Title:
Self-Assembly of Telechelic Tyrosine End-Capped PEO Star Polymers in Aqueous Solution
Languages of Item:
English
Abstract:
We investigate the self-assembly of two telechelic star polymer-peptide conjugates based on poly(ethylene oxide) (PEO) four-arm star polymers capped with oligotyrosine. The conjugates were prepared via N-carboxy anhydride-mediated ring-opening polymerization from PEO star polymer macroinitiators. Self-assembly occurs above a critical aggregation concentration determined via fluorescence probe assays. Peptide conformation was examined using circular dichroism spectroscopy. The structure of self-assembled aggregates was probed using small-angle X-ray scattering and cryogenic transmission electron microscopy. In contrast to previous studies on linear telechelic PEO-oligotyrosine conjugates that show self-assembly into β-sheet fibrils, the star architecture suppresses fibril formation and micelles are generally observed instead, a small population of fibrils only being observed upon pH adjustment. Hydrogelation is also suppressed by the polymer star architecture. These peptide-functionalized star polymer solutions are cytocompatible at sufficiently low concentration. These systems present tyrosine at high density and may be useful in the development of future enzyme or pH-responsive biomaterials. © 2017 American Chemical Society.
Authors:
Charlotte J. C. Edwards-Gayle
Francesca Greco
Ian W. Hamley
Robert P. Rambo
Mehedi Reza
Janne Ruokolainen
Dimitrios Skoulas
Hermis Iatrou
Journal:
Biomacromolecules
Publisher:
American Chemical Society (ACS)
Keywords:
Amino acids; Circular dichroism spectroscopy; Dichroism; Ethylene; High resolution transmission electron microscopy; Peptides; Polyethylene oxides; Ring opening polymerization; Solutions; Transmission electron microscopy; X ray scattering, Critical aggregation concentration; Cryogenic transmission electron microscopy; Fluorescence probes; Low concentrations; N-Carboxyanhydride; Peptide conformation; pH responsive biomaterials; Poly (ethylene oxide) (PEO), Self assembly, macrogol; polymer; tyrosine; tyrosine derivative; macrogol; peptide; tyrosine; water, aqueous solution; Article; beta sheet; chemical structure; circular dichroism; conjugate; density; fibril; micelle; pH; polymerization; priority journal; transmission electron microscopy; X ray crystallography; cell line; chemistry; human; hydrogel; infrared spectroscopy; nuclear magnetic resonance spectroscopy; size exclusion chromatography; small angle scattering; solution and solubility; X ray diffraction, Cell Line; Chromatography, Gel; Circular Dichroism; Humans; Hydrogels; Magnetic Resonance Spectroscopy; Microscopy, Electron, Transmission; Peptides; Polyethylene Glycols; Polymerization; Scattering, Small Angle; Solutions; Spectroscopy, Fourier Transform Infrared; Tyrosine; Water; X-Ray Diffraction
Main subject category:
Science
Official URL (Publisher):
DOI:
10.1021/acs.biomac.7b01420
