, and proliferation and therefore were concluded to be nontoxic for cells. In addition, the TiCaPCON films with Ag, Pt, and Zn NPs on their surface demonstrated good osteoconductive characteristics.

Brno University of Technology Technicka 2896 2 616 69 Brno Czech Republic

CEITEC Brno University of Technology Technická 3058 10 61600 Brno Czech Republic

CRISMAT UMR 6508 CNRS ENSICAEN 6Bd Marechal Juin 14050 Caen France

N N Blokhin National Medical Research Center of Oncology of Ministry of Health of Russia Kashirskoe shosse 24 Moscow 115478 Russia

National Research University of Electronic Technology MIET Shokin Square 1 Zelenograd Moscow Region 124498 Russia

National University of Science and Technology MISIS Leninsky prospect 4 Moscow 119049 Russia

State Research Center for Applied Microbiology and Biotechnology Obolensk Moscow Region 142279 Russia

References provided by Crossref.org

Comparison of Different Approaches to Surface Functionalization of Biodegradable Polycaprolactone Scaffolds