Cellular biology is regulated by the exchange of electric charge and chemicals between the intracellular and extracellular environments. Such exchange is operated by ionic channels, which are protein tunnels across the cell membrane walls filled with ions and water. Ionic channels are responsible for fundamental functions in the life of organisms: control of electrical signaling in the nervous system; coordination of muscle contraction (in particular the heart); regulation of uptake of foodstuffs in the intestine, secretion of hormones, and many more. Recent discoveries in bio- and nano-technology have given the opportunity of building synthetic nanochannels, which have a wide range of applications: biosensing, DNA detection, drug delivery and nanofluidics. The study of ionic transport is thus crucial for controlling the flow of ions across the nanopore and for understanding how biological channels function. To this purpose, theoretical and computational modeling of ionic transport can be used as a supporting tool to experimental analysis and design of bio-synthetic structures. In this thesis work a novel contribution to the modeling and simulation of ion channels is the introduction of a hierarchy of hydrodynamic models for charge transport through ionic channels. Special interest is devoted to the analysis of temperature changes and consequent thermal exchanges, which are usually neglected in conventional theories. Extensively conducted simulations indicate that temperature changes affect ion permeation in the nanochannels studied here. Simulations also display a strong dependence of the computed solutions on saturation velocity parameter, which can affect system behaviour with respect to heat changes since it prescribes the collision frequency of ions. Lack of quantitative information of such parameter is a limitation of the present analysis and deserves further experimental investigation. Finally, computational experiments demonstrate that the effect of nonlinear convective terms is relatively small so that they can be neglected without severely affecting the accuracy of the prediction of system dynamics.

Thermo-electro-chemical modeling and simulation of ion transport in nanochannels

MANGANINI, FABIO
2012/2013

Abstract

Cellular biology is regulated by the exchange of electric charge and chemicals between the intracellular and extracellular environments. Such exchange is operated by ionic channels, which are protein tunnels across the cell membrane walls filled with ions and water. Ionic channels are responsible for fundamental functions in the life of organisms: control of electrical signaling in the nervous system; coordination of muscle contraction (in particular the heart); regulation of uptake of foodstuffs in the intestine, secretion of hormones, and many more. Recent discoveries in bio- and nano-technology have given the opportunity of building synthetic nanochannels, which have a wide range of applications: biosensing, DNA detection, drug delivery and nanofluidics. The study of ionic transport is thus crucial for controlling the flow of ions across the nanopore and for understanding how biological channels function. To this purpose, theoretical and computational modeling of ionic transport can be used as a supporting tool to experimental analysis and design of bio-synthetic structures. In this thesis work a novel contribution to the modeling and simulation of ion channels is the introduction of a hierarchy of hydrodynamic models for charge transport through ionic channels. Special interest is devoted to the analysis of temperature changes and consequent thermal exchanges, which are usually neglected in conventional theories. Extensively conducted simulations indicate that temperature changes affect ion permeation in the nanochannels studied here. Simulations also display a strong dependence of the computed solutions on saturation velocity parameter, which can affect system behaviour with respect to heat changes since it prescribes the collision frequency of ions. Lack of quantitative information of such parameter is a limitation of the present analysis and deserves further experimental investigation. Finally, computational experiments demonstrate that the effect of nonlinear convective terms is relatively small so that they can be neglected without severely affecting the accuracy of the prediction of system dynamics.
JEROME, JOSEPH W.
ING - Scuola di Ingegneria Industriale e dell'Informazione
18-dic-2013
2012/2013
Tesi di laurea Magistrale
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10589/88365