scholarly journals Hydrogels of Polycationic Acetohydrazone-Modified Phosphorus Dendrimers for Biomedical Applications: Gelation Studies and Nucleic Acid Loading

Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 120 ◽  
Author(s):  
Evgeny K. Apartsin ◽  
Alina E. Grigoryeva ◽  
Audrey Malrin-Fournol ◽  
Elena I. Ryabchikova ◽  
Alya G. Venyaminova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polyethylene Glycol ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Biomedical Applications ◽  
Structural Units ◽  
Transmission Electron ◽  
Phosphate Buffered Saline ◽  
Acid Loading

In this work, we report the assemblage of hydrogels from phosphorus dendrimers in the presence of biocompatible additives and the study of their interactions with nucleic acids. As precursors for hydrogels, phosphorus dendrimers of generations 1–3 based on the cyclotriphosphazene core and bearing ammonium or pyridinium acetohydrazones (Girard reagents) on the periphery have been synthesized. The gelation was done by the incubation of dendrimer solutions in water or phosphate-buffered saline in the presence of biocompatible additives (glucose, glycine or polyethylene glycol) to form physical gels. Physical properties of gels have been shown to depend on the gelation conditions. Transmission electron microscopy revealed structural units and well-developed network structures of the hydrogels. The hydrogels were shown to bind nucleic acids efficiently. In summary, hydrogels of phosphorus dendrimers represent a useful tool for biomedical applications.

The Influence of Introduction of Polyethylene Glycol on Synthesis of Bimodal Mesoporous γ-Al2O3

2013 ◽  
Vol 709 ◽  
pp. 89-92
Author(s):  
Xiang Li ◽  
Xin Mei Liu ◽  
Zi Feng Yan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polyethylene Glycol ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Relative Crystallinity ◽  
X Ray ◽  
Transmission Electron ◽  
Increasing Trend ◽  
Opposite Tendency

In the presence of polyethylene glycol (PEG2W),bimodal mesoporous γ-Al2O3 was successfully synthesized via hydrothermal method. The samples were respectively characterized by X-ray diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), thermogravimetric and differential scanning calorimeter (TG-DSC). Introduction of PEG2W can increase the relative crystallinity of AACH and γ-Al2O3. The BET surface area and pore volume of alumina shows an increasing trend with increasing of PEG2W content, while the pore size shows an opposite tendency. The PEG2W also plays an important role in inducing the formation of the nanorod-like alumina.

Supramolecular chemistry at interfaces: host-guest interactions for attaching PEG and 5-fluorouracil to the surface of porous nanosilica

2016 ◽  
Vol 5 (6) ◽  
Author(s):  
Tuong Vi Tran ◽  
Uyen Vy Vo ◽  
Dong Yen Pham ◽  
Dai Lam Tran ◽  
Thi Hiep Nguyen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Transmission Electron Microscopy ◽  
Cell Proliferation ◽  
Polyethylene Glycol ◽  
Inclusion Complex ◽  
Spherical Shape ◽  
Burst Release ◽  
Anticancer Drug Delivery ◽  
Transmission Electron

AbstractPorous nanosilica (PNS) has been attracting much attention in fabrication of nanocarriers for a drug delivery system (DDS). However, the unmodified PNS-based carriers exhibited a significant initial burst release of drug, which may limit their potential clinical application. In this study, PNS was surface conjugated with cyclodextrin (CD) which was functionalized with adamantylamine-polyethylene glycol (APEG) for 5-fluorouracil (5-FU) delivery, in which case CD was used due to its ability to form a stable inclusion complex with 5-FU and APEG. The conjugated PNS (PNSC@APEG) was successfully prepared with spherical shape and diameter around 50 nm, determined by transmission electron microscopy (TEM). In addition, 5-FU was efficiently trapped in PNSC@APEG particles, which were around 63.4%±3.8% and was slowly released up to 3 days in phosphate buffer saline (PBS). Furthermore, the cell proliferation kit I (MTT) assay data showed that PNSC@APEG was a biocompatible nanocarrier. These results indicated that PNSC@APEG nanoparticles have a great potential as novel carriers for anticancer drug delivery.

Analytical and Structural Electron Microscopy of Metal-Cell Interactions.

1987 ◽  
Vol 110 ◽  
Author(s):  
Neil A. Coombs ◽  
Robert M. Pilliar ◽  
George C. Weatherly
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleic Acids ◽  
Metal Uptake ◽  
Analytical Transmission Electron Microscopy ◽  
Gingival Fibroblasts ◽  
Nickel Chromium ◽  
Transmission Electron ◽  
Structural Abnormalities ◽  
Carbon Substrates

AbstractHuman gingival fibroblasts have been grown in culture on thin (10–50nm) substrates of nickel, chromium and titanium and examined by structural and analytical transmission electron microscopy. Cells grown on titanium show no signs of metal uptake and have morphologies very similar to controls grown on carbon substrates. However, cells grown on nickel and chromium show significant metal uptake and some structural abnormalities. The majority of the ingested nickel and chromium appears to be associated with nucleic acids.

Transmission Electron Microscopy Reveals an Optimal HIV-1 Nucleocapsid Aggregation with Single-stranded Nucleic Acids and the Mature HIV-1 Nucleocapsid Protein

2006 ◽  
Vol 364 (3) ◽  
pp. 496-511 ◽  
Author(s):  
Gilles Mirambeau ◽  
Sébastien Lyonnais ◽  
Dominique Coulaud ◽  
Laurence Hameau ◽  
Sophie Lafosse ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleic Acids ◽  
Nucleocapsid Protein ◽  
Transmission Electron ◽  
Hiv 1

A Novel Method of Immuno-Gold Staining For TEM and HVEM

1985 ◽  
Vol 43 ◽  
pp. 438-439
Author(s):  
Leona Cohen-Gould ◽  
Thomas F. Robinson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polyethylene Glycol ◽  
Specific Antibodies ◽  
Antigenic Sites ◽  
Transmission Electron ◽  
Curing Characteristics ◽  
Marker Substances ◽  
Novel Method ◽  
Lowicryl K4m

Advances in Immunochemistry allow for labelling of various tissue components with highly specific antibodies, that in turn may be labelled with marker substances such as flourescein for light microscopy, or any of a number of electron-dense substances, such as ferritin and colloldal gold, for localization with scanning and transmission electron miscroscopy. The methods used for transmission electron microscopy are designed to minimize damage to antigenic sites while preserving ultrastructure. The methods include embedding of the tissue in resins with low-temperature curing characteristics such as Polyethylene glycol (PEG) or Lowicryl K4M (Chemische Werke Lowl, F.R.G.). The tissue is embedded, sectioned, and mounted on grids. The Immuno-reactions are then carried out on these mounted sections.

Dispersions of Engineered Nanoparticles in Physiological Liquids

2015 ◽  
Vol 1085 ◽  
pp. 363-369
Author(s):  
Anna Godymchuk ◽  
Elena Yunda ◽  
Natalia Kosova ◽  
Elizaveta Karepina ◽  
Denis Kuznetsov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Zirconium Dioxide ◽  
Diffraction Method ◽  
Laser Diffraction ◽  
Engineered Nanoparticles ◽  
Isotonic Solution ◽  
Aluminum Oxides ◽  
Transmission Electron ◽  
Phosphate Buffered Saline

Increasing production of nanomaterials makes the study of nanoparticles fate in the environment of immediate interest. Nanomaterials are known to radically change their properties when released into the environment. In this work, the ability of nanoparticles to form stable dispersions in physiological solutions has been demonstrated. The dispersions were prepared by mixing nanopowders of zinc (13.58 m2/g), copper (24.66 m2/g), aluminum oxides (54.75 m2/g), and zirconium dioxide (8.10 m2/g) with phosphate buffered saline, an isotonic solution of glucose and artificial lysosomal fluid. With the help of laser diffraction method and transmission electron microscopy it was shown that unstable suspensions (with the dispersoid size of 6...49 μm) and aggregative-stable lyosols (with the particles size of 20...300 nm) were formed in dispersions of nanoparticles in physiological media.

Synthesis and Hemolytic Activity of Magnesium Hydroxide Nanoparticles

2014 ◽  
Vol 971-973 ◽  
pp. 228-231 ◽  
Author(s):  
Wei Zhou ◽  
Xiao Lan Qiao ◽  
Ling Zhang ◽  
Jing Yu Guo ◽  
Jun Zheng
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Powder Diffraction ◽  
Magnesium Hydroxide ◽  
Biomedical Applications ◽  
Magnesium Nitrate ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Magnesium Hydroxide Nanoparticles

nanomagnesium hydroxide (Mg (OH)2) is promising potential material for biomedical applications, such as nanomedicine. However, little is known about the hemolysis of nanostructured Mg (OH)2.In the present investigation, Mg (OH)2nanoparticles synthesized by precipitation technique using magnesium nitrate and sodium hydroxide. The phase structure and morphology of the Mg (OH)2nanoparticles are characterized by X-ray powder diffraction (XRD), selected area electronic diffraction (SAED) and transmission electron microscopy (TEM) respectively. Hemolytic activitiesin vitroare carried out on the synthesized nanoMg (OH)2samples and the studies reveal that Mg (OH)2nanoparticles have mild activity against erythrocytes.

The structure of carbon in chemically vapor deposited SiC monofilaments

1990 ◽  
Vol 5 (12) ◽  
pp. 2865-2876 ◽  
Author(s):  
X. J. Ning ◽  
P. Pirouz ◽  
K. P. D. Lagerlof ◽  
J. DiCarlo
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Structural Units ◽  
Turbostratic Carbon ◽  
Transmission Electron ◽  
Coating Layers ◽  
Chemically Vapor Deposited ◽  
Outer Coating

The microstructures of carbon-rich regions in chemically vapor deposited SCS-6 SiC fibers have been studied by electron diffraction and high resolution transmission electron microscopy. The microstructures of the carbon in the substrate filament and the outer coating layers of the fiber are consistent with different distributions of Oberlin's model of Basic Structural Units (BSUs)1 while that of the inner substrate coating is consistent with turbostratic carbon (TC).

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