Adhesion of gram-negative rod-shaped bacteria on 1D nano-ripple glass pattern in weak magnetic fields

Innovative antibacterial electrospun nanofibers mats depending on piezoelectric generation

This paper introduces a new approach of testing piezoelectric nanofibers as antibacterial mat. In this work, both Polyvinylidene fluoride (PVDF) and PVDF embedded with thermoplastic polyurethane nanofibers are synthesized as nanofibers mat via electrospinning technique. Then, such mat is analyzed as piezoelectric material to generate electric voltage under different mechanical excitations. Furthermore, morphological and chemical characteristics have been operated to prove the existence of beta sheets piezoelectricity of the synthesized nanofibers mats. Then, the synthesized nanofibers surfaces have been cyclically stretched and exposed to bacteria specimen. It has been noticed that the generated voltage and the corresponding localized electric field positively affect the growth of bacteria and reduces the formation of K. penomenue samples bacteria colonies. In addition, the effect of both stretching frequency and pulses numbers have been studied on the bacteria count, growth kinetics, and protein leakage. Our contribution here is to introduce an innovative way of the direct impact of the generated electric field from piezoelectric nanofibers on the reduction of bacteria growth, without depending on traditional anti-bacterial nanoparticles. This work can open a new trend of the usability of piezoelectric nanofibers through masks, filters, and wound curing mats within anti-bacterial biological applications.

Alterations of bacterial dielectric characteristics due to pulsed magnetic field exposure

The effect of exposure to 0·1 Hz–0·1 kHz pulsed magnetic fields on models of gram-positive and gram-negative bacterial cells was investigated. The possible alterations in the electrical characteristics of dead and alive bacteria cells were monitored by using dielectric spectroscopy. The dielectric dispersions of cells were obtained over the range 42 Hz–8 MHz by measuring their dielectric permittivity and conductivity. The acquired results indicated exposure enhancement and inhibition effects on both bacterial models in different frequency windows. The spectroscopy results for all bacterial cells indicated two sizeable dispersions in low- and high-frequency ranges (so-called α- and β-dispersions) due to different polarization mechanisms. Remarkable variations in the dielectric relaxations were observed due to exposure as a result of possible alterations in the counterion clouds and ionic membrane permeability, plasma and cell wall charge residues. In conclusion, both bacterial models demonstrated considerable response to exposure, resulting in a significant electrochange in the cell membrane/wall structure. Moreover, by performing dielectric spectroscopy, it is possible to distinguish between normal and abnormal cells. It is worth mentioning that the observed results can be achieved when using resonance frequencies outside the range used in the study.

Adhesion of gram-negative rod-shaped bacteria on 1D nano-ripple glass pattern in weak magnetic fields

This research project has major applications in the healthcare and biomedical industries. Bacteria reside in human bodies and play an integral role in the mechanism of life. However, their excessive growth or the invasion of similar agents can be dangerous and may cause fatal or incurable diseases. On the other hand, increased exposure to electromagnetic radiation and its impact on health and safety is a common concern to medical science. Some nanostructure materials have interesting properties regarding facilitating or impeding cell growth. An understanding of these phenomena can be utilized to establish the optimum benefit of these structures in healthcare and medical research. We focus on the commonly found rod‐shaped, gram‐negative bacteria and their orientation and community development on the cellular level in the presence of weak magnetic fields on one dimensional nano‐ripple glass patterns to investigate the impact of nanostructures on the growth pattern of bacteria. The change in bacterial behavior on nanostructures and the impact of magnetic fields will open up new venues in the utilization of nanostructures. It is noticed that bacterial entrapment in nano‐grooves leads to the growth of larger colonies on the nanostructures, whereas magnetic fields reduce the size of colonies and suppress their growth.