COLL 543 |
| Patrick S. Stayton, Allan S. Hoffman, and Noah Malmstadt. Department of Bioengineering, University of Washington, Box 352125, Seattle, WA 98195 |
| “Intelligent” or “smart” polymers are sharply responsive to small physical or chemical stimuli. For example, a small change in temperature or pH, or specific light irradiation can cause the smart polymer to precipitate in water. Conjugation of these unusual polymers to affinity proteins, antibodies and enzymes can lead to stimuli-induced phase separations. By conjugating the smart polymer next to an affinity protein’s binding site, immobilizing the polymer-protein conjugate onto a surface, and then stimulating the polymer to collapse, we have been able to block the active site and turn the protein “off”. By reversing the stimulus, we can unblock the site and turn the protein back “on”. We can also trigger the release of a bound ligand with appropriate stimuli. We have demonstrated size-controlled binding of biotinylated proteins to streptavidin. We have conjugated single-stranded oligonucleotides (ODNs) to a smart polymer and also to streptavidin, allowing hybridization of the ODNs to control the distance of the polymer from the active site. We recently cloned a streptavidin mutant having the peptide cell receptor –GRGDS- inserted into its sequence, and complexed a biotinylated temperature-sensitive polymer to the streptavidin to provide for temperature-controlled cell attachment to a polymer surface. We recently synthesized photo-sensitive polymers and conjugated them to a specific site on a surface-immobilized enzyme, and then photo-induced "on-off" control of the enzyme-substrate reactions. Most recently we have applied smart polymers and their conjugates in microfluidic devices for diagnostic and lab-on-a-chip applications. |
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“Smart” Polymers on Surfaces and Colloids
2:00 PM-4:50 PM, Thursday, April 1, 2004 Marriott -- Grand Ballroom J, Oral
Division of Colloid and Surface Chemistry |