White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

Development of tissue engineered blood vessels using cell-seeded acellular porcine arterial scaffolds

Tatterton, Mark Richard (2015) Development of tissue engineered blood vessels using cell-seeded acellular porcine arterial scaffolds. M.D. thesis, University of Leeds.

[img]
Preview
Text
MRT MD Thesis-2015.pdf - Final eThesis - complete (pdf)
Available under License Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales.

Download (12Mb) | Preview

Abstract

The patency rate of small diameter synthetic bypass grafts remains poor. The aim of this study was to develop a biocompatible, acellular, arterial scaffold, assess the scaffolds regenerative capacity using ovine vascular cells and begin preliminary studies of a vascular tissue bioreactor for the development of a tissue engineered graft for peripheral and coronary arterial bypass. Porcine carotid arteries were decellularised using a protocol developed at the University of Leeds. Arteries were incubated sequentially in disodium ethylenediaminetetraacetic acid, hypotonic solution, sodium dodecyl sulphate [0.1% w/v], DNAse and RNAse, hypertonic solution and 0.1% (v/v) peracetic acid. To ensure decellularisation, representative arterial histological sections were stained using haematoxylin and eosin and 4’,6-diamidino-2-phenylindole to confirm removal of cells and cell nuclei. The total DNA content of treated arteries was also determined. Biocompatibility of the acellular scaffolds was assessed using contact and extract cytotoxicity assays using both primary cells (porcine and ovine endothelial cells and smooth muscle cells) and two distinct cell lines (murine 3T3 and BHK cells). Ovine endothelial cells were harvested from the femoral arteries of sheep following digestion with collagenase. Ovine smooth muscle cells were isolated from ovine arterial explant cultures. To determine correct cell phenotype, immuno-staining was performed using a variety of primary antibodies to vascular cell markers by indirect immunofluorescence. Ovine vascular cells were then seeded onto the luminal surface of the decellularised vessels in both a two-dimensional and three-dimensional manner. A cell viability assay (Live / Dead Stain ®) was performed to confirm the viability of seeded cells. A vascular bioreactor was successfully assembled and preliminary sterility runs were performed in preparation for future scaffold pre-conditioning. The decellularisation protocol resulted in porcine carotid arteries that were free from cells with >90% of the total DNA being removed. The decellularised porcine carotid artery was not cytotoxic to any test cells. Indirect immunofluorescence performed on the harvested cells confirmed correct ovine endothelial cell and smooth muscle cell phenotype after cell isolation using magnetic bead separation. Ovine vascular cells were successfully seeded onto the luminal matrix of decellularised arteries in both two-dimensional and three-dimensional experiments. Seeded cells were viable at 48 hours post incubation. A vascular bioreactor was successfully assembled and was kept free from macroscopic microbial contamination for a maximum of fourteen days. In conclusion, porcine carotid arteries were successfully decellularised using an established decellularisation protocol. The remaining acellular scaffolds demonstrated capability in allowing the attachment and proliferation of xenogeneic vascular cells onto the scaffold surface. Further work developing a vascular bioreactor in order assess the functionality and ongoing cell viability of the seeded scaffold will be needed to assess the efficacy of decellularised porcine carotid artery as a viable conduit for arterial bypass.

Item Type: Thesis (M.D.)
Academic Units: The University of Leeds > Faculty of Biological Sciences (Leeds)
The University of Leeds > Faculty of Medicine and Health (Leeds)
The University of Leeds > Faculty of Medicine and Health (Leeds) > Institute of Molecular Medicine (LIMM) (Leeds)
Identification Number/EthosID: uk.bl.ethos.682271
Depositing User: Dr Mark Richard Tatterton
Date Deposited: 07 Apr 2016 08:56
Last Modified: 26 Apr 2016 15:45
URI: http://etheses.whiterose.ac.uk/id/eprint/12460

You do not need to contact us to get a copy of this thesis. Please use the 'Download' link(s) above to get a copy.
You can contact us about this thesis. If you need to make a general enquiry, please see the Contact us page.

Actions (repository staff only: login required)