Aims: This study aimed to evaluate the effect of electroporation on the growth characteristics and antimicrobial activity of lactic acid bacteria (LAB) including Bifidobacterium longum ATCC 15707, Lactobacillus acidophilus ATCC 314, Lactobacillus casei ATCC 393 and Lactobacillus fermentum ATCC 14931. Methodology and results: Electroporation with the strength of electric field at 1.0–3.0 kV/cm for 2-4 millisecond were applied on the bacterial cultures. All bacterial cultures showed significant (P<0.05) increased in cell viability (40%-325%) upon electroporation. Such treatment also increased the acidity of the cell where the pH of cells decreased upon treatment. In tandem with the increased viability, electroporated bacterial cultures also showed higher proteolytic activity compared to the control (P<0.05). The electroporation treatment also increased (P<0.05) the bacteriocin activity of treated cells compared to the control. However, the molecular weight of bacteriocins produced were not affected by electroporation. Treated cells also possessed better antimicrobial activity. According to the results collected, all treated LAB strains showed 11.5%-113.8% higher (P<0.05) inhibitory activity compared to untreated control against tested pathogenic bacteria, Escherichia coli and Listeria monocytogenes that commonly associated with food contamination. Microarray data analysis showed that electroporation regulated the entities encoding for surface protein and transporter. Conclusion, significance and impact of study The results from this study suggested that electroporation could enhance the growth characteristics and antimicrobial activity of LAB by modifying the surface regions of the cells. This result may serve as the reference for food manufacturers to opt for effective biopreservation method and produce food with extended shelf life.
Electroporation ; Lactobacillales

A project of control of a high voltage pulse generator based on Arduino and its peripheral pulse sensor and temperature sensor was proposed for cell irreversible electroporation (IRE) test. By programming Arduino board, the analog photoelectric signal and the partial voltage signal of thermistor collected by pulse and temperature sensors were converted into digital signal and temperature value. The threshold of ECG R wave (>550) and temperature threshold (<37 oC) was set as trigger condition to control an 800 W high voltage pulse generator to release a fixed period pulse. Human lung cancer cells cultured in vitro were used to test and verify, and cell staining was used to evaluate the perforation. The results showed that Arduino and its sensors were sensitive to trigger and feedback. When the high voltage pulse generator was controlled to release 100 pulses with the parameters of 600 V, 1 200 V/cm and 100 ms pulse width, more than 95% of the cells showed nonthermal irreversible electroporation.
Electroporation ; Humans

Electrochemotherapy was instituted for sarcoma, and the tumor inhibitory ratio, curing ratio, vascular endothelial growth factor, microvessel density and mechanism were measured and analyzed. The results indicate that the curing ratio of electrochemotherapy for sarcoma is 84.6%. The present research provides experimental evidence for the security, mechanism and feasibility of electrochemotherapy in clinical practice.
Animals ; Antineoplastic Agents ; administration & dosage ; Bleomycin ; administration & dosage ; Drug Delivery Systems ; methods ; Electrochemotherapy ; methods ; Electroporation ; methods ; Mice ; Sarcoma 180 ; therapy ; Vascular Endothelial Growth Factor A ; analysis

OBJECTIVETo estimate electroporation (EP) influence on malignant and normal cells.

METHODSTwo cell lines including human malignant melanoma (Me-45) and normal human gingival fibroblast (HGFs) were used. EP parameters were the following: 250, 1 000, 1 750, 2 500 V/cm; 50 µs by 5 impulses for every case. The viability of cells after EP was estimated by MTT assay. The ultrastructural analysis was observed by transmission electron microscope (Zeiss EM 900).

RESULTSIn the current study we observed the intracellular effect following EP on Me-45 and HGF cells. At the conditions applied, we did not observe any significant damage of mitochondrial activity in both cell lines treated by EP. Conversely, we showed that EP in some conditions can stimulate cells to proliferation. Some changes induced by EP were only visible in electron microscopy. In fibroblast cells we observed significant changes in lower parameters of EP (250 and 1 000 V/cm). After applying higher electric field intensities (2 500 V/cm) we detected many vacuoles, myelin-like bodies and swallowed endoplasmic reticulum. In melanoma cells such strong pathological modifications after EP were not observed, in comparison with control cells. The ultrastructure of both treated cell lines was changed according to the applied parameters of EP.

CONCLUSIONSWe can claim that EP conditions are cell line dependent. In terms of the intracellular morphology, human fibroblasts are more sensitive to electric field as compared with melanoma cells. Optimal conditions should be determined for each cell line. Summarizing our study, we can conclude that EP is not an invasive method for human normal and malignant cells. This technique can be safely applied in chemotherapy for delivering drugs into tumor cells.

Adult ; Cell Line ; Cell Line, Tumor ; Cell Shape ; Cell Survival ; Cells, Cultured ; Electrochemotherapy ; Electroporation ; Fibroblasts ; chemistry ; cytology ; Gingiva ; chemistry ; cytology ; Humans ; Male ; Melanoma ; chemistry ; physiopathology ; therapy

Joule heating has long been considered as the principal component of tissue damage in electrical injury. Recent studies suggest electroporation, a nonthermally medicated mechanism of cell membrane damage, is also an important factor. This study is significant because it directly addresses whether nonthermal mechanisms of cell damage can cause tissue necrosis without visible thermal changes.
Burns ; Wounds and Injuries ; Electroporation

Geobacillus thermoglucosidasius is a kind of Gram-positive facultative anaerobic bacteria. The fast growth rate under high temperature and less susceptibility to microbial contamination enable G. thermoglucosidasius to be a desirable producer of biofuels and high-value-added chemicals for the next-generation industrial biotechnology. However, compared with the classical model strain Escherichia coli, the applications of G. thermoglucosidasius are hampered by its low transformation efficiency. This study aimed at obtaining competent cells with high transformation efficiency through inactivating restriction enzymes, adding cell membrane inhibitors and cell wall weakening agents. The results showed that the electro-transformation efficiency achieved 1.2×10⁴ CFU/(μg DNA) by knocking out four genes encoding restriction enzymes. Adding a certain amount of tween 80, dl-threonine and glycine further increased the competent efficiency about 22.5, 44, and 334 times, respectively. The electro-transformation efficiency was enhanced to 4.6×10⁶ CFU/(μg DNA) under the optimized conditions, laying a foundation for genetic manipulation and metabolic engineering of G. thermoglucosidasius.
Electroporation ; Electroporation Therapies ; Bacillaceae ; Cell Membrane ; Escherichia coli/genetics*

Pancreatic cancer has a very poor prognosis. Complete surgical resection remains the only current curative treatment. Locally advanced pancreatic cancer (LAPC) is considered as unresectable because of involvement of celiac and/or mesenteric vessels. The treatment of LAPC is a challenge. Current guidelines suggest systemic therapy. However, the majority of patients will never experience conversion to surgical resection. Thus, in these patients, ablation is an alternative therapy for local control, which causes local destruction while ideally avoiding injury to surrounding healthy tissue. Irreversible electroporation (IRE) is an energy delivery system, effective in ablating tumors by inducing irreversible membrane destruction of cells. IRE demonstrated to be safe in previous studies. However, it is not free from complications, even serious. Here, we reported two cases of the IRE in LAPC patients.
Electroporation ; Humans ; Membranes ; Pancreatic Neoplasms ; Prognosis

This study firstly introduced the mechanism, benefits and applications of irreversible electroporation(IRE) for tumor ablation. In addition, this study also introduced the most advanced IRE systems cleared by FDA or CFDA and IRE research equipment. The clinically licensed IRE systems include the Nanoknife 3.0 of Angiodynamics, the Dophi
Electricity ; Electroporation ; Heart Rate ; Humans ; Neoplasms/therapy*

Irreversible electroporation (IRE) is an emerging tissue ablation technique. Compared with thermal ablation technique such as radiofrequency, IRE can achieve focal ablation in a shorter time without heat sink effect while sparing the tissue scaffold. IRE has been demonstrated to be a feasible therapeutic modality for the liver, pancreatic, and prostatic cancer. In recent years, several studies regarding of catheter-directed IRE for digestive tract, bronchus, urinary tract, and myocardium have been performed, which preliminarily demonstrated the safety and efficacy of IRE for tissue ablation under endoscopic or interventional technique. This study summarized the research progress of catheter-directed IRE for tissue ablation. The critical technique and future direction of catheter-based IRE are prosp.
Catheter Ablation ; Catheters ; Electroporation ; Endoscopy ; Humans

PURPOSE: Alteration of p53 and telomerase activity may be responsible for gastric carcino- genesis. In this study, we tried to observe modulation of telomerase activity by wild type p53 in gastric cancer cell lines. MATERIALS AND METHODS: We used five gastric cancer cell lines (KATO-III, AGS, SNU-1, SNU-5, SNU-16). In order to find p53 mutation, we used western blot and PCR-SSCP. The TRAP-eze kit which supplied by Oncor (Gaithersburg, MD) was used to detect telomerase activity of the five gastric carcinoma cell lines. The wild type p53 gene was transfected by electroporation method. RESULTS: The expression of p53 protein was increased in four gastric carcinoma cell lines and one cell line (KATO-III) did not express. We found p53 point mutation in exon 5 and 8, and the p53 gene was deleted in KATO-III. The telomerase activity were observed in all five gastric carcinoma cell lines and there were no difference in telomere repeat length among five cell lines. After transfection with wild type p53, we could not find the change of telomerase activity in KATO-III. CONCLUSION: Although activation of telomerase activity and mutation of p53 gene may be needed in gastric carcinogenesis, the telomerase activity was not affected by restoration of p53 function in gastric carcinoma cell lines.
Blotting, Western ; Carcinogenesis ; Cell Line* ; Electroporation ; Exons ; Genes, p53* ; Point Mutation ; Stomach Neoplasms ; Telomerase* ; Telomere ; Transfection