Adsorption/desorption of human serum albumin at the surface of poly(lactic acid) nanoparticles prepared by a solvent evaporation process.

Biocompatible and biodegradable nanoparticles of poly(lactic acid) (100% L-lactic units = PLA) were prepared by an emulsion, microfluidization, and solvent evaporation method using human serum albumin (HSA) as a surface agent. A radiolabeling technique was employed to quantify the serum albumin bound to the nanoparticles and to measure its desorption kinetics in various media at 22 degrees C and 37 degrees C (phosphate buffer pH 7.4, serum albumin 40 g/L in phosphate buffer pH 7.

Body distribution of fully biodegradable [14C]-poly(lactic acid) nanoparticles coated with albumin after parenteral administration to rats.

Fully biodegradable polylactic acid (PLA) nanoparticles (90-250 nm) coated with human serum albumin (HSA) were prepared by high-pressure emulsification and solvent evaporation, using the protein as surfactant. A new analytical tool was developed, based on Mie's law and size exclusion chromatography, to establish that, after evaporation of the solvent, the protein saturates the surface of the nanoparticles, masking the PLA core. According to this technique, no HSA is encapsulated in the polymer matrix.