“…We harnessed this thermodynamic driving force to control BCP self-assembly in two dimensions and stabilized the resulting membranes by exploiting the interface between an aqueous two-phase system (ATPS; Fig. 1a ), which forms when immiscible aqueous solutions of chemically incompatible polymers are brought into contact 17 , 18 . Fig.…”
Section: The Solvent-displacement Methodsmentioning
Membranes are widely used for separation processes in applications such as water desalination, batteries and dialysis, and are crucial in key sectors of our economy and society1. The majority of technologically exploited membranes are based on solid polymers and function as passive barriers, whose transport characteristics are governed by their chemical composition and nanostructure. Although such membranes are ubiquitous, it has proved challenging to maximize selectivity and permeability independently, leading to trade-offs between these pertinent characteristics2. Self-assembled biological membranes, in which barrier and transport functions are decoupled3,4, provide the inspiration to address this problem5,6. Here we introduce a self-assembly strategy that uses the interface of an aqueous two-phase system to template and stabilize molecularly thin (approximately 35 nm) biomimetic block copolymer bilayers of scalable area that can exceed 10 cm2 without defects. These membranes are self-healing, and their barrier function against the passage of ions (specific resistance of approximately 1 MΩ cm2) approaches that of phospholipid membranes. The fluidity of these membranes enables straightforward functionalization with molecular carriers that shuttle potassium ions down a concentration gradient with exquisite selectivity over sodium ions. This ion selectivity enables the generation of electric power from equimolar solutions of NaCl and KCl in devices that mimic the electric organ of electric rays.
“…We harnessed this thermodynamic driving force to control BCP self-assembly in two dimensions and stabilized the resulting membranes by exploiting the interface between an aqueous two-phase system (ATPS; Fig. 1a ), which forms when immiscible aqueous solutions of chemically incompatible polymers are brought into contact 17 , 18 . Fig.…”
Section: The Solvent-displacement Methodsmentioning
Membranes are widely used for separation processes in applications such as water desalination, batteries and dialysis, and are crucial in key sectors of our economy and society1. The majority of technologically exploited membranes are based on solid polymers and function as passive barriers, whose transport characteristics are governed by their chemical composition and nanostructure. Although such membranes are ubiquitous, it has proved challenging to maximize selectivity and permeability independently, leading to trade-offs between these pertinent characteristics2. Self-assembled biological membranes, in which barrier and transport functions are decoupled3,4, provide the inspiration to address this problem5,6. Here we introduce a self-assembly strategy that uses the interface of an aqueous two-phase system to template and stabilize molecularly thin (approximately 35 nm) biomimetic block copolymer bilayers of scalable area that can exceed 10 cm2 without defects. These membranes are self-healing, and their barrier function against the passage of ions (specific resistance of approximately 1 MΩ cm2) approaches that of phospholipid membranes. The fluidity of these membranes enables straightforward functionalization with molecular carriers that shuttle potassium ions down a concentration gradient with exquisite selectivity over sodium ions. This ion selectivity enables the generation of electric power from equimolar solutions of NaCl and KCl in devices that mimic the electric organ of electric rays.
“…Hydrophilic polymers play an important role in a broad range of drug-delivery systems. − In particular, poly(ethylene glycol) (PEG) is employed frequently due to its favorable properties like biocompatibility and the stealth effect . Nevertheless, recent studies found anti-PEG antibodies that cause accelerated drug clearance. − Other hydrophilic polymers showed promising results in drug-delivery systems as well, for example, poly(glycerol)s, poly(oxazoline)s, and poly(vinylpyrrolidone). − Poly(glycerol)s are polyethers that share a close structural similarity with PEG, are also highly hydrophilic and biocompatible with a low viscosity in water .…”
Section: Introductionmentioning
confidence: 99%
“…Hydrophilic polymers play an important role in a broad range of drug-delivery systems. 1 − 3 In particular, poly(ethylene glycol) (PEG) is employed frequently due to its favorable properties like biocompatibility and the stealth effect. 4 Nevertheless, recent studies found anti-PEG antibodies that cause accelerated drug clearance.…”
Hydrophilic polymers have found ubiquitous use in drug delivery and novel polymer materials to advance drug delivery systems are highly sought after. Herein, an amylose mimic (PEGose) was combined with poly(lactic acid) (PLA) in an amphiphilic block copolymer to form PEG-free nanoparticles as an alternative to PEG-based nanomedicines. The block copolymer self-assembled into 150−200 nm particles with a narrow dispersity in aqueous environment. The formed nanoparticles were capable of encapsulation, the sustained release of both hydrophilic and hydrophobic dyes. Moreover, the nanoparticles were found to be remarkably stable and had a very low cytotoxicity and a high propensity to penetrate cells. These results highlight the potential of PEGose-b-PLA to be used in drug delivery with a new hydrophilic building block.
Completely water‐based multicompartment systems have attracted a broad interest in recent years, mainly due to their versatile features such as permeability. Here, the associative formation of water‐in‐water (w/w) emulsions based on ultra‐high molecular weight poly(N,N‐dimethylacrylamide) (PDMA) and poly(4‐acryloylmorpholine) (PAM) is studied. The system is investigated using a combination of fluorescence microscopy and spectroscopy techniques. The system phase‐separates into aqueous droplets at very low polymer concentrations and exhibits intriguing physical properties. The formed emulsion droplets are extremely fluid (5–10 mPa.s), enable fast (5 µm2 s−1), nearly complete (mobile fraction ≈0.8) and unhindered diffusion within and across compartments, which is a hallmark of fluids. Furthermore, the very low interfacial tension (0.18–0.40 mN m−1) enables droplet coalescence leading to equilibrium formation of various emulsion structures. These properties show similarities to cell cytoplasm and coacervates and hence this type of w/w emulsion formed via associative non‐ionic interactions is a new direction in the field of synthetic cells and synthetic biology.
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