The modulation of biological interactions with artificial surfaces is a vital aspect of biomaterials research. Protein adsorption is established as an early biological response to implanted materials that influences biocompatibility, hence an understanding of how to direct specific protein and cellular responses is critical for the development of future biomaterials. The effects of protein adsorption and subsequent cellular interactions on a variety of surfaces are investigated. Acrylic-based hydrogels are used as a model system in which to investigate both tear and serum protein adsorption from simple and complex solutions. The effect of surface topography, created by colloidal silica, on serum protein adsorption and conformation as well as cell adhesion is also investigated. Tantalum (Ta) and oxidised polystyrene (PSox) are investigated for their ability to support cell adhesion when precoated with various serum proteins. Protein interactions are examined using a combination of quartz crystal microbalance with dissipation (QCM-D), surface plasmon resonance (SPR), dual polarisation interferometry (DPI) and enzyme-linked immunosorbent assay (ELISA) while cellular interactions are analysed using QCM-D, microscopy and adhesion assays. The QCM-D technique was evaluated for its ability to provide new insight into cell-surface interactions. Most tear and serum proteins were found to adsorb onto the acrylic hydrogels, however, lysozyme was found to absorb into the hydrogel matrix and decrease the hydration, which may lead to an adverse biological response. Fibronectin adsorbed onto nanotextured colloidal silica surfaces was found to be conformationally changed compared to flat controls which is likely to correlate with the reduced endothelial cell adhesion observed on these textured surfaces. Ta and PSox precoated with either serum or fibronectin were shown to support cell adhesion and spreading, while surfaces precoated with albumin were not. QCM-D responses varied between underlying surfaces, protein precoating, ECM deposition, cytoskeletal activity and length of exposure indicating that alterations in cell-material responses are reflected in QCM-D measurements. QCM-D parameters were found to correlate with adhered cell numbers, cell contact area and cytoskeletal activity. The results highlight that characterisation of interfacial interactions with a wide range of analytical techniques is necessary to gain insight into cell-protein-material interactions which can then be utilised in the development of new generations of biomaterials with improved properties designed for specific applications.
| Identifer | oai:union.ndltd.org:ADTP/234878 |
| Date | January 2006 |
| Creators | Lord, Megan Susan, Graduate School of Biomedical Engineering, Faculty of Engineering, UNSW |
| Publisher | Awarded by:University of New South Wales. Graduate School of Biomedical Engineering |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright Megan Susan Lord, http://unsworks.unsw.edu.au/copyright |
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