Characterization of Spirulina-derived extracellular vesicles and their potential as a vaccine adjuvant.

Spirulina is an edible cyanobacterium that increasingly gaining recognition for it untapped potential in the biomanufacturing of pharmaceuticals. Despite the rapidly accumulating information on extracellular vesicles (EVs) from most other bacteria, nothing is known about Spirulina extracellular vesicles (SPEVs). This study reports the successful isolation, characterization and visualization of SPEVs for the first time and it further investigates the potential therapeutic benefits of SPEVs using a mouse model.

Chemically-Induced Lipoprotein Breakdown for Improved Extracellular Vesicle Purification.

Extracellular vesicles (EVs) are nanosized biomolecular packages involved in intercellular communication. EVs are released by all cells, making them broadly applicable as therapeutic, diagnostic, and mechanistic components in (patho)physiology. Sample purity is critical for correctly attributing observed effects to EVs and for maximizing therapeutic and diagnostic performance.

Altered ubiquitin signaling induces Alzheimer's disease-like hallmarks in a three-dimensional human neural cell culture model.

Alzheimer's disease (AD) is characterized by toxic protein accumulation in the brain. Ubiquitination is essential for protein clearance in cells, making altered ubiquitin signaling crucial in AD development. A defective variant, ubiquitin B + 1 (UBB), created by a non-hereditary RNA frameshift mutation, is found in all AD patient brains post-mortem.

Hyaluronic acid: An overlooked extracellular vesicle contaminant.

The variable presence of contaminants in extracellular vesicle (EV) samples is one of the major contributors to a lack of inter-study reproducibility in the field. Well-known contaminants include protein aggregates, RNA-protein complexes and lipoproteins, which resemble EVs in shape, size and/or density. On the contrary, polysaccharides, such as hyaluronic acid (HA), have been overlooked as EV contaminants.

Selective labeling of phosphatidylserine for cryo-TEM by a two-step immunogold method.

Immunogold labeling in transmission electron microscopy (TEM) utilizes the high electron density of gold nanoparticles conjugated to proteins to identify specific antigens in biological samples. In this work we applied the concept of immunogold labeling for the labeling of negatively charged phospholipids, namely phosphatidylserine, by a simple protocol, performed entirely in the liquid-phase, from which cryo-TEM specimens can be directly prepared. Labeling included a two-step process using biotinylated annexin-V and gold-conjugated streptavidin.

Encapsulation of Thymol and Eugenol Essential Oils Using Unmodified Cellulose: Preparation and Characterization.

Essential oils (EOs) are volatile natural organic compounds, which possess pesticidal properties. However, they are vulnerable to heat and light, limiting their range of applications. Encapsulation of EOs is a useful approach to overcome some of these limitations.

Sucrose-based cryoprotective storage of extracellular vesicles.

Advancements in extracellular vesicle (EV) studies necessitate the development of optimized storage conditions to ensure preservation of physical and biochemical characteristics. In this study, the most common buffer for EV storage (phosphate-buffered saline/PBS) was compared to a cryoprotective 5% sucrose solution. The size distribution and concentration of EVs from two different sources changed to a greater extent after -80 °C storage in PBS compared to the sucrose solution.

Phase Change Material with Gelation Imparting Shape Stability.

Blending two gelators with different chemistries (12-hydroxystearic acid and a bis-urea derivative, Millithix MT-800) was used to impart shape stability to CrodaTherm 29, a bio-based phase change material (PCM), melting/crystallizing at near-ambient temperature. The gelators immobilized the PCM by forming an interpenetrating fibrillar network. 15 wt % concentration of the gelators was found to be effective in preventing liquid PCM leakage.

Molecular self-assembly under nanoconfinement: indigo carmine scroll structures entrapped within polymeric capsules.

Molecular self-assembly forms structures of well-defined organization that allow control over material properties, affording many advanced technological applications. Although the self-assembly of molecules is seemingly spontaneous, the structure into which they assemble can be altered by carefully modulating the driving forces. Here we study the self-assembly within the constraints of nanoconfined closed spherical volumes of polymeric nanocapsules, whereby a mixture of polyester-polyether block copolymer and methacrylic acid methyl methacrylate copolymer forms the entrapping capsule shell of nanometric dimensions.

Extracellular Vesicle MicroRNA That Are Involved in β-Thalassemia Complications.

Beta thalassemia major (βT) is a hereditary anemia characterized by transfusion-dependency, lifelong requirement of chelation, and organ dysfunction. MicroRNA (miRNA) can be packed into extracellular vesicles (EVs) that carry them to target cells. We explored EV-miRNA in βT and their pathophysiologic role.

Cryogenic Electron Microscopy Methodologies as Analytical Tools for the Study of Self-Assembled Pharmaceutics.

Many pharmaceutics are aqueous dispersions of small or large molecules, often self-assembled in complexes from a few to hundreds of molecules. In many cases, the dispersing liquid is non-aqueous. Many pharmaceutical preparations are very viscous.

Synergistic Effect of Two Organogelators for the Creation of Bio-Based, Shape-Stable Phase-Change Materials.

Two organogelators of different chemistry (a fatty acid derivative and a -urea derivative), as well as their blends, were used to impart shape stability to a bio-based phase-change material (PCM) bearing a near-ambient phase-transition temperature. Characterization of the individual gelators and their blends revealed their ability to immobilize the PCM by forming a continuous fibrillar network. The fibrils formed by the fatty acid derivative were helical, while the -urea derivative formed smooth fibrils.

Structure elucidation of silica-based core-shell microencapsulated drugs for topical applications by cryogenic scanning electron microscopy.

We present here a technology to microencapsulate drugs by the sol-gel process, and cryo-SEM methodology that allows the nanostructural characterization of the formed capsules in their native state without any artifacts, related to their drying prior to imaging. The methodology utilizes three signals generated by the electron beam scanning the specimen: Secondary electrons, backscattered electrons, and x-rays. The first gives topographical information of the fracture-surface of the thermally-fixed specimen, the second gives contrast between elements of different atomic numbers, and the third allows the identification of those elements.

Flow induced stability of pluronic hydrogels: Injectable and unencapsulated nucleus pulposus replacement.

Poloxamers, or pluronics, have been proposed as biomimetic substitutes for physiological gels. Concern regarding their ability to resist swelling under fluid flows has impeded their implementation. Using a combination of techniques including cryo-TEM and rapid X-ray imaging, we found that rapid flow rates stabilized the gels against dissolution.

Extracellular Vesicle Characteristics in β-thalassemia as Potential Biomarkers for Spleen Functional Status and Ineffective Erythropoiesis.

β-thalassemia major (β-TM) is a therapeutically challenging chronic disease in which ineffective erythropoiesis is a main pathophysiological factor. Extracellular vesicles (EVs) are membrane-enclosed vesicles released by cells into biological fluids; they are involved in intercellular communication and in multiple physiological and pathological processes. The chaperone heat-shock protein 70 (HSP70), which is released from cells via EVs, aggravates ineffective erythropoiesis in β-TM.

A direct-imaging cryo-EM study of shedding extracellular vesicles from leukemic monocytes.

The human leukemia monocytic cell line (THP-1) is known to shed extracellular vesicles (EVs) under various stimulations. We studied the effects of two types of common stimulation types, lipopolysaccharide (LPS) and starvation conditions by high resolution cryogenic electron microscopy, namely, cryo-SEM and cryo-TEM. Cryo-SEM data of cells undergoing EV blebbing and shedding is presented here for the first time.

Cryo-Imaging of Hydrogels Supermolecular Structure.

Gelatin, derived from collagen, has both the mechanical properties required for tissue growth, as well the functional domains required for cell binding. In its natural state, gelatin derives its properties from a network of structured, intertwined, triple helical chains, which is stabilized by hydrogen bonds at temperatures below 37 °C. The mechanical properties of such a structure can be further controlled by additional enzymatic cross-linking.

Biomineralization pathways in a foraminifer revealed using a novel correlative cryo-fluorescence-SEM-EDS technique.

Foraminifera are marine protozoans that are widespread in oceans throughout the world. Understanding biomineralization pathways in foraminifera is particularly important because their calcitic shells are major components of global calcium carbonate production. We introduce here a novel correlative approach combining cryo-SEM, cryo-fluorescence imaging and cryo-EDS.

Transport of membrane-bound mineral particles in blood vessels during chicken embryonic bone development.

During bone formation in embryos, large amounts of calcium and phosphate are taken up and transported to the site where solid mineral is first deposited. The initial mineral forms in vesicles inside osteoblasts and is deposited as a highly disordered calcium phosphate phase. The mineral is then translocated to the extracellular space where it penetrates the collagen matrix and crystallizes.

Nanostructure formation in the lecithin/isooctane/water system.

We present here for the first time a study of the self-assembled nanostructures in the lecithin/isooctane/water system by direct-imaging techniques, namely, cryogenic transmission electron microscopy (cryo-TEM) and cryogenic scanning electron microscopy (cryo-SEM). Along the dilution line [water]/[lecithin] = 5, we identified a nanostructural development with the increase of lecithin concentration. The system changes from a single reverse micellar phase, through a reverse micellar phase coexisting with a lamellar phase, and finally to a reverse liquid crystalline cubic phase and a lamellar phase.