The Biodielectric Analysis For The Characterization Of Human Hepatic Carcinoma Cell Of SMMC-7721

Objective The dielectric characterization of human hepatic carcinoma cell line SMMC-7721cells andhuman liver cell line HL-7702cells were measured by non-invasived AC impedance technique. At the same time,mathematical model of liver cells was established by curve fitting to evaluate those changes in theelectrophysiological properities of hepatoma cells, and to provide a electrophysiological technical support for thedevelopment of anticancer drugs, liver cancer early diagnosis and screening.Methods The cellular models of SMMC-7721cell and HL-7702cell have been established in vitro culture.After that, spectra of the permittivity and conductivity of the two cells were measured using Agilent4294AImpedance Analyzer in the range of0.01MHz~100MHz. the dielectric characteristic parameters of the hepaticcarcinoma cells were extracted by using many kinds of comprehensive analysis tools, such as permittivityspectroscopy, conductivity spectroscopy, complex plots, loos factor and loss tangent. with the dielectriccharacteristic parameters, application and, the mathematical models of hepatoma cells have been established byresidual analysis and numerical calculation from trinomial Cole-Cole equations. Then, the reasons for changes inthe electrophysiological properties of hepatocellular carcinoma cells have been discussed by comparingphysiological characteristics between SMMC-7721and HL-7702.Result1) The dielectric behavior of SMMC-7721cell and HL-7702cell showed dependence of frequency. thepermittivity decreases and conductivity increase with the frequency increasing.2) The dielectric behavior of SMMC-7721cell and HL-7702cell showed dependence of the cell volumefraction (Φ). The increased Φ leads to the increased of maximum dielectric constant increment (Δεmax), maximumconductivity increment (Δκmax), the dielectric loss factor peak (P1,P2,P3) and the dielectric loss tangent peak.3) The dielectric increment (Δε1, Δε2, Δε3) and the relaxation distribution factor (β1, β3) are positivelyassociated with Φ.But the relaxation distribution factor (β2) showed a negative correlation with Φ. Thecharacteristic frequency (fC1, fC2, fC3) had no correlation with Φ.4) The low-frequency limit of permittivity (εL) and the high-frequency limit of permittivity (εh) ofSMMC-7721increased of10.7%(P>0.05) and3.47%(P <0.001) compared with HL-7702cell, respectively.The low-frequency limit of conductivity (κL) and the high-frequency limit of conductivity (κh) of SMMC-7721decreased of3.69%(P <0.01) and0.91%(P>0.05) compared with HL-7702cell, respectively. The dielectricloss factor peak (P1, P2, P3, P4) of SMMC-7721increased up to31.70%(P <0.001),5.84%(P <0.001),11.41%(P <0.001) and5.48%(P>0.05) compared with HL-7702cell,respectively. The degradation rate of thecharacteristic frequency (fC1, fC2, fC3) of SMMC-7721were13.78%(P <0.05),19.94%(P<0.01) and21.27%(P<0.001) comparing with control group.5) The cell diameter of SMMC-7721and HL-7702were16.97±2.79um and15.58±1.93um respectively.The former was larger8.91%(P <0.001) than the latter.ConclusionThe dielectric characteristics of human hepatic carcinoma cell line SMMC-7721Cells: 1) Frequency dependency that dielectric constant (ε), the dielectric loss increment (Δε”), conductivity (κ),the conductivity loss increment (Δκ”) and loss tangent increment (Δtgδ) change with frequency.2) Φ-dependent that ε, Δε”, Δκ’, Δκ” and Δtgδ will increase with Φ increasing, meanwhile, κ will decreasewhen Φ is increasing.3) In the cells there are three characteristic frequencies (fC1, fC2, fC3), which fC1, fC2, fC3derived fromcytomembrane, nuclear envelope, nucleolus.4) The dielectric increment (Δε1, Δε2, Δε3) and the relaxation distribution factor (β1, β3) are positivelyassociated with Φ.But the relaxation distribution factor (β2) showed a negative correlation with Φ. Thecharacteristic frequency (fC1, fC2, fC3) had no correlation with Φ.5) Comparing with HL-7702cell, in addition to conductivity reduced, the nsulating property, the dielectricloss (Δε”, Δκ”) and Δtgδ from the dielectric behavior of SMMC-7721cells have increased.6) The SMMC-7721cells have lower frequency than HL-7702cells in characteristic frequency. Thatreason may be that SMMC-7721cells have larger cell diameter than HL-7702cells.Hence, the dielectric characteristic parameters of cells can be used as measurement index that can be used toovserve cell internal structure (such as cytomembrane, nuclear envelope, nucleolus) and offer a theoreticalfoundation for enrichment, isolation, purification of hepatoma cells when a variety of factors,for instance, drugs,temperature, pressure, centrifugal force, etc, effect on cells.