In vitro and in vivo evaluation of cytotoxicity,antioxidant, antibacterial,antifungal, and cutaneous wound healing properties of gold nanoparticles produced via a green chemistry synthesis using Gundelia tournefortii L. as a capping and reducing agent

The exploitation of various plant materials for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. The aim of the experiment was chemical characterization and evaluation of cytotoxicity, antioxidant, antibacterial, antifungal, and cutaneous wound healing activities of gold nanoparticles using aqueous extract of Gundelia tournefortii L. leaves (AuNPs@GT). These nanoparticles were characterized by fourier transformed infrared spectroscopy (FT‐IR), field emission scanning electron microscopy (FE‐SEM), energy dispersive X‐ray spectroscopy (EDS), and UV–visible spectroscopy. DPPH free radical scavenging test was done to assess the antioxidant properties, which indicated similar antioxidant potentials for AuNPs@GT and butylated hydroxytoluene. Agar diffusion tests were applied to determine the antibacterial and antifungal characteristics. Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), and Minimum Fungicidal Concentration (MFC) were specified by macro‐broth dilution assay. AuNPs@GT indicated higher antibacterial and antifungal effects than all standard antibiotics (p ≤ 0.01). Also, AuNPs@GT inhibited the growth of all bacteria and fungi and removed them at 2‐4 mg/mL concentrations (p ≤ 0.01). In vivo experiment, after creating the cutaneous wound, the rats were randomly divided into six groups: untreated control, treatment with Eucerin basal ointment, treatment with 3% tetracycline ointment, treatment with 0.2% HAuCl₄ ointment, treatment with 0.2% G. tournefortii ointment, and treatment with 0.2% AuNPs@GT ointment. These groups were treated for 10 days. For histopathological and biochemical analysis of the healing trend, a 3 × 3 cm section was prepared from all dermal thicknesses at day 10. Use of AuNPs@GT ointment in the treatment groups substantially reduced (p ≤ 0.01) the wound area, total cells, neutrophil, and lymphocyte and remarkably raised (p ≤ 0.01) the wound contracture, hydroxyl proline, hexosamine, hexuronic acid, fibrocyte, fibroblast, and fibrocytes/fibroblast rate compared to other groups. The synthesized AuNPs@GT had great cell viability dose‐dependently (Investigating the effect of the plant on HUVEC cell line) and revealed this method was nontoxic. The results showed that the leave aqueous extract of G. tournefortii is very good bioreductant in the synthesis of gold nanoparticles for treatment of bacterial, fungal, and skin diseases.     

Uranyl sensor based on a N,N′-bis(salicylidene)-2-hydroxy-phenylmethanediamine and multiwall carbon nanotube electrode

The electrochemical determination of uranyl was investigated by using carbon paste electrode modified with a Schiff base namely N,N??-bis(salicylidene)-2-hydroxy-phenylmethanediamine (SHPMD/CPE) and also in the presence of carbon nanotube (SHPMD/CNT/CPE). The both modified electrodes displayed an irreversible peak at E _pa?=?0.798?V versus Ag/AgCl. The electrocatalytic reduction of uranyl has been studied on SHPMD/CNT/CPE, using cyclic and differential pulse voltammetry, chronocoulometry and linear sweep techniques. Electrochemical parameters including the diffusion coefficient (D), the electron transfer coefficient (??), the ionic exchange current (i) and the redox reaction rate constant (K) were determined for the reduction of uranyl on the surface of the modified electrodes. Linear range concentration is 0.002?C0.6???mol?L^?1 and the detection limit of uranyl is 0.206?nmol?L^?1. The proposed method was used to detect uranyl in natural waters and good recovery was achieved.     

DFT Study of Endohedral Atoms Effect on Electrophilicity of B16N16 Boron Nitride Nanocage: Comparative Analyses

Endohedral derivatives of B₁₆N₁₆ nanocage (M@B₁₆N₁₆, M?=?Li⁺, Na⁺, K⁺, Mg²⁺, Ne, O^2?, S^2?, F^?, Cl^?) and its iso-electronic fullerne M@C₃₂ have been employed to investigate the relation between the trapped atom/ion and electrophilicity of the B₁₆N₁₆ and C₃₂ nanocages. The electrophilicity index, ??, of these endohedral nanocages has been evaluated from the ionization potential and the electron affinity computed by vertical ionization/affinity at the B3LYP/6-311++G(df,pd) level. Obtained results illustrate that the nature of trapped atom/ion affects HOMO-LUMO band gap, global electrophilicity indices and reactivity of B₁₆N₁₆ and C₃₂ nanocages. Encapsulation B₁₆N₁₆ with different atom/ions may be a possible method for modifying HOMO-LUMO energy gap, electrophilicity and so chemical characteristics of and C₃₂ nanocages.     

Coefficient estimates for a class of meromorphic bi-univalent functions

Applying the Faber polynomial coefficient expansions to a class of meromorphic bi-univalent functions, we obtain the general coefficient estimates for such functions and also examine their early coefficient bounds. A function univalent in the open unit disk is said to be bi-univalent if its inverse map is also univalent there. Both the technique and the coefficient bounds presented here are new on their own kind. We hope that this article will generate future interest in applying our approach to other related problems.     

Kinetic,Equilibrium and Isotherm Studies of Cadmium Removal from Aqueous Solutions by Oxidized Multi‐Walled Carbon Nanotubes and the Functionalized Ones with Thiosemicarbazide and Their Toxicity Investigations: A Comparison

The multi‐walled carbon nanotubes (MWCNTs) were first oxidized by nitric acid to form a MWCNT‐COOH. Then, it was modified with thiosemicarbazide to produce MWCNT‐semi. Thus, these carbon materials, MWCNTs, MWCNT‐COOH and MWCNT‐semi, have been used as efficient adsorbents for the removal of cadmium from aqueous solutions. The influence of variables including pH, concentration of the cadmium, amount of adsorbents and contact time was investigated by the batch method. The kinetic studies carried out using different kinetic models such as pseudo‐first‐order, pseudo‐second‐order, and intraparticle diffusion models. The sorption process with each adsorbent was well described by pseudo‐second‐order kinetics which it was agreed well with the experimental data. The values of regression coefficient of various adsorption isotherms like Langmuir, Freundlich and Tempkin to obtain the characteristic parameters of each model have been carried out. The results showed which the Langmuir isotherm for all adsorbents and Tempkin model for MWCNT‐COOH and MWCNT‐semi was found to best represent the measured sorption data. Toxicity of these samples was evaluated in human embryonic kidney HEK293 and human breast cancer SKBR3 cell lines after culturing cells for 24 h. Cellular investigations showed that the modified MWCNTs in particular MWCNT‐semi have considerably significant toxic impact on SKBR3 as compared to HEK293 at concentration 3 µg/mL.     

An Efficient Three‐Component Synthesis of Pyranoquinoline Derivatives

Pyranoquinoline derivatives have been synthesized via three‐component reaction of 4‐hydroxy‐1‐methyl‐2(1H)‐quinolinone and dialkyl acetylenedicarboxylates in the presence of nucleophiles such as alkyl isocyanides and triphenylphosphine.     

Electronic structures, intramolecular interactions, and aromaticity of substituted 1-(2-iminoethylidene) silan amine: a density functional study

The intramolecular hydrogen bond, molecular structure, π electrons delocalization, and vibrational frequencies in 1-(2-iminoethylidene) silan amine and its derivatives have been investigated by means of density functional method with 6-311++G** basis set, in gas phase, water, and carbon tetrachloride solutions. The obtained results showed that the hydrogen bond strength is mainly governed by resonance variations inside the chelate ring induced by the substituent groups. Furthermore, the topological properties of the electron density distributions for N–H···N intramolecular hydrogen bond were analyzed in terms of the Bader's theory of atoms in molecules. On the other hand, the aromaticity of the ring formed is measured using several well-established indices of aromaticity such as nucleus-independent chemical shift, harmonic oscillator models of the aromaticity, para-delocalization index, average two-center indices, aromatic fluctuation index, and π-fluctuation aromatic index. Natural population analysis data, the electron density and Laplacian properties, as well as γ(NH) and ν(NH) were further used for estimation of the hydrogen bonding interactions and the forces driving their formation.     

Synthesis,Characterization and Application of Cellulose Based Nano-Biocomposite Hydrogels

Nano-hydroxyapatite/cellulose-graft-polyacrylamide biocomposite hydrogels of different molar ratios were prepared to examine their potential application as a carrier for colon targeted drug delivery in vitro. The particle size of the synthesized nano-hydroxyapatite was found to be 122 nm. The swelling behavior of the composite hydrogels was observed in acidic and basic aqueous solution that simulated lower small intestine, colon and stomach fluids. The hydrogel could be applied in drug-delivery systems and acetylsalicylic acid was used as a model compound to test such a possibility. Finally, the synthesized biocomposite hydrogels with the 96.97% maximum encapsulation and 85.67% release efficiency in the basic medium were found to be a suitable candidate to carry and release of colon-targeted drugs.