Evaluating the use of laser processing and polishing techniques to generate micro-patterned surfaces for controlling fibroblast cell behaviour

The aim of this thesis was to develop novel micro and nano polymer substrates through different surface patterning techniques to compare their effect on human lung fibroblast (LL24) and bovine aorta endothelium (BAE-1) cell behaviours. The cells ability to adhere, proliferate and migrate were studied through the use of MTT assays and live cell tracking. Laser processing in a directional manner resulted in polyurethane surfaces having a ploughed field effect with micron-scale features a novel surface. In contrast, abrasive polishing in a directional and random manner resulted in polyurethane surfaces having sub-micron scale features orientated in a linear or random manner. The cell results showed that for both the LL24 and BAE-1 cells the laser and randomly organised abrasive surface prompted cell adhesion when compared to the linear polished surface and non-patterned surfaces. The linear polished features did not enhance cell proliferation for wither cell type when compared to the flat surface. For cell migration a clear difference can be seen between the cell types with the LL24 cells showing a decrease in cell migration on the laser and random abrasive surface. The BAE-1 cells showed enhanced migration on the non-patterned surface when compared to the other surfaces. This work was expanded to include different polished surfaces through the use of different grades of polishing paper. The results for the LL24 cells showed that though the polished surfaces promoted adhesion when compared to the non-patterned surface there was no clear difference between the surfaces for cell proliferation and migration. The BAE-1 cells results showed a similarity to the LL24 cells with the polished surfaces promoting adhesion when compared to the non-patterned surface. There was a clear distinction for the proliferation results with the LL24 cells showing enhanced proliferation on the scratched surface, this is in contrast to the BAE-1 cells which were enhanced on the non-patterned surfaces compared to the scratched surfaces. A final study was performed to introduce the use of machine grinding to generate surfaces with micro-sized features and their ability to affect cell behaviour. Results are presented which show that polyurethane castings of the ground surfaces can promote LL24 cell adhesion and migration, demonstrating that this method can be a cost effective technique to be used in this field.