Thesis (Ph.D.)--Aberdeen University, 2009. / Title from web page (viewed on July 8, 2009). Includes bibliographical references.

The addition of silicon ions (10-500 μM) to the culture medium of MG63 osteoblast-like cells showed no changes in cell viability, metabolic activity, proliferation or morphology. Silicon ions resulted in a concentration-dependent increase in the expression of vascular endothelial growth factor (VEGF) by the MG63 cells. Addition of magnesium ions (1-50 mM) to the culture medium of MG63 cells caused a dose-dependent decrease in cell viability, metabolic activity and proliferation at each time point. In general, silicon and magnesium ions had no effect on the viability of a human endothelial cell line (HUVEC). A slight decreasing trend to the metabolic activity of the HUVECs was observed with increasing concentrations of silicon ions at all time points, but this decreasing trend was more pronounced with the addition of magnesium ions. The highest magnesium ion concentration studied (50 mM) caused a change in HUVEC morphology from a typical cobblestone appearance to a fibroblast-like shape. Lastly, the effect of silicon ions on angiogenesis <i>in vitro</i> was studied using two different <i>in vitro</i> assays. The first, using Matrigel as an extracellular matrix coating for the guidance of endothelial cells to form tube-like structures (an indicator of angiogenesis), proved unreliable for studying the promotion of angiogenesis. Additionally, tube-like structures were also observed with osteoblasts cells, raising questions about the efficiency of this assay. The second assay, AngioKit, was a suitable model for studying stimulation and inhibition of tube-like formation. Results obtained using this assay showed that silicon ions alone (500 μM) did not stimulate tube-like formation, but a significant increase in tube-like formation was observed with MG63 cell-conditioned media, with (500 μM) and without silicon ions, when compared to the control medium.