scholarly journals Fabrication of CaCO3-Coated Vesicles by Biomineralization and Their Application as Carriers of Drug Delivery Systems

2022 ◽  
Vol 23 (2) ◽  
pp. 789
Author(s):  
Chiho Miyamaru ◽  
Mao Koide ◽  
Nana Kato ◽  
Shogo Matsubara ◽  
Masahiro Higuchi
Keyword(s):  
Membrane Vesicles ◽  
Drug Carriers ◽  
Bilayer Membrane ◽  
Coated Vesicles ◽  
Acidic Condition ◽  
Cancer Therapies ◽  
Hydrophilic Drugs ◽  
Transmission Electron ◽  
Cancer Tissues ◽  
20 Nm

We fabricated CaCO3-coated vesicles as drug carriers that release their cargo under a weakly acidic condition. We designed and synthesized a peptide lipid containing the Val-His-Val-Glu-Val-Ser sequence as the hydrophilic part, and with two palmitoyl groups at the N-terminal as the anchor groups of the lipid bilayer membrane. Vesicles embedded with the peptide lipids were prepared. The CaCO3 coating of the vesicle surface was performed by the mineralization induced by the embedded peptide lipid. The peptide lipid produced the mineral source, CO32−, for CaCO3 mineralization through the hydrolysis of urea. We investigated the structure of the obtained CaCO3-coated vesicles using transmission electron microscopy (TEM). The vesicles retained the spherical shapes, even in vacuo. Furthermore, the vesicles had inner spaces that acted as the drug cargo, as observed by the TEM tomographic analysis. The thickness of the CaCO3 shell was estimated as ca. 20 nm. CaCO3-coated vesicles containing hydrophobic or hydrophilic drugs were prepared, and the drug release properties were examined under various pH conditions. The mineralized CaCO3 shell of the vesicle surface was dissolved under a weakly acidic condition, pH 6.0, such as in the neighborhood of cancer tissues. The degradation of the CaCO3 shell induced an effective release of the drugs. Such behavior suggests potential of the CaCO3-coated vesicles as carriers for cancer therapies.

scholarly journals Exosomes Derived from M2 Macrophages Exert a Therapeutic Effect via Inhibition of the PI3K/AKT/mTOR Pathway in Rats with Knee Osteoarthritic

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zha Xi Da-wa ◽  
Ma Jun ◽  
Liu Chao-Zheng ◽  
Yang Sen-Lin ◽  
Lu Chuan ◽  
...  
Keyword(s):  
Tissue Repair ◽  
Membrane Vesicles ◽  
Bilayer Membrane ◽  
M2 Macrophage ◽  
Protective Effects ◽  
M2 Macrophages ◽  
M1 Macrophages ◽  
Novel Approach ◽  
Transmission Electron ◽  
Stimulation Of

Macrophages are commonly classified as M1 macrophages or M2 macrophages. M2 macrophages are obtained by stimulation of IL-4 with anti-inflammatory and tissue repair effects. Exosomes are 30–150 nm lipid bilayer membrane vesicles derived from most living cells and have a variety of biological functions. Previous studies have shown that macrophage exosomes can influence the course of some autoimmune diseases, but their effect on knee osteoarthritis (KOA) has not been reported. Here, we analyze the roles of exosomes derived from M2 macrophage phenotypes in KOA rats. Exosomes were isolated from the supernatant of M2 macrophages and identified via transmission electron microscopy (TEM), Western blotting, and DLS. The results showed that M2 macrophage exosomes significantly attenuated the inflammatory response and pathological damage of articular cartilage in KOA rats. In addition, a key protein associated with KOA including Aggrecan, Col-10, SOX6, and Runx2 was significantly increased, while MMP-13 was significantly suppressed following treatment with M2 macrophage exosomes. The present study indicated that M2 macrophage exosomes exerted protective effects on KOA rats mainly mediated by the PI3K/AKT/mTOR signal pathway. These findings provide a novel approach for the treatment of KOA.

Low Energy Ar Ion Milling of FIB TEM Specimens from 14 nm and Future FinFET Technologies

2018 ◽  
Author(s):  
C.S. Bonifacio ◽  
P. Nowakowski ◽  
M.J. Campin ◽  
M.L. Ray ◽  
P.E. Fischione
Keyword(s):  
Field Effect Transistor ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Effect Transistor ◽  
20 Nm ◽  
Argon Ion

Abstract Transmission electron microscopy (TEM) specimens are typically prepared using the focused ion beam (FIB) due to its site specificity, and fast and accurate thinning capabilities. However, TEM and high-resolution TEM (HRTEM) analysis may be limited due to the resulting FIB-induced artifacts. This work identifies FIB artifacts and presents the use of argon ion milling for the removal of FIB-induced damage for reproducible TEM specimen preparation of current and future fin field effect transistor (FinFET) technologies. Subsequently, high-quality and electron-transparent TEM specimens of less than 20 nm are obtained.

Utilizing Nanoprobing and Circuit Diagnostics to Identify Key Failure Mechanism of Otherwise Nonvisible Defects in 20 nm Logic Devices

2014 ◽  
Author(s):  
M.K. Dawood ◽  
C. Chen ◽  
P.K. Tan ◽  
S. James ◽  
P.S. Limin ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Contact Layer ◽  
Fault Isolation ◽  
Tem Analysis ◽  
Logic Devices ◽  
Technology Advancement ◽  
Transmission Electron ◽  
Voltage Contrast ◽  
Almost All ◽  
20 Nm

Abstract In this work, we present two case studies on the utilization of advanced nanoprobing on 20nm logic devices at contact layer to identify the root cause of scan logic failures. In both cases, conventional failure analysis followed by inspection of passive voltage contrast (PVC) failed to identify any abnormality in the devices. Technology advancement makes identifying failure mechanisms increasingly more challenging using conventional methods of physical failure analysis (PFA). Almost all PFA cases for 20nm technology node devices and beyond require Transmission Electron Microscopy (TEM) analysis. Before TEM analysis can be performed, fault isolation is required to correctly determine the precise failing location. Isolated transistor probing was performed on the suspected logic NMOS and PMOS transistors to identify the failing transistors for TEM analysis. In this paper, nanoprobing was used to isolate the failing transistor of a logic cell. Nanoprobing revealed anomalies between the drain and bulk junction which was found to be due to contact gouging of different severities.

scholarly journals (Ti,Al)O2 Whiskers Grown during Glow Discharge Nitriding of Ti-6Al-7Nb Alloy

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2658
Author(s):  
Krzysztof Szymkiewicz ◽  
Jerzy Morgiel ◽  
Łukasz Maj ◽  
Małgorzata Pomorska
Keyword(s):  
Surface Hardening ◽  
Surface Defects ◽  
Plasma Nitriding ◽  
Surface Roughening ◽  
Effective Surface ◽  
Plan View ◽  
Gas Nitriding ◽  
Transmission Electron ◽  
Temperature Window ◽  
20 Nm

Plasma nitriding of titanium alloys is capable of effective surface hardening at temperatures significantly lower than gas nitriding, but at a cost of much stronger surface roughening. Especially interesting are treatments performed at the lower end of the temperature window used in such cases, as they are least damaging to highly polished parts. Therefore identifying the most characteristic defects is of high importance. The present work was aimed at identifying the nature of pin-point bumps formed at the glow discharged plasma nitrided Ti-6Al-7Nb alloy using plan-view scanning and cross-section transmission electron microscopy methods. It helped to establish that these main surface defects developed at the treated surface are (Ti,Al)O2 nano-whiskers of diameter from 20 nm to 40 nm, and length up to several hundreds of nanometers. The performed investigation confirmed that the surface imperfection introduced by plasma nitriding at the specified range should be of minor consequences to the mechanical properties of the treated material.

Immunogold-Silver Staining (IGSS) of (NCP and CP) BVDV Infected Subcellular Fraction Bands

1997 ◽  
Vol 3 (S2) ◽  
pp. 155-156
Author(s):  
C.E. Hearne ◽  
D.L. Johnson ◽  
H. Van Campen
Keyword(s):  
Subcellular Fraction ◽  
Membrane Vesicles ◽  
Bovine Viral Diarrhea ◽  
Fixed Angle ◽  
Cell Monolayers ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Transmission Electron ◽  
Viral Diarrhea Virus ◽  
Bovine Turbinate

Pre-embedding immunogold-silver (IGSS) techniques are useful to localize antigens in cell monolayers and agarose embedded cell suspensions for transmission electron microscopy. Procedural centrifugations, however, present a challenge when attempting to localize antigens in subcellular fractions. Using a Beckman Airfuge Ultracentrifuge to concentrate the subcellar fraction bands and resuspending the organelles in agarose simplifies IGSS processing and resin embedding procedures.Control bovine turbinate (BT), and BT cells infected with cytopathic (cp NADL) and non-cytopathic (ncp NY-1) strains of bovine viral diarrhea virus (BVDV) were fractioned according to Bienz et al (1992). Bands containing membrane vesicles (Fig 2) were collected and each fraction band was pelleted at 169,000g for 20 min using an A-95 fixed angle rotor in a Beckman Airfuge Ultracentrifuge. Each fraction pellet was resuspended in 50μl of 30% agarose, solidified, and trimmed to < lmm. IGSS procedures were carried out according to Nanoprobes, Inc., Stoney Brook, NY, and Hearne & Van Campen (1996).

Low-temperature route to nanoscale P3N5 hollow spheres

2003 ◽  
Vol 18 (10) ◽  
pp. 2359-2363 ◽  
Author(s):  
Hongzhou Gu ◽  
Yunle Gu ◽  
Zhefeng Li ◽  
Yongcheng Ying ◽  
Yitai Qian
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hollow Spheres ◽  
Molar Ratio ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Influence Of Temperature On ◽  
Wide Gap ◽  
20 Nm ◽  
High Degree

Nanoscale hollow spheres of amorphous phosphorus nitride (P3N5) were synthesized by reacting PCl3 with NaN3 at 150–250 °C. Transmission electron microscope images show that the hollow spheres have a diameter of 150–350 nm, and the thickness of the shell is 20 nm. A very small amount of curly films were also found in the sample prepared at 150 °C. The infrared spectrum indicates a high degree of purity. X-ray photoelectron spectroscopy indicates the presence of P and N, with a molar ratio of 1:1.62 for P:N. Ultraviolet-visible absorption spectroscopy shows an absorption band at 265–315 nm. Under photoluminescent excitation at 230 nm, the P3N5 emits ultraviolet light at 305 nm. With a band gap of 4.28 eV, the products may be a wide gap semiconductor. A possible mechanism and the influence of temperature on the formation of the hollow spheres are also discussed.

A Facile Fynthesis of ZnS Nanostructures via Liquid-Solid Reactions

2014 ◽  
Vol 979 ◽  
pp. 184-187
Author(s):  
Weerachon Phoohinkong ◽  
Thitinat Sukonket ◽  
Udomsak Kitthawee
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Inorganic Salts ◽  
Chloride Salt ◽  
X Ray ◽  
Commercial Grade ◽  
Transmission Electron ◽  
Salt Addition ◽  
20 Nm ◽  
Scanning Electron

Zinc sulfide (ZnS) nanostructures are important materials for many technologies such as sensors, infrared windows, transistors, LED displays, and solar cells. However, many methods of synthesizing ZnS nanostructures are complex and require expensive equipment. In this study, a liquid-solid chemical reaction without surfactant was used to synthesize ZnS at room temperature. In addition, commercial grade zinc oxide (ZnO) particles were used as a precursor. The effect of the addition of acids and inorganic salts were investigated. The products were characterized by field emission scanning electron microscopy (FESEM) coupled with energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The results show that the nanoparticles of ZnS were obtained in hydrochloric acid and acetic acid addition. The diameters were in the range of 10 to 20 nm and 50 to 100 nm, respectively. In the case of a sodium chloride salt addition, a ZnS structure was obtained with a particle size of approximately 5 nm and a flake-like morphology.

scholarly journals Bio-conjugated silver nano-materials and shape-directing role of cetyltrimethylammonium bromide

2013 ◽  
Vol 2 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Zaheer Khan ◽  
Qamer Faisal ◽  
Rabia Ahmad
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Electron Microscopic ◽  
Tem Analysis ◽  
Alstonia Scholaris ◽  
Irregular Shapes ◽  
Transmission Electron ◽  
Electron Microscopic Technique ◽  
Visible Spectra ◽  
Transmission Electron Microscopic ◽  
20 Nm

Conventional UV-visible spectrophotometric and transmission electron microscopic technique were used to determine the morphology of silver nanoplates (AgNP) using Alstonia scholaris aqueous leaves extract for the first time. The visible spectra showed the presence of three well defined surface plasmon absorption (SRP) bands at 500, 550 and 675 nm which attributed to the anisotropic growth of Ag-nanoplates. Transmission electron microscopic (TEM) analysis of AgNP showed formation of truncated triangular, polyhedral with some irregular shapes nanoplates in the size range 7-20 nm. Cetyltrimethylammonium bromide (CTAB) has no significant effect on the shape of the spectra, position of SRP bands, size and the size distribution of AgNP. Effects of various [CTAB] were also discussed in the green extra-cellular synthesis of AgNP using Alstonia scholaris leaves extract.

scholarly journals Evaluating biological activity of folic acid-modified and 10-hydroxycamptothecin-loaded mesoporous silica nanoparticles

2021 ◽  
Author(s):  
Mei-Xia Zhao ◽  
Di-Feng Chen ◽  
Xue-Jie Zhao ◽  
Lin-Song Li ◽  
Yong-Fang Liu
Keyword(s):  
Folic Acid ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Folate Receptor ◽  
Mesoporous Silica Nanoparticles ◽  
Drug Carriers ◽  
Transmission Electron ◽  
Before And After ◽  
Drug Efficiency

Targeted nanocarrier can selectively deliver anti-tumor drugs to cancer sites improving drug efficiency. Accordingly, a targeted nanocarrier (MSN-FA) was synthesized based on folic acid (FA) modified mesoporous silica nanoparticles (MSNs). These loaded with 10-hydroxycamptothecin (HCPT) to obtain the nano-drug MSN-FA@HCPT. These nanocarriers were characterized by transmission electron microscopy (TEM), zeta potential, ultraviolet-visible spectroscopy (UV-Vis), fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). Notably, the nanocarriers were nearly spherical before and after loading HCPT and exhibited good dispersibility. Also, folate receptor (FR) over-expressing HeLa cells and FR deficient HepG2 cells were used to evaluate in vitro cellular uptake and cytotoxicity of MSN-FA@HCPT and MSN@HCPT. Interestingly, FA-modified nanocarriers enhanced the cytotoxicity of HCPT by improving drug targeting to tumor cells. Also, apoptotic and mitochondrial membrane potential (MMP) reducing effects of MSN-FA@HCPT were more prominent than the MSNs without FA modification. MSN-FA@HCPT can be excellent drug carriers with profound biomedical applications.

Self-Organized Composition Modulation In Omvpe Ga1−xInxAsySb1−y/GaSb Epitaxial Heterostructures

1999 ◽  
Vol 583 ◽  
Author(s):  
Y-C. Chen ◽  
V. Bucklen ◽  
K. Rajan ◽  
C. A. Wang ◽  
G. W. Charache ◽  
...  
Keyword(s):  
Cross Section ◽  
Three Dimensional ◽  
Component Composition ◽  
Organometallic Vapor Phase Epitaxy ◽  
Composition Modulation ◽  
Self Organized ◽  
Transmission Electron ◽  
Epitaxial Heterostructures ◽  
20 Nm ◽  
Lattice Matched

AbstractMicrostructures of lattice-matched Ga1−xInxAsySb1−y grown by organometallic vapor phase epitaxy (OMVPE) on (100) 6°→ (111)B GaSb substrates have been examined in detail by transmission electron microscopy. A three-dimensional self-organized composition modulation (SOCM) microstructure was found with an orientation inclined 10 degrees to the surface orientation when viewed in (011) cross-section. The periodicity of the SOCM increased from ˜13 nm to 20 nm, as x increased from 0.1 to 0.2 while the orientation of the SOCM remained the same. The fact that the orientation was not sensitive to the component composition indicated that substrate misorientation plays a major role in deciding this SOCM orientation. This may open fabrication opportunities for three-dimensional natural superlattices by engineering on the substrate misorientation.

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