Electro-mechanical and Polarization-Induced Antibacterial Response of 45S5 Bioglass–Sodium Potassium Niobate Piezoelectric Ceramic Composites

Abstract

Besides the excellent osteoconductivity and biocompatibility of 45S5 bioglass (BG), poor mechanical and electrical properties as well as susceptibility toward bacterial adhesion limit its widespread clinical applications. In this context, the present study investigates the effect of addition of piezo­electric sodium potassium niobate (Na0.5K0.5NbO3; NKN) on mechanical, dielectric, and antibacterial response of BG. BG–xNKN (x = 0, 10, 20, and 30 vol%) composites were synthesized at 800 °C for 30 min. The phase analyses using spectral techniques revealed the formation of the composite without any reaction between BG and piezo­electric ceramic NKN. The dielectric and electrical measurements were performed over a wide range of temperature (30–500 °C) and frequency (1 Hz–1 MHz) which suggests that space charge and dipolar polarizations are the dominant polarization mechanisms. The complex impedance analyses suggest that the average activation energies for grain and grain boundary resistances for BG–xNKN (x = 10, 20, and 30 vol%) composites are 0.59, 0.87, 0.94 and 0.76, 0.93, 1.06 eV, respectively. The issue of bacterial infection has been addressed by electrical polarization of the developed composite samples, at 20 kV for 30 min. Statistical analyses reveal that the viability of Gram-positive (S. aureus) and Gram-negative (E. coli) bacterial cells has been reduced significantly on positively and negatively charged BG–NKN composite samples, respectively. The qualitative analyses using the Kirby–Bauer test supports the above findings. Nitro blue tetrazolium and lipid peroxide assays were performed to understand the mechanism of such antibacterial response, which suggested that the combined effect of NKN addition and polarization significantly enhances the superoxide production, which kills the bacterial cells. Overall, incorporation of NKN in BG enhances the mechanical, electrical, and dielectric properties as well as improves the antibacterial response of polarized BG–xNKN composites.

Multifunctional Response of Piezoelectric Sodium Potassium Niobate (NKN)-Toughened Hydroxyapatite-Based Biocomposites

“…The quantitative analysis, i.e., bacterial viability, was measured using MTT assay. The samples were cultured in 24 well tissue culture plates with an equal amount of bacterial cells (200 μL per well with 0.1 OD, i.e., optical density).The detailed procedure is reported elsewhere …”

“…Few studies reported the effect of charge induced by the polarization on the biological effect of NKN. , It has been suggested that the formation of new bones is influenced by the piezoelectric behavior of the implant material . The negatively charged surfaces promote the osteoblast cell activity .…”

Piezoelectric Nanomaterial‐Mediated Physical Signals Regulate Cell Differentiation for Regenerative Medicine

“…Electroactive nanomaterials are generally divided into two categories: conductive nanomaterials and nonconductive nanomaterials. Piezoelectric nanomaterials belong to the category of nonconductive nanomaterials and are widely used in many fields such as antimicrobial, [ 23,24 ] tumor treatment, [ 25 ] and biosensing. [ 26,27 ] Interestingly, traces of naturally occurring piezoelectric materials can be found in components of the human body such as bones, skin, amino acids, and proteins.…”

“…in many fields such as antimicrobial, [23,24] tumor treatment, [25] and biosensing. [26,27] Interestingly, traces of naturally occurring piezoelectric materials can be found in components of the human body such as bones, skin, amino acids, and proteins.…”

Electret‐induced antibacterial response of Mg1‐xCaxSi1‐xZrxO3 (x = 0–0.4) bioceramics

“…[5][6][7] Therefore, the development of polarizable prosthetic implants has attracted significant attention in recent years. 1,2,4,[8][9][10][11][12][13][14] In orthopedic implants, the predominant portion (65%) of bacterial infections is attributed to gram-positive (GP) bacteria, especially, Staphylococcus epidermidis and Staphylococcus aureus. However, gramnegative (GN) bacteria, for example, Escherichia coli and Pseudomonas aeruginosa are responsible for approximately 11% of total bacterial infections in orthopedic implants.…”