Polypeptide Nanoparticles Obtained from Emulsion Polymerization of Amino Acid N -Carboxyanhydrides.

Polypeptide nanoparticles were obtained by the miniemulsion polymerization of S -( o -nitrobenzyl)-l-cysteine (NBC) N -carboxyanhydride (NCA). Through process optimization, reaction conditions were identified that allowed the polymerization of the water sensitive NCA to yield nanoparticles of about 220 nm size. Subsequent UV-irradiation of the nanoparticle emulsions caused the in situ removal of the nitrobenzyl group and particle cross-linking through disulfide bond formation accompanied by the shrinkage of the particles.