@article{2959186,
    title = "Self-Assembly of Telechelic Tyrosine End-Capped PEO Star Polymers in Aqueous Solution",
    author = "Charlotte J. C. Edwards-Gayle and Francesca Greco and Ian W. Hamley and Robert P. Rambo and Mehedi Reza and Janne Ruokolainen and Dimitrios Skoulas and Hermis Iatrou",
    journal = "Biomacromolecules",
    year = "2017",
    volume = "19",
    number = "1",
    pages = "167--177",
    publisher = "American Chemical Society (ACS)",
    issn = "1525-7797, 1526-4602",
    doi = "10.1021/acs.biomac.7b01420",
    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",
    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."
}