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Title: Applications of nucleic acid aptamers in bioanalysis and targeted delivery
Author: Bandhaya, Achirapa
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2013
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The development of sophisticated analytical platforms for many biological specimens owes its success not only to aptamers’ high affinity and specificity for their targets, but also to their versatility. Functions, such as detection/capturing and signalling, can be built into an aptamer molecule. Despite a significant number of reports describing methods of aptamer-based target detection, not many of them are readily transferred into practical use in laboratories where antibodies remain the preferred affinity molecules. The studies presented herein, initially aimed to investigate the adaptability of aptamers as recognition tool in bioanalysis and targeted delivery, offer insights into the issues involved when optimising an aptamer for such applications. The first two results sections of this thesis focus on the development of protocols for aptamer-based assays to maximise the simplicity and robustness of target detection. A putative RNA aptamer with apparent affinity for a synthetic peptide containing a phosphotyrosine residue was further characterised in order to elucidate the context-dependence of its interaction with the target. Since the aptamer had been selected for an application in phosphoproteomics, techniques commonly used in the field, such as dot-blotting and electrophoretic mobility-shift assay, were explored for their compatibility with the aptamer. Surface plasmon resonance analysis was also used to validate the target binding of this aptamer. In the following chapter, the feasibility of using the selective removal of aptamer by target exposure as a means for detecting the presence of bacteria was investigated. The aptamer in each sample was quantified by capillary gel electrophoresis. An aptamer’s role as targeting molecule is described in the final part of the results section. The AS1411 aptamer with affinity for cell-surface nucleolin was conjugated to gold nanorods to facilitate a selective accumulation of these nanoparticles for photothermal ablation of cancer cells. Challenges associated with each of these techniques and suggestions for possible ways to overcome them are discussed.
Supervisor: Cass, Tony Sponsor: Government of Thailand ; Mahāwitthayālai Mahidon
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available