Development Of Multi-parameter Adjustable Nanosecond Pulse Generator And Its Biomedical Effects Research

Nanosecond pulse electric field plays important role in industry, environment protection and biomedicine and so on. So far there is not portable and multi-parameter adjustable nanosecond pulse generator. Therefore, it has scientific significance and application value to develope a high-performance, nanosecond pulse generator. This paper developed the nanosecond pulse generator which is based on principle of single transmission line. The square-wave high-voltage nanosecond pulse generator bases on LC network, which achieves by simulating the single transmission with lumped parameter inductance and capacitance. The generator is mainly composed of a high voltage DC power, nanosecond pulse forming system, the pulse shaping and counting system. The output pulse amplitude is 4kV to 15kV with continuous adjustment, the pulse width is 50ns to 500ns and the rising time is 8ns. The generator with liquid crystal display and protection can control pulse frequency and output number. The laboratory tests show that the generator can be easily adjusted, which satisfy the requirements of biomedical experiments.The pulse generator was verified that it is easy to adjusted to satisfy the biomedical experiments. And nanosecond pulse electric field can effectively induce apoptosis of SKOV3 cells. This paper found out the optimum combination of pulse parameters induced apoptosis by analyzing orthogonal design cell experiments. Apoptosis of tumor cells were confirmed from Statistically and morphology, Respectively, such as flow cytometry, scanning electron microscopy, AO(acridine orange)/EB(ethidium bromide) fluorescence detection methods, Hoechst 33342 staining.Nanosecond pulsed electric fields could induce the cell membrane electroporation and then lead to apoptosis, thus mechanism of organelle membranes electroporation is the key of inducing apoptosis of nanosecond pulsed electric field. Molecular dynamics simulation was carried out on cell membrane bilayers to probe mechanism of electroporation, induced by intense nanosecond pulse electric field, of cellular organelle membrane. Studies on the process of electroporation and its pore size in lipid bilayers have been conducted from the atomic level. Furthermore, this paper investigated the mechanism of electroporation formation. Results reveal that the initial defect formation on the surface of the membrane was induced by swing and rotation of dipoles at the lipid molecules which were subjected to nanosecond, high intensity pulsed electric field. Electroporation formation in lipid bilayers was induced by dipoles reorientation. There is a mutual coupling among multiple pores. Electroporation is formed within 4-5ns and maintains dynamic stability. The result agreed with coarse-grained lipid molecules model simulation.