Sol-gel method for encapsulating molecules
US6495352B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 2000 |
| Grant date | Dec 17, 2002 |
| Priority date | — |
| Expiry date | Apr 13, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S436/829
- WIPO fieldBiotechnology
- WIPO sectorChemistry
Abstract
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…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.