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A digital controlled pulse generator for a novel tumor therapy combining irreversible electroporation with nanosecond pulse stimulation
摘要： The irreversible electroporation with microsecond electric pulses is a new ablation technique adopted in the tumor therapy worldwide. On the other hand, the nsPEF (nanosecond pulsed electric field) has been proved to provide a means to induce immunogenic cell death and elicits antitumor immunity, which is under intensive in-vitro and in-vivo studies and in clinical trials. Normally, one needs two different types of electric pulse generators for producing the pulses in the ranges of nanosecond and microsecond, respectively. In order to realize these two types of tumor treatments in complementary and optimize electrical pulse parameters, we have developed a compact high-voltage pulse generator with a wide pulse width tuning range, based on a capacitor discharging configuration digitally controlled by a silicon carbide MOSFET switching array through a pair of optic-coupler drivers. The developed digital pulse generator is capable of adjusting: pulse width over 100ns-100μs, voltage over 0-2kV and repetition rate up to 1.2 kHz. The pulse generator is designed in simulation, implemented and verified in experiments. The pulse generator is shown to deliver a complementary treatment on Murine melanoma B16 cell lines, i.e. triggering the cell early apoptosis under the 300ns pulse stimulation while a complete killing under the 100ns pulses. The pulse generator is further demonstrated to induce antitumor immunity in a preliminary in vivo study on the mice model.
关键词： apoptosis,Silicon Carbide MOSFET array,irreversible electroporation,nanosecond pulse stimulation
更新于2025-09-23 15:21:01
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Graphene-Enabled, Spatially Controlled Electroporation of Adherent Cells for Live-Cell Super-resolution Microscopy
摘要： The incorporation of exogenous molecules into live cells is essential for both biological research and therapeutic applications. In particular, for the emerging field of super-resolution microscopy of live mammalian cells, it remains a challenge to deliver tailored, often cell-impermeable, fluorescent probes into live cells for target labeling. Here, utilizing the outstanding mechanical, electrical, and optical properties of graphene, we report a facile approach that enables both high-throughput delivery of fluorescent probes into adherent mammalian cells and in situ super-resolution microscopy on the same device. ~90% delivery efficiencies are achieved for free dyes and dye-tagged affinity probes, short peptides, and whole antibodies, thus enabling high-quality super-resolution microscopy. Moreover, we demonstrate good spatiotemporal controls, which, in combination with the ready patternability of graphene, allow for the spatially selective delivery of two different probes for cells at different locations on the same substrate.
关键词： electroporation,graphene,intracellular delivery,live-cell labeling,super-resolution microscopy
更新于2025-09-23 15:19:57
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[Lecture Notes in Computer Science] Intelligent Information and Database Systems Volume 9012 || Automated Analysis of Images from Confocal Laser Scanning Microscopy Applied to Observation of Calcium Channel Subunits in Nerve Cell Model Line Subjected Electroporation and Calcium
摘要： We assess a possibility of applying automated image analysis to immunofluorescence microphotographs from confocal laser scanning microscopy (CLSM). Several modes of automated analysis were tested to inspect differentiation of voltage dependent calcium channel subunits from a model of nerve cells PC12 (rat pheochromocytoma) subjected to electroporation (EP), with regard to extracellular calcium level. The objective of the experiments was evaluating sensitivity of the channel expression to the presence of calcium and electroporation voltage. For this purpose non-selective nanopores of a controlled conductivity were generated in the cell membrane using electroporation, at physiological or increased extracellular calcium concentrations. Introduction of Ca2+ into the cells was possible through electropores and physiological voltage-dependent calcium channels. Two subunits of calcium channel (α1H and α1G) were immunofluorescentically stained and the automated analysis of changes in cellular morphology was performed, based on comparative assessment of the fluorescence signal. The automated analysis allowed apparently higher observation capabilities. The results showed morphological changes in the channel subunits and higher expression of the channel, following its exposition to electric field or calcium.
关键词： Calcium channel subunits,Electroporation,Fluorescence image analysis
更新于2025-09-23 15:19:57
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Femtosecond Laser Induced Surface Micro-Structure Building by Material Ejection and Ablation on Cu and Al
摘要： Theoretical and experimental approaches verifying the fluidic operation of a partially shielded digital microfluidics device are presented in this paper. This paper is motivated by recent demand from the synthetic biology community for electrowetting on dielectric (EWD) enabled in-droplet electroporation, but is generalizable to a range of EWD applications that require shielding structures to be patterned on the EWD. An electrode patterned in an additional metal layer on the insulator that supports EWD actuation reduces the effective strength of the EW force due to dielectric shielding at the droplet contact line. A numerical model was developed to predict the impact of the partially shielding electrode on threshold voltage, EW force, fluid velocity, and droplet transport time. Compared with a batch of devices lacking the extra electrode, the presence of the added metal layer resulted in a 29% increase in threshold voltage, an 82% increase in transport time, and a 44% decrease in average transport velocity. Each trend agrees with the simulation results obtained from the fluid transport model. These results support the development of design rules for microfluidic devices that require partially shielding metal layers to integrate with EWD device architectures.
关键词： gene transfer,Fluidics,model,transport,electroporation,electrowetting on dielectric,electrotransfer,digital microfluidics,mechanics,finite element model,device
更新于2025-09-19 17:13:59
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[IEEE 2018 EMF-Med 1st World Conference on Biomedical Applications of Electromagnetic Fields (EMF-Med) - Split, Croatia (2018.9.10-2018.9.13)] 2018 EMF-Med 1st World Conference on Biomedical Applications of Electromagnetic Fields (EMF-Med) - Modeling of Joule heating in tissues induced by high- and low-voltage pulse combinations for gene electrotransfer
摘要： Gene electrotransfer is a promising technique for safe and efficient gene therapy. It relies on locally delivered electric pulses to transfer previously injected foreign DNA into the cell. Applied pulses tissue (electroporation) and concomitant heat generation due to Joule effect. In our study we used finite element method to calculate electric field and temperature distribution during typical electrotransfer pulsing protocol (i.e. combination of 100 microsecond high-voltage pulse and 400 millisecond low-voltage pulse with pulse lag time of 1 second) in isotropic tissue (e.g. liver) and anisotropic tissue (e.g. skeletal muscle). For parallel plate electrodes results show negligible temperature rise in tissue bulk due to high voltage pulse and up to a few °C rise due to the low-voltage 400 ms-long pulse, depending on tissue conductivity.
关键词： COST EMF-MED,gene therapy,Joule heating,FEM,electric field,electroporation,gene electrotransfer
更新于2025-09-10 09:29:36