高胆固醇血症家兔红细胞在交、直流电场中的电泳行为

本文对高胆固醇血症家兔红细胞在交、直流电场中的电泳行为进行了多指标测定,结果显示,高脂组与正常组相比红细胞聚集能力增强,变形能力及膜流动性下降,表明高脂血症可能较易导致血栓形成。中药有效成分8501有对抗高脂引起的红细胞上述改变的作用,提示8501可能对血栓和动脉粥样硬化斑块形成有防治作用。

Study of Cellular Experiment of Electric Pulse Imposed on Cancer Cell

The objective of the study is the cytocidal and inhibitory effect of energy-controllable pulse on ovarian cancer cell line SKOV3. Ovarian cancer cell suspension were treated by electric pulse with different parameters. The inhibitory rate (IR) was assayed by modified colorimetric MTT methods, the growth curves of two test groups and one control group were also measured, and the ultrastructural changes were observed under electron microscopy (EM) and scan electron microscopy (SEM). It was found that the treated SKOV3 cell proliferated more slowly. IR was increased with the enhancement of pulse parameters. The ultrastructural study showed that morphological changes occurred obviously. Swollen mitochondria, fractured ridges, cyto-plasmic vacuoles and membrane holes appeared in most of the processed cells, and a part of bilayer membrane was ruptured. It is indicated that irreversible electric breakdown occurred in some of the treated cells, and the electric pulse could kill cancer cell and inhibit its recovery and growth.

High efficiency DNA delivery into swine oocytes and embryos by electronic pulse delivery (EPD)

The production of transgenic swine for xenotransplantation has been proposed as an optimal option to overcome the chronic shortage of human organ donors. Generation of genetically engineered swine has been elusive due to the difficulties in gene transfer. In order to achieve effective gene delivery, a key step for the genetic modification, we applied electronic pulse delivery (EPD) technology to introduce HZKb-DC DNA construct into swine eggs. Using the developed EPD ProtocolsTM, we have achieved good viability of the EPD treated oocytes, satisfactory embryonic development of the EPD treated embryos, and stable DNA transfer into the swine embryos with high efficiency. Thus, application of the EPD technology promises to effectively facilitate the generation of large trangenic mammals.

Effects of Various Pulsed Electric Field Conditions on Cell Disintegration and Mass Transfer of Sugar Beet

Pulsed electric field is an innovative method for non-thermal food processing. The effects of pulsed electric field on cell disintegration and mass transfer in sugar beet were studied. Sugar beet slices were treated by various Field strengths （0.5-6 kV cm^-1）, capacity of capacitors （0.5, 8 and 32 μF） and pulse numbers （1-100 pulses）. The cell disintegration index and energy input for each treated sample was evaluated. The results showed that the cell membrane of PEF （Pulsed Electric Field） treated samples using 2 kV cm^-1, 8 μF after 20 pulses, and 3 kV cm1, 8 μF after 10 pulses were rapidly disintegrated in less than 1 min. Most important parameters during cell permeabilization were the total energy input followed by field strength. Energy efficiency index was defined as cell disintegration index per energy input unit. The maximum efficiency index was achieved using 2 kV cm^-1, 8 μF after 5 pulses. Comparison between PEF pretreatment and thermal method showed that large amount of sugar may be extracted after PEF pretreatment using field strength of 2 Kv cm^-1, 8μF in less than 10 min at ambient temperature. In.addition, the consumed energy for thermal treatment was approximately 20 to 50 times more than PEF pretreatment. Optimizing the field conditions in PEF treatment is an important factor to achieve high amount of sugar extraction from sugar beet.

Effect of Electrical Stimulation on the Growth of Endothelial Cell

Exogenous electrical stimulation plays an important role on endothelial cells and vessels. Study on the effect of electrical stimulation on endothelial cells might be helpful to regulate cell metabolism on a certain extent, or provide new ideas for vascular tissue engineering. A bioreactor that can apply electrical stimulation was designed on the basis of parallel-plate chamber. To investigate the possible effect of electrical stimulation on human umbilical vein endothelial cells （HUVECs）, the different levels and duration＇s electrical stimulations were applied to HUVECs in culture. The cell morphology was observed by microscopy and the levels of endothelial nitric oxide synthase （eNOS） gene were measured by RT-PCR. Different levels and durations of electrical stimulation produce different effects on eNOS gene expression. The eNOS gene expressions of the experimental group ceils under the voltage of 50 mV, 100 mV, 150 mV and 200 mV were significantly lower than that of the control group after 3-hour electrical stimulation, while the eNOS gene levels of the experimental group cells in 6-hour electrical stimulation were higher than those of the control group under all tested voltages. After 12-hour stimulation, the eNOS gene levels of HUVECs decreased under 50 mV, and then gradually increased until 200 inV. The low voltage of 6-hour electrical stimulation is more appropriate for HUVECs growth.

Effect and mechanism of electronic magnetic pulse on peripheral lymphocytes in dogs

Objective To study the effects of electronic magnetic pulse (EMP) on peripheral lymphocytes in dogs and to explore the mechanisms of the biological effects of EMP.Methods T, TH and Ts lymphocytes were estimated by acid phosphatase cytochemistry. Apoptotic lymphocytes and Bax and Bcl-2 proteins related to apoptosis were observed with in situ terminal labeling and immunocytochemistry.Results Peripheral T lymphocyte subpopulations decreased obviously after EMP irradiation with (2 - 12) × 104 V/m. Apoptotic percentages of lymphocytes increased with the elevation of EMP doses. Ten days after different intensity radiation, the Bax protein was found to be elevated in accord with the peak value of lymphocyte apoptosis. However, Bcl-2 protein decreased obviously.Conclusion A definite field intensity EMP could induce injury to lymphocytes. Apoptosis induced by EMP is one of the main causes of peripheral lymphocyte death and leads to immunosuppression of the body.These results suggest that people should pay more attention to the injury caused by EMP, especially to the immunological functions of the body.

Review of micro/nano technologies and theories for electroporation of biological cells

Electroporation (EP) is one of the important techniques for the introduction of genes and drugs into cells with intense pulsed electric field to induce nanometer-sized electropores on cell membranes.Recently,micro/nano technology has been applied to many novel micro EP devices which can not only significantly increase uptake of biomolecules,DNA transfection and cell viability,but also enable large-scale single-cell EP.However,most EP theories developed in the past three decades can not precisely predict the experimental results of EP of biological cells.With the advanced micro EP chips for large-scale single-cell EP experiments,more precise EP theoretical models can be developed to describe the complicated multiscale dynamic behavior of EP.

“Petal effect”-inspired superhydrophobic and highly adhesive coating on magnesium with enhanced corrosion resistance and biocompatibility

With properties of complete degradation and favorable mechanical behavior, Mg and its alloys are regarded as the next generation medical metal materials. However, fast degradation and poor surface biocompatibility hinder their clinical applications. Inspired by the ＂petal effect＂, we successfully constructed a superhydrophobic and highly adhesive coating on pure Mg via a simple hydrothermal treatment in a solution containing sodium oleate. The superhydrophobicity of the fabricated coating results from its flake-like micro-nanostructure and the low-surface-energy oleate group. Water droplet on the superhydrophobic coating cannot roll off even when the sample is turned upside down, owing to the sealed air-pockets and the van der Waals’ attraction at the solidliquid interface, indicating a highly adhesive force. The chemical and mechanical stability of the superhydrophobic coating were measured. Potentiodynamic polarization and electrochemical impedance spectroscopy measurements suggest enhanced corrosion resistance of the as-prepared sample.Furthermore, cell cytotoxicity, migration and adhesion data of human umbilical vein endothelial cells（HUVECs） reveal an improved cytocompatibility of the modified surface. Finally,hemolysis assay and platelet adhesion assay suggest an improved hemocompatibility. It is believed that the facile and low-cost method can expand the new application of superhydrophobic surface with highly adhesive on Mg in biomedical fields.