title: Breast Cancer Cell Detection and Profiling Using Nanomaterial-Derived Scaffolds
Creators: name: Akpe, Victor
Publisher: name: Griffith University
Year: 2021
Subjects: subject: Breast cancer
subject: Circulating tumour cells
subject: Cell culture preparation
subject: Electrochemical biosensor development
subject: Assay screening
subject: Fluorescence imaging
subject: Batch-assay studies
subject: Chemotherapeutic dose uptake

description: Background: The concentration of circulating tumour cells (CTCs) or cancer cell per mL in clinical blood sample is estimated to contain 106 white blood cells and 109 red bloods, suggesting CTCs are very rare. Other characteristics of cancer cells such as vulnerability in vitro, their minuscule sizes and variability (4-10 [microns]) in cluster, and the cancer cell subtypes and phenotypes etc. have been areas of intense research. Technological innovations have therefore focused on platforms for cancer cell detection, selective cancer cell capture, cancer cell separation/analysis platforms etc. Additionally, there has been increasing interest in biological and synthetic materials as cell-based scaffolds for preclinical screening. Methods: Breast cancer cells (BC) derived from a human adenocarcinoma were profiled using nanomaterial-derived scaffolds. This thesis utilises the following techniques to study the properties of BCs: cell culture preparation, electrochemical biosensor development, assay screening, fluorescence imaging, batch-assay studies, and estimation of the chemotherapeutic dose uptake of cancer cells in various assay systems (as outlined in detail in the relevant chapters). Results: Chapter 2 reviews the current literature and covers a broad spectrum related to the etiology of cancer cells and the mode of cellular invasion. Various nanotechnology platforms of selective CTC capture, separation, and detection of CTC encumbrance in patients' whole blood samples, as well as the significance of CTC as biological markers for tumour detection were extensively reviewed in that chapter. Chapter 3 utilises various cellular biological markers to characterise BC cell surface using an amperometry detection method. The positive assay produced six-fold current output compared to the negative controls. The nanozyme which contained iron oxide loaded with gold particles produced a wide capturing range (10-105 cells/ml) in phosphate-buffered saline (pH = 7.4). The limit of detection (LOD) was calculated at 0.4 U/ml. The cancer cells captured were later used in the post-expansion of BC cells in vitro, suggesting the potential expansion of BC phenotypes in cell-based scaffolds of 2D, 3D or 3D coculture platforms. Chapter 4 used substrate casts developed to potentiate growth inhibition of MCF-7 cells prior to cisplatin addition to the cells (Chapters 4 and 5). The results from Chapter 4 suggests that cisplatin exposed to MCF-7 cells on SNP: PEG substrate casts was more effective by 26-fold than in the control sample; 32 times more effective than SNP: PEG: fruit ethyl acetate extract of Terminalia ferdinandiana cast, and 8-fold more effective than SNP: PEG: leaf methanolic extract of the Terminalia ferdinandiana cast. Chapter 5 focuses on a table algorithm to reduce systematic errors from sample preparations, which otherwise can make the data incomprehensible, especially for cross-prediction performance as assay models. Lastly, Chapter 6 comments and summarises some of the cancer models in the 3D study and highlights future directions for the development and integration of 3D co-culture cell models on biosensor platforms for the detection and profiling cancer cells. Conclusions: Overall, the following objectives have been addressed in this thesis : (1) development of assay cascade methods for the efficient capture of BC cells and in the post-expansion of captured cells in vitro; (2) the development of an electrochemical based amplification method for BC detection and profiling the biomarker expression levels on BC cells; (3) development of an assay cascade method for differentiating BC cells and as synergistic platforms for effective drug dosing; and (4) the development of a simple algorithm for screening irrelevant cell-based scaffolds.