PLLA/PMMA blend in polymer nanoparticles: influence of processing methods

The preparation and synthesis of PLLA/PMMA blend nanoparticles by miniemulsion/solvent evaporation, miniemulsion polymerization, and seeded emulsion polymerization strategies is herein presented. We evaluate the effect of nanoparticle preparation technique and blend ratio over nanoparticle morphology and blend miscibility, and our results indicate that the nanoparticle processing method can greatly influence the final morphology characteristics of blend nanoparticles. By miniemulsion/solvent evaporation, miscible blend and homogeneous nanoparticles were obtained, and an increase in PMMA content led to a concomitant increase of nanoparticle size. Miniemulsion polymerization, on the other hand, resulted in an immiscible blend with a core-shell-like morphology nanoparticles. Under the conditions used, seeded emulsion polymerization led to the formation of secondary smaller particles of pure PMMA in addition to miscible PLLA/PMMA blend nanoparticles. PLLA/PMMA nanoparticles were further used to encapsulate a hydrophobic drug with high entrapment efficiency, showing to be a promising hydrophobic compound carrier.