Biomimetic supported membranes from amphiphilic block copolymers

Abstract

A unique combination of surface chemistry and self-assembly of amphiphilic block copolymers was employed to obtain-for the first time-solid-supported biomimetic polymer bilayers. An organized monolayer from sulfur-functionalized poly(butadiene)-b-poly(ethylene oxide) was covalently attached to ultrasmooth gold upon Langmuir-Blodgett transfer. Hydrophobic interactions, on the other hand, were exploited to attach the second monolayer. As a result, we obtained a homogeneous hydrophilichydrophobic-hydrophilic structure, similar to supported lipid bilayers by architecture, stability and fluidity. Our polymer bilayers, however, outperform such lipid membranes with regard to tunability of thickness and stability in gaseous environments. As characterized by surface analysis tools (AFM, SPR), solid-supported polymer membranes are smooth with a thickness of ca. 11 nm, resistant to rinsing with aqueous solutions and stable upon drying and rehydration. These properties could be attractive for nanotechnological applications, such as immobilization of functional molecules or nanoparticles, sensor development or preparation of chemically responsive functional surfaces.

Synthesis and Functional Reconstitution of Light‐Harvesting Complex II into Polymeric Membrane Architectures

“…99 %, Roth) and prepared by film rehydration [24] and subsequent extrusion.P igments were extracted as described by Paulsen et al [6] Polymer modification with lipoic acid for the formation of tethered bilayers was done as described by Belegrinou et al [23] Proteins and PPs were prepared using the TNT-coupledt ranscription-translation wheat germ extract system (Promega, L4140). Protein was expressed in the presence or absence of pigmente xtract.…”

Self-assembled Structures from Amphiphilic Peptides

“…[30] To create polymersomes/membranes in our laboratories, we used amphiphilic block-copolymers, including (PMOXA-b-PDMS-b-PMOXA), [31] (PEG-b-PMCL), [32] (PEG-b-PMCL-b-PDMAEMA) [33] and (PB-b-PEG). [34] Initially we struggled to extend the applicable self-assembling materials to include amphiphilic peptides. Solely hydrophobic interactions and geometrical aspects were not sufficient to achieve the desired selfassembly into peptosomes.…”

Proteopolymersomes: In vitro production of a membrane protein in polymersome membranes

“…Compared to incorporation into intrinsically labile lipid bilayer membranes (liposomes), polymersomes offer a new and more stable alternative for studying integral membrane proteins 23 and to develop screening protocols using a relatively robust system. 6 We are currently investigating proteopolymersomes for screening applications.…”

“…To overcome the issues of stability, block copolymers have been explored as more stable alternatives, both in vesicular (polymersomes) 5 and in planar membrane form. 6 The possibility of inserting membrane proteins into block copolymer membranes has been shown by reconstituting isolated membrane proteins, in particular bacterial porins, in block copolymer vesicles. [7][8][9] Here, we report the first successful insertion of an integral membrane protein into block copolymer membrane vesicles (proteopolymersomes) by a cell-free in vitro synthesis method (Fig.…”