Biopolymer mimicry with polymeric wormlike micelles: Molecular weight scaled flexibility, locked‐in curvature, and coexisting microphases

Abstract

Giant and stable wormlike micelles formed in water from a series of poly(ethylene oxide) (PEO)‐based diblock copolymer amphiphiles mimicked the flexibility of various cytoskeletal filaments. The worm diameter (d) was found by cryo‐transmission electron microscopy to scale with the length of the hydrophobic chain (Nh) of the copolymer as d ∼ Nh0.61. By fluorescence video imaging of worm dynamics, we also showed that the persistence length (lP) of wormlike micelles scaled as lP ∼ d2.8, consistent with a fluid aggregate (∼d3) rather than a solid rod (∼d4). By polymerizing the unsaturated bonds of assembled copolymers, fluid worms were converted to solid‐core worms, extending the bending rigidity from that of intermediate filament biopolymers to actin filaments and, in principle, microtubules. Through partial crosslinking, polymerized worms further locked in spontaneous curvature at a novel fluid‐to‐solid percolation point. The dynamics of distinct, branched conformations were also imaged for recently discovered Y‐junctioned wormlike micelles composed of diblocks of high molecular weight (>10–15 kg/mol). Finally, block copolymers of hydrophilic weight fraction close to the transition between a vesicle‐ and worm‐former assembled into both structures, allowing encapsulation of wormlike micelles in giant vesicles reminiscent of cytoskeletal filaments enclosed within cells. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 168–176, 2004

Grafting Short Peptides onto Polybutadiene‐block‐poly(ethylene oxide): A Platform for Self‐Assembling Hybrid Amphiphiles

“…FM is widely used to study cellular structures and dynamics, but has recently been established also as a reliable and convenient technique for visualizing micrometer-sized wormlike micelles and vesicles. [20][21][22] Unlike cryo-TEM, FM allows direct observation of samples in aqueous solutions without requiring fixation and constraint in thin films, and thus provides more equilibrated and convenient access to length and dynamic measurements of soft objects. The w EO values of the CF-grafted PBD-b-PEO that correspond to wormlike micelles and vesicles are quantitatively comparable to the PBD-b-PEO morphological phase diagram, [9] thus suggesting that the self-assembly of such hybrids in water is likewise dictated by the hydrophobichydrophilic balances.…”

Elasticity, dynamics and relaxation in biopolymer networks

“…For these reasons, actin networks have become a paradigm also for similar structures in the extracellular matrix in animals [6] (mostly consisting of elastin and collagens embedded in a viscoelastic gel of proteoglycans) and plants (where the universal scaffolding material is cellulose [35]), and are consequently also in the focus of this review. I just mention in passing semidilute solutions of fd-viruses [1] and sufficiently strongly entangled wormlike micelles [8,13,7] as yet two other systems that share many features in their mechanical response with biopolymer networks, and which are in this respect analyzed and interpreted in essentially the same way.…”

Self-aggregates of cholesterol-modified carboxymethyl konjac glucomannan conjugate: Preparation, characterization, and preliminary assessment as a carrier of etoposide

“…Through non-covalent association arising from intra-and/or inter-molecular interactions among hydrophobic segments in the aqueous medium, these polymeric amphiphiles consisting of hydrophilic and hydrophobic segments can form micelle or micelle-like self-aggregates with hydrophobic cores and hydrophilic shells (Akiyoshi, 2002;Akiyoshi, Deguchi, Moriguchi, Yamaguchi, & Sunamoto, 1993;Dalhaimer, Bermudez, & Discher, 2004;Kakizawa, Harada, & Kataoka, 2001;Mortensen, 2001;Rotureau, Chassenieux, Dellacherie, & Durand, 2005;). Because these self-aggregates have potential uses in biotechnology and medicine fields due to their unique supramolecular structures, many polymeric amphiphiles have been explored, and their physicochemical properties also have been widely investigated (Benita & Levy, 1993;Jones & Leroux, 1999;Kang & Leroux, 2004;Qiu & Bae, 2007).…”