Electrochemotherapy (ECT) is a novel cancer treatment in which electric pulses (EPs) inducing cell membrane pored (electroporation) are used as a means of delivering antitumor drugs to the cytoplasm of cancer cells. The minimal thresholds of electric field strength of in vitro tumor cell line and tumor tissue are 450-650 V/cm and 400-600 V/cm, respectively. The typical electrical requirement is 600-1300 V/cm, pulse width of 100 micros, 8 pulses, 1 Hz. More than 10 kinds of antitumor drugs have been applied to ECT, in which the most efficacious drug is Bleomycin, and then Cisplatin. Some exciting inhibitory effects on cells in vitro and on solid tumors in clinical trials have been noticed. The factors influencing ECT effects include the electric parameters, diameter of electrode, distribution of electric field lines, size of tumor, model of drugs injection and kinds of drugs. Some questions of ECT are still open, such as the dosages and kinds of drugs for clinical trials, model of drug injection, influence on normal tissues, therapeutic mechanism.
Antibiotics, Antineoplastic ; administration & dosage ; Antineoplastic Agents ; administration & dosage ; Bleomycin ; administration & dosage ; Cisplatin ; administration & dosage ; Electric Stimulation Therapy ; methods ; Electrochemistry ; Electroporation ; methods ; Humans ; Neoplasms ; therapy

In this paper are analyzed the effect of electrochemotherapy and its mechanism. The favorable parameter of electric pulses (EP) was studied in vitro using the S-180 cells exposed to various EP. After the tumor model was copied, the tumor-bearing mice were randomly divided into four groups: control, chemotherapy, electrotherapy, and electrochemotherapy. The tumor inhibitory ratio, the cure ratio and the level of oxygen free radicals (OFR) were determined. The inhibitory ratio and cure ratio of electrochemotherapy group were significantly higher than those in the chemotherapy, electrotherapy and control groups (P < 0.05). The injury of OFR was decreased while the immunological competence was increased. The mechanism of electrochemotherapy may be related with the enhancement of cell membranepermeability, the depression of drug resistance, the improvement of immunological competence, and so on.
Animals ; Antineoplastic Agents ; administration & dosage ; Bleomycin ; administration & dosage ; Drug Delivery Systems ; methods ; Electric Stimulation Therapy ; methods ; Electrochemistry ; Electroporation ; methods ; Mice ; Random Allocation ; Sarcoma 180 ; therapy

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

This study evaluated the effects of electric pulses combined with antitumor drugs on S180 tumor cells. It was found that the growth of S180 sarcoma was inhibited with a maximum inhibition ratio of 95.5% after the use of electric pulses in combination with the injection of bleomycin (BLM), and the blood vessels of tumor were obviously fewer than those of the untreated tumor in vivo. The mitochondria of S180 tumor cells were swollen after the use of electric pulses in combination with adriamycin. The results showed that electrochemotherapy has evident inhibitory effect on the growth of S180 sarcoma and the mechanism may involve the suppression of tumor angiogenesis and changes in the ultrastructures of tumor cells.
Animals ; Antimetabolites, Antineoplastic ; administration & dosage ; Bleomycin ; administration & dosage ; Combined Modality Therapy ; Electric Stimulation Therapy ; methods ; Electrochemistry ; Mice ; Neovascularization, Pathologic ; prevention & control ; Sarcoma 180 ; blood supply ; therapy

This article reports the experiment studies on treating the S-180 sarcomas of KM mice with high-intensity electric pulse and antitumor drug (cyclophosphamide). The results showed that the experimental group of electric field combined with drug has the best effect on tumor, compared with the control group. In addition, electric field can inhibit the formation of vas Capillaries and decrease the supply of nutrition for tumor cell. In conclusion, electric field has inhibited the growth of tumor.
Animals ; Antineoplastic Agents ; therapeutic use ; Combined Modality Therapy ; Cyclophosphamide ; administration & dosage ; Electric Stimulation Therapy ; methods ; Injections, Intralesional ; Mice ; Sarcoma 180 ; pathology ; therapy ; Treatment Outcome

This is our first time report of S-180 cell handled with various voltages, capacity and pulse number. Many pores on the S-180 cell membrane can be observed under scanning electron microscope. By the stains of trypan blue, we have known the influence of electric parameters on the ratio of poration. The results show that the ratio of electroporation has positive correlation with the voltages and the pulse number while negative correlation with the capacity.
Animals ; Cell Membrane Permeability ; Electromagnetic Fields ; Electroporation ; methods ; Mice ; Sarcoma 180 ; ultrastructure ; Tumor Cells, Cultured