Publication Date

1995

Document Type

Dissertation/Thesis

First Advisor

Lin, C. T. (Chhui-Tsu)

Degree Name

M.S. (Master of Science)

Department

Department of Chemistry

LCSH

Colloids--Spectra||Enzymes--Spectra||Gels (Pharmacy)--Spectra

Abstract

The work contained in this thesis focuses on the use of sol-gel glass as a means of encapsulating biomaterials in order to form a biogel. A new sol-gel procedure using buffer and/or micellar solutions has been developed to immobilize local anesthetic drugs, enzymes, proteins and other biological molecules into an optically transparent glass. The sol-gel process involves hydrolysis and poly condensation of alkoxides. This hydrolysis leads to the formation of silanol groups (Si-OH) and alcohols. The silanol methoxy groups continue to form during aging. After aging, the drying stage involves careful removal of the solvent phase, and the resulting dried gels, termed xerogels, are rigid transparent materials with good thermal and dimensional stability. The fine pore networks in the dried gels (<100 A) do not scatter visible radiation and therefore allow the diffusion of small molecules. The techniques of absorption spectroscopy and low temperature (77 K) photoluminescence are utilized in order to monitor the gels at various stages throughout their drying process. Dibucaine was selected as a direct emission probe at 77K for determining the forms of the anesthetic drug (freebase, monoprotonated, and/or diprotonated) and the drug's location (hydrophobic core, interfacial layer or hydrophilic region) in the micelles. The proteins horseradish peroxidase, cytochrome c, cytochrome c peroxidase, and cytochrome c oxidase were also selected to immobilize in the sol-gel glass along with complexes of each. This allowed for the differentiation It has been demonstrated that enzymes can be trapped within the matrix of the sol-gel glass while still retaining high catalytic activity in the xerogel. There is improved stability of enzymes due to the lateral diffusion and conformational mobility of entrapped proteins being restricted, and the lack of direct contact with outside (ambient) conditions. The optical transparency of these silicate biogels makes them uniquely suitable for the development of fluorescent, luminescent and colorimetric enzyme sensors. Because all living organisms obtain the energy required for life through oxidation-reduction processes, the process of encapsulating the cytochrome c and its redox partners allows one to look at a way to study the detailed mechanisms of enzyme catalyzed reactions. This includes long range electron transfer (ET) and redox linked proton pumping, while the encapsulation of local anesthetic drugs could lead to a new drug delivery system.

Comments

Includes bibliographical references (pages [99]-102)

Extent

ix, 102 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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