Dynamics of magnetic nanoparticle chain formation and its effects on proton transverse relaxation rates

Rahi Varsani

Research output: ThesisDoctoral Thesis

Abstract

[Truncated abstract] Magnetic nanoparticles have several important biomedical applications including targeted drug delivery, hyperthermia treatment and MRI contrast enhancement. A magnetic nanoparticle suspension exposed to a uniformmagnetic field can result in linear agglomeration through a process known as chain formation. Importantly, the effects of magnetic nanoparticle chain formation on biomedical applications are not well understood and could be favourable or unfavourable depending on the specific application.

It has been observed in recent literature that chain formation can reduce the proton transverse relaxation rates of magnetic nanoparticle suspensions, affecting their performance as MRI contrast agents over time. The time dependent behaviour of relaxation rates presents challenges for interpreting data for applications such as quantitative MRI. Understanding the physics behind chain formation and its effects on proton transverse relaxation rates is an important area of study that could lead to the development of enhanced magnetic nanoparticle systems for biomedical applications.

A major aim of the research was to study the effects of magnetic nanoparticle parameters such as concentration and size on the rate and extent of chain formation. This was achieved through the application of a coarse-grain chaining simulation model across an array of magnetic nanoparticle suspension parameters. The simulation results led to the development of an analytical model that predicts the dynamic exponent of a system from its volume fraction and magnetic coupling parameter.
LanguageEnglish
QualificationDoctor of Philosophy
StateUnpublished - 2014

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nanoparticles
protons
hyperthermia
agglomeration
delivery
drugs
simulation
exponents
physics
augmentation

Cite this

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title = "Dynamics of magnetic nanoparticle chain formation and its effects on proton transverse relaxation rates",
abstract = "[Truncated abstract] Magnetic nanoparticles have several important biomedical applications including targeted drug delivery, hyperthermia treatment and MRI contrast enhancement. A magnetic nanoparticle suspension exposed to a uniformmagnetic field can result in linear agglomeration through a process known as chain formation. Importantly, the effects of magnetic nanoparticle chain formation on biomedical applications are not well understood and could be favourable or unfavourable depending on the specific application. It has been observed in recent literature that chain formation can reduce the proton transverse relaxation rates of magnetic nanoparticle suspensions, affecting their performance as MRI contrast agents over time. The time dependent behaviour of relaxation rates presents challenges for interpreting data for applications such as quantitative MRI. Understanding the physics behind chain formation and its effects on proton transverse relaxation rates is an important area of study that could lead to the development of enhanced magnetic nanoparticle systems for biomedical applications. A major aim of the research was to study the effects of magnetic nanoparticle parameters such as concentration and size on the rate and extent of chain formation. This was achieved through the application of a coarse-grain chaining simulation model across an array of magnetic nanoparticle suspension parameters. The simulation results led to the development of an analytical model that predicts the dynamic exponent of a system from its volume fraction and magnetic coupling parameter.",
keywords = "Magnetic nanoparticles, MRI, Relaxometry, Microscopy, Chain formation, Agglomeration, Dipolar interactions, Proton relaxivity",
author = "Rahi Varsani",
year = "2014",
language = "English",

}

TY - THES

T1 - Dynamics of magnetic nanoparticle chain formation and its effects on proton transverse relaxation rates

AU - Varsani,Rahi

PY - 2014

Y1 - 2014

N2 - [Truncated abstract] Magnetic nanoparticles have several important biomedical applications including targeted drug delivery, hyperthermia treatment and MRI contrast enhancement. A magnetic nanoparticle suspension exposed to a uniformmagnetic field can result in linear agglomeration through a process known as chain formation. Importantly, the effects of magnetic nanoparticle chain formation on biomedical applications are not well understood and could be favourable or unfavourable depending on the specific application. It has been observed in recent literature that chain formation can reduce the proton transverse relaxation rates of magnetic nanoparticle suspensions, affecting their performance as MRI contrast agents over time. The time dependent behaviour of relaxation rates presents challenges for interpreting data for applications such as quantitative MRI. Understanding the physics behind chain formation and its effects on proton transverse relaxation rates is an important area of study that could lead to the development of enhanced magnetic nanoparticle systems for biomedical applications. A major aim of the research was to study the effects of magnetic nanoparticle parameters such as concentration and size on the rate and extent of chain formation. This was achieved through the application of a coarse-grain chaining simulation model across an array of magnetic nanoparticle suspension parameters. The simulation results led to the development of an analytical model that predicts the dynamic exponent of a system from its volume fraction and magnetic coupling parameter.

AB - [Truncated abstract] Magnetic nanoparticles have several important biomedical applications including targeted drug delivery, hyperthermia treatment and MRI contrast enhancement. A magnetic nanoparticle suspension exposed to a uniformmagnetic field can result in linear agglomeration through a process known as chain formation. Importantly, the effects of magnetic nanoparticle chain formation on biomedical applications are not well understood and could be favourable or unfavourable depending on the specific application. It has been observed in recent literature that chain formation can reduce the proton transverse relaxation rates of magnetic nanoparticle suspensions, affecting their performance as MRI contrast agents over time. The time dependent behaviour of relaxation rates presents challenges for interpreting data for applications such as quantitative MRI. Understanding the physics behind chain formation and its effects on proton transverse relaxation rates is an important area of study that could lead to the development of enhanced magnetic nanoparticle systems for biomedical applications. A major aim of the research was to study the effects of magnetic nanoparticle parameters such as concentration and size on the rate and extent of chain formation. This was achieved through the application of a coarse-grain chaining simulation model across an array of magnetic nanoparticle suspension parameters. The simulation results led to the development of an analytical model that predicts the dynamic exponent of a system from its volume fraction and magnetic coupling parameter.

KW - Magnetic nanoparticles

KW - MRI

KW - Relaxometry

KW - Microscopy

KW - Chain formation

KW - Agglomeration

KW - Dipolar interactions

KW - Proton relaxivity

M3 - Doctoral Thesis

ER -