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Title: Sol-gel method for encapsulating molecules

Patent ·
OSTI ID:874945
 [1];  [1];  [1];  [2]
  1. Albuquerque, NM
  2. San Francisco, CA
+ Show Author Affiliations

A method for encapsulating organic molecules, and in particular, biomolecules using sol-gel chemistry. A silica sol is prepared from an aqueous alkali metal silicate solution, such as a mixture of silicon dioxide and sodium or potassium oxide in water. The pH is adjusted to a suitably low value to stabilize the sol by minimizing the rate of siloxane condensation, thereby allowing storage stability of the sol prior to gelation. The organic molecules, generally in solution, is then added with the organic molecules being encapsulated in the sol matrix. After aging, either a thin film can be prepared or a gel can be formed with the encapsulated molecules. Depending upon the acid used, pH, and other processing conditions, the gelation time can be from one minute up to several days. In the method of the present invention, no alcohols are generated as by-products during the sol-gel and encapsulation steps. The organic molecules can be added at any desired pH value, where the pH value is generally chosen to achieve the desired reactivity of the organic molecules. The method of the present invention thereby presents a sufficiently mild encapsulation method to retain a significant portion of the activity of the biomolecules, compared with the activity of the biomolecules in free solution.

Research Organization:
Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
DOE Contract Number:
AC04-94AL85000
Assignee:
Sandia Corporation (Albuquerque, NM)
Patent Number(s):
US 6495352
OSTI ID:
874945
Country of Publication:
United States
Language:
English

References (6)

Aqueous Sol−Gel Process for Protein Encapsulation journal August 2000
Enzymatic activity of glucose oxidase encapsulated in transparent glass by the sol-gel method journal May 1992
Synthesis of Sol-Gel Matrices for Encapsulation of Enzymes Using an Aqueous Route journal January 1998
Encapsulation of proteins in transparent porous silicate glasses prepared by the sol-gel method journal February 1992
Encapsulation of enzymes and cells in sol-gel matrices for biosensor applications conference December 1999
Inorganic gels for immobilization of biocatalysts: inclusion of invertase-active whole cells of yeast (saccharomyces cerevisiae) into thin layers of SiO2 gel deposited on glass sheets journal January 1989

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sol-gel
method
encapsulating
molecules
organic
biomolecules
chemistry
silica
sol
prepared
aqueous
alkali
metal
silicate
solution
mixture
silicon
dioxide
sodium
potassium
oxide
water
ph
adjusted
suitably
value
stabilize
minimizing
rate
siloxane
condensation
allowing
storage
stability
prior
gelation
added
encapsulated
matrix
aging
film
formed
depending
acid
processing
conditions
time
minute
days
alcohols
generated
by-products
encapsulation
steps
chosen
achieve
reactivity
sufficiently
mild
retain
significant
portion
activity
compared
free
alkali metal
silicon dioxide
aqueous alkali
silica sol
sol-gel chemistry
organic molecule
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