SYNTHESIS AND pH-SENSITIVE SELF-ASSEMBLY OF DENDRITIC POLY(AMIDOAMINE)-b-POLY(L-GLUTAMATE) BIOHYBRIDS

Dendritic poly(amidoamine)-b-poly(L-glutamate) (PAMAM-b-PLG) biohybrids were synthesized by the ring-pening polymerization of gamma-benzyl-L-glutamate N-carboxyanhydride monomer, followed by the deprotection of benzyl groups on poly(benzyl-L-glutamate), and were characterized by H-1-NMR, FT-IR and gel permeation chromatography. The self-assembly behavior of the PAMAM-b-PLG biohybrid was investigated by means of UV-Vis, dynamic light scattering (DLS), transmission electronic microscopy (TEM) and H-1-NMR. UV-Vis analysis demonstrated that the critical aggregation concentration of PAMAM-b-PLG was dependent on the pH value of aqueous solutios. DLS results further evidenced that the PAMAM-b-PLG biohybrid exhibited a pH-sensitive self-assembly behavior, and the average size of the self-assembled nanoparticles decreased gradually with the increasing pH value of the PAMAM-b-PLG solution. The self-assembled nanoparticles gave a nearly spherical morphology, and the pH-induced self-assembly had no obvious effect on the morphology of nanoparticles.