The aims of the project were to produce and characterise phosphate-based glasses and glass-fibres, which were to be utilised as cell delivery vehicles. Initially the project aim was to attach muscle cells to the fibres in order to formulate alternative therapies for diseases such as Muscular Dystrophy. However, as the project progressed other cell types were also evaluated for the biocompatibility of the glass-fibres produced. Using a custom built fibre-rig (UCL) glass fibres were produced from compositions based on the ternary P205-CaO-Na20 glass system. These glasses were composed of ionic components that already exist in the body and thus minimal inflammatory responses were expected. This glass system had been investigated within the department, where the P205 content was fixed at 45 mol%, with the CaO and Na20 mol% making up the remainder. Initial studies revealed that fibres could not be produced from these compositions, and this was attributed to the structure of the glasses. By increasing the phosphate content to 50 and 55 mol% P205i glass fibres were successfully produced. Thus it was ascertained that a minimum of 50 mol% P205 was required for fibre production. Further analysis revealed that these ternary compositions proved to be too soluble for cell attachment. A quaternary component, boric oxide (B203), was added in order to reduce the degradation rates obtained. This was added due to the fact that B203 is a well known glass former. Further analysis revealed that B203 did reduce the degradation rates, however, these compositions also proved to be too soluble for cell attachment and proliferation to occur. A further quaternary component, iron oxide (Fe20s), was investigated. This was because iron is a naturally occurring ion within the body therefore, no inflammatory responses were expected. Fe2C > 3 was incorporated at 1 - 5 mol% substituted for Na20. It was seen that there was an order of magnitude difference with the degradation rates ranging from 1 - 5 mol% Fe203. Furthermore, it was seen that compositions containing 4-5 mol% Fe2C > 3 were sufficient for successful cell attachment and differentiation of muscle precursor cells. A further series of glasses were also investigated, incorporating silicon as the quaternary component. Silica was chosen due to the large volume of literature focusing on silica based glasses, with the well known Bioglass . Silicon was incorporated at 1- 5 mol%, and it was seen that silicon totally disrupted the glass network.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:684727 |
| Date | January 2005 |
| Creators | Ifthkar, A. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1445248/ |
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