Characterization of modified alginate-poly-L-lysine microcapsules.

Various modifications of alginate-poly-L-lysine microcapsules were made, such as the inclusion of polyethylenimine (PEI) or carboxyl methyl cellulose (CMC) in the core and the coating of bis(polyoxyethylene bis[amine]) (PEGA) onto the microcapsule membrane surface. A characterization of the modified microcapsules in terms of mechanical and mass transfer properties as well as their chemical composition was performed. The PEI treatment greatly enhanced the mechanical stability of the microcapsules, and this treatment did not affect the coating process of poly-L-lysine or PEGA. PEGA was found to be able to coat the microcapsules while the mass transfer property was similar to the poly-L-lysine coated ones.