Toward understanding lipid reorganization in RNA lipid nanoparticles in acidic environments.

The use of lipid nanoparticles (LNPs) for therapeutic RNA delivery has gained significant interest, particularly highlighted by recent milestones such as the approval of Onpattro and two mRNA-based SARS-CoV-2 vaccines. However, despite substantial advancements in this field, our understanding of the structure and internal organization of RNA-LNPs -and their relationship to efficacy, both in vitro and in vivo- remains limited. In this study, we present a coarse-grained molecular dynamics (MD) approach that allows for the simulations of full-size LNPs.

A fluorescent nanosensor paint detects dopamine release at axonal varicosities with high spatiotemporal resolution.

The neurotransmitter dopamine (DA) controls multiple behaviors and is perturbed in several major brain diseases. DA is released from large populations of specialized structures called axon varicosities. Determining the DA release mechanisms at such varicosities is essential for a detailed understanding of DA biology and pathobiology but has been limited by the low spatial resolution of DA detection methods.

Quantum defects as versatile anchors for carbon nanotube functionalization.

Single-wall carbon nanotubes (SWCNTs) are used in diverse applications that require chemical tailoring of the SWCNT surface, including optical sensing, imaging, targeted drug delivery and single-photon generation. SWCNTs have been noncovalently modified with (bio)polymers to preserve their intrinsic near-infrared fluorescence. However, demanding applications (e.

Molecular Profiles of Amyloid-β Proteoforms in Typical and Rapidly Progressive Alzheimer's Disease.

The molecular determinants of atypical clinical variants of Alzheimer's disease, including the recently discovered rapidly progressive Alzheimer's disease (rpAD), are unknown to date. Fibrilization of the amyloid-β (Aβ) peptide is the most frequently studied candidate in this context. The Aβ peptide can exist as multiple proteoforms that vary in their post-translational processing, amyloidogenesis, and toxicity.

3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly .

Male ithomiine butterflies (Nymphalidae: Danainae) have hairpencils on the forewings (i.e., androconia) that disseminate semiochemicals during courtship.

Quantum Defects as a Toolbox for the Covalent Functionalization of Carbon Nanotubes with Peptides and Proteins.

Single-walled carbon nanotubes (SWCNTs) are a 1D nanomaterial that shows fluorescence in the near-infrared (NIR, >800 nm). In the past, covalent chemistry was less explored to functionalize SWCNTs as it impairs NIR emission. However, certain sp defects (quantum defects) in the carbon lattice have emerged that preserve NIR fluorescence and even introduce a new, red-shifted emission peak.

Transport and programmed release of nanoscale cargo from cells by using NETosis.

Cells can take up nanoscale materials, which has important implications for understanding cellular functions, biocompatibility as well as biomedical applications. Controlled uptake, transport and triggered release of nanoscale cargo is one of the great challenges in biomedical applications of nanomaterials. Here, we study how human immune cells (neutrophilic granulocytes, neutrophils) take up nanomaterials and program them to release this cargo after a certain time period.

Exfoliated near infrared fluorescent silicate nanosheets for (bio)photonics.

Imaging of complex (biological) samples in the near-infrared (NIR) is beneficial due to reduced light scattering, absorption, phototoxicity, and autofluorescence. However, there are few NIR fluorescent materials known and suitable for biomedical applications. Here we exfoliate the layered pigment CaCuSiO (Egyptian Blue, EB) via ball milling and facile tip sonication into NIR fluorescent nanosheets (EB-NS).

Chemistry of the Androconial Secretion of the Ithomiine Butterfly Oleria onega.

Ithomiine butterflies use pyrrolizidine alkaloids (PAs) as precursors for male pheromones, such as dihydropyrrolizines or lactones. In contrast to most other ithomiine genera, none of these compounds have ever been detected in Oleria species. The absence of these compounds is thought to be the result of limited access to PA-containing plants.

Near-Infrared Imaging of Serotonin Release from Cells with Fluorescent Nanosensors.

Serotonin is an important neurotransmitter involved in various functions of the nervous, blood, and immune system. In general, detection of small biomolecules such as serotonin in real time with high spatial and temporal resolution remains challenging with conventional sensors and methods. In this work, we designed a near-infrared (nIR) fluorescent nanosensor (NIRSer) based on fluorescent single-walled carbon nanotubes (SWCNTs) to image the release of serotonin from human blood platelets in real time.

Geographic contrasts between pre- and postzygotic barriers are consistent with reinforcement in Heliconius butterflies.

Identifying the traits causing reproductive isolation and the order in which they evolve is fundamental to understanding speciation. Here, we quantify prezygotic and intrinsic postzygotic isolation among allopatric, parapatric, and sympatric populations of the butterflies Heliconius elevatus and Heliconius pardalinus. Sympatric populations from the Amazon (H.

Chirality enriched carbon nanotubes with tunable wrapping via corona phase exchange purification (CPEP).

Single-walled carbon nanotubes (SWCNTs) have unique photophysical properties and serve as building blocks for biosensors, functional materials and devices. For many applications it is crucial to use chirality-pure SWCNTs, which requires sophisticated processes. Purification procedures such as wrapping by certain polymers, phase separation, density gradient centrifugation or gel chromatography have been developed and yield distinct SWCNT species wrapped by a specific polymer or surfactant.

Nanobody-Conjugated Nanotubes for Targeted Near-Infrared In Vivo Imaging and Sensing.

Fluorescent nanomaterials such as single-walled carbon nanotubes (SWCNTs) have many advantages in terms of their photophysics, but it is difficult to target them to specific locations in living systems. In contrast, the green fluorescent protein (GFP) has been genetically fused to proteins in many cells and organisms. Therefore, GFP can be seen not only as a fluorophore but as a universal target/handle.

Carbon Nanotubes Encapsulated in Coiled-Coil Peptide Barrels.

Specific functionalization of 1D nanomaterials such as near infrared (nIR) fluorescent single-walled carbon nanotubes (SWCNTs) is essential for colloidal stability and tailoring of their interactions with the environment. Here, we show that de novo designed alpha-helical coiled-coil peptide barrels (αHBs) with appropriate pores encapsulate and solubilize SWCNTs. In contrast, barrels without or with narrow pores showed a much smaller efficiency.

Male sex pheromone components in butterflies released by the androconia affect female choice.

Sex-specific pheromones are known to play an important role in butterfly courtship, and may influence both individual reproductive success and reproductive isolation between species. Extensive ecological, behavioural and genetic studies of butterflies have made a substantial contribution to our understanding of speciation. Male pheromones, although long suspected to play an important role, have received relatively little attention in this genus.

The Scent Chemistry of Heliconius Wing Androconia.

Neotropical Heliconius butterflies are members of various mimicry rings characterized by diverse colour patterns. In the present study we investigated whether a similar diversity is observed in the chemistry of volatile compounds present in male wing androconia. Recent research has shown that these androconia are used during courting of females.

Cell-permeable nanobodies for targeted immunolabelling and antigen manipulation in living cells.

Functional antibody delivery in living cells would enable the labelling and manipulation of intracellular antigens, which constitutes a long-thought goal in cell biology and medicine. Here we present a modular strategy to create functional cell-permeable nanobodies capable of targeted labelling and manipulation of intracellular antigens in living cells. The cell-permeable nanobodies are formed by the site-specific attachment of intracellularly stable (or cleavable) cyclic arginine-rich cell-penetrating peptides to camelid-derived single-chain VHH antibody fragments.

Tuning Selectivity of Fluorescent Carbon Nanotube-Based Neurotransmitter Sensors.

Detection of neurotransmitters is an analytical challenge and essential to understand neuronal networks in the brain and associated diseases. However, most methods do not provide sufficient spatial, temporal, or chemical resolution. Near-infrared (NIR) fluorescent single-walled carbon nanotubes (SWCNTs) have been used as building blocks for sensors/probes that detect catecholamine neurotransmitters, including dopamine.

Versatile and Efficient Site-Specific Protein Functionalization by Tubulin Tyrosine Ligase.

A novel chemoenzymatic approach for simple and fast site-specific protein labeling is reported. Recombinant tubulin tyrosine ligase (TTL) was repurposed to attach various unnatural tyrosine derivatives as small bioorthogonal handles to proteins containing a short tubulin-derived recognition sequence (Tub-tag). This novel strategy enables a broad range of high-yielding and fast chemoselective C-terminal protein modifications on isolated proteins or in cell lysates for applications in biochemistry, cell biology, and beyond, as demonstrated by the site-specific labeling of nanobodies, GFP, and ubiquitin.

Homoserine Lactones, Methyl Oligohydroxybutyrates, and Other Extracellular Metabolites of Macroalgae-Associated Bacteria of the Roseobacter Clade: Identification and Functions.

Twenty-four strains of marine Roseobacter clade bacteria were isolated from macroalgae and investigated for the production of quorum-sensing autoinducers, N-acylhomoserine lactones (AHLs). GC/MS analysis of the extracellular metabolites allowed us to evaluate the release of other small molecules as well. Nineteen strains produced AHLs, ranging from 3-OH-C10:0-HSL (homoserine lactone) to (2E,11Z)-C18:2-HSL, but no specific phylogenetic or ecological pattern of individual AHL occurrence was observed when cluster analysis was performed.

A new arabinomannan from the cell wall of the chlorococcal algae Chlorella vulgaris.

A new arabinomannan has been isolated from the cell wall of the green algae Chlorella vulgaris by extraction with 0.1 M NaOH, dialysis and SEC fractionation. M(w) was about 8000 u.