Toward Functional Synthetic Cells: In‐Depth Study of Nanoparticle and Enzyme Diffusion through a Cross‐Linked Polymersome Membrane

Abstract

Understanding the diffusion of nanoparticles through permeable membranes in cell mimics paves the way for the construction of more sophisticated synthetic protocells with control over the exchange of nanoparticles or biomacromolecules between different compartments. Nanoparticles postloading by swollen pH switchable polymersomes is investigated and nanoparticles locations at or within polymersome membrane and polymersome lumen are precisely determined. Validation of transmembrane diffusion properties is performed based on nanoparticles of different origin—gold, glycopolymer protein mimics, and the enzymes myoglobin and esterase—with dimensions between 5 and 15 nm. This process is compared with the in situ loading of nanoparticles during polymersome formation and analyzed by advanced multiple‐detector asymmetrical flow field‐flow fractionation (AF4). These experiments are supported by complementary i) release studies of protein mimics from polymersomes, ii) stability and cyclic pH switches test for in polymersome encapsulated myoglobin, and iii) cryogenic transmission electron microscopy studies on nanoparticles loaded polymersomes. Different locations (e.g., membrane and/or lumen) are identified for the uptake of each protein. The protein locations are extracted from the increasing scaling parameters and the decreasing apparent density of enzyme‐containing polymersomes as determined by AF4. Postloading demonstrates to be a valuable tool for the implementation of cell‐like functions in polymersomes.

Retracted: Control of Nanoparticle Release by Membrane Composition for Dual‐Responsive Nanocapsules

“…In a recent study post‐loading of pH responsive, swollen polymeric vesicles was shown to be triggered first by the degree of softness of nanoparticles, followed by nanoparticle size, charge, and composition, whereas crosslinking and charge of swollen membrane of polymeric vesicles also play a dominate role in the post‐loading process. These insights in the post‐loading process of swollen pH‐responsive polymeric vesicles motivated us to pay attention to larger pH and temperature dual‐responsive polymeric nanocapsules, established by our group for the post‐loading of nanoparticles, using dendritic glycopolymers (PEI‐Mal 5 presented in Scheme ) as protein mimics. This should give guidelines to which kind of membrane in polymeric nanocapsules is more favorable for the step‐wise controllable release of post‐loaded nanoparticles.…”

Cell‐Inspired All‐Aqueous Microfluidics: From Intracellular Liquid–Liquid Phase Separation toward Advanced Biomaterials

“…Nature has evolved for billions of years to develop elaborate and sophisticated living organisms, which can provide sources of inspired solutions for various intriguing and enduring scientific and technique questions . Although a single cell is the simplest unit of living organisms, it is rich in high degrees of structural and functional complexities .…”

Effect of the Structure of Therapeutic Adenosine Analogues on Stability and Surface Electrostatic Potential of their Complexes with Poly(propyleneimine) Dendrimers

“…The results of ultrafiltration experiments were confirmed by AF4, an elution‐based chromatography‐like separation method commonly applied for the characterization of nanoparticles, polymers, and proteins. The advantages of AF4 include a broad separation range accessible by a single channel and significantly reduced risk of shear degradation . The application of this method constitutes a significant extension of our previous studies on the complexation patterns of glycosylated branched polymers .…”