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Development of Enzyme-Containing Functional Nanoparticles
Annual rept. 7 Oct 2009-6 Oct 2010
ICX AGENTASE INC PITTSBURGH PA
Pagination or Media Count:
Enzymes demonstrate great potential for numerous applications however their practicality is limited by instability in harsh environments, such as temperature extremes limiting both operational stability as well as long-term shelf life. In this work, we seek to overcome enzyme instability at elevated temperatures through the encapsulation of enzymes within polyN-isopropylacrylamide, NiPAAm colloidal nanoparticles. Nanoparticles composed of NiPAAm undergo a transition from being highly hydrophilic and swollen at room temperature to shrunken and hydrophobic at elevated temperatures. We are taking advantage of this phenomenon by encapsulating and covalently immobilizing enzymes within the particles. Enzymes denature at high temperatures, unfolding in the process. Encapsulation within NiPAAm particles prevents denaturation as the shrinking polymer network prevents the enzyme from unfolding at high temperatures. Glucose oxidase and organophosphorus hydrolase were functionalized with hydrophobic and polymerizable chemical groups and encapsulated within NiPAAmStyrene particles using an enzyme friendly emulsion polymerization technique. The particles undergo a volume transition from approximately 100nm to 50nm in size. Thermal stability studies in aqueous conditions were conducted at temperatures up to 70 C, resulting in a 2-10 fold improvement in enzyme pot-life. Lyophilization of these novel materials extends their shelf over that of native enzyme from 3 weeks to over 3 months.
APPROVED FOR PUBLIC RELEASE