Reversible microencapsulation of a core material

Abstract

Abstract Disclosed is a process for microencapsulating a core material and subsequently releasing the core material by selectively disrupting the membranes of the microcapsules. The encapsulation technique involves the formation of a semipermeable membrane, e.g., around a droplet, through the formation of multiple ionic salt bonds between a polyionic polymer in the droplet and a crosslinking polyionic polymer which possesses multiple ionic groups of opposite charge. The membrane can be selectively disrupted by exposing it first to a solution of competing crosslinking multivalent (preferably di or trivalent) ions followed by a solution of a competing polyionic polymer of the same charge as the polymer in the original droplet. Alternatively, a mixed solution of the two competing solutions may be used together. For example, a membrane comprising anionic alginate salt bonded to cationic polymer can be selectively disrupted by exposing the membrane to a mixed solution of monatomic, multivalent cations, e.g. Ca++ ions, and a water-soluble polymer have plural anionic moieties, e.g., heparin, and subsequently sequestering the monatomic cations. The process may be used to encapsulate and subsequently release cell cultures without damage to the cells.

Inventors

• 👤 Franklin Lim

Bibliographic Details