scholarly journals The Promising Role of Chitosan–Poloxamer 188 Nanocrystals in Improving Diosmin Dissolution and Therapeutic Efficacy against Ferrous Sulfate-Induced Hepatic Injury in Rats

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2087
Author(s):  
Neamet S. Lotfy ◽  
Thanaa M. Borg ◽  
Elham A. Mohamed
Keyword(s):  
Water Solubility ◽  
Chemical Interaction ◽  
High Surface ◽  
High Surface Area ◽  
Dissolution Enhancement ◽  
Hepatic Tissue ◽  
Poloxamer 188 ◽  
Ft Ir ◽  
Electrostatic And Steric Stabilization ◽  
Oxide Synthase

Diosmin (DSN) exhibits poor water solubility and low bioavailability. Although nanocrystals (NCs) are successful for improving drug solubility, they may undergo crystal growth. Therefore, DSN NCs were prepared, employing sonoprecipitation utilizing different stabilizers. The optimum stabilizer was combined with chitosan (CS) as an electrostatic stabilizer. NCs based on 0.15% w/v poloxamer 188 (PLX188) as a steric stabilizer and 0.04% w/v CS were selected because they showed the smallest diameter (368.93 ± 0.47 nm) and the highest ζ-potential (+40.43 ± 0.15 mV). Mannitol (1% w/v) hindered NC enlargement on lyophilization. FT-IR negated the chemical interaction of NC components. DSC and XRD were performed to verify the crystalline state. DSN dissolution enhancement was attributed to the nanometric rod-shaped NCs, the high surface area, and the improved wettability. CS insolubility and its diffusion layer may explain controlled DSN release from CS-PLX188 NCs. CS-PLX188 NCs were more stable than PLX188 NCs, suggesting the significance of the combined electrostatic and steric stabilization strategies. The superiority of CS-PLX188 NCs was indicated by the significantly regulated biomarkers, pathological alterations, and inducible nitric oxide synthase (iNOS) expression of the hepatic tissue compared to DSN suspension and PLX188 NCs. Permeation, mucoadhesion, and cellular uptake enhancement by CS may explain this superiority.

scholarly journals Pd Nanoparticles Stabilized on the Cross-Linked Melamine-Based SBA-15 as a Catalyst for the Mizoroki–Heck Reaction

2021 ◽  
Author(s):  
Ayat Nuri ◽  
Abolfazl Bezaatpour ◽  
Mandana Amiri ◽  
Nemanja Vucetic ◽  
Jyri-Pekka Mikkola ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Surface ◽  
High Surface Area ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
Significant Activity ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Ft Ir

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract

scholarly journals Synthesis of a high-surface area V2O5/TiO2–SiO2 catalyst and its application in the visible light photocatalytic degradation of methylene blue

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24368-24376 ◽  
Author(s):  
Ajay Kumar Adepu ◽  
Srinath Goskula ◽  
Suman Chirra ◽  
Suresh Siliveri ◽  
Sripal Reddy Gujjula ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Bet Surface Area ◽  
Titanium Silicate ◽  
Ft Ir ◽  
Synthesized Materials ◽  
Visible Light Photocatalytic

In the present study, we synthesized several high-surface area V2O5/TiO2–SiO2 catalysts (vanado titanium silicate, VTS). The synthesized materials are characterized by PXRD, FE-SEM/EDAX, TEM, BET-surface area, FT-IR, UV-Vis, XPS, fluorescence and photocatalytic studies.

Synthesis and Electrochemical Properties of Graphene Oxide/Acenaphthenequinone Composite

NANO ◽  
2015 ◽  
Vol 10 (02) ◽  
pp. 1550023 ◽  
Author(s):  
Chunnian Chen ◽  
Xuwang Fu ◽  
Wei Fan ◽  
Ting Ma
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
High Surface ◽  
High Surface Area ◽  
Impedance Spectra ◽  
Electrochemical Supercapacitors ◽  
Galvanostatic Charge ◽  
Ft Ir ◽  
A Current ◽  
Cycling Life

This paper reports a new graphene oxide (GO)/acenaphthenequinone composite as efficient electrode in electrochemical supercapacitors. The nanosheets of GO provide high surface area and conductivity. The microneedle-like acenaphthenequinone contributes convincible specific capacitance. The structure and morphology of GO/acenaphthenequinone composite have been characterized by field-emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR) spectra and Raman spectra. According to the cyclic voltammetry (CV), galvanostatic charge/discharge, impedance spectra and cycling life analyses, the GO/acenaphthenequinone composite exhibits brilliant supercapacitors performance with a specific capacitance of 248.7 F g-1 at a scan rate of 1 mV s-1 and enhanced stability of about 82% (147.5 F g-1) of initial capacitance (179.8 F g-1) after 500 cycles at a current density of 1 A g-1.

Porous Silicas for Enhanced Drug Release

2014 ◽  
Vol 91 ◽  
pp. 79-81
Author(s):  
Abina M. Crean ◽  
Robert J. Ahern ◽  
Rakesh Dontireddy ◽  
Walid Faisil ◽  
John P. Hanrahan ◽  
...  
Keyword(s):  
Surface Area ◽  
Water Solubility ◽  
Solid Dispersions ◽  
High Surface ◽  
High Surface Area ◽  
Porous Silica ◽  
High Energy ◽  
Drug Dissolution ◽  
Drug Candidates ◽  
Drug Molecules

Low drug water-solubility is a major challenge to overcome in the development of tablet or capsule dosage forms for a large number of promising drug candidates. Strategies to improve drug solubility and dissolution involve chemical, physical and formulation approaches. An emerging formulation approach to increase drug dissolution and solubility involves the creation of solid dispersions of drug molecules on to a high surface area inorganic carrier, such as porous silica. The combined benefits of a hydrophilic inorganic substrate, increased drug surface area and a high-energy drug form facilitate rapid drug dissolution into aqueous based media and can create supersaturated drug solutions. The work presented provides a brief overview of the silica grades investigated, processes employed to load drugs onto the silica substrates, provide some examples of the ability of silica to enhance drug dissolution and highlight some of the challenges in the development of these novel drug delivery systems.

scholarly journals Photocatalytic Degradation of Organics by Using Nanocrystalline Titania

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Sana Ahmad ◽  
Anam Nazir ◽  
Tousif Hussain
Keyword(s):  
Titanium Dioxide ◽  
Catalytic Activity ◽  
Titanium Dioxide Nanoparticles ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Crystalline Form ◽  
Titanium Butoxide ◽  
Fine Spray ◽  
Ft Ir

Titanium dioxide nanoparticles were prepared by a modified sol-gel route. Titanium butoxide was used as precursor and nebulizer was used for a fine spray of particles. The prepared powders were characterized by FT-IR, SEM, XRD, and TGA-DTA methods. The results indicated that nanoparticles with small size and high surface area were synthesized. XRD result indicated that TiO2 nanoparticles were obtained in pure anatase crystalline form with a crystallite size of 40 nm. The catalytic activity of as-synthesized nanoparticles was tested for the degradation of formic acid and toluene.

scholarly journals Dissolution Enhancement of Gliclazide Using pH Change Approach in Presence of Twelve Stabilizers with Various Physico-Chemical Properties

2009 ◽  
Vol 12 (3) ◽  
pp. 250 ◽  
Author(s):  
Roya Talari ◽  
Ali Nokhodchi ◽  
Seyed Abolfazl Mostafavi ◽  
Jaleh Varshosaz
Keyword(s):  
Dissolution Rate ◽  
Fine Particles ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
High Energy ◽  
Dissolution Enhancement ◽  
Ph Change ◽  
Fast Dissolution

Purpose: The micronization using milling process to enhance dissolution rate is extremely inefficient due to a high energy input, and disruptions in the crystal lattice which can cause physical or chemical instability. Therefore, the aim of the present study is to use in situ micronization process through pH change method to produce micron-size gliclazide particles for fast dissolution hence better bioavailability. Methods: Gliclazide was recrystallized in presence of 12 different stabilizers and the effects of each stabilizer on micromeritic behaviors, morphology of microcrystals, dissolution rate and solid state of recrystallized drug particles were investigated. Results: The results showed that recrystallized samples showed faster dissolution rate than untreated gliclazide particles and the fastest dissolution rate was observed for the samples recrystallized in presence of PEG 1500. Some of the recrystallized drug samples in presence of stabilizers dissolved 100% within the first 5 min showing at least 10 times greater dissolution rate than the dissolution rate of untreated gliclazide powders. Micromeritic studies showed that in situ micronization technique via pH change method is able to produce smaller particle size with a high surface area. The results also showed that the type of stabilizer had significant impact on morphology of recrystallized drug particles. The untreated gliclazide is rod or rectangular shape, whereas the crystals produced in presence of stabilizers, depending on the type of stabilizer, were very fine particles with irregular, cubic, rectangular, granular and spherical/modular shape. The results showed that crystallization of gliclazide in presence of stabilizers reduced the crystallinity of the samples as confirmed by XRPD and DSC results. Conclusion: In situ micronization of gliclazide through pH change method can successfully be used to produce micron-sized drug particles to enhance dissolution rate.

scholarly journals Visible Light Responsive Nickel and Sulphur Co-Doped TiO2 Mesoporous Nanomaterial for the Degradation of Orange-II Dye and Antibacterial Activity on Escherichia coli

2018 ◽  
Vol 4 (5) ◽  
pp. 555-559
Author(s):  
K.V. Divya Lakshmi ◽  
T. Siva Rao
Keyword(s):  
Escherichia Coli ◽  
Anatase Phase ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Orange Ii ◽  
Doped Tio2 ◽  
Optimum Reaction ◽  
Ft Ir ◽  
Co Doped

Nickel and sulfur co-doped TiO2 photocatalyst were prepared by using sol-gel method with dopants precursors of nickel nitrate and thiourea. Prepared samples were characterized by XRD, UV-Vis-DRS, TEM, BET, FT-IR and SEM-EDX. These characterization and experimental results revealed that there is a formation of anatase phase, decreased band gap 2.62 eV for NIST-2, small particle size 7.3 nm and high surface area 142.62 m2/g. The FT-IR frequency shift for Ti-O-Ti was observed from 569 cm-1 to 460-560 cm-1 for co-doped TiO2. The efficiency of photocatalytic and antibacterial was evaluated by degradation of Orange-II dye and Escherichia coli (MTCC-443) respectively. The complete degradation of Orange-II was achieved in 120 min at optimum reaction parameters for NIST-2 at pH-3, catalyst dosage-100 mg/L and initial dye concentration at 10 mg/L.

scholarly journals A Novel N-Doped Nanoporous Bio-Graphene Synthesized from Pistacia lentiscus Gum and Its Nanocomposite with WO3 Nanoparticles: Visible-Light-Driven Photocatalytic Activity

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6569
Author(s):  
Maryam Afsharpour ◽  
Mehdi Elyasi ◽  
Hamedreza Javadian
Keyword(s):  
Visible Light ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Nanoporous Structure ◽  
Pistacia Lentiscus ◽  
Nitrogen Doped ◽  
Visible Light Driven ◽  
Ft Ir ◽  
Natural Carbon

This paper reports the synthesis of a new nitrogen-doped porous bio-graphene (NPBG) with a specific biomorphic structure, using Pistacia lentiscus as a natural carbon source containing nitrogen that also acts as a bio-template. The obtained NPBG demonstrated the unique feature of doped nitrogen with a 3D nanoporous structure. Next, a WO3/N-doped porous bio-graphene nanocomposite (WO3/NPBG-NC) was synthesized, and the products were characterized using XPS, SEM, TEM, FT-IR, EDX, XRD, and Raman analyses. The presence of nitrogen doped in the structure of the bio-graphene (BG) was confirmed to be pyridinic-N and pyrrolic-N with N1 peaks at 398.3 eV and 400.5 eV, respectively. The photocatalytic degradation of the anionic azo dyes and drugs was investigated, and the results indicated that the obtained NPBG with a high surface area (151.98 m2/g), unique electronic properties, and modified surface improved the adsorption and photocatalytic properties in combination with WO3 nanoparticles (WO3-NPs) as an effective visible-light-driven photocatalyst. The synthesized WO3/NPBG-NC with a surface area of 226.92 m2/g displayed lower bandgap and higher electron transfer compared with blank WO3-NPs, leading to an increase in the photocatalytic performance through the enhancement of the separation of charge and a reduction in the recombination rate. At the optimum conditions of 0.015 g of the nanocomposite, a contact time of 15 min, and 100 mg/L of dyes, the removal percentages were 100%, 99.8%, and 98% for methyl red (MR), Congo red (CR), and methyl orange (MO), respectively. In the case of the drugs, 99% and 87% of tetracycline and acetaminophen, respectively, at a concentration of 10 mg/L, were removed after 20 min.

scholarly journals Adsorption of Nitrogen on Mn(II) Metal-organic Framework Nanoparticles

2021 ◽  
pp. 4164-4177
Author(s):  
Idongesit Justina Mbonu ◽  
Olusegun Kehinde Abiola
Keyword(s):  
Density Functional ◽  
High Pressures ◽  
Metal Organic Framework ◽  
High Surface ◽  
High Surface Area ◽  
Good Thermal Stability ◽  
Adsorption Of Nitrogen ◽  
Metal Organic ◽  
Ft Ir ◽  
Organic Framework

Adsorption of N2 on mixed ligand benzoic acid and 1, 10-phenanthroline ligands of Mn(II) metal-organic framework (MOF)–nanoparticles were demonstrated. The adsorption capacity and pore size distribution of the synthesized MOF were conducted experimentally by measuring the N2 adsorption isotherm at 77.3 K. The resulting data were fitted to Brunauer-Emmett-Teller (BET), de Boer, Dubinin-Redusbkevich (DR), Banet-Joyner-Halenda (BJH), Horvath-Kawazoe (HK) and Density Functional Theory (DFT) models to describe the adsorptive behaviour of the synthesized nanoparticles. The DSC analysis shows the high chemical stability of this compound. The FT-IR measurement reports present the abundant of highly coordinated functional groups. And the adsorption properties evaluated by different adsorption models compared with existing adsorbent materials suggest Mn-MOF with good thermal stability, high surface area and pore openings, is a promising material for storing gases and energy because at low or high pressures, it can adsorb nitrogen gas due to its large openings.

scholarly journals Silica-Based Stimuli-Responsive Systems for Antitumor Drug Delivery and Controlled Release

Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Avelino Corma ◽  
Pablo Botella ◽  
Eva Rivero-Buceta
Keyword(s):  
Water Solubility ◽  
High Surface ◽  
High Surface Area ◽  
Membrane Receptors ◽  
Specific Cell ◽  
Stimuli Responsive ◽  
Precise Control ◽  
Good Biocompatibility ◽  
Near Future ◽  
Real Patients

The administration of cytotoxic drugs in classical chemotherapy is frequently limited by water solubility, low plasmatic stability, and a myriad of secondary effects associated with their diffusion to healthy tissue. In this sense, novel pharmaceutical forms able to deliver selectively these drugs to the malign cells, and imposing a space-time precise control of their discharge, are needed. In the last two decades, silica nanoparticles have been proposed as safe vehicles for antitumor molecules due to their stability in physiological medium, high surface area and easy functionalization, and good biocompatibility. In this review, we focus on silica-based nanomedicines provided with specific mechanisms for intracellular drug release. According to silica nature (amorphous, mesostructured, and hybrids) nanocarriers responding to a variety of stimuli endogenously (e.g., pH, redox potential, and enzyme activity) or exogenously (e.g., magnetic field, light, temperature, and ultrasound) are proposed. Furthermore, the incorporation of targeting molecules (e.g., monoclonal antibodies) that interact with specific cell membrane receptors allows a selective delivery to cancer cells to be carried out. Eventually, we present some remarks on the most important formulations in the pipeline for clinical approval, and we discuss the most difficult tasks to tackle in the near future, in order to extend the use of these nanomedicines to real patients.

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