scholarly journals Synthesis and Cytotoxicity Studies of Wood-Based Cationic Cellulose Nanocrystals as Potential Immunomodulators

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1603
Author(s):  
Yusha Imtiaz ◽  
Beza Tuga ◽  
Christopher W. Smith ◽  
Alexander Rabideau ◽  
Long Nguyen ◽  
...  
Keyword(s):  
Cellulose Nanocrystals ◽  
Chemical Properties ◽  
Neutral Red ◽  
Cationic Polymers ◽  
Experimental Conditions ◽  
Physiological Processes ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Cytotoxicity Studies ◽  
Low Cytotoxicity

Polysaccharides have been shown to have immunomodulatory properties. Modulation of the immune system plays a crucial role in physiological processes as well as in the treatment and/or prevention of autoimmune and infectious diseases. Cellulose nanocrystals (CNCs) are derived from cellulose, the most abundant polysaccharide on the earth. CNCs are an emerging class of crystalline nanomaterials with exceptional physico-chemical properties for high-end applications and commercialization prospects. The aim of this study was to design, synthesize, and evaluate the cytotoxicity of a series of biocompatible, wood-based, cationic CNCs as potential immunomodulators. The anionic CNCs were rendered cationic by grafting with cationic polymers having pendant +NMe3 and +NH3 moieties. The success of the synthesis of the cationic CNCs was evidenced by Fourier transform infrared spectroscopy, dynamic light scattering, zeta potential, and elemental analysis. No modification in the nanocrystals rod-like shape was observed in transmission electron microscopy and atomic force microscopy analyses. Cytotoxicity studies using three different cell-based assays (MTT, Neutral Red, and LIVE/DEAD®) and three relevant mouse and human immune cells indicated very low cytotoxicity of the cationic CNCs in all tested experimental conditions. Overall, our results showed that cationic CNCs are suitable to be further investigated as immunomodulators and potential vaccine nanoadjuvants.

scholarly journals Tailoring of Hydrotalcite-Derived Cu-Based Catalysts for CO2 Hydrogenation to Methanol

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1058 ◽  
Author(s):  
Leone Frusteri ◽  
Catia Cannilla ◽  
Serena Todaro ◽  
Francesco Frusteri ◽  
Giuseppe Bonura
Keyword(s):  
Metallic Copper ◽  
Chemical Properties ◽  
Active Phase ◽  
Co2 Hydrogenation ◽  
High Dispersion ◽  
Experimental Conditions ◽  
Typical Structure ◽  
Methanol Production ◽  
Physico Chemical ◽  
Space Time Yield

Ternary CuxZnyAlz catalysts were prepared using the hydrotalcite (HT) method. The influence of the atomic x:y:z ratio on the physico-chemical and catalytic properties under CO2 hydrogenation conditions was probed. The characterization data of the investigated catalysts were obtained by XRF, XRD, BET, TPR, CO2-TPD, N2O chemisorption, SEM, and TEM techniques. In the “dried” catalyst, the typical structure of a hydrotalcite phase was observed. Although the calcination and subsequent reduction treatments determined a clear loss of the hydrotalcite structure, the pristine phase addressed the achievement of peculiar physico-chemical properties, also affecting the catalytic activity. Textural and surface effects induced by the zinc concentration conferred a very interesting catalyst performance, with a methanol space time yield (STY) higher than that of commercial systems operated under the same experimental conditions. The peculiar behavior of the hydrotalcite-like samples was related to a high dispersion of the active phase, with metallic copper sites homogeneously distributed among the oxide species, thereby ensuring a suitable activation of H2 and CO2 reactants for a superior methanol production.

scholarly journals Optimization of Innovative Three-Dimensionally-Structured Hybrid Vesicles to Improve the Cutaneous Delivery of Clotrimazole for the Treatment of Topical Candidiasis

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 263 ◽  
Author(s):  
Maria Letizia Manca ◽  
Iris Usach ◽  
José Esteban Peris ◽  
Antonella Ibba ◽  
Germano Orrù ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Yeast Cells ◽  
Unilamellar Vesicles ◽  
Transmission Electron ◽  
Physico Chemical

New three-dimensionally-structured hybrid phospholipid vesicles, able to load clotrimazole in a high amount (10 mg/mL), were obtained for the first time in this work by significantly reducing the amount of water (≤10%), which was replaced with a mixture of glycerol and ethanol (≈90%). A pre-formulation study was carried out to evaluate the effect of both the composition of the hydrating medium and the concentration of the phospholipid on the physico-chemical properties of hybrid vesicles. Four different three-dimensionally-structured hybrid vesicles were selected as ideal systems for the topical application of clotrimazole. An extensive physico-chemical characterization performed using transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM), 31P-NMR, and small-angle X-ray scattering (SAXS) displayed the formation of small, multi-, and unilamellar vesicles very close to each other, and was capable of forming a three-dimensional network, which stabilized the dispersion. Additionally, the dilution of the dispersion with water reduced the interactions between vesicles, leading to the formation of single unilamellar vesicles. The evaluation of the in vitro percutaneous delivery of clotrimazole showed an improved drug deposition in the skin strata provided by the three-dimensionally-structured vesicles with respect to the commercial cream (Canesten®) used as a reference. Hybrid vesicles were highly biocompatible and showed a significant antifungal activity in vitro, greater than the commercial cream Canesten®. The antimycotic efficacy of formulations was confirmed by the reduced proliferation of the yeast cells at the site of infection in vivo. In light of these results, clotrimazole-loaded, three-dimensionally-structured hybrid vesicles appear to be one of the most innovative and promising formulations for the treatment of candidiasis infections.

scholarly journals Eudragit S100 Entrapped Liposome for Curcumin Delivery: Anti-Oxidative Effect in Caco-2 Cells

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 114 ◽  
Author(s):  
Vincenzo De Leo ◽  
Sante Di Gioia ◽  
Francesco Milano ◽  
Paola Fini ◽  
Roberto Comparelli ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Polymeric Coating ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Eudragit S100 ◽  
Natural Polyphenol ◽  
Anti Oxidant ◽  
Small Unilamellar Vesicles

Curcumin is a natural polyphenol with strong antioxidant activity. However, this molecule shows a very poor bioavailability, instability, and rapid metabolism in vivo. In this work curcumin was loaded in Eudragit-coated liposomes to create a gastroresistant carrier, able to protect its load from degradation and free it at the site of absorption in the colon region. Small unilamellar vesicles were prepared and coated with Eudragit by a pH-driven method. The physico-chemical properties of the prepared systems were assessed by light scattering, transmission electron microscopy, infrared spectroscopy, and differential scanning calorimetry. The uptake of vesicles by Caco-2 cells and the anti-oxidant activity in cells were evaluated. The produced vesicles showed dimensions of about forty nanometers that after covering with Eudragit resulted to have micrometric dimensions at acid pH. The experiments showed that at pH > 7.0 the polymeric coating dissolves, releasing the nanometric liposomes and allowing them to enter Caco-2 cells. Delivered curcumin loaded vesicles were then able to decrease significantly ROS levels as induced by H2O2 in Caco-2 cells. The proposed work showed the possibility of realizing effective gastroresistant curcumin liposome formulations for the delivery of antioxidant molecules to Caco-2 cells, potentially applicable to the treatment of pathological conditions related to intestinal oxidative stress.

Characterization of Spent Catalysts during Hydrodemetallization of Atmosphere Residue

2011 ◽  
Vol 236-238 ◽  
pp. 538-542
Author(s):  
Yong Jun Liu
Keyword(s):  
Chemical Properties ◽  
Analytical Techniques ◽  
Resonance Spectroscopy ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Spent Catalysts ◽  
C Nmr

The deactivation behavior of industrial hydrodemetallization catalysts was investigated in the presented work. The main objective of the study is to contribute to a better understanding of the nature of the coke and metal deposition on the used catalysts by applying chemical analysis and various advanced analytical techniques, such as X-ray diffraction analysis (XRD), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and solid-state carbon-13 nuclear magnetic resonance spectroscopy (13C NMR). The results are discussed scientifically based on the physico–chemical properties of origin and used catalysts.

scholarly journals Bactericidal Effect of Cotton Fabric Treated with Polymer Solution Containing Silver Nanoparticles of Different Sizes and Shapes

2020 ◽  
Vol 32 (6) ◽  
pp. 1335-1342
Author(s):  
Kh. E. Yunusov ◽  
A.A. Sarymsakov ◽  
S.V. Mullajonova ◽  
F.M. Turakulov ◽  
S. Sh. Rashidova
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Properties ◽  
Bactericidal Effect ◽  
Cotton Fabrics ◽  
Sodium Carboxymethylcellulose ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Vis Spectroscopy ◽  
Silver Nitrate Concentration

Stable silver nanoparticles in solutions of sodium-carboxymethylcellulose (Na-CMC) were synthesized and their structure and physico-chemical properties were evaluated. The form and sizes of silver nanoparticles formed in solutions of CMC and cotton fabrics were studied using UV-VIS spectroscopy, atomic force microscopy and transmission electron microscopy methods. It was found that silver nitrate concentration increase in sodium carboxymethylcellulose solutions, as well as photoirradiation of the hydrogel lead to the changes of the silver nanoparticles size and shape. Investigations have also shown that spherical silver nanoparticles with sizes of 5-35 nm and content of 0.0086 mass% in cotton fabrics possess high bactericidal activity. Stabilization of silver nanoparticles has preserved bactericidal and bacteriostatic activities during the washing of cotton fabrics and textiles on their base.

The Method of Coating Fe3O4 with Carbon Nanoparticles to Modify Biological Properties of Oxide Measured in Vitro

2017 ◽  
Vol 100 (4) ◽  
pp. 905-915 ◽  
Author(s):  
Tomasz Niemiec ◽  
Mariusz Dudek ◽  
Natalia Dziekan ◽  
Sławomir Jaworski ◽  
Aleksandra Przewozik ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Chemical Vapor ◽  
Medical Application ◽  
Processing Parameters ◽  
Biological Properties ◽  
Experimental Conditions ◽  
Low Cytotoxicity ◽  
Vitro Model ◽  
Physical And Chemical

Abstract The coating of nanoparticles on materials for medical application [e.g., the coating of Fe3O4 nanopowder (IONP) with a carbon nanolayer] serves to protect and modify the selected biological, physical, and chemical properties of the coated material. Increases in chemical stability, changes in biocompatibility, and a modified surface structure are examples of the effects caused by the formation of carbon coatings. In the current study, Fe3O4 nanoparticles were coated with a carbon nanolayer (IONP@C) in a plasmochemical reactor (using radio-frequency plasma-enhanced chemical vapor deposition methods) under various experimental conditions. Based on data from X-ray diffraction, Raman, and IR spectroscopy, the best processing parameters were determined in order to produce a carbon coating that would not change the structure of the IONP. The materials with the best cover, i.e., a uniform carbon nanolayer, were used in cytotoxic tests to investigate their biological properties using the human HepG2 hepatocarcinoma cell line and chicken embryo red blood cells as an in vitro model. The obtained results proved the low cytotoxicity of Fe3O4 micropowder and IONP in contrast to IONP@C, which reduced cell viability, increased hemolysis, and generally was more toxic than bare Fe3O4.

Surface decontamination in fuel manufacture plants by chelating solution of nanoparticles

2017 ◽  
Vol 0 (0) ◽  
Author(s):  
T. M. Morsi ◽  
Ahmed M. Elbarbary ◽  
Mohamed M. Ghobashy ◽  
Sameh H. Othman
Keyword(s):  
Cyano Group ◽  
Chemical Properties ◽  
Germanium Detector ◽  
Gravimetric Analysis ◽  
Uniform Size ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Radiation Induced ◽  
Surface Decontamination ◽  
Thermal Stability Of

AbstractA nanoparticles chelating solution was synthesized by copolymerization of acrylonitrile (AN) and methacrylic acid (MAA) by radiation induced polymerization technique using 17 kGy irradiation doses. A high copolymer yield was obtained by using 80/20% of AN/MAA and comonomer concentration of 50% (w/w) at a dose rate of 2.58 KGy/h. The resultant cyano group (–CN) of nano-poly(AN/MAA) was converted by chemical modification using hydroxylamine (NH2–OH) to an amidoxime group [–C(=NOH)NH2], which was then confirmed by Fourier transform infrared spectroscopy (FTIR). The physico-chemical properties of poly(AN/MAA) and amidoximated poly(AN/MAA) nanoparticles were studied by FTIR, transmission electron microscopy (TEM), dynamic light scattering (DLS) and thermal gravimetric analysis (TGA). The morphological analysis by TEM and DLS showed a spherical and uniform size of the amidoximated poly(AN/MAA) nanoparticles. TGA results indicated that the thermal stability of poly(AN/MAA) increased by the amidoximation process. The surface decontamination due to uranium was also investigated by the prepared chelating nanoparticles solution. A high purity germanium detector (HPGe) was used as a surface contamination detection tool. The results showed the presence of peaks at different energies, namely, 186.2 keV for Ra-226 (U-238) and 143.76 keV, 163.35 keV and 205.31 for U-235 before the decontamination process. The disappearance of these peaks after decontamination confirmed the applicability and efficiency of the nanoparticles solution in uranium surface decontamination.

scholarly journals Effect of Pt Particle Size and Phosphorous Addition on Furfural Hydrogenation Over Pt/Al2O3

2021 ◽  
Author(s):  
Miren Agote-Arán ◽  
Shahram Alijani ◽  
Chiara Coffano ◽  
Alberto Villa ◽  
Davide Ferri
Keyword(s):  
Infrared Spectroscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Chemical Properties ◽  
Irreversible Adsorption ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Large Particles ◽  
Scanning Transmission ◽  
Furfural Hydrogenation ◽  
Catalytic Cycles

AbstractPt/Al2O3 catalysts with different Pt particle sizes and after phosphorous deposition were studied for liquid phase catalysed furfural hydrogenation. The activity and selectivity were related to various physico-chemical properties studied by scanning transmission electron microscopy, N2 physisorption, 31P nuclear magnetic resonance, diffuse reflectance Fourier transform infrared spectroscopy and attenuated total reflectance infrared spectroscopy. The results indicate that the large particles obtained upon calcination of 1 wt% Pt/Al2O3 at 600 °C exhibited higher turnover frequency per surface Pt; nonetheless, the overall activity decreased due to the loss of surface Pt upon sintering. While in certain cases phosphorous can act as promoter, the addition of this element to Pt/Al2O3 resulted in catalyst poisoning, which was ascribed to Pt encapsulation/blockage effects related to formation of AlPO4. Finally, gradual deactivation of Pt/Al2O3 was observed over five consecutive catalytic cycles which was caused by Pt sintering (from 0.6 to 2.0 nm) as well as by irreversible adsorption of organic reaction intermediates. Graphic Abstract

Preparation and characterization of nanoparticles composed of methylated N-(4-N,N-dimethyl aminobenzyl) chitosan for oral delivery of cyclosporine A

2016 ◽  
Vol 8 (2) ◽  
Author(s):  
Reza Mahjub ◽  
Robabeh Allahyar ◽  
Morteza Rafiee-Tehrani ◽  
Farid Abedin Dorkoosh
Keyword(s):  
Oral Delivery ◽  
Polymeric Nanoparticles ◽  
Chemical Properties ◽  
Simulated Intestinal Fluid ◽  
Equal Concentration ◽  
Prepared Nanoparticles ◽  
Transmission Electron ◽  
Physico Chemical

AbstractCyclosporine is considered a highly lypophilic compound meaning low bioavailability through oral administration. In this study, cyclosporine was entrapped in a novel aromatic, quaternized derivative of chitosan (i.e. methylated N-(4-N,N-dimethyl aminobenzyl) chitosan) in order to improve solubility and bioavailability. Methylated N-(4,N,N-dimethyl aminobenzyl) chitosan was synthesized by the Schiff base reaction method. Polymeric nanoparticles containing cyclosporine was prepared and the physico-chemical properties of prepared nanoparticles were determined. The nanoparticles were studied morphologically using transmission electron microscopy (TEM). Finally, the release of cyclosporine from nanoparticles was studied in vitro using simulated intestinal fluid adjusted to pH of 6.8. For the preparation of nanoparticles, different formulations were studied and it was found that proper nanoparticles were prepared in equal concentration (1 mg/mL) of polymer and sodium tri-poly phosphate (TPP). The size, zeta potential, PdI, EE% and LE% of the prepared nanoparticles were reported as 173±36 nm, 23.1±4.18 mV, 0.243±0.05, 97.1±4.38% and 3.2±0.21%, respectively. The TEM images of nanoparticles revealed spherical to sub-spherical nanoparticles with no sign of agglomeration. This study suggests that preparations of nanoparticles composed of methylated N-(4,N,N-dimethyl aminobenzyl) chitosan can be a good candidate for improving the oral bioavailability of cyclosporine.

Cationic Cellulose Nanocrystals: Synthesis, Characterization and Cytotoxicity Studies

2015 ◽  
Vol 1718 ◽  
pp. 91-96 ◽  
Author(s):  
Rajesh Sunasee ◽  
Usha D. Hemraz ◽  
Karina Ckless ◽  
James S. Burdick ◽  
Yaman Boluk
Keyword(s):  
Cellulose Nanocrystals ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Cationic Polymers ◽  
Mcf7 Cells ◽  
Aspect Ratios ◽  
Cytotoxicity Studies ◽  
Cytotoxicity Effects ◽  
Surface Modified

ABSTRACTCellulose nanocrystals (CNCs) have emerged as a new class of renewable material for various applications due to their remarkable properties and commercialization prospect. The relative low density, expected low cost, non-toxic character, uniform nanosize distribution, high aspect ratios, high surface area, thermal properties and high modulus of elasticity make CNCs attractive nanomaterials that recently prompted the industrial production of CNCs in North America. Surface functionalization of CNCs continues to be an exciting area of research for the design of novel CNC-based materials. In this work, we report the synthesis, characterization and cytotoxicity studies of novel cationic surface modified CNC derivatives. The negative surface of CNC was rendered positive after grafting with cationic polymers via surface-initiated living radical polymerization method. The modified CNCs were characterized by both spectroscopic and microscopic techniques. Their cytotoxicity effects were evaluated using MTT assay in two cell lines such as mouse macrophages (J774.A1) and human breast cancer (MCF7). Preliminary studies indicated that only one of the modified CNCs caused significant decrease in J774.A1 cell viability (50%), at the highest concentration tested (100 µg/mL). However this concentration is well above of what would be applicable for biomedical purposes. MCF7 cells were not affected by any of the cationic CNCs at any concentration. A detailed cytotoxicity study is currently underway to fully understand the interaction of these cationic CNCs with the biological systems for possible bio-inspired applications.

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