| The ECM is a very complex, heterogeneous mixture of proteins, peptides, and hormones, which has proven difficult to model in vitro. Currently, a number of model substrates and systems have been developed utilizing polymers, layer-by-layer methods, and self-assembled monolayers (SAMs). SAMs of alkanethiolates on gold in particular, have proven to be useful model substrates with a number of key advantages; SAMs are chemically well defined, synthetically flexible, conductive, compatible with live-cell high resolution fluorescence microscopy techniques, can be patterned at the micro- and nanoscale, and most importantly, they can be made to resist non-specific protein adsorption. These advantages allow for fabrication of complex, flexible substrates for studies of cell phenomena at the molecular level.;To tailor SAMs on gold with precise spatial control and quantification of ligand density, smart SAM surfaces have been developed to immobilize a variety of ligands using the hydroquinone. By installing the peptide ligand sequence RGD (an epitope for the ECM protein fibronectin), cells have been biospecifially adhered to SAMs to study cell behavior based on specific ligand-receptor interactions. During the course of my thesis, I have combined analytical techniques with the unique capabilities of surface chemistry to study cell biology problems regarding ligand-receptor and small molecule-protein interactions. I have fabricated flexible biological substrates capable of binding different cellular ligands based on SAMs and hydrogels to observe their effects on cell behavior.;In chapter 1, I review the relevant literature on SAMs and cell adhesion and migration. In chapter 2 and 3, two methods combining microfluidics and SAMs are described. In chapter 4, alcohol oxidation was used to functionalize simple SAMs. In chapter 5, this method was extended to create protein affinity platforms. In chapter 6, cell adhesion was monitored at the nanoscale using DPN and evaporative lithography. In chapter 7, hydrogels were created to monitor cell adhesion in 3D. Chapter 8 is dissertation conclusions and future directions. These interactions and substrates were characterized by a variety of techniques including XPS, fluorescence microscopy, electrochemistry, and mass spectrometry. |
