ja3096587_si_001.pdf (1.53 MB)
Living Unimodal Growth of Polyion Complex Vesicles via Two-Dimensional Supramolecular Polymerization
journal contribution
posted on 2013-01-30, 00:00 authored by Yasutaka Anraku, Akihiro Kishimura, Yuichi Yamasaki, Kazunori KataokaUnderstanding the dynamic behavior of molecular self-assemblies
with higher-dimensional structures remains a key challenge to obtaining
well-controlled and monodispersed structures. Nonetheless, there exist
few systems capable of realizing the mechanism of supramolecular polymerization
at higher dimensions. Herein, we report the unique self-assembling
behavior of polyion complexes (PICs) consisting of poly(ethylene glycol)-polyelectrolyte
block copolymer as an example of two-dimensional supramolecular living
polymerization. Monodispersed and submicrometer unilamellar PIC vesicles
(nano-PICsomes) displayed time-dependent growth while maintaining
a narrow size distribution and a unilamellar structure. Detailed analysis
of the system revealed that vesicle growth proceeded through the consumption
of unit PICs (uPICs) composed of a single polycation/polyanion pair
and was able to restart upon the further addition of isolated uPICs.
Interestingly, the resulting vesicles underwent dissociation into
uPICs in response to mechanical stress. These results clearly frame
the growth as a two-dimensional supramolecular living polymerization
of uPICs.