Microsystems manufacturing technologies for pharmaceutical toxicity testing

Macdonald, Niall Patrick (2013) Microsystems manufacturing technologies for pharmaceutical toxicity testing. PhD thesis, University of Glasgow.

Abstract

To meet the demands of political, ethical and scientific pressures on animal testing, research into possible alternatives is required. Data obtained with animal models often cannot be related to humans. Testing with current cell-based assays, microdosing and pharmacokinetic models contribute to reducing animal testing and improving the drug development process. Micro-fabrication and rapid prototyping techniques offer potential solutions to reduce the need for animal toxicity testing.
The aim of this research was to develop biological platforms for in vitro toxicity testing to provide physiologically relevant, high-throughput solutions to reduce animal testing. This was achieved by investigating and integrating microfabrication methods of microfluidics, dielectrophoresis and additive manufacturing.
Three approaches were taken: (i) micro-pattern protein arrays for primary hepatocyte cell culture enclosed within microfluidics devices for high-throughput toxicity testing. It was observed that hepatocytes attached to the micro-pattern within microfluidics and maintained viability, however liver specific functions observed by florescence assays, the P450 enzymes, were observed to be reduced compared to Petri dish conditions. (ii) A biomimetic dielectrophoretic cell patterning technique to form liver lobule-like tissue structures within agar on a paper substrate was developed for toxicity testing. Observation of these biomimetic micro liver structures showed high viability (80-90%) and an increase in liver specific function marker albumin protein (20%) compared to control samples after 48 hours. (iii) Rapid prototyping methods were explored with regard to fabrication of microfluidic chips for the automated trapping, imaging and analysis of zebrafish embryos. Monolithic microfluidic chips for zebrafish were developed to be suitable for optical based toxicity assays. The biocompatibility of 3D printed materials was investigated. A method to render the photopolymer Dreve Fototec 7150 compatible with zebrafish culture was observed to provide 100% viability.
Future development of this research will aim to (i) develop the liver lobule-like system to use layers of multiple cell types to form complex micro-liver models using additive manufactured microfluidic systems for toxicity testing. (ii) Automation of zebrafish handing using additive manufactured microfluidic devices for in-situ analysis of dechorionated zebrafish for high-throughput toxicity studies.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: toxicity testing replacements, microfluidics, microfabrication, dielectrophoresis, 3D printing, stereolithography, hepatocytes, lab-on-a-chip, zebrafish, biocompatibility
• Subjects: Q Science > Q Science (General); Q Science > QR Microbiology; T Technology > TA Engineering (General). Civil engineering (General)
• Colleges/Schools: College of Science and Engineering > School of Engineering > Biomedical Engineering
• Supervisor's Name: Cooper, Prof. Jonathan
• Date of Award: 2013
• Depositing User: Dr Niall Patrick Macdonald
• Unique ID: glathesis:2013-5070
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Apr 2014 07:47
• Last Modified: 14 Apr 2014 07:54
• URI: https://theses.gla.ac.uk/id/eprint/5070