Systematic study of the structural parameters affecting the self-assembly of cyclic peptide–poly(ethylene glycol) conjugates

Abstract

Self-assembling cyclic peptides (CP) consisting of amino acids with alternating d- and l-chirality form nanotubes by hydrogen bonding, hydrophobic interactions, and π-π stacking in solution. These highly dynamic materials are emerging as promising supramolecular systems for a wide range of biomedical applications. Herein, we discuss how varying the polymer conformation (linear vs. brush), as well as the number of polymer arms per peptide unimer affects the self-assembly of PEGylated cyclic peptides in different solvents, using small angle neutron scattering. Using the derived information, strong correlations were drawn between the size of the aggregates, solvent polarity, and its ability to compete for hydrogen bonding interactions between the peptide unimers. Using these data, it could be possible to engineer cyclic peptide nanotubes of a controlled length.

Bisurea-Functionalized RAFT Agent: A Straightforward and Versatile Tool toward the Preparation of Supramolecular Cylindrical Nanostructures in Water

“…[7][8][9] Shortly after, Boué and co-workers designed aromatic bisurea functionalized PEG which self-assemble in a wide range of solvents into long rigid cylinders, which are in dynamic equilibrium with their unimers. 10 Beyond these examples, numerous other supramolecular motifs, such as ureido-pyrimidinone, 12 peptides, [13][14][15] cyclodextrins 16 or benzenetricarboxamide 17,18 have been used to direct the assembly of synthetic water-soluble macromolecules into cylindrical structures. In most of the studies, low molar mass polymers were used, in particular oligo(ethylene glycol)s, and their functionalization by the sticker units was achieved by post-polymerization strategies.…”

Stimuli-responsive membrane activity of cyclic-peptide–polymer conjugates

“…The key component for the design of stimuli responsive nanotubes is the cyclic peptide used as building block. Cyclo( l -Trp– d -Leu– l -Lys– d -Leu– l -Trp– d -Leu– l -Lys– d -Leu) ( 21 ) was used, as the formation of nanotubes using this peptide in combination with a polymeric shell is well established 17,20,27,28…”

Oligo‐Urea with No Alkylene Unit Self‐Assembles into Rod‐Like Objects in Water

“…This reduced aggregation may be due to limited hydrophobic interactions or to the particular topology of the stickers. It is also of interest to compare the structure of the objects formed by PEO5U to a recently reported cyclic peptide‐poly(ethylene glycol) conjugate . Both systems form rod‐like objects in water and are composed of a central H‐bonded sticker (eight H‐bonds vs ten in the case of PEO5U) decorated by two PEG chains of the same size (2000 g mol −1 ).…”