Endogenous electric field as a bridge for antibacterial ion transport from implant to bacteria

Abstract

Tissue implant-related infections are among the most serious complications after surgical implantation, including orthopedics and dentistry. Implants with antibacterial ion release systems are efficient and economical antibiotic substitutes to fight against bacterial infections. However, the excessive amount of released antibacterial ions may cause biological toxicity while killing bacteria. This raises a fundamental issue on how to properly control the amounts of ions and their efficacy. Here, we develop low-dose antibacterial ions-incorporated ferroelectric implants (copper-doped potassium sodium niobate, K 0.5 Na 0.5 NbO 3 -Cu, KNNCu) whose surface potential can be tuned via external polarization. The released Cu 2+ ions can be targeted to bacteria via endogenous electric field (EEF) between KNNCu implants and negatively charged bacteria. Intriguingly, the antibacterial efficacy of the implants is determined by the amount of Cu 2+ ions that reaches bacteria, instead of the total amount of released Cu 2+ ions. The amount of Cu 2+ ions reaching bacteria from the high-surface-potential implant is 2.4 times that from the lowsurface-potential implant within 12 h, resulting in the increased antibacterial ratio from about 65% to 100%, while remaining low cell toxicity. This work provides insights into the specific role of the EEF in guiding mass transport between charged materials and living organisms, and a new perspective for the design of high-performance antibacterial biomaterials.

Copper Precursor Salt‐Dependent Antimicrobial Activity of Graphite Oxide Composites Against Escherichia coli and Staphylococcus Aureus: Synthesis and Characterization

“…These bind to the bases, thus decreasing the stability of the helix. [ 67 ] Finally, Table 2 summarizes the binding energy, full width at half maximum (FWHM), and chemical percent of the Cu/GrO composites for the high‐resolution C 1 s , O 1 s , and Cu 2 p regions.…”

“…The migration rate of antibacterial ions under an endogenous electrical field is proportional to the potential gradient and the ionic mobility of the electric field. [ 67 ] In this sense, the bacterial cell membrane is composed of negatively charged lipids, and the bacterial environment between the cell membrane and the surface of the positively charged composites can generate electrostatic membrane‐Cu + or Cu 2+ ions interactions.…”

Biomedical Implants with Charge‐Transfer Monitoring and Regulating Abilities

“…Zhai et al. [ 186 ] prepared a copper oxide‐doped KNN, and the Cu ions accumulated in the bacteria under the action of the electric field formed by KNN, presenting good antibacterial capacities. Similarly, Se, which is an effective anticancer element, was doped into the KNN piezoceramic, realizing the wireless combination of electrotherapy and chemotherapy.…”

“…[185] When the ferroelectric material is doped with functional elements, the formed electric field can also promote the enrichment of the doped ions to the cells, thus endowing the implanted material with more physiological functions. Zhai et al [186] prepared a copper oxide-doped KNN, and the Cu ions accumulated in the bacteria under the action of the electric field formed by KNN, presenting good antibacterial capacities. Similarly, Se, which is an effective anticancer element, was doped into the KNN piezoceramic, realizing the wireless combination of electrotherapy and chemotherapy.…”

Biodegradable ZnxNi1−xS hollow nanospheres for NIR-driven photothermal antibacterial therapy

“…Generally, many strategies have been explored to reduce the toxicity of nanomaterials, such as improving their biosafety or reducing the release rate of metal ions through surfacemodification strategies, [21][22][23] controlling the release of ions through external related stimuli (including heat, light, pH and magnetic fields [24][25][26] ), or reducing the accumulation degree by promoting the metabolic rate of materials in the body. 27,28 For instance, Xi et al synthesized ultra-small FeS 2 nanoparticles decorated with carbon nanospheres, whose carbon shells not only prevented the aggregation of FeS 2 but also accelerated the release of Fe 2+ through photothermal effects to achieve the synergistic hyperthermia/Fe 2+ therapy.…”