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Accession Number ADA564802
Title Development of Enzyme-Containing Functional Nanoparticles.
Publication Date Aug 2012
Media Count 13p
Personal Author A. Leech J. Walker
Abstract 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 poly(N- 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 NiPAAm/Styrene 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.
Keywords Encapsulation
Enzyme based decontamination systems
Glucose oxidase
Hydrophobic properties
Organic phosphorus compounds
Organophosphorus hydrolase
Shelf life
Thermal instability

Source Agency Non Paid ADAS
NTIS Subject Category 57B - Biochemistry
99C - Polymer Chemistry
95B - Tissue Preservation & Storage
Corporate Author Defense Threat Reduction Agency, Fort Belvoir, VA.
Document Type Technical report
Title Note Annual rept. 7 Oct 2009-6 Oct 2010.
NTIS Issue Number 1304
Contract Number HDTRA-1-08-1-0054

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