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The high performance of bone implants depends on the positive response of osteoblasts to the surface of the materials manufactured for the implant. Cell response in turn strongly depends on the nature of the initial interaction of macromolecules involved in cell adhesion and proliferation with the atomic structure of the surface of the material used for the implant. The initial interaction between bone specific extracellular matrix proteins and the solid substrate influences cell response at the cell-implant interface. This interaction is crucial for implant stability, long-term durability, and osseointegration. Despite extensive research undertaken to develop high-quality material for implants in order to improve the cell-substrate interaction, little is known about the significance of the atomic structure of the substrate and the role of molecular machinery involved in cell-substrate interaction. Using a combined approach involving material sciences and cell and molecular biology, the objectives of this research are to evaluate the response of pre-osteoblast and fibroblast cell lines to novel bulk polycrystalline and single crystal titanium based material and assess the role of crystal size and orientation. / Novel bulk nano-structured titanium substrates were produced by the process of high-pressure torsion (HPT). These materials have a significant advantage compared to conventional titanium-based materials by having higher surface wettablity, mechanical properties as well as a distinct surface oxide layer and atomic structure. A co-culture system was adapted to investigate the differential response of pre-osteoblast and fibroblast cell lines to titanium and titanium dioxide single-crystal substrates. / The results of this study provide clear evidence that crystal size and specific crystallographic orientation can be used to improve cell adhesion and proliferation. The nanostructured titanium substrates show strong interaction with pre-osteoblast cells as evident by the higher expression of fibronectin and the formation of extensive focal adhesion. Differential cell behaviour of pre-osteoblasts and fibroblasts are observed in cultures grown on the substrates with specific crystallographic orientations. The degree of cell attachment of the pre-osteoblasts is considerably higher on Ti-(1120) crystal face compared with the fibroblasts. These findings have profound implications for the improved osseointegration and inhibition of fibrosis leading to long-term implant consolidation and stability.

The FRIABLE1 (FRB1) gene is identified to be a novel glycosyltransferase involved in cell adhesion, based on reverse genetics and immunocytochemistry studies. A total of 31 FRB1 paralogues were found in Arabidopsis thaliana using a bioinformatics approach. The following expression analysis has revealed 6 FRB1 paralogues to be pollen-specific. One pollen-specific FRB1 paralogue, At1g14970, exhibits longer silique lengths when exposed to higher than normal temperature at 28oC in its T-DNA insertional knockout when compared to Columbia wildtype plants. This may be due to the loss of temperature sensing and the continuous stimulated pollen tube cell wall growth or the up-regulation of genes that encode other glycosyltransferases. Thus, the identification of FRB1 paralogues and homologues in both rice and poplar may have tremendous potential to increase their yield in global warming for agricultural and industrial benefits.

Thesis (Ph. D.)--Rutgers University, 2007. / "Graduate Program in Microbiology and Molecular Genetics." Includes bibliographical references (p. 86-107).

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 4 uppsatser.

Thesis (Ph. D. in Microbiology and Immunology)--Vanderbilt University, May 2008. / Title from title screen. Includes bibliographical references.

Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 2005. / "December 2004" Includes bibliographical references (leaves 342-379).

Thesis (Ph.D.). / Written for the Dept. of Biochemistry. Title from title page of PDF (viewed 2008/05/09). Includes bibliographical references.