Structural characterization of mRNA lipid nanoparticles (LNPs) in the presence of mRNA-free LNPs.

Lipid nanoparticles (LNPs) have emerged as a versatile platform for mRNA delivery across a range of applications, including disease prevention, cancer immunotherapy, and gene editing. Structural models of mRNA lipid nanoparticles (mRNA-LNPs) have also been proposed based on characterization of samples by using various advanced techniques. Among these, small angle neutron scattering (SANS) has proven essential for elucidating the lipid distribution within mRNA-LNPs, a factor crucial to both their preparation and efficacy.

pH-Dependent Packing Mode Variations and Chirality Inversion in Short Peptide Self-Assembly.

Precise control of structures and morphologies in peptide self-assembly has been challenging. We report the self-assembly of amphiphilic peptides IH, designed with a modular structure featuring three consecutive isoleucine residues as a hydrophobic tail and a C-terminal histidine-based hydrophilic headgroup. Microscopic, neutron scattering, and spectroscopic techniques demonstrate that the designed peptides self-assemble into β-sheet nanofibrils, with their helix handedness exhibiting subtle pH-dependent inversion.

Design and testing of high-temperature and high-pressure cell for SANS at CSNS.

With the stable operation of the Small-Angle Neutron Scattering (SANS) instrument at the China Spallation Neutron Source, the demand for diverse sample environments has significantly increased. Common atmospheric pressure conditions are no longer sufficient for user experiments, making it essential to develop new sample environment equipment that allows the samples to be tested under a joint high-temperature and high-pressure (HTHP) condition. In situ HTHP-SANS experiments are crucial for studying materials such as shale, gas hydrate, biological proteins, and colloids.

Elucidating Self-Assembly Tunability via a Designer Zwitterionic Surfactant-like Peptide.

Although complex electrostatic interactions play a vital role in defining protein architectures, it remains a challenge to exploit them to precisely tune peptide nanostructures instead of trigger assembly in the field of peptide self-assembly due to the inherent difficulty in accurately determining the protonation/deprotonation states of charge residues. We here design a zwitterionic β-sheet peptide Ac-IGGHE-NH containing a basic His and an acidic Glu residue, whose charged states (cationic, zwitterionic, and anionic) were found to be not only dependent on solution pH but also closely related to peptide concentration. As a result, the nature and magnitude of intermolecular electrostatic interactions of Ac-IGGHE-NH, as well as specific His-His interactions, were orchestrated well by varying the two solution conditions, eventually leading to different assembled architectures.

Enzyme-Mimicking Active Site Clefts Demonstrated by Self-Assembled Peptide Nanoribbons with Polar Zippers.

Due to the inherent limitations of natural enzymes, biomimetic enzymes have received tremendous attention, among which those arising from peptide self-assembly are of particular interest due to their resemblance to natural enzymes in composition and hierarchical structures, as well as their structural robustness and designability. Despite considerable advances achieved in this area, it remains a major challenge to construct active site clefts through peptide self-assembly. Here, we report the design of polar zippers between peptide β-sheets to mimic the catalytic microenvironment of natural enzymes.

Heavy-Atom-Free Supramolecular Photosensitizers Derived from Conventional Fluorophores.

Heavy-atom-free photosensitizers (PSs) offer advantages such as efficient generation of reactive oxygen species (ROS), low dark cytotoxicity, good photostability, and high biocompatibility. Although the development of new PSs through organic synthesis has been a focus of active research, supramolecular chemistry offers a complementary pathway. This study presents a versatile supramolecular strategy to convert conventional fluorophores into heavy-atom-free PSs using a cyclic peptide-based scaffold that densely assembles fluorophore moieties.

Chirality Inversion upon Coassembly of Stereoisomeric Short Peptides with Like-Handedness.

Despite numerous reports devoted to chirality inversion during the self-assembly of single chiral components, chirality inversion in the coassembly of two or more chiral components remains largely unexplored. Here we report the supramolecular chirality inversion via the coassembly of the two different stereoisomers of a minimalistic amphiphilic IK sequence with like-handedness in their self-sorting assembly. The coassembled nanofibrils exhibit noticeable helix inversion in a wide range of mixing ratios, compared to individual peptide nanofibrils.

Synergistic π-Tunnel Clamps in β-Sheets for Long-Range Dry-State Conduction: Toward Neural Restoration.

The ordered arrangement of π-π networks within nanostructures is advantageous for the construction of artificial electronic transport (ETp) systems. Building such structures with biocompatible peptides offers a potential for prescribed structural addressability and enhanced ETp capability with implications for targeted neural tissue engineering. However, creating ordered π-π tunnels in peptide nanostructures composed entirely of natural amino acids presents challenges resulting from the flexible side chains and the free movement of aromatic residues, causing unpredictable orientation.

Fluid Control of Dip Coating for Efficient Large-Area Organic Solar Cells.

As a classical low-cost technique, dip coating has not been used for printable electronics. Here, the study demonstrates large-area organic solar cells can be made by dip coating. The correlation is revealed among Van der Waals forces in precursor film, aggregation state of polymer, and fibrous orientation in active layer; the relationship is also expounded between fluid mechanics of the confined liquid in polymer scaffold and the continuity of the acceptor phase.

An Ultrastrong Multilayer Core-Shell Nanostructure in Aluminum-Lithium Castings.

Al-Li alloys with a high Li content have the advantages of low density and high stiffness but usually suffer from poor strength, instability of nanoprecipitates, and severe anisotropy, limiting their practical application. Here, we introduce a stable multilayer core-shell nanostructure in aluminum-lithium alloy castings to address these challenges. By quantifying the precipitates' composition and structures using atom probe tomography (APT) and small angle neutron scattering (SANS), it was found that there exists a unique type of Li-rich, coherent, nanoscale single-core double-shell particles in this alloy, which is different from the previously reported core-shell structures.

Small-Angle Neutron Scattering for Lithium-Based Battery Research: Progress and Perspective.

Lithium-based batteries have become the mainstream energy storage system due to their high energy density and long cycle life, driving rapid advancements in smart electronics and electric vehicles. However, the development of lithium-based batteries has encountered several difficult technical challenges, including safety issues and capacity degradation, which result from uncontrollable dendrite growth, complex interface reactions, and volume expansion. There is an urgent need to develop in situ characterization techniques to elucidate the complex evolution processes during battery operation.

Small-angle neutron scattering differentiates molecular-level structural models of nanoparticle interfaces.

The highly anisotropic and nonadditive nature of nanoparticle surfaces restricts their characterization by limited types of techniques that can reach atomic or molecular resolution. While small-angle neutron scattering (SANS) is a unique tool for analyzing complex systems, it has been traditionally considered a low-resolution method due to its limited scattering vector range and wide wavelength spread. In this article, we present a novel perspective on SANS by showcasing its exceptional capability to provide molecular-level insights into nanoparticle interfaces.

Transitioning Room-Temperature Phosphorescence from Solid States to Aqueous Phases via a Cyclic Peptide-Based Supramolecular Scaffold.

Aqueous room-temperature phosphorescence (RTP) materials have garnered considerable attention for their significant potential across various applications such as bioimaging, sensing, and encryption. However, establishing a universally applicable method for achieving aqueous RTP remains a substantial challenge. Herein, we present a versatile supramolecular strategy to transition RTP from solid states to aqueous phases.

Harnessing Cross-strand π-π Interlocking for Synergistic Enhancement of Immune Checkpoint Blocking and Ferroptosis.

The dynamic nature of noncovalent bonds in peptide self-assembly allows for selective accommodation of guest molecules. However, it remains unclear how to harness coassembly to reinforce the host peptides and simultaneously improve the application defects of guest molecules. This study aims to achieve supramolecular synergy between the host and guest, further expanding the functional space of the hybrid nanostructures.

Production of Branched Alkanes by Upcycling of Waste Polyethylene over Controlled Acid Sites of SO/ZrO-AlO Catalyst.

Branched alkanes, which enhance the octane number of gasoline, can be produced from waste polyethylene. However, achieving highly selective production of branched alkanes presents a significant challenge in the upcycling of waste polyethylene. Here, we report a one-pot process to convert polyethylene into gasoline-range hydrocarbons (C-C) with yield of 73.

Continuous polyamorphic transition in high-entropy metallic glass.

Polyamorphic transition (PT) is a compelling and pivotal physical phenomenon in the field of glass and materials science. Understanding this transition is of scientific and technological significance, as it offers an important pathway for effectively tuning the structure and property of glasses. In contrast to the PT observed in conventional metallic glasses (MGs), which typically exhibit a pronounced first-order nature, herein we report a continuous PT (CPT) without first-order characteristics in high-entropy MGs (HEMGs) upon heating.

Spatiotemporal-Dependent Confinement Effect of Bubble Swarms Enables a Fractal Hierarchical Assembly with Promoted Chirality.

The submarine-confined bubble swarm is considered an important constraining environment for the early evolution of living matter due to the abundant gas/water interfaces it provides. Similarly, the spatiotemporal characteristics of the confinement effect in this particular scenario may also impact the origin, transfer, and amplification of chirality in organisms. Here, we explore the confinement effect on the chiral hierarchical assembly of the amphiphiles in the confined bubble array stabilized by the micropillar templates.

Upcycling of polyethylene to gasoline through a self-supplied hydrogen strategy in a layered self-pillared zeolite.

Conversion of plastic wastes to valuable carbon resources without using noble metal catalysts or external hydrogen remains a challenging task. Here we report a layered self-pillared zeolite that enables the conversion of polyethylene to gasoline with a remarkable selectivity of 99% and yields of >80% in 4 h at 240 °C. The liquid product is primarily composed of branched alkanes (selectivity of 72%), affording a high research octane number of 88.

Controlled Assembly and Disassembly of Higher-Order Peptide Nanotubes.

The controlled peptide self-assembly and disassembly are not only implicated in many cellular processes but also possess huge application potential in a wide range of biotechnology and biomedicine. β-sheet peptide assemblies possess high kinetic stability, so it is usually hard to disassemble them rapidly. Here, we reported that both the self-assembly and disassembly of a designed short β-sheet peptide IIIGGHK could be well harnessed through the variations of concentration, pH, and mechanical stirring.

Observation of Topological Hall Effect in a Chemically Complex Alloy.

The topological Hall effect (THE) is the transport response of chiral spin textures and thus can serve as a powerful probe for detecting and understanding these unconventional magnetic orders. So far, the THE is only observed in either noncentrosymmetric systems where spin chirality is stabilized by Dzyaloshinskii-Moriya interactions, or triangular-lattice magnets with Ruderman-Kittel-Kasuya-Yosida-type interactions. Here, a pronounced THE is observed in a Fe-Co-Ni-Mn chemically complex alloy with a simple face-centered cubic (fcc) structure across a wide range of temperatures and magnetic fields.

Study of Precipitates in Oxide Dispersion-Strengthened Steels by SANS, TEM, and APT.

In this work, the nanostructure of oxide dispersion-strengthened steels was studied by small-angle neutron scattering (SANS), transmission electron microscopy (TEM), and atom probe tomography (APT). The steels under study have different alloying systems differing in their contents of Cr, V, Ti, Al, and Zr. The methods of local analysis of TEM and APT revealed a significant number of nanosized oxide particles and clusters.

Bioinspired Self-Assembly of Metalloporphyrins and Polyelectrolytes into Hierarchical Supramolecular Nanostructures for Enhanced Photocatalytic H Production in Water.

Polypeptides, as natural polyelectrolytes, are assembled into tailored proteins to integrate chromophores and catalytic sites for photosynthesis. Mimicking nature to create the water-soluble nanoassemblies from synthetic polyelectrolytes and photocatalytic molecular species for artificial photosynthesis is still rare. Here, we report the enhancement of the full-spectrum solar-light-driven H production within a supramolecular system built by the co-assembly of anionic metalloporphyrins with cationic polyelectrolytes in water.

Supra-Cyanines: Ultrabright Cyanine-Based Fluorescent Supramolecular Materials in Solution and in the Solid State.

Fluorescent materials with high brightness play a crucial role in the advancement of various technologies such as bioimaging, photonics, and OLEDs. While significant efforts are dedicated to designing new organic dyes with improved performance, enhancing the brightness of existing dyes holds equal importance. In this study, we present a simple supramolecular strategy to develop ultrabright cyanine-based fluorescent materials by addressing long-standing challenges associated with cyanine dyes, including undesired cis-trans photoisomerization and aggregation-caused quenching.