Irreversible electroporation (IRE) is a novel technique that deals with killing undesirable cells, mainly cancer cells, directly without using any cytotoxic drugs. Commonly in this technique very high electric field up to 1000 V/cm is used but for very short exposure time (nanoseconds). Low electric fields (LEFs) are used before to internalize molecules and drugs inside the cells (electroendocytosis) but mainly not in killing the cells. The aim of this work is to determine the ability of using LEFs to kill cancer cells (Hela cells). The Physics idea is in making LEFs energy equivalent to IRE energy. Four IRE protocols were selected to represent very high, high, moderate and mild voltages IRE, then we make equivalent energy for each of these protocols using different LEFs' parameters of different amplitudes (7, 10, 14 and 20 V), different pulse numbers (40, 80, 160 and 320 pulses), different frequencies from 0.5 to 106.86 Hz and different pulse widths from 9.38 to 2000 ms. Each of the calculated LEF equivalent to IRE was applied on Hela cell line. The results show complete destruction of the cancer cells for all the tested exposure protocols. This damage was not due to thermal effect because the measured temperature was not changed before and after the exposure. The possible effect mechanism is discussed. It was concluded that the lethal effect on the cancer cells can be achieved using LEFs if the same energy equivalent to IRE is used. This work will help in using low-risk drug-free techniques in cancer treatment.
BACKGROUND: The early detection of human breast cancer represents a great chance of survival. Malignant tissues have more water content and higher electrolytes concentration while they have lower fat content than the normal. These cancer biochemical characters provide malignant tissue with high electric permittivity (ε´) and conductivity (σ). OBJECTIVE: To examine if the dielectric behavior of normal and malignant tissues at low frequencies (α dispersion) will lead to the threshold (separating) line between them and find the threshold values of capacitance and resistance. These data are used as input for deep learning neural networks, and the outcomes are normal or malignant. METHODS: ε´ and σ in the range of 50 Hz to 100 KHz for 15 human malignant tissues and their corresponding normal ones have been measured. The separating line equation between the two classes is found by mathematical calculations and verified via support vector machine (SVM). Normal range and the threshold value of both normal capacitance and resistance are calculated. RESULTS: Deep learning analysis has an accuracy of 91.7%, 85.7% sensitivity, and 100% specificity for instant and automatic prediction of the type of breast tissue, either normal or malignant. CONCLUSIONS: These data can be used in both cancer diagnosis and prognosis follow-up.
Bacteria growing in biofilms cause a wide range of environmental, industrial and public health risks. Because biofilm bacteria are very resistant to antibiotics, there is an urgent need in medicine and industry to develop new approaches to eliminating bacterial biofilms. One strategy for controlling these biofilms is to generate an antibiofilm substance locally at the attachment surface. Direct electric current (DC) and nanoparticles (NPs) of metal oxides have outstanding antimicrobial properties. In this study we evaluated the effect of titanium oxide nanoparticle (TiO$_2$-NP) concentrations from 5 to 160 $\mu$g/mL on Bacillus cereus and Pseudomonas aeruginosa biofilms, and compared this with the effect of a 9 V, 6 mA DC electric field for 5, 10 and 15 min. TiO$_2$-NPs were characterized using transmission and scanning electron microscopes, X-ray diffraction and FTIR. They exhibited an average size of 22-34 nm. The TiO$_2$-NP concentrations that attained LD50 were $104 \pm 4$ $\mu$g/mL and $63 \pm 3$ $\mu$g/mL for B. cereus and P. aeruginosa, respectively. The eradication percentages obtained by DC at 5, 10, and 15 min exposure were 21%, 29%, and 33% respectively for B. cereus and 30%, 39%, and 44% respectively for P. aeruginosa. Biofilm disintegration was verified by exopolysaccharide, protein content and cell surface hydrophobicity assessment, as well as scanning electron microscopy. These data were correlated with the reactive oxygen species produced. The results indicated that both DC and TiO$_2$-NPs have a lethal effect on these bacterial biofilms, and that the DC conditions used affect the biofilms in a similar way to TiO$_2$-NPs at concentrations of 20-40 $\mu$g/mL.
Conclusive results of the effect of extremely low frequency magnetic fields (ELF MF) exposure on memory are controversial. The aim of the present study was to investigate and follow up the effect of exposure to 1, 2 and 3 mT ELF MF for 30 min daily for 7 days on mice long-term memory. Passive avoidance task was used, and assessments were carried out one day, one and two weeks after exposure. The results showed that all intensities impaired long-term memory compared to the control after one day and one week. 3mT group was more affected than 1 mT group after one day and more affected than 1 and 2 mT groups after one week. After 2 weeks of exposure, memory was significantly impaired only in 3 mT group in comparison to control and 1 mT groups. We concluded that ELF MF impair long-term memory, this impairment was more significant with the increase of exposure intensity. Memory impairment was temporary along the studied design in all studied exposure intensities.
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