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E-Thesis 195 views 77 downloads

Microstructure and mechanical properties of fibrin gels. / Thomas Marc Davies

Swansea University Author: Thomas Marc Davies

Abstract

"This thesis reports an extensive study of the structural and rheological characteristics of the three-dimensional fibrin clot network. The importance of blood clotting in the area of NanoHealth is testified to by the fact that complications due to thrombosis accounts for about 10 per cent of a...

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Published: 2009
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
URI: https://cronfa.swan.ac.uk/Record/cronfa42760
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Abstract: "This thesis reports an extensive study of the structural and rheological characteristics of the three-dimensional fibrin clot network. The importance of blood clotting in the area of NanoHealth is testified to by the fact that complications due to thrombosis accounts for about 10 per cent of all deaths in hospitals in the UK. It is therefore imperative to understand the clotting process of blood as fully as possible. The techniques implemented include confocal laser scanning microscopy, and rheo logical methods such as Fourier transform mechanical spectroscopy. Both techniques provide a foundation for performing a fractal analysis as a quantitative basis for defining, where appropriate, morphological/micro structural differentiation in clotting. Fractal analysis provides the framework for structural complexity and allows us to develop relationships between the structural features of blood clots and their rheological properties. The experimental methods involve following the mechanical properties of a gelling system up to and beyond the gel point. The mechanical (viscoelastic) properties of fibrin are significant and unique among polymers. Hence, they are essential to the physiology of blood clotting and vital for the understanding and therefore prevention and treatment of thrombosis. An unsatisfactory aspect of work in this area is that the micro structures of such clots are usually reported in only adjectival terms (e.g., "dense" or "tight") - usually on the basis of a visual inspection of fragments of desiccated clots in SEM micrographs. This work includes an extensive approach using confocal microscopy to visualise fibrin clot networks, with several forms of fractal analysis investigated for quantifying structural complexity. The present study is the first to report a modification of the fractal characteristics of incipient clots in fibrin-thrombin gels due to the availability of thrombin. This work confirms the hypothesis that the self-similar (fractal) stress relaxation behaviour recorded at the Gel Point of samples of coagulating blood (Evans et al., 2008) is associated with the micro structural characteristics of the incipient blood clot's fibrin network. It also supports the hypothesis that in various pathologies prothrombotic conditions can modify the underlying micro structure of a blood clot. The provision of a new technique capable of detecting the formation of altered clot microstructures at their incipient state could have significant clinical diagnostic potential e.g. in thromboembolic disease screening applications."
Keywords: Bioengineering.
College: Faculty of Science and Engineering