Antibacterial Performance of TiCaPCON Films Incorporated with Ag, Pt, and Zn: Bactericidal Ions Versus Surface Microgalvanic Interactions

Abstract

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.

Comparison of Different Approaches to Surface Functionalization of Biodegradable Polycaprolactone Scaffolds

“…The spectra were fitted using CasaXPS software after subtracting Shirley-type background. The binding energy (BE) values for all carbon, titanium, and nitrogen environments were taken from the available literature [23,[25][26][27]. The BE scale was calibrated by shifting CH x component to 285.0 eV.…”

Preparation of antibacterial and osteoconductive 3D-printed PLGA/Cu(I)@ZIF-8 nanocomposite scaffolds for infected bone repair

“…The addition of copper into mesoporous bioactive glass scaffolds or Cu-Zn nanoparticles into chitosan/nano-hydroxyapatite scaffolds conferred antibacterial and osteoproliferative properties on the scaffolds [10,33], Jin et al revealed that Zn-implanted titanium had antibacterial effects on E. coli and stimulated the spreading activity, adhesion, ALP activity and extracellular matrix mineralization of rat mesenchymal stem cells [14]. Znmodified TiCaPCON films showed a significantly antibacterial effect against E. coli and S. aureus strains and good osteoconductive characteristics [13]. In our present study, the PLGA/Cu(I)@ZIF-8 scaffolds provided a continuous release of Cu(I) ions even after 24 days of incubation in SBF solution; while ZIF-8 nanoparticles themselves possessed antibacterial activity [15].…”

“…Based on the antibacterial and bone-forming activity of copper, copper coated Ti6Ai4V nails have also been studied to treat implant-related infections [8]. Zinc ions are also known to contribute to antibacterial and osteoconductive effects [9][10][11][12][13][14]. For example, zinc (Zn)-doped mesoporous hydroxyapatite microspheres/ collagen (Zn-MHMs/Coll) scaffolds enhanced osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells and accelerated the formation and healing of bone compared to pure Coll scaffolds or MHMs/ Coll scaffolds [9].…”

Colorimetric and electrochemical detection of pathogens in water using silver ions as a unique probe

“…Silver ions have shown high bactericidal activity by inhibiting DNA and protein synthesis 21 . The antibacterial property of silver ions has already been utilized in topical antiseptics and in coatings for orthopedic implants 22 – 24 . The silver leads to changes in protein structure and inactivation of many enzymes 25 .…”

“…2 These authors contributed equally: Virendra Kumar and Adity Chopra. * email: vkbhalla@imtech.res.in and in coatings for orthopedic implants [22][23][24] . The silver leads to changes in protein structure and inactivation of many enzymes 25 .…”