Study of morphological and compositional influence on bioartificial hepatic microenvironments within electrospun polycaprolactone scaffolds
View/ Open
Date
16/08/2022Author
Bate, Thomas
Metadata
Abstract
Liver disease is a leading cause of death throughout the world and has seen rising mortality
rates since the 1970s in contrast to other leading causes of death such as cardiovascular
disease and cancer. A quarter of the global population is predicted to have non-alcoholic fatty
liver disease (NAFLD) and are at risk of developing chronic conditions such as fibrosis and
hepatocellular carcinoma (HCC). There currently exist no approved pharmaceutical
therapeutics for the treatment of liver disease and disease management is particularly
complex to negotiate. End-stage liver disease presents a significant threat to life and the only
cure is to replace the chronically damaged liver with a transplant. To ease the burden on liver
disease patients and health workers, it is necessary to find pharmaceutical and regenerative
therapies that can effectively hinder disease progression. Reaching such treatments implies
the use of in-vitro methods to produce liver models for testing target and drug molecules, for
the expansion of cells with regenerative capacity and for bioartificial liver devices. In-vitro
hepatocyte culture methods have progressed in recent decades from standard 2D tissue
culture to 3D organoids and scaffolded cultures which provide a biomimetic environment and
elicit phenotypic responses from hepatocytes in-vitro. This thesis has sought to optimise
electrospun polycaprolactone (PCL) scaffolds for the culture of hepatocytes, with a focus on
morphology and composition, through three methods: 1) assessment of the influence of
electrospun PCL fibre diameter and morphology on hepatocyte culture 2) the inclusion of rat
liver extracellular matrix (rLECM) into hybrid PCL:rLECM scaffolds 3) the inclusion of human
liver ECM (hLECM) into hybrid PCL:hLECM scaffolds with a comparison of donor-to-donor
variance. All fabricated scaffolds were subject to physical and chemical analyses and cultured
with an immortalised hepatic cell line (HepG2) or Primary Mouse Hepatocytes (PMHs). The
biological influence of the scaffolds on cell cultures was assessed through proliferation
analysis, immunohistochemistry and RT-qPCR gene expression analysis of cultured cells. Our
results show that fibre morphology affects the attachment, morphology and proliferation of
hepatocytes. The architecture of the cells upon the scaffolds also shows to affect cell function
through significant upregulation of key hepatic phenotypic markers on scaffolds with higher
porosity. Incorporation of both rLECM and hLECM into electrospun scaffolds with
morphological consistency has been demonstrated. rLECM at concentrations of 5 w/w% and
10 w/w% shows to significantly increase the proliferative activity of HepG2 cultures. The
incorporation of hLECM at a 1 w/w% concentration demonstrated variable proliferative activity
of HepG2 between tissue donors whilst functional gene expression is maintained across
donors. Biological differences between the immortalised cell line (HepG2) and Primary Mouse
Hepatocytes are reflected in functional response differences observed upon different scaffold
microenvironments. These studies show that the morphology and composition of electrospun
polycaprolactone scaffolds can have a measurable impact on hepatocyte cultures and our
methods hold potential for the development of utile in-vitro hepatic microenvironments.
Collections
Related items
Showing items related by title, author, creator and subject.
-
Scaffolds and signals: design and development of a 3D printed bioreactor and electrospun polymer scaffolds for kidney tissue engineering
Burton, Todd Peter (The University of Edinburgh, 2019-07-03)There is a pressing need for further advancement in tissue engineering of functional organs with a view to providing a more clinically relevant model for drug development and reduce the dependence on organ donation. ... -
The Impact of Additional Training on Scaffolding Teachers Knowledge of Emotional Understanding
Mackay, Kathryn (The University of Edinburgh, 2015) -
Scaffolding Teachers' Interaction With Children Via The Application Of Emotion Works Within The Classroom
Clements, Fiona (The University of Edinburgh, 2015)