scholarly journals Fusion-dependent formation of lipid nanoparticles containing macromolecular payloads

Nanoscale ◽  
2019 ◽  
Vol 11 (18) ◽  
pp. 9023-9031 ◽  
Author(s):  
Jayesh A. Kulkarni ◽  
Dominik Witzigmann ◽  
Jerry Leung ◽  
Roy van der Meel ◽  
Josh Zaifman ◽  
...  
Keyword(s):  
Lipid Nanoparticles ◽  
Dense Core ◽  
Electron Dense Core

Neutralization of the pH (and ionizable lipid) drives the fusion of precursor vesicles into the electron-dense core structures attributed to lipid nanoparticles.

Observation of virus-like particles in thin sections of the plumose anemone, Metridium senile

2001 ◽  
Vol 81 (5) ◽  
pp. 879-880 ◽  
Author(s):  
William H. Wilson ◽  
David M. Chapman
Keyword(s):  
West Coast ◽  
Sea Anemone ◽  
Dense Core ◽  
Icosahedral Structure ◽  
The West ◽  
Thin Sections ◽  
Virus Like Particles ◽  
Metridium Senile ◽  
Electron Dense Core

Virus-like particles (VLPs) were observed in thin sections of the plumose anemone, Metridium senile, collected from seawater off the west coast of Sweden in 1969. The VLPs were observed in the nucleus of spiroblasts and amoebocytes; they were either pentagonal or hexagonal in section, indicating an icosahedral structure. Virus-like particles were ∼60 nm in diameter, with an electron-dense core 40 nm in width; they had no apparent tail. This is the first substantial report of viruses observed in sea anemone cells.

Fibrils, Tubules, and Crystals in Cells Infected with Epizootic Hemorrhagic Disease Virus

1980 ◽  
Vol 38 ◽  
pp. 480-481
Author(s):  
Ruth D. Breckon ◽  
Neil M. Foster
Keyword(s):  
Disease Virus ◽  
Morphological Features ◽  
Dense Core ◽  
Hemorrhagic Disease ◽  
Epizootic Hemorrhagic Disease Virus ◽  
Epizootic Hemorrhagic Disease ◽  
Infected Cells ◽  
Dark Staining ◽  
Electron Dense Core ◽  
In Cells

Epizootic hemorrhagic disease virus (EHDV), an orbivirus taxonomically and an arbovirus epidemiologically, replicated in cytoplasmic matrixes of infected cells.1-3 Filaments and macrotubules were observed in the cytoplasm and in association with viroplasms in EHDV-infected cells.1-3 In two studies,2,3 the diameters of the macrotubules were similar to that of the virion, i.e., 53 and 62 nm. One study1 reported that the outer and inner diameters of macrotubules were 40-50 and 35-40 nm and the diameter of the virions was 59 nm with an electron-dense core of 40 nm. Another report4 gave macrotubule outer and inner diameters of ca 35 and 25 nm and a virus diameter of ca 60 nm with an RNA core of 30 nm. Many tubules contained dark-staining centers similar in diameters to that of the interiors of the macrotubules and the EHDV RNA cores.4 This report describes additional morphological features associated with EHDV-infected cells.

scholarly journals Attachment Organelle Formation Represented by Localization of Cytadherence Proteins and Formation of the Electron-Dense Core in Wild-Type and Mutant Strains of Mycoplasma pneumoniae

2003 ◽  
Vol 185 (3) ◽  
pp. 1082-1091 ◽  
Author(s):  
Shintaro Seto ◽  
Makoto Miyata
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Immunofluorescence Microscopy ◽  
Protein Localization ◽  
Gliding Motility ◽  
Dense Core ◽  
Wild Type ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
In The Wild ◽  
Electron Dense Core

ABSTRACT Cytadherence proteins of Mycoplasma pneumoniae are localized at the attachment organelle, which is involved in adhesion, gliding motility, and cell division. The localization of these proteins in cytadherence-deficient mutants was examined by immunofluorescence microscopy. In the class I-2 mutant, which has a frameshift mutation in the hmw2 gene, fluorescent foci for HMW1 and HMW3 were found with reduced intensity, and P1 adhesin showed reduced focusing. However, foci for P90, P40, P30, and P65 were not observed in this mutant. In the class IV-22 mutant, which lacks expression of P1, P90, and P40, the other cytadherence proteins (HMW1, HMW3, P30, and P65) were focused. In a mutant lacking HMW1, signals for HMW3, P90, P40, P30, and P65 were not found, and P1 was distributed throughout the cell. These results suggest that HMW1 is essential for the localization of all other cytadherence proteins, while HMW2 is essential for the localization of P90, P40, P30, and P65. The electron-dense core in cytadherence mutants was observed by thin-section electron microscopy, suggesting that its formation depends on HMW1 and HMW2 and that P1 localization occurs independent of the formation of the electron-dense core. Doubly stained preparations visualized by immunofluorescence microscopy showed that the P1 adhesin, P90, and P40 colocalized to a subregion of the attachment organelle in the wild-type strain. HMW1 and HMW3 also colocalized to a different subregion of the attachment organelle, while P30 and P65 localized at more distal ends of cell poles than HMW1 and HMW3. These differences were more pronounced in cytadherence mutants. These results suggest that there are three distinct subcellular protein localization sites in the attachment organelle, which were represented by HMW1-HMW3, P1-P90-P40, and P30-P65.

scholarly journals Snapshots into carbon dots formation through a combined spectroscopic approach

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Francesco Rigodanza ◽  
Max Burian ◽  
Francesca Arcudi ◽  
Luka Đorđević ◽  
Heinz Amenitsch ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Ad Hoc ◽  
Organic Molecules ◽  
Dense Core ◽  
Carbon Nanodots ◽  
Small Organic Molecules ◽  
The Core ◽  
Ligand Shell ◽  
Shell Design ◽  
Electron Dense Core

AbstractThe design of novel carbon dots with ad hoc properties requires a comprehensive understanding of their formation mechanism, which is a complex task considering the number of variables involved, such as reaction time, structure of precursors or synthetic protocol employed. Herein, we systematically investigated the formation of carbon nanodots by tracking structural, chemical and photophysical features during the hydrothermal synthesis. We demonstrate that the formation of carbon nanodots consists of 4 consecutive steps: (i) aggregation of small organic molecules, (ii) formation of a dense core with an extended shell, (iii) collapse of the shell and (iv) aromatization of the core. In addition, we provide examples of routes towards tuning the core-shell design, synthesizing five novel carbon dots that all consist of an electron-dense core covered by an amine rich ligand shell.

scholarly journals Ultrastructure and gliding motility of Mycoplasma amphoriforme, a possible human respiratory pathogen

Microbiology ◽  
2006 ◽  
Vol 152 (7) ◽  
pp. 2181-2189 ◽  
Author(s):  
Jennifer M. Hatchel ◽  
Rebecca S. Balish ◽  
Matthew L. Duley ◽  
Mitchell F. Balish
Keyword(s):  
Time Lapse ◽  
Gliding Motility ◽  
Dense Core ◽  
Respiratory Pathogen ◽  
Mycoplasma Species ◽  
Close Relative ◽  
Avian Pathogen ◽  
Underlying Mechanisms ◽  
Electron Dense Core ◽  
Triton X

Despite their small size and reduced genomes, many mycoplasma cells have complex structures involved in virulence. Mycoplasma pneumoniae has served as a model for the study of virulence factors of a variety of mycoplasma species that cause disease in humans and animals. These cells feature an attachment organelle, which mediates cytadherence and gliding motility and is required for virulence. An essential component of the architecture of the attachment organelle is an internal detergent-insoluble structure, the electron-dense core. Little information is known regarding its underlying mechanisms. Mycoplasma amphoriforme, a close relative of both M. pneumoniae and the avian pathogen Mycoplasma gallisepticum, is a recently discovered organism associated with chronic bronchitis in immunosuppressed individuals. This work describes both the ultrastructure of M. amphoriforme strain A39T as visualized by scanning electron microscopy and the gliding motility characteristics of this organism on glass. Though externally resembling M. gallisepticum, M. amphoriforme cells were found to have a Triton X-100-insoluble structure similar to the M. pneumoniae electron-dense core but with different dimensions. M. amphoriforme also exhibited gliding motility using time-lapse microcinematography; its movement was slower than that of either M. pneumoniae or M. gallisepticum.

CHANGES IN THE APPEARANCE OF HYPOTHALAMO-NEUROHYPOPHYSIAL NEUROSECRETORY GRANULES ASSOCIATED WITH THEIR MATURATION

1973 ◽  
Vol 57 (3) ◽  
pp. 531-NP ◽  
Author(s):  
M. A. CANNATA ◽  
J. F. MORRIS
Keyword(s):  
Osmium Tetroxide ◽  
Dense Core ◽  
Neurosecretory Granules ◽  
Neural Lobe ◽  
The Difference ◽  
Electron Dense Core ◽  
Different Parts

SUMMARY The appearance of neurosecretory granules (NSG) in different parts of the hypothalamo-neurohypophysial system (paraventricular and supraoptic neurosecretory neurones and their processes within the hypothalamus and in the neural lobe) of the rat was studied after fixation at different pH's (5·0, 6·0, 7·0 or 8·0) using a triple-aldehyde mixture followed by osmium tetroxide. Differences between the areas studied were most marked at pH 8·0. At this pH a significantly greater proportion of granules retained an electron-dense core within the perikarya and adjacent processes than within the neural lobe, where only 5% of all granules remained dense-cored. At pH 8·0 comparison of NSG in paraventricular and supraoptic areas showed that a significantly higher proportion of granules remained dense-cored in the paraventricular region. This difference was particularly marked in the neurosecretory processes. The difference in response to fixation at pH 8·0 between hypothalamus and neural lobe may reflect changes in the nature of the granule resulting from 'maturation'. If so, maturation starts within the perikaryon and proceeds as the granules pass down the axons to the neural lobe, where very few remain immature. The differences between paraventricular and supraoptic regions might be explained as a result of faster maturation of granules containing vasopressin than those containing oxytocin.

Relationship between golgi apparatus and axonal reticulum in sympathetic ganglion cells

1978 ◽  
Vol 36 (2) ◽  
pp. 598-599
Author(s):  
J. Quatacker ◽  
W. De Potter
Keyword(s):  
Golgi Apparatus ◽  
Sympathetic Ganglion ◽  
Phosphotungstic Acid ◽  
Ganglion Cells ◽  
Low Ph ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Large Dense Core Vesicles ◽  
Cervical Ganglia ◽  
Axoplasmic Reticulum

Mucopolysaccharides have been demonstrated biochemically in catecholamine-containing subcellular particles in different rat, cat and ox tissues. As catecholamine-containing granules seem to arise from the Golgi apparatus and some also from the axoplasmic reticulum we examined wether carbohydrate macromolecules could be detected in the small and large dense core vesicles and in structures related to them. To this purpose superior cervical ganglia and irises from rabbit and cat and coeliac ganglia and their axons from dog were subjected to the chromaffin reaction to show the distribution of catecholamine-containing granules. Some material was also embedded in glycolmethacrylate (GMA) and stained with phosphotungstic acid (PTA) at low pH for the detection of carbohydrate macromolecules.The chromaffin reaction in the perikarya reveals mainly large dense core vesicles, but in the axon hillock, the axons and the terminals, the small dense core vesicles are more prominent. In the axons the small granules are sometimes seen inside a reticular network (fig. 1).

The Structure and Development of Microbodies in the Fat Body and other Tissues of an Insect (Calpodes Ethlius)

1970 ◽  
Vol 28 ◽  
pp. 148-149
Author(s):  
M. Locke ◽  
J. T. McMahon
Keyword(s):  
Electron Microscopy ◽  
Liquid Crystals ◽  
Fat Body ◽  
Competitive Inhibitor ◽  
Dense Core ◽  
Urate Oxidase ◽  
Blood Proteins ◽  
Free Base ◽  
The Core ◽  
The Matrix

The fat body of insects has always been compared functionally to the liver of vertebrates. Both synthesize and store glycogen and lipid and are concerned with the formation of blood proteins. The comparison becomes even more apt with the discovery of microbodies and the localization of urate oxidase and catalase in insect fat body.The microbodies are oval to spherical bodies about 1μ across with a depression and dense core on one side. The core is made of coiled tubules together with dense material close to the depressed membrane. The tubules may appear loose or densely packed but always intertwined like liquid crystals, never straight as in solid crystals (Fig. 1). When fat body is reacted with diaminobenzidine free base and H2O2 at pH 9.0 to determine the distribution of catalase, electron microscopy shows the enzyme in the matrix of the microbodies (Fig. 2). The reaction is abolished by 3-amino-1, 2, 4-triazole, a competitive inhibitor of catalase. The fat body is the only tissue which consistantly reacts positively for urate oxidase. The reaction product is sharply localized in granules of about the same size and distribution as the microbodies. The reaction is inhibited by 2, 6, 8-trichloropurine, a competitive inhibitor of urate oxidase.

Portein-gold labelling of ultrathin sections of wheat spot mosaic-affected wheat plants

1990 ◽  
Vol 48 (3) ◽  
pp. 680-681
Author(s):  
K. S. Zaychuk ◽  
M. H. Chen ◽  
C. Hiruki
Keyword(s):  
Osmium Tetroxide ◽  
Rnase A ◽  
Leaf Ultrastructure ◽  
Double Membrane ◽  
Young Root ◽  
Leaf Tissues ◽  
Membrane Bound ◽  
Ultrathin Sections ◽  
Gold Labelling ◽  
Electron Dense Core

Wheat spot mosaic (WSpM), which frequently occurs with wheat streak mosaic virus was first reported in 1956 from Alberta. Singly isolated, WSpM causes chlorotic spots, chlorosis, stunting, and sometimes death of the wheat plants. The vector responsible for transmission is the eriophyid mite, Eriophyes tulipae Kiefer. The examination of leaf ultrastructure by electron microscopy has revealed double membrane bound bodies (DMBB’s) 0.1-0.2 μm in diameter. Dispersed fibrils within these bodies suggested the presence of nucleic acid. However, neither ribosomes characteristic of bacteria, mycoplasma and the psittacosis group of organisms nor an electron dense core characteristic of many viruses was commonly evident.In an attempt to determine if the DMBB’s contain nucleic acids, RNase A, DNase I, and lactoferrin protein were conjugated with 10 nm colloidal gold as previously described. Young root and leaf tissues from WSpM-affected wheat plants were fixed in glutaraldehyde, postfixed in osmium tetroxide,and embedded in Spurr’s resin.

Enhancement of oral bioavailability of pentoxifylline by solid lipid nanoparticles

2009 ◽  
Vol 00 (00) ◽  
pp. 090820062440031-9 ◽  
Author(s):  
Jaleh Varshosaz ◽  
Mohsen Minayian ◽  
Elaheh Moazen
Keyword(s):  
Solid Lipid Nanoparticles ◽  
Oral Bioavailability ◽  
Lipid Nanoparticles ◽  
Solid Lipid
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