Thesis

Imaging of breast cancer using SERS and SESORS

Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2019
Thesis identifier
  • T15372
Person Identifier (Local)
  • 201563015
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • Breast cancer is one of the leading causes of oncologic mortality and morbidity among women worldwide. It is estimated that every 10 minutes one person is diagnosed with the disease in the UK, while 1 in 8 women will develop breast cancer at some point in their lives. Although different techniques, for the characterisation of cancer phenotype, exist there are still limitations as these approaches are destructive, require processed/fixed samples and are not suitable for 3D tumour samples and in vivo models. Surface enhanced Raman spectroscopy (SERS) overcomes these limitations as a non-destructive bioanalytical method that offers high specificity, selectivity and multiplex capacities, in comparison to conventional imaging techniques. The main aim of this research is to create a platform for targeting, detecting and tracking the intracellular distribution of estrogen receptor alpha (ERα) biomarker in breast cancer, using SERS combined with antibody functionalised gold nanoparticles (AuNPs). Specifically, the anti-ERα antibody functionalised AuNPs (ERα-AuNPs) were conjugated with 1,2-bis(4-pyridyl)ethylene (BPE) Raman reporter that enabled the spatial and temporal understanding of where ERα was located at a single cell level. The nanotags showed excellent biocompatibility with no cellular toxicity. 3D SERS cell mapping, under different endocytosis inhibition conditions, confirmed that ERα-AuNPs were using a temperature-dependent way for their uptake. Additionally, dynamin and membrane ERα were shown to be responsible, at least in a part, for the nanotags’ uptake in MCF-7 cells. Therefore, SERS provided an excellent biological insight of ERα-AuNPs uptake by generating 3D images of the entire cell volume, without the need for destructive, time consuming and expensive imaging methods such as transition electron microscopy (TEM). 2D and 3D SERS also confirmed the strong targeting effect of ERα-AuNPs against ERα since a higher SERS signal and nanotag accumulation were observed in MCF-7 cells (ERα+) compared to SKBR-3 (ERα-) breast cancer cells. SERS was also used for investigating the efficacy of fulvestrant, the first-in-class approved selective estrogen receptor degrader (SERD). The results confirmed that ERα-AuNPs can be used as a tool for identifying and characterising different breast cancer cells, based on ERα expression, and informing about SERDs activity in breast cancer. SERS also provided an excellent bioanalytical tool for the characterisation of breast cancer phenotype and the assessment of fulvestrant activity in a 3D environment using live MCF-7 spheroids formed in a microfluidic device. The results confirmed the great penetration capabilities and strong targeting effect of ERα-AuNPs towards ERα, compared to nonspecific anti-HER2 antibody functionalised AuNPs (HER2-AuNPs). Additionally, fulvestrant activity was found to have a lower therapeutic effect the 3D MCF-7 spheroids in comparison to the 2D cell cultures demonstrating that 2D and 3D tumour models had different biological and architectural behaviours that affected their sensitivity to fulvestrant. Therefore, SERS and microfluidics were used as a powerful analytical tool, that effectively bridged the gap between the 2D monolayer cultures and animal models, for breast cancer cells characterisation and investigation of fulvestrant efficacy. Finally, this thesis investigated the potentials for detection of ERα ex vivo and in vivo using a handheld SORS instrument with back scattering optics. SESORS allowed the detection of ERα-AuNP nanotags through tissue barriers of up to 15 mm thickness. Most importantly, it was possible to detect and track ex vivo the ERα-AuNPs incubated in live breast tumour spheroids buried at 10 mm porcine tissue. The in vivo work indicated that SESORS was detecting scattered photon from areas deeper than the breast cancer tumour, mainly due to the fixed optical arrangements of the spectrometer. Nevertheless, a higher signal was detected ex vivo in breast tumours in comparison to the liver after their removal from sacrificed animals, suggesting the strong targeting effect of ERα-AuNP nanotags to the tumour site. This thesis highlights the performance and capabilities of SERS, microfluidics and SESORS on detecting, targeting and tracking ERα and opens up exciting opportunities for using these techniques as non-destructive and sensitive tools for improved biomedical imaging in a clinical environment.
Advisor / supervisor
  • Graham, Duncan
  • Brunton, Val
  • Faulds, Karen
Resource Type
Note
  • This thesis was previously held under moratorium from 27/11/19 to 27/11/21
DOI
Date Created
  • 2019
Former identifier
  • 9912770192602996

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