A NOVEL BIODEGRADABLE SYSTEM BASED ON GELATIN NANOPARTICLES AND POLY(LACTIC-CO-GLYCOLIC ACID) MICROSPHERES FOR PROTEIN AND PEPTIDE DRUG-DELIVERY

Gelatin nonparticle-poly(lactic-co-glycolic acid) (PLGA) microsphere c omposites were prepared by encapsulating protein-loaded gelatin nanopa rticles in PLGA microspheres. This encapsulation was conducted by usin g a phase separation method and a solvent extraction method. The avera ge diameter of the gelatin nanoparticle-PLGA microsphere composites is between 160 and 175 mu m. Protein loading efficiency is 93.2% for the nanoparticle-microsphere composite prepared by the phase separation m ethod, while it is 31.31% for the composite prepared by the solvent ex traction method. Protein release experiments indicate that this new co mposite system possesses sustained release characteristics. This syste m also demonstrates the capability of preventing the denaturation of p rotein drugs.