title: Self-assembled polypeptide-block-poly(vinylpyrrolidone) as prospective drug-delivery systems.
abstract: Poly(beta-benzyl-L-aspartate)-block-poly(vinylpyrrolidone) diblock copolymers (PAsp(OBzl)-b-PVP) having both hydrophobic and hydrophilic segments of various lengths were synthesized by a combination of ATRP and ROP. These amphiphilic diblock copolymers formed polymeric micelles consisting of a hydrophobic PAsp(OBzl) core and a hydrophilic PVP shell in aqueous solution. The block copolymer was characterized using (1)H NMR and gel permeation chromatography (GPC) analysis. Due to its core-shell structure, this block polymer forms unimolecular micelles in aqueous solutions. The micelle properties of PAsp(OBzl)-b-PVP diblock copolymer were extensively studied by dynamic light scattering (DLS), fluorescence spectroscopy, and transmission electron microscopy (TEM). PAsp(OBzl)-b-PVP copolymers displayed the lowest CMC and demonstrated little cytotoxicity when exposed to SW-1990 pancreatic cancer cells. In order to assess its application in biomedical area, the anti-inflammation drug prednisone acetate was loaded as the model drug in the polymeric nanoparticles. In vitro release behavior of prednisone acetate was investigated, which showed a dramatic responsive fast/slow switching behavior according to the pH-responsive structural changes of a micelle core structure. All of theses features are quite feasible for utilizing it as a novel intelligent drug-delivery system.
authors.affiliation: Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Zeng
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Renzhong
authors.initials: R
authors.lastname: Qiao
mesh_terms: D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002850:Chromatography, Gel; D016503:Drug Delivery Systems; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology; D011205:Povidone / Q000737:chemistry* / Q000494:pharmacology; D011241:Prednisone / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D008823:Micelles; D010455:Peptides; D011205:Povidone; D011241:Prednisone