Alginate is a popular biomaterial in tissue engineering. When crosslinked with calcium ions (Ca2+), alginate forms a hydrogel which provides necessary mechanical support as a scaffold. The material properties as well as the biological properties of alginate scaffold are of great importance. In this thesis, the aim is to use traditional methods, such as scanning electron microscopy (SEM) and light microscopy, and emerging X-ray imaging techniques, such as micro-computed tomography (micro-CT) and synchrotron radiation (SR) X-ray imaging, to characterize the alginate scaffolds. Firstly, the material properties of freeze-dried alginate scaffolds were evaluated using micro-CT, as it is a non-destructive and non-invasive imaging method, and can provide three-dimensional information. Alginate scaffolds made with different sodium alginate concentrations and frozen to different temperatures were scanned and analyzed in micro-CT. Results indicated that lower freezing temperature and higher sodium alginate concentration lead to smaller pore size and porosity. Secondly, cell culture experiments were carried out to study the biological properties and the interactions of alginate hydrogel with cells. A Schwann cell line was either blended with alginate solution before crosslinking with calcium chloride (CaCl2) or put around alginate gel in the culture dish. Light microscopy of sectioned slices showed that cells surrounding the alginate gel could not grow into the gel, while cells blended with alginate solution before crosslinking could proliferate inside the hydrogel. Cells grown inside a thin slice of alginate gels appeared to be in better condition and were larger in size and also grew in clusters. Thirdly, in order to image soft tissue buried inside alginate gels, such as brain slices, novel imaging methods based on synchrotron radiation (SR) were applied, such as absorption and phase contrast imaging, diffraction-enhanced imaging (DEI) and also combined with computed tomography (CT). Synchrotron-based monochromatic X-ray imaging proved to be good at distinguish objects of similar density, especially biological soft tissue samples, even without any staining material, such as osmium tetroxide (OsO4). These three pieces of research work show the potential in applying the emerging X-ray imaging in soft tissue engineering.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-10192010-194128 |
| Date | 25 October 2010 |
| Creators | Guan, Yijing |
| Contributors | Chen, Daniel X.B., Chapman, Dean, Cooper, David M. L., Schreyer, David, Dinh, Anh |
| Publisher | University of Saskatchewan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-10192010-194128/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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