Micellization Behavior Comparision of Polypeptide Graft Copolymer and Block-Graft Copolymer in Ethanol

Abstract

Poly(ethylene glycol)-block-poly(γ-benzyl L-glutamate)-graft-poly(ethylene glycol) (PEG-b-PBLG-g-PEG) copolymer and poly(γ-benzyl L-glutamate)-graftpoly(ethylene glycol) (PBLG-graft-PEG) copolymer were synthesized by the ester exchange reaction of PEG chain with PBLG-block-PEG copolymer and PBLG homopolymer, respectively. The micellization behaviors of PEG-b-PBLG-g-PEG and PBLG-graft-PEG in ethanol were investigated by transmission electron microscopy (TEM) and viscometry. Effects of both the introduction of PBLG homopolymer and the change of testing temperature on the critical aggregation concentration (CAC) of the two polypeptide copolymers in ethanol were mainly studied. Nuclear magnetic resonance (NMR) spectroscopy and fourier transform infrared spectroscopy (FTIR) were used to research the chain conformations of polypeptide segments of the two polypeptide copolymers in solvent and in the solid state, respectively.

Molecular weight controls the elongation of oblate-shaped degradable poly(γ-benzyl-l-glutamate)nanoparticles

“…3C, especially), suggesting a tendency to form super-helices. Similar images of oblate-shaped nanoparticles have been obtained before by others for PBLG nanoparticles (Segura-Sánchez et al, 2010;Zhu, 2010). Further, super-helices have also been described by Cai et al (Cai et al, 2009) when precipitating high molecular weight PBLG (110 and 520 kg mol −1 ) in THF/DMF.…”