Molecular MRI using exogenous enzymatic sensors and endogenous chemical exchange contrast

Molecular magnetic resonance imaging (MRI) methods have the potential to provide detailed information regarding cellular and molecular processes at small scales within the human body. Nuclear signals from chemical samples can be probed using specialised MRI techniques, to highlight molecular contras...

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Main Author: Taylor, Alexander John
Format: Thesis (University of Nottingham only)
Language:English
Published: 2016
Subjects:
Online Access:https://eprints.nottingham.ac.uk/35819/
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author Taylor, Alexander John
author_facet Taylor, Alexander John
author_sort Taylor, Alexander John
building Nottingham Research Data Repository
collection Online Access
description Molecular magnetic resonance imaging (MRI) methods have the potential to provide detailed information regarding cellular and molecular processes at small scales within the human body. Nuclear signals from chemical samples can be probed using specialised MRI techniques, to highlight molecular contrast from particular enzymes or metabolites. The aim of the work described in this thesis is to investigate both exogenous and endogenous contrast mechanisms using fluorine MRI and chemical exchange saturation transfer (CEST) respectively, in order to detect molecular changes in vitro. Initial theoretical work investigates the factors which affect fluorine MRI signals and provides a theoretical framework to determine the sensitivity of such experiments. A novel paramagnetic fluorine sensor to detect enzyme activity is then characterised using high field nuclear magnetic resonance (NMR), showing 60 to 70–fold increases in T1 relaxation values upon enzyme interaction. The effects on the fluorine lineshape from varying sample temperature and solvent were investigated. The possibility of imaging is demonstrated, but further investigations using the theoretical framework found pre–clinical implementation of the sensor is limited by the achievable experimental sensitivity. Efforts then focussed on CEST molecular methods, which are not limited by sensitivity. A protocol is developed to target amide protons in an in vitro cancer cell model, with parameters optimised following simulation of the expected contrast. Analysis of CEST results were aided through use of a support vector machine (SVM) to distinguish group differences between cancer cells and control samples. A linear classifier was found to be suitable to discriminate between samples.
first_indexed 2025-11-14T19:27:48Z
format Thesis (University of Nottingham only)
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institution University of Nottingham Malaysia Campus
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language English
last_indexed 2025-11-14T19:27:48Z
publishDate 2016
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spelling nottingham-358192025-02-28T13:31:51Z https://eprints.nottingham.ac.uk/35819/ Molecular MRI using exogenous enzymatic sensors and endogenous chemical exchange contrast Taylor, Alexander John Molecular magnetic resonance imaging (MRI) methods have the potential to provide detailed information regarding cellular and molecular processes at small scales within the human body. Nuclear signals from chemical samples can be probed using specialised MRI techniques, to highlight molecular contrast from particular enzymes or metabolites. The aim of the work described in this thesis is to investigate both exogenous and endogenous contrast mechanisms using fluorine MRI and chemical exchange saturation transfer (CEST) respectively, in order to detect molecular changes in vitro. Initial theoretical work investigates the factors which affect fluorine MRI signals and provides a theoretical framework to determine the sensitivity of such experiments. A novel paramagnetic fluorine sensor to detect enzyme activity is then characterised using high field nuclear magnetic resonance (NMR), showing 60 to 70–fold increases in T1 relaxation values upon enzyme interaction. The effects on the fluorine lineshape from varying sample temperature and solvent were investigated. The possibility of imaging is demonstrated, but further investigations using the theoretical framework found pre–clinical implementation of the sensor is limited by the achievable experimental sensitivity. Efforts then focussed on CEST molecular methods, which are not limited by sensitivity. A protocol is developed to target amide protons in an in vitro cancer cell model, with parameters optimised following simulation of the expected contrast. Analysis of CEST results were aided through use of a support vector machine (SVM) to distinguish group differences between cancer cells and control samples. A linear classifier was found to be suitable to discriminate between samples. 2016-12-16 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/35819/1/Alex_Taylor_thesis_revised_minor_corrections_added.pdf Taylor, Alexander John (2016) Molecular MRI using exogenous enzymatic sensors and endogenous chemical exchange contrast. PhD thesis, University of Nottingham. MRI 19F MRI CEST Matrix metalloproteinase Enzymatic sensor MRI contrast
spellingShingle MRI
19F MRI
CEST
Matrix metalloproteinase
Enzymatic sensor
MRI contrast
Taylor, Alexander John
Molecular MRI using exogenous enzymatic sensors and endogenous chemical exchange contrast
title Molecular MRI using exogenous enzymatic sensors and endogenous chemical exchange contrast
title_full Molecular MRI using exogenous enzymatic sensors and endogenous chemical exchange contrast
title_fullStr Molecular MRI using exogenous enzymatic sensors and endogenous chemical exchange contrast
title_full_unstemmed Molecular MRI using exogenous enzymatic sensors and endogenous chemical exchange contrast
title_short Molecular MRI using exogenous enzymatic sensors and endogenous chemical exchange contrast
title_sort molecular mri using exogenous enzymatic sensors and endogenous chemical exchange contrast
topic MRI
19F MRI
CEST
Matrix metalloproteinase
Enzymatic sensor
MRI contrast
url https://eprints.nottingham.ac.uk/35819/