Use of natural polysaccharides in the microencapsulation techniques

The encapsulation of chemicals and biological materials in natural carrier polymers has proven to be of great use in a variety of scientific and industrial applications. The natural polymers used as carrier materials in the encapsulation technology have the great advantage of being nontoxic, biocompatible and biodegradable. The most used natural polymers are algal polysaccharides such as alginate, carrageenan and agarose. Chitosan, an aminopolysaccharide derived from chitin, and gellan gum, an extracellular anionic polysaccharide secrete from microorganisms, have also been proposed for some applications. Chemical and physical properties, such as monomeric composition, degree of substitution, kinetic of gel formation: gel strength and shrinkage of matrices produced with such polysaccharides, can greatly affect both cell viability and rate of release of drugs, vaccines and other molecules entrapped in the gel matrix.