Effect of Channel Width on Human Umbilical Vein Endothelial Cell (HUVEC) Culture in Microfluidic Channels

Capillary electrophoresis is a powerful separation technique that can achieve high efficiency separations of charged analytes. However, one limitation of capillary electrophoresis is the adsorption of cationic proteins and peptides onto the inner surface of the capillary wall, due to the negatively charged silanol groups on the bare fused silica capillaries. This can lead to poor separation efficiencies and band broadening. Gold nanoparticles have been known to exhibit unique interactions with biomolecules, which has led to an increased interest in these particles for pharmaceutical applications and separation science. Our group is attempting to investigate two different approaches for the separation a number of opioid peptides using gold nanoparticles. Approach 1: Using a recently reported method for the preparation of a gold nanoparticle modified capillaries(1). The open tubular capillary column is produced by treating the inner surface of a fused silica capillaries with 3-triethoxysilylpropylamine, followed by the introduction of freshly prepared citrate stabilized gold nanoparticles (particle size≈25nm). The electroosmotic flow, apparent electrophoretic mobilities, resolution and plate numbers for the analytes of interest are compared to those obtained by conventional capillary zone electrophoresis on bare silica. Approach 2: We are also attempting to separate opioid peptides using the same citrate stabilized gold nanoparticles using capillaries treated with a layer of a positively charged poly(diallyldimethylammonium) chloride, that would adsorb the negativity charged gold nanoparticles, and compared it to conventional capillary zone electrophoresis on bare silica(2).