Polymer, Vol.99, 281-291, 2016
OEGylated collagen mimetic polypeptides with enhanced supramolecular assembly
Collagen mimetic polypeptides (CMPs) pendanted with linear or dendritic oligoethylene glycols (OEG) via ether linkage were synthesized, and their thermoresponsiveness, secondary structures and supra-molecular assembly investigated. High molar masses of OEGylated CMPs were achieved by polyamidation of tripeptide precursors through activated ester strategy. Pendanted linear OEGs confer CMP with enhanced triple helix conformation, while pendanted dendritic OEGs offer CMPs with characteristic thermoresponsive properties. In order to examine the effects of OEGylation, CMP with naked hydroxyl groups was also prepared. These OEGylated CMPs show intrinsic supramolecular assembly behavior in solutions which was explored with UV/vis and CD spectroscopies, as well as dynamic light scattering. Effects of polypeptide structures, molar masses, solvent polarity and substrates on the supramolecular assembly of the OEGylated CMPs were investigated, and we propose the solvent-favorable dendrons on the periphery and solvent-unfavorable polypeptide backbone form radial amphiphilicity, which enhance the supramolecular assembly of OEGylated CMPs to form long fibers. (C) 2016 Elsevier Ltd. All rights reserved.