Methods for encapsulation and microcapsules produced thereby
Inventors
Gorecka, Elzbieta • Dziadek, Jaroslaw • AMBROZIAK, WOJCIECH
Assignees
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Publication Number
US-10478401-B2
Publication Date
2019-11-19
Expiration Date
Abstract
The invention relates to methods for encapsulating a material comprising the steps of: (a) providing an aqueous solution or suspension of the material that is to be encapsulated, (b) warming the aqueous solution or suspension to a temperature that is sufficient to enable dissolution of a first biocompatible polymer in the aqueous solution or suspension without adversely affecting the properties of the material to be encapsulated, (c) dissolving the first biocompatible polymer in the aqueous solution or suspension, (d) de-aerating the solution or suspension obtained in step (c), (e) emulsifying the solution or suspension obtained in (d) in a biocompatible oil comprising a surfactant to create microdroplets, and (f) hardening the microdroplets by dropwise addition of an aqueous solution comprising Zn2+ ions and a second biocompatible polymer to form microcapsules; the invention further relates to microcapsules obtained by methods of the invention and their uses.
Core Innovation
The disclosure provides an emulsification/external gelation approach for encapsulating a material. An aqueous solution or suspension of the material to be encapsulated is de-aerated, emulsified in a biocompatible oil comprising a surfactant to create microdroplets, and combined with a first biocompatible polymer comprising carboxylic groups for coordination to Zn2+ ions.
Microcapsules are formed by dropwise addition of an aqueous solution comprising Zn2+ ions together with a second biocompatible polymer comprising a moiety for ionically binding the first biocompatible polymer. During this formation, the Zn2+ ions bind and cross-link the carboxylic groups of the first biocompatible polymer, and the first biocompatible polymer ionically binds and cross-links the second biocompatible polymer so that the material to be encapsulated is encapsulated within discrete microcapsules.
The document further specifies that the microcapsules are not comprising calcium alginate and that the compositions can include zinc alginate and chitosan microcapsules, with microcapsule characteristics such as size distribution.
Claims Coverage
The identified independent claims center on two inventive features: forming microdroplets in an emulsion with a first biocompatible polymer comprising carboxylic groups for Zn2+ coordination, and forming microcapsules by Zn2+ cross-linking together with ionic binding to a second biocompatible polymer.
Microdroplets in a biocompatible oil emulsion
An aqueous solution or suspension of the material to be encapsulated is de-aerated and emulsified in a biocompatible oil comprising a surfactant to create microdroplets of the first biocompatible polymer and the material that is to be encapsulated.
Zn2+-cross-linked microcapsules with a second biocompatible polymer
Microcapsules are formed by dropwise addition of an aqueous solution comprising Zn2+ ions and a second biocompatible polymer comprising a moiety for ionically binding the first biocompatible polymer, whereby Zn2+ ions bind and cross-link the carboxylic groups of the first biocompatible polymer and the first biocompatible polymer ionically binds and cross-links the second biocompatible polymer to encapsulate the material.
The coverage is built around an emulsion of microdroplets containing a first biocompatible polymer with carboxylic groups, followed by Zn2+ coordination and ionic binding to a second biocompatible polymer to form microcapsules encapsulating the material.
Stated Advantages
Reduced aggregation/clumping.
Good yield and retention.
Documented Applications
Encapsulated bacteria and bacteriophage, including stability of encapsulated bacteriophage with viable PFU retention.
Antibacterial growth inhibition and inhibition of bacterial growth using the microcapsules.
Survival in a GI tract model (chicken).
Use as a medicament and in feed/water treatment to prevent or treat bacterial infection, especially Salmonella in poultry.
Encapsulation of materials including bacteria, bacteriophage, and mixtures, and proteins/enzymes as potential encapsulated materials.
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