TiCaPCON-Supported Pt- and Fe-Based Nanoparticles and Related Antibacterial Activity

Abstract

A rapid increase in the number of antibiotic-resistant bacteria urgently requires the development of new more effective yet safe materials to fight infection. Herein, we uncovered the contribution of different metal nanoparticles (NPs) (Pt, Fe, and their combination) homogeneously distributed over the surface of nanostructured TiCaPCON films in the total antibacterial activity toward eight types of clinically isolated bacterial strains ( Escherichia coli K261, Klebsiella pneumoniae B1079k/17-3, Acinetobacter baumannii B1280A/17, Staphylococcus aureus no. 839, Staphylococcus epidermidis i5189-1, Enterococcus faecium Ya-235: VanA, E. faecium I-237: VanA, and E. coli U20) taking into account various factors that can affect bacterial mechanisms: surface chemistry and phase composition, wettability, ion release, generation of reactive oxygen species (ROS), potential difference and polarity change between NPs and the surrounding matrix, formation of microgalvanic couples on the sample surfaces, and contribution of a passive oxide layer, formed on the surface of films, to general kinetics of the NP dissolution. The results indicated that metal ion implantation and subsequent annealing significantly changed the chemistry of the TiCaPCON film surface. This, in turn, greatly affected the shedding of ions, ROS formation, potential difference between film components, and antibacterial activity. The presence of NPs was critical for ROS generation under UV or daylight irradiation. By eliminating the potential contribution of ions and ROS, we have shown that bacteria can be killed using direct microgalvanic interactions. The possibility of charge redistribution at the interfaces between Pt NPs and TiO 2 (anatase and rutile), TiC, TiN, and TiCN components was demonstrated using density functional theory calculations. The TiCaPCON-supported Pt and Fe NPs were not toxic for lymphocytes and had no effect on the ability of lymphocytes to activate in response to a mitogen. This study provides new insights into understanding and designing of antibacterial yet biologically safe surfaces.

Biodegradable Nanohybrid Materials as Candidates for Self-Sanitizing Filters Aimed at Protection from SARS-CoV-2 in Public Areas

“…The XPS Ti2p 3/2 peak was fitted using three components (Figure 6a): TiC (BE = 455.3 eV, FWHM = 1.2 eV), TiN (BE = 456.6 eV FWHM = 1.8 eV) and TiO 2 (BE = 458.5 eV, FWHM = 1.2 eV), indicating the presence of carbide, nitride and oxide states on the Ti surface. As shown before, the structure of the Ti2p spectrum for a layer deposited in such conditions does not vary with the current values [35,36]. The implantation of Ag ions after the titania deposition led to significant changes of the Ti2p environment.…”

Pristine and Antibiotic-Loaded Nanosheets/Nanoneedles-Based Boron Nitride Films as a Promising Platform to Suppress Bacterial and Fungal Infections

“…A slight change in the bacteria-killing rate after the treatment in NSS can be explained by a change in surface chemistry. For example, the amount of C–O groups at the surface of TiCaPCON films was reported to be higher after immersion in NSS . It is known that bacteria prefer to colonize a solid substrate rather than dwell in a planktonic state.…”

“…For example, the amount of C−O groups at the surface of TiCaPCON films was reported to be higher after immersion in NSS. 58 It is known that bacteria prefer to colonize a solid substrate rather than dwell in a planktonic state. Thus, it is reasonable to assume that bacteria have died because of their physical destruction during their contact with sharp edges of BN nanosheets and nanoneedles.…”

“…To address this important issue, thoughtful and planned experiments should be carried out. A positive example is the recent work by Ponomarev et al 58 in which, by eliminating the potential contribution of bactericidal ions and ROS, it has been demonstrated that bacteria can be killed using direct microgalvanic interactions. To meet safety issues, the right balance between material toxicity and biocompatibility must be maintained.…”

Biomedical Implants with Charge‐Transfer Monitoring and Regulating Abilities

“…The construction of a heterogeneous junction can also regulate the energy band structure of implant materials. A variety of methods have been developed to load metal nanoparticles such as Au, [ 207 ] Pt, [ 208 ] Ag, [ 209 ] Fe, [ 210 ] and Co [ 193 ] to the surface of TiO 2 film. Because the Fermi level of TiO 2 and the metal particles are different, the energy band of TiO 2 will bend and form a potential barrier after contact with the metal particles, namely, the Schottky barrier.…”