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    Zwitterionic Dendrimersomes: A Closer Xenobiotic Mimic of Cell Membranes
    (Weinheim : Wiley-VCH, 2022-10-31) Joseph, Anton; Wagner, Anna M.; Garay-Sarmiento, Manuela; Aleksanyan, Mina; Haraszti, Tamás; Söder, Dominik; Georgiev, Vasil N.; Dimova, Rumiana; Percec, Virgil; Rodriguez-Emmenegger, Cesar
    Building functional mimics of cell membranes is an important task toward the development of synthetic cells. So far, lipid and amphiphilic block copolymers are the most widely used amphiphiles with the bilayers by the former lacking stability while membranes by the latter are typically characterized by very slow dynamics. Herein, a new type of Janus dendrimer containing a zwitterionic phosphocholine hydrophilic headgroup (JDPC) and a 3,5-substituted dihydrobenzoate-based hydrophobic dendron is introduced. JDPC self-assembles in water into zwitterionic dendrimersomes (z-DSs) that faithfully recapitulate the cell membrane in thickness, flexibility, and fluidity, while being resilient to harsh conditions and displaying faster pore closing dynamics in the event of membrane rupture. This enables the fabrication of hybrid DSs with components of natural membranes, including pore-forming peptides, structure-directing lipids, and glycans to create raft-like domains or onion vesicles. Moreover, z-DSs can be used to create active synthetic cells with life-like features that mimic vesicle fusion and motility as well as environmental sensing. Despite their fully synthetic nature, z-DSs are minimal cell mimics that can integrate and interact with living matter with the programmability to imitate life-like features and beyond.
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    Enhanced Concanavalin A Binding to Preorganized Mannose Nanoarrays in Glycodendrimersomes Revealed Multivalent Interactions
    (Weinheim : Wiley-VCH, 2021) Kostina, Nina Yu; Söder, Dominik; Haraszti, Tamás; Xiao, Qi; Rahimi, Khosrow; Partridge, Benjamin E.; Klein, Michael L.; Percec, Virgil; Rodriguez‐Emmenegger, Cesar
    The effect of the two-dimensional glycan display on glycan-lectin recognition remains poorly understood despite the importance of these interactions in a plethora of cellular processes, in (patho)physiology, as well as its potential for advanced therapeutics. Faced with this challenge we utilized glycodendrimersomes, a type of synthetic vesicles whose membrane mimics the surface of a cell and offers a means to probe the carbohydrate biological activity. These single-component vesicles were formed by the self-assembly of sequence-defined mannose-Janus dendrimers, which serve as surrogates for glycolipids. Using atomic force microscopy and molecular modeling we demonstrated that even mannose, a monosaccharide, was capable of organizing the sugar moieties into periodic nanoarrays without the need of the formation of liquid-ordered phases as assumed necessary for rafts. Kinetics studies of Concanavalin A binding revealed that those nanoarrays resulted in a new effective ligand yielding a ten-fold increase in the kinetic and thermodynamic constant of association. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH
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    Unraveling the Mechanism and Kinetics of Binding of an LCI-eGFP-Polymer for Antifouling Coatings
    (Weinheim : Wiley-VCH, 2021) Söder, Dominik; Garay-Sarmiento, Manuela; Rahimi, Khosrow; Obstals, Fabian; Dedisch, Sarah; Haraszti, Tamás; Davari, Mehdi D.; Jakob, Felix; Heß, Christoph; Schwaneberg, Ulrich; Rodriguez-Emmenegger, Cesar
    The ability of proteins to adsorb irreversibly onto surfaces opens new possibilities to functionalize biological interfaces. Herein, the mechanism and kinetics of adsorption of protein-polymer macromolecules with the ability to equip surfaces with antifouling properties are investigated. These macromolecules consist of the liquid chromatography peak I peptide from which antifouling polymer brushes are grafted using single electron transfer-living radical polymerization. Surface plasmon resonance spectroscopy reveals an adsorption mechanism that follows a Langmuir-type of binding with a strong binding affinity to gold. X-ray reflectivity supports this by proving that the binding occurs exclusively by the peptide. However, the lateral organization at the surface is directed by the cylindrical eGFP. The antifouling functionality of the unimolecular coatings is confirmed by contact with blood plasma. All coatings reduce the fouling from blood plasma by 8894% with only minor effect of the degree of polymerization for the studied range (DP between 101 and 932). The excellent antifouling properties, combined with the ease of polymerization and the straightforward coating procedure make this a very promising antifouling concept for a multiplicity of applications.