The over-reliance on antibiotics and their enormous misuse has led to warnings of a future without effective medicines and so, the need for alternatives to antibiotics has become a must. Non-traditional antibacterial treatment was performed by using an aray of nanocomposites synergised with exposure to electromagnetic waves. In this manuscript, electrospun poly(vinyl alcohol) (PVA) nanofiber mats embedded with silver nanoparticles (Ag NPs) were synthesized. The nanocomposites were characterized by Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Current-Voltage (I-V) curves, and Thermogravimetric analysis (TGA) along with analysis of antibacterial impact against E. coli and S. aureus bacteria, studied by bacterial growing analysis, growth kinetics, and cellular cytotoxicity. The results indicated a spherical grain shape of silver of average size 20 nm and nanofibers’ mean diameter of less than 100 nm. The nanocomposite mats showed good exposure to bacteria and the ability to sustain release of silver for a relatively long time. Moreover, the applied electromagnetic waves (EMWs) were shown to be a synergistic co-factor in killing bacteria even at low concentrations of Ag NPs. This caused pronounced alterations of the bacterial preserved packing of the cell membrane. Thereby, the treatment with nanocomposite mats under EM wave exposure elucidated maximum inhibition for both bacterial strains. It was concluded that the functioning of nanofiber with silver nanoparticles and exposure to electromagnetic waves improved the antibacterial impact compared to each one alone.

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There is critical need to do a lot of experimental studies to calculate of the relative biological effects of non-ionizing radiation and comparing its effect with ionizing radiation to re-determine the safe exposure dose to non-ionizing radiation. This research is concerned with studying the relative fraction of damage (RFD) of the extremely low frequency electromagnetic fields (4kV/m-50 Hz) to high energy photons (6 MeV) on some biophysical properties of rats bone. In this regard, 100 male albino rats are used and divided into sub groups of 10 rats each. One group of animals was used as control group (unexposed group) and did not receive any treatment. Similar to occupational workers, four groups of animals were exposed 8h/day for periods from 1 to 4 weeks and were immediately sacrificed at the end of the exposure period. Four groups of animals exposed 8h/day for periods from 1 to 4 weeks and remained 45 days post exposure periods, then sacrificed. The last group of animals was exposed to a high energy dose of6 MeV of dose (1rad). Femur bone samples of each animal from all groups were collected and prepared for further biophysical investigations. In addition, RFD of magnetic fields exposures are calculated for each group relative to dose of 6 MeV-1 rad photons. Results of exposure to the electric field showed significant deterioration effect on the biomechanical parameters of femurs as a consequential defect of bone strength and bone quality as compared to the unexposed ones. Also, the results obtained from the groups that udergone a post exposure period of 45-days did not show amendment in bone biophysical characteristics, which means that permanent effects and chronic damage of bone tissues may have resulted. On the other hand, the RFD ratios illustrated that the effect of exposure to ELF EMF has no lower effect than the exposure to ionizing radiation and should not be underestimated.

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.

Magnetic cobalt nanostructured was synthesized by a two-stage method. First, a solution of cobalt precursor droplets was prepared by an ultrasonic nebulizer. Second, the arc discharge method between two electrodes in an inert gas at atmospheric pressure is used to obtain the nanostructured cobalt powder. The sample obtained was characterized by X-ray diffraction (XRD). Scanning electron microscope (SEM), High Resolution Transmission Electron Microscope (HR-TEM), UV-Vis Spectrophotometry, zeta potential (ZP) and vibrating sample magnetometer (VSM). The dielectric constant, and AC conductivity of the prepared sample was determined in the frequency range of 4 Hz to 8 MHz. The investigations showed that the Co nanoparticles prepared in this way have smaller and homogeneous nanoparticles with spherical shape morphology with good stability and unique magnetic properties as compared with the bulky one. The dielectric properties analysis shows an enhancement in the dielectric constant and the AC conductivity of the Co nanoparticles.