Hydrogen-Bonding-Induced Chain Folding and Vesicular
Assembly of an Amphiphilic Polyurethane
- Publication date
- Publisher
Abstract
We have reported synthesis and vesicular
assembly of a novel amphiphilic
polyurethane with hydrophobic backbone and hydrophilic pendant carboxylic
acid groups which were periodically grafted to the backbone via a
tertiary amine group. In aqueous medium the polymer chain adopted
a folded conformation which was stabilized by intrachain H-bonding
among the urethane groups. Such a model was supported by concentration
and solvent-dependent FT-IR, powder XRD, and urea-mediated “denaturation”
experiments. Folded polymer chains further formed vesicular assembly
which was probed by dynamic light scattering, TEM, AFM, SEM, and fluorescence
microscopic studies, and dye encapsulation experiments. pH-dependent
DLS and fluorescence microscopic studies revealed stable polymersome
in entire tested pH window of 3.5–11.0. Zeta potential measurements
showed a negatively charged surface in basic pH while a charge-neutral
surface in neutral and acidic pH. MTT assay with CHO cell line indicated
good cell viability