Cell Surface Interaction on a Multi - Scale

Sarah, Akua Mensah (2014-12-15)


The increasing rate of cancer patients worldwide, and especially Africa has led to numerous efforts to battle it. One approach to this has been localized drug delivery to reduce the quantity of drugs needed for therapeutic effect. Poly-di-methyl-siloxane (PDMS) is an elastomer with much focus on it as a microfluidic device. PDMS is one polymer of choice for localized drug delivery due to its biocompatibility, transparency, and ease of fabrication. However, its highly hydrophobic nature does not allow it to be used without modification. This work presents results of experimental and computational methods for PDMS surface modification. Also computational results of shear assay model for the effects on surface modification on cell adhesion is present. Modifying the surface of the PDMS was done by varying the mix ratio and curing temperatures after fabrication. The results from the experiment shows that low base to curing agent ratio and increasing curing temperature gives a highly stiff PDMS. Also, the PDMS treatment via boiling water and Ultraviolet Ozone (UVO) methods makes it hydrophilic with the generation of hydroxyl (OH) group on the substrates. These studies provided understanding of cell-surface interaction on a multi-scale. Morphological studies with Scanning Electron Microscope (SEM) reveal a layer and textured featured formed on UVO treated and PLGA coated PDMS. Shear assay model showed that cells on modified PDMS surface low energy release rate on application of shear load. This signifies that cells adhered to the modified surfaces better, thus could not be easily detached.