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Biomimetic design to afford smart functional biomaterials with exquisite properties represents synthetic challenges and provides unique perspectives. In this context, elastin‐like polypeptides (ELPs) recently became highly attractive building blocks in the development of lipoprotein‐based membranes. In addition to the bioengineered post‐translational modifications of genetically encoded recombinant ELPs developed so far, we report here a simple and versatile method to design biohybrid brush‐like lipid‐grafted‐ELPs using chemical post‐modification reactions. We have explored a combination of methionine alkylation and click chemistry to create a new class of hybrid lipoprotein mimics. Our design allowed the formation of biomimetic vesicles with controlled permeability, correlated to the temperature‐responsiveness of ELPs. [ABSTRACT FROM AUTHOR]

Elastin‐like polypeptides (ELPs) have been proposed as a simple model of intrinsically disordered proteins (IDPs) which can form membraneless organelles by liquid–liquid phase separation (LLPS) in cells. Herein, the behavior of fluorescently labeled ELP is studied in cytomimetic aqueous two‐phase system (ATPS) encapsulated protocells that are formed using microfluidics, which enabled confinement, changes in temperature, and statistical analysis. The spatial organization of ELP could be observed in the ATPS. Furthermore, changes in temperature triggered the dynamic formation and distribution of ELP‐rich droplets within the ATPS, resulting from changes in conformation. Proteins were encapsulated along with ELP in the synthetic protocells and distinct partitioning properties of these proteins and ELP in the ATPS were observed. Therefore, the ability of ELP to coacervate with temperature can be maintained inside a cell‐mimicking system. [ABSTRACT FROM AUTHOR]

Abstract: Recently, supramolecular hydrogels have attracted increasing interest owing to their tunable stability and inherent biocompatibility. However, only few studies have been reported in the literature on self‐healing supramolecular nucleoside hydrogels, compared to self‐healing polymer hydrogels. In this work, we successfully developed a self‐healing supramolecular nucleoside hydrogel obtained by simply mixing equimolar amounts of guanosine (G) and isoguanosine (isoG) in the presence of K+. The gelation properties have been studied systematically by comparing different alkali metal ions as well as mixtures with different ratios of G and isoG. To this end, rheological and phase diagram experiments demonstrated that the co‐gel not only possessed good self‐healing properties and short recovery time (only 20 seconds) but also could be formed at very low concentrations of K+. Furthermore, nuclear magnetic resonance (NMR), powder X‐ray diffraction (PXRD), and circular dichroism (CD) spectroscopy suggested that possible G2isoG2‐quartet structures occurred in this self‐healing supramolecular nucleoside hydrogel. This co‐gel, to some extent, addressed the problem of isoguanosine gels for the applications in vivo, which showed the potential to be a new type of drug delivery system for biomedical applications in the future. [ABSTRACT FROM AUTHOR]

Supramolecular nucleoside-based hydrogels have the potential to be utilized in drug delivery, regenerative medicine and for the construction of nanoscopic devices. Isoguanosine, its 2′-deoxyribonucleoside and the 2′-deoxy-2′-fluororibonucleoside form hydrogels in alkali metal salt solutions. Gel stability depends on the metal ions used (Li+, Na+, K+, Rb+, Cs+). All isoguanosine gels show long-term stability of several months, whereas guanosine gels collapse within minutes or hours. Rheological data confirm a 15 times higher hydrogel stability for isoguanosine compared to guanosine. Isoguanosine gel stability covers a broad pH range (pH 3–10), and the stability at physiological Na+ ion concentration is striking. SEM images reveal that isoguanosine self-assembles into helical stacked fibers that are interconnected whereas guanosine forms discrete ribbons. Moreover, isoguanosine gels display excellent loading and release ability for small molecules. [ABSTRACT FROM AUTHOR]

Structurally modified nucleosides are central players in the field of nucleic acid chemistry. Adenine-thymine (AT) pyrimido[4,5-d]pyrimidine furanosyl and pyranosyl arabinonucleosides have been synthesized for the first time. Single-crystal X-ray diffraction analysis reveals novel base pairs that, in synergy with the sugar residues, direct the emergence of distinct networks containing channels and cavities. The microscopic noncovalent connections can be translated into macroscopic levels in which robust organogels are formed by the furanoside but not the pyranoside. The influences of the sugars are also displayed by the different shaped superstructures of the free nucleosides in solution. The readout of the information in the base moiety is therefore tailored by the sugar configuration, and the interplays exert subtle effects on the structures, from solid to gel and to the solution state. The potential for forming these appealing base pairs and higher structures enables these intriguing nucleosides to serve as unique building blocks in various areas or to construct innovative nucleic acid structures. [ABSTRACT FROM AUTHOR]

Supramolecular morphogenesis is a fundamentally important process in fields ranging from structural biology to materials chemistry. Our previous works demonstrated that the sugar structural parameters can decree the supramolecular morphogenesis of Janus-type nucleosides. However, the chiral effect in this regards has not yet been tackled. Here, the self-associated superstructures of J-AT l -ribonucleoside (J-AT-L, 1 ) was investigated in both solid state and solution by single-crystal X-ray analysis and scanning electron microscope (SEM). The results indicate a high mirror symmetry in both monomeric level and hydrogen bond patterns in solid state between compound 1 and its enantiomeric counterpart J-AT d -ribonucleoside (J-AT-D, 2 ), except the distinct interactions between A–B and B–B conformers. The SEM experiments display that J-AT-L forms a porous microsphere-flower-like superstructure, instead of a radial-petal-flower-like superstructure of the d -enantiomer ( 2 ), which could be attributed to the different interactions of A–B and B–B conformers among these two series. This study provides for the first time the evidences of how the chiral information of the monomeric J-AT nucleosides is translated into the diverse supramolecular morphologies. [ABSTRACT FROM AUTHOR]

The intrinsic structural diversity of the nucleosides is one of the essential properties for their wide participation in myriads of chemical or biochemical processes. Two unique regio-isomeric Janus-type AT nucleosides with the 5′-deoxyribose attached on N1 or N3 position has been synthesized through Vorbrueggen or transglycosylation reactions. These two isomers display different supramolecular morphologies in solution state from their N8 glycosylated counterpart. The underneath structural details of the N3 glycosylated isomer were revealed by the single-crystal X-ray analysis. In addition to a novel base pair pattern was identified which is entirely different from the reverse Watson-Crick base pair adopted by its N8 isomer, an interesting water-filled columnar nanotuble-like structure was also found in its solid state. This study not only enriches the structural varieties of AT Janus-type nucleosides, but also provides specific information concerning the effect of the sugar glycosylation position on the properties of these new type of pyrimido[4,5-d]pyrimidine nucleosides. [ABSTRACT FROM AUTHOR]