The Dielectric Spectra Of Human Gastric Cell

Objective To measure dielectric spectral characteristics of human gastric cells（GES-1） and human gastric cancer cells （MGC-803） by applying AC impedancetechnology, the analysis methods of GES-1and MGC-803along with parameters ofmathematical models was established. Using the mathematical models and parameters ofgastric cancer cells, we intend to prove the internal relations between parameters ofmathematical models and gastric cancer cells. In this way, paving the a better way forachieving early detection of Gastric cancer and master the pathogenesis of electricalcharacteristics of gastric cancer cells.Methods GES-1and MGC-803were selected as an object in this study, we performcell culture work,then prepare cell suspension to make cultured cells into a sphericalmorphology after centrifugating to acquire the same concentration of the two cellsuspension. Dielectric spectroscopy of GES-1and MGC-803cell suspensions wasmeasured by the Agilent4294A impedance analyzer over the frequency range from0.1MHz to100M Hz, using of plan plots,loss factor,imaginary part of conductivity and losstangent to make sure characteristic parameters. Finally, we observe the change of two cellCole-Cole parameters by Cole-Cole formula and curve fitting residual analysis.Result（1） Dielectric spectroscopy of GES-1and MGC-803have frequency-dependent: withthe frequency increasing, the dielectric constant increment（Δε=ε-εh） of two cellsdecrease,while the conductivity increment （Δκ=κ-κL） increase in the10kHz—100MHz range.（2） Dielectric spectroscopy of two cells have a hematocrit dependence:When thehematocrit goes up， Maximum dielectric constant increment （Δκmax=κh-κL）, themaximum conductivity increment （Δκmax=κh-κL）,dielectric loss factor peakP1=ε”p（f₁）,P2=κ”p（f₂）,P3=κ”p（f₃）and dielectric loss tangent peak tgδpall increase.（3） The dielectric relaxation of GES-1cells show three characteristic frequency（f₁,f₂,f₃）and f₁=0.276±0.075MHz,f₂=1.453±0.272MHz，f₃=11.689±2.943MHz.The dielectric spectral characteristics of MGC-803cells also dependson hematocrit from0.01M Hz to100M Hz range. The dielectric relaxation of MGC-803cells show three characteristic frequency （f₁,f₂,f₃），and f₁=0.452±0.059MHz,f₂=1.3±0.103MHz,f₃=10.849±1.388MHz.（4） The dielectric spectral behavior of the MGC-803and GES-01were characterizedby three Cole-Cole mathematical model and curve fitting residual was less than5%.（5） The curve ε is not a significant difference between MGC-803and GES-01,but theconductivity （κ）curve was upper than GES-1, increasd by3.19%at κLand10.32%up of κhat Hct30%. It shows that MGC-803cell conductive propertiesincrease. Dielectric loss factor peak P1drops by14.89%, P2increases by16.67%,compared with GES-01,the first characteristic frequency raises by28%,the secondcharacteristic frequency goes up by41.38%,the third characteristic frequencyincreases but not statistically significant.Conclusion（1） Dielectric behavior of GES-1and MGC-803have three characteristics: thefrequency dependence is that the dielectric constant increment and conductivityincrement are with the frequency changes; when the hematocrit go up, Δε and Δκincreases that we called hematocrit dependence; dielectric relaxation has threecharacteristic frequency （f₁,f₂,f₃） which f₁derived from the cell membrane,f₂fromthe nuclear membrane,and f₃from the nucleolus.（2） Compared with the human gastric cells,the human gastric cancer cells shows thatthe value of κL and κh increase and that the first characteristic frequency and thesecond characteristic frequency raises,while the third characteristic frequencydecreased.（3） Establishment of the mathematical model of the human gastric cancer cell （MGC-803） will improve the electrical properties of gastric cancer related disease andprovide new means of research and evaluation.