Micro-patterned plasma and ultra-violet ozone modification of polymer surfaces.

In this study the surface chemical modification of Iwaki TM tissue culture polystyrene (TCPS) and Nunclon TM polystyrene (PS) dishes by; (i) plasma deposition/modification of n-Hexane, isopropyl alcohol (IPA) and acetone, and (ii) an Ultra-Violet/Ozone (UV/Ozone) oxidation treatment have been investigated as methods of influencing cell attachment behaviour. In particular, the effects of the surface oxygen chemistry, surface topography and water wettability on the attachment and proliferation of Chinese hamster ovarian (CHO) and human skin fibroblast (1BR.3N) cells has been investigated. The monomers used for plasma deposition/modification are traditionally non-polymerizable through conventional polymerization mechanisms i.e. they do not contain unsaturated bonds. The deposition conditions identified and used in this study were specifically chosen to minimize precursor fragmentation and rearrangement and to optimize micro-pattern resolution. This required careful sample positioning within the plasma chamber, a low incident radio-frequency power (lOW) and the use of moderate monomer flow rates (10-56 SCCM (cm3(STP).m-1)). Surface chemical modifications were characterised using X-ray photoelectron spectroscopy (XPS), water contact angle analysis and surface energy calculation using the Owens and Wendt method. Determination of the type and quantity of surface chemical species present, before and after surface modifications, has given an insight into the modification processes and mechanisms of the systems studied. Additionally, Fourier transform infra-red (FTIR) spectroscopy of IPA plasma deposited films and UV/Ozone modified PS films was carried out to confirm the chemical functionalities observed by XPS. Visualization of chemically heterogeneous patterns, by optical microscopy, and identification of parameters that influence pattern resolution was achieved by water condensation upon micro-patterned surface regions. Atomic force microscopy (AFM) was used to study the physical effects of modifications (film deposition rates/surface micro-pattern resolution) and to compare topography by determination of root mean square (RMS) surface roughness (Rq). The optimization of each of the physicochemical properties for both of the modification systems and relation to the visual cell culture observations (position/proliferation) have been highlighted within this study. The surface modification methods were used to develop tissue culture supports and study the selective attachment and proliferation behaviour of the cell types studied. By observation of cell morphology, and taking this as a sign of normal cell functionality, the attachment and proliferation for the cell lines used was seen to be highly dependent on the surface oxygen concentration present i.e. the polarity of the substrates. Proliferation, spatial control and outgrowth of surface chemical patterns by cells on substrates prepared for tissue culture was found to be dependent on the pattern resolution and the cell type under observation.

Grantor dc:publisher.institution

Robert Gordon University

Year dc:date.issued

2006

Author dc:creator

• Mitchell, Stephen Alister

Advisor dc:contributor.advisor

• A.G. Shard, N. Emmison and R.H. Bradley

• Polystyrene surface modification
• Tissue culture polystyrene (TCPS)
• Plasma deposition
• UV/ozone oxidation
• Surface oxygen chemistry
• Cell attachment behaviour
• Wettability and topography

Language dc:language

en

Identifier

oai:rgu-repository.worktribe.com:2807493
https://doi.org/10.48526/rgu-wt-2807493

OAI identifier oai:identifier

oai:rgu-repository.worktribe.com:2807493