Self-Assembly of Telechelic Tyrosine End-Capped PEO Star Polymers in Aqueous Solution

Charlotte J. C. Edwards-Gayle, Francesca Greco, Ian W. Hamley*, Robert P. Rambo, Mehedi Reza, Janne Ruokolainen, Dimitrios Skoulas, Hermis Iatrou

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

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 oligotyr-osine. 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 electronmicroscopy. In contrast to previous studies on linear telechelic PEO oligotyrosine conjugates that show self-assembly into beta-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.

Original languageEnglish
Pages (from-to)167-177
Number of pages11
JournalBiomacromolecules
Volume19
Issue number1
DOIs
Publication statusPublished - Jan 2018
MoE publication typeA1 Journal article-refereed

Keywords

  • DRUG-DELIVERY
  • CELL-ADHESION
  • PEPTIDE
  • HYDROGELS
  • PROTEIN
  • NANOPARTICLES
  • COPOLYMERS
  • BINDING
  • SPECTROSCOPY
  • FLUORESCENCE

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