THESIS
2013
xvi, 136 pages : illustrations ; 30 cm
Abstract
A nonlinear dynamic electro-mechanical model for a single-cell electroporation device
(EP) is proposed based on micro EP experimental results. This model considers the behavior
of electromechanical components of a biological cell, the electric components of the media
together with the device’s electrical components. There are four state variables for the
proposed EP model including the voltage across the micro electrodes for EP, the
transmembrane voltage, the average radius of pores and the cell membrane pore density. The
numerical simulation of the model demonstrates good agreement with the experimental data.
The predicted current responses show a much better agreement (8% error) with the micro EP
experiments in comparison with the previous models. The model predicts the critic...[
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A nonlinear dynamic electro-mechanical model for a single-cell electroporation device
(EP) is proposed based on micro EP experimental results. This model considers the behavior
of electromechanical components of a biological cell, the electric components of the media
together with the device’s electrical components. There are four state variables for the
proposed EP model including the voltage across the micro electrodes for EP, the
transmembrane voltage, the average radius of pores and the cell membrane pore density. The
numerical simulation of the model demonstrates good agreement with the experimental data.
The predicted current responses show a much better agreement (8% error) with the micro EP
experiments in comparison with the previous models. The model predicts the critical
transmembrane voltage which is in good agreement with previous derived values from
experiments. In addition, the proposed model can explain various aspects of structural
changes of the cell membrane during different stages of electroporation, such as the Current-Voltage (I-V) characteristics of the cell membrane, the number of electropores and average pore radius. The numerical I-V characteristics of a nanoscale electropore on the cell
membrane during EP illustrates the formation and expansion of the electropore during
different stages of EP is analogous to the electric breakdown of the PNP junction in a
semiconductor DIAC (diode for alternating current). The proposed model illustrates that the
cell size is important to determine the system specifications. Based on the proposed EP model,
a single-cell EP system is designed and fabricated to determine the cell size using on-chip
micro Coulter counter and to apply the optimal electric field to achieve high EP efficiency and
cell viability. The fabricated single-cell EP microchip is tested using HeLa cells.
An EP electric field optimizer microchip is designed and fabricated to derive the optimal
applied electric field for different sizes of the suspended HeLa cells. Compare to
commercialized Electroporators, the fabricated device reduces the required applied voltage
from several kV to several volts. The viability and permeability of HeLa cell line for the
typical macro EP system are 50% and 65% respectively. For the open loop micro EP systems,
the typical viable and permeabilized HeLa cells for applied electric field of 1.1 kV/cm are
76% and 75% respectively. The smart closed loop micro EP system improves the viability
and permeabilization of cells to more than 90%.
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