Emulsion based microencapsulation of proteins in poly(L-lactic acid) films and membranes for the controlled release of drugs

Abstract

[EN] The aim of this study was to develop micro- or macro-porous substrates of poly(L-lactic acid) (PLLA) for the sustained release of water-soluble proteins. A model protein, bovine serum albumin (BSA), was incorporated into the hydrophobous PLLA matrix by emulsifying an aqueous BSA solution into an organic PLEA solution. The work focused on the effect of the fabrication procedure on substrates' microstructure and protein delivery kinetics. The films were prepared by solvent casting or freeze-extraction, after which the protein release profiles from both matrices were compared. A homogeneous distribution of BSA in the PLLA-films and membranes was obtained. In vitro release of the protein from the freeze extraction membranes was more significant than the release from the solvent cast films. BSA was found to be released from the freeze-extraction membranes in two stages: an initial fast release followed by a sustained release. The release from the solvent cast films was more moderated and accompanied by the polymer degradation.