Solid-State Nanopore Real-Time Assay for Monitoring Cas9 Endonuclease Reactivity.

The field of nanopore sensing is now moving beyond nucleic acid sequencing. An exciting avenue is the use of nanopore platforms for the monitoring of biochemical reactions. Biological nanopores have been used for this application, but solid-state nanopore approaches have lagged.

The structural organisation of pentraxin-3 and its interactions with heavy chains of inter-α-inhibitor regulate crosslinking of the hyaluronan matrix.

Pentraxin-3 (PTX3) is an octameric protein, comprised of eight identical protomers, that has diverse functions in reproductive biology, innate immunity and cancer. PTX3 interacts with the large polysaccharide hyaluronan (HA) to which heavy chains (HCs) of the inter-α-inhibitor (IαI) family of proteoglycans are covalently attached, playing a key role in the (non-covalent) crosslinking of HC•HA complexes. These interactions stabilise the cumulus matrix, essential for ovulation and fertilisation in mammals, and are also implicated in the formation of pathogenic matrices in the context of viral lung infections.

Evolution of SARS-CoV-2 spike trimers towards optimized heparan sulfate cross-linking and inter-chain mobility.

The heparan sulfate (HS)-rich extracellular matrix (ECM) serves as an initial interaction site for the homotrimeric spike (S) protein of SARS-CoV-2 to facilitate subsequent docking to angiotensin-converting enzyme 2 (ACE2) receptors and cellular infection. More recent variants, notably Omicron, have evolved by swapping several amino acids to positively charged residues to enhance the interaction of the S-protein trimer with the negatively charged HS. However, these enhanced interactions may reduce Omicron's ability to move through the HS-rich ECM to effectively find ACE2 receptors and infect cells, raising the question of how to mechanistically explain HS-associated viral movement.

Grain and Domain Microstructure in Long Chain -Alkane and -Alkanol Wax Crystals.

Waxes comprise a diverse set of materials from lubricants and coatings to biological materials such as the intracuticular wax layers on plant leaves that restrict water loss to inhibit dehydration. Despite the often mixed hydrocarbon chain lengths and functional groups within waxes, they show a propensity for ordering into crystalline phases, albeit with a wealth of solid solution behavior and disorder modes that determine chemical transport and mechanical properties. Here, we reveal the microscopic structure and heterogeneity of replica leaf wax models based on the dominant wax types in the plant, namely CH and CHOH and their binary mixtures.

Active Remote Focus Stabilization in Oblique Plane Microscopy.

Light-sheet fluorescence microscopy (LSFM) has demonstrated great potential in the life sciences owing to its efficient volumetric imaging capabilities. For long term imaging, the light-sheet typically needs to be stabilized to the detection focal plane for the best imaging results. Current light-sheet stabilization methods rely on fluorescence emission from the sample, which may interrupt the scientific imaging and add to sample photobleaching.

Multimodal nanoparticle analysis enabled by a polymer electrolyte nanopore combined with nanoimpact electrochemistry.

Nanopores are emerging as a powerful tool for the analysis and characterization of nanoparticles at the single entity level. Here, we report that a PEG-based polymer electrolyte present inside the nanopore enables the enhanced detection of nanoparticles at low ionic strength. We develop a numerical model that recapitulates the electrical response of the glass nanopore system, revealing the response to be sensitive to the position of the polymer electrolyte interface.

Mechanical and suture-holding properties of a UV-cured atelocollagen membrane with varied crosslinked architecture.

The mechanical competence and suturing ability of collagen-based membranes are paramount in guided bone regeneration (GBR) therapy, to ensure damage-free implantation, fixation and space maintenance. However, contact with the biological medium can induce swelling of collagen molecules, yielding risks of membrane sinking into the bone defect, early loss of barrier function, and irreversibly compromised clinical outcomes. To address these challenges, this study investigates the effect of the crosslinked network architecture on both mechanical and suture-holding properties of a new atelocollagen (AC) membrane.

Nanobiopsy investigation of the subcellular mtDNA heteroplasmy in human tissues.

Mitochondrial function is critical to continued cellular vitality and is an important contributor to a growing number of human diseases. Mitochondrial dysfunction is typically heterogeneous, mediated through the clonal expansion of mitochondrial DNA (mtDNA) variants in a subset of cells in a given tissue. To date, our understanding of the dynamics of clonal expansion of mtDNA variants has been technically limited to the single cell-level.

Hidden Impurities Generate False Positives in Single Atom Catalyst Imaging.

Single-atom catalysts (SACs) are an emerging class of materials, leveraging maximum atom utilization and distinctive structural and electronic properties to bridge heterogeneous and homogeneous catalysis. Direct imaging methods, such as aberration-corrected high-angle annular dark-field scanning transmission electron microscopy, are commonly applied to confirm the atomic dispersion of active sites. However, interpretations of data from these techniques can be challenging due to simultaneous contributions to intensity from impurities introduced during synthesis processes, as well as any variation in position relative to the focal plane of the electron beam.

Direct Visualization of Chemical Transport in Solid-State Chemical Reactions by Time-of-Flight Secondary Ion Mass Spectrometry.

Systematic control and design of solid-state chemical reactions are required for modifying materials properties and in novel synthesis. Understanding chemical dynamics at the nanoscale is therefore essential to revealing the key reactive pathways. Herein, we combine focused ion beam-scanning electron microscopy (FIB-SEM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) to track the migration of sodium from a borate coating to the oxide scale during hot corrosion testing.

Single-cell nanobiopsy enables multigenerational longitudinal transcriptomics of cancer cells.

Single-cell RNA sequencing has revolutionized our understanding of cellular heterogeneity, but routine methods require cell lysis and fail to probe the dynamic trajectories responsible for cellular state transitions, which can only be inferred. Here, we present a nanobiopsy platform that enables the injection of exogenous molecules and multigenerational longitudinal cytoplasmic sampling from a single cell and its progeny. The technique is based on scanning ion conductance microscopy (SICM) and, as a proof of concept, was applied to longitudinally profile the transcriptome of single glioblastoma (GBM) brain tumor cells in vitro over 72 hours.

NanoLocz: Image Analysis Platform for AFM, High-Speed AFM, and Localization AFM.

Atomic Force Microscopy (AFM), High-Speed AFM (HS-AFM) simulation AFM, and Localization AFM (LAFM) enable the study of molecules and surfaces with increasingly higher spatiotemporal resolution. However, effective and rapid analysis of the images and movies produced by these techniques can be challenging, often requiring the use of multiple image processing software applications and scripts. Here, NanoLocz, an open-source solution that offers advanced analysis capabilities for the AFM community, is presented.

Porous Polymeric Nanofilms for Recreating the Basement Membrane in an Endothelial Barrier-on-Chip.

Organs-on-chips (OoCs) support an organotypic human cell culture . Precise representation of basement membranes (BMs) is critical for mimicking physiological functions of tissue interfaces. Artificial membranes in polyester (PES) and polycarbonate (PC) commonly used in models and OoCs do not replicate the characteristics of the natural BMs, such as submicrometric thickness, selective permeability, and elasticity.

Synthesis and investigation of a [6]cycloparaphenylene gold(I) -heterocyclic carbene complex.

[]cycloparaphenylenes ([]CPPs) as well as -heterocyclic carbene (NHC) gold(I)-complexes are intriguing building blocks for material and life sciences due to their extraordinary structures resulting in unique photophysical properties. Herein, we report the combination of a [6]CPP with a -heterocyclic carbene serving as a ligand in a linear gold(I)-complex possessing the form [AuBr(NHC)]. Solid-state structures of both the precursor and the complex are presented and discussed.

Automated Scanning Probe Tip State Classification without Machine Learning.

The manual identification and in situ correction of the state of the scanning probe tip is one of the most time-consuming and tedious processes in atomic-resolution scanning probe microscopy. This is due to the random nature of the probe tip on the atomic level, and the requirement for a human operator to compare the probe quality via manual inspection of the topographical images after any change in the probe. Previous attempts to automate the classification of the scanning probe state have focused on the use of machine learning techniques, but the training of these models relies on large, labeled data sets for each surface being studied.

Universality of Hair as a Nucleant: Exploring the Effects of Surface Chemistry and Topography.

The ability to control crystal nucleation through the simple addition of a nucleating agent (nucleant) is desirable for a huge range of applications. However, effective nucleating agents are known for only a small number of systems, and many questions remain about the mechanisms by which they operate. Here, we explore the features that make an effective nucleant and demonstrate that the biological material hair-which naturally possesses a chemically and topographically complex surface structure-has excellent potential as an effective nucleating agent.

Automated Purification of DNA Origami with SPRI Beads.

DNA origami synthesis is a well-established technique with wide-ranging applications. In most cases, the synthesized origami must be purified to remove excess materials such as DNA oligos and other functional molecules. While several purification techniques are routinely used, all have limitations, and cannot be integrated with robotic systems.

Competitive Specific Anchorage of Molecules onto Surfaces: Quantitative Control of Grafting Densities and Contamination by Free Anchors.

The formation of surfaces decorated with biomacromolecules such as proteins, glycans, or nucleic acids with well-controlled orientations and densities is of critical importance for the design of in vitro models, e.g., synthetic cell membranes and interaction assays.

Structural insights into hybrid immiscible blends of metal-organic framework and sodium ultraphosphate glasses.

Recently, increased attention has been focused on amorphous metal-organic frameworks (MOFs) and, more specifically, MOF glasses, the first new glass category discovered since the 1970s. In this work, we explore the fabrication of a compositional series of hybrid blends, the first example of blending a MOF and inorganic glass. We combine ZIF-62(Zn) glass and an inorganic glass, 30NaO-70PO, to combine the chemical versatility of the MOF glass with the mechanical properties of the inorganic glass.

MOF-based heterogeneous catalysis in continuous flow incorporation onto polymer-based spherical activated carbon supports.

We present an approach to harnessing the tuneable catalytic properties of complex nanomaterials for continuous flow heterogeneous catalysis by combining them with the scalable and industrially implementable properties of carbon pelleted supports. This approach, in turn, will enable these catalytic materials, which largely currently exist in forms unsuitable for this application ( powders), to be fully integrated into large scale, chemical processes. A composite heterogeneous catalyst consisting of a metal-organic framework-based Lewis acid, MIL-100(Sc), immobilised onto polymer-based spherical activated carbon (PBSAC) support has been developed.

Next-Generation Nanopore Sensors Based on Conductive Pulse Sensing for Enhanced Detection of Nanoparticles.

Nanopore sensing has been successfully used to characterize biological molecules with single-molecule resolution based on the resistive pulse sensing approach. However, its use in nanoparticle characterization has been constrained by the need to tailor the nanopore aperture size to the size of the analyte, precluding the analysis of heterogeneous samples. Additionally, nanopore sensors often require the use of high salt concentrations to improve the signal-to-noise ratio, which further limits their ability to study a wide range of nanoparticles that are unstable at high ionic strength.