Antifungal Activity of Chitosan Polymeric Nanoparticles and Correlation with Their pH Against Mucor circinelloides Causing Mucormycosis, Along with Penicillium notatum and Aspergillus Species.

Mucormycosis is uncommon, yet it is more prevalent among individuals with underlying health conditions and those who are immunocompromised. Chitosan is studied because of its appealing properties and diverse applications. The purpose of this work is to synthesize chitosan nanoparticles (CSNPs) by ionic gelation method at various pH levels and test them against Mucor and other filamentous fungus. Field Emission Scanning Electron Microscope, Zeta sizer, Zeta potential, and Fourier Transformed Infrared Spectroscopy were used to characterize CSNPs. Hydrodynamic size increased considerably with increasing pH. Our CSNPs were tested against fungal isolates of Aspergillus Flavus RCMB 02783, Aspergillus Fumigatus RCMB 02564, and Aspergillus Niger RCMB 02588, Penicillium Notatum (NCPF 2881) and   (M. circinelloides CNRMA 03.894) causing mucromycosis. Antifungal activity was investigated using Minimum inhibitory concentration (MIC), Minimum Fungicidal concentration (MFC), Disc diffusion assay, and Antifungal inhibitory percentages methods. The best antifungal efficacy results were obtained through CSNPs prepared at pH = 4.4 at very low concentration for MIC (1.03 or 2.75 µg/mL) with 100% M. circinelloides inhibition followed by pH = 4.6 with MIC (73 or 208 µg/mL) and 93%  M. cirecinelloides inhibition %. Future usage of these materials in masks or wound dressing to avoid fungal infections, including mucormycosis following COVID-19, penicillium, and aspergillosis toxicity and infections.

Changing the morphology of one-dimensional titanate nanostructures affects its tissue distribution and toxicity.

The present research investigated the impact of the morphology change of titanate (TiO2) nanostructures on its tissue distribution and toxicity. The TiO2 nanotubes, rods, and ribbons were synthesized by the hydrothermal technique, and the morphology was adjusted by alteration of the hydrothermal duration time. The characterization techniques were X-ray diffraction, high-resolution transmission electron microscopy, dynamic light scattering, and the Brunauer-Emmett-Teller method for measuring the surface area. The intravenously administrated dose (5 mg/kg) was injected as a single dose for 1 day and consecutively for 42 days. The quantitative analysis of accumulated TiO2 nanostructures in the liver, spleen, and the heart was performed using an inductively coupled plasma emission spectrometer, and the organs' toxicity was estimated by histopathological analysis. The prepared nanostructures exhibited differences in morphology, crystallinity, size distribution, surface area, zeta potential, and aspect ratio. The results revealed a tissue distribution difference between the liver, spleen, and heart of these nanostructures, the distribution order was the liver, spleen, and the heart for all TiO2 nanostructures. The toxicity was induced with different degrees. The nanotubes were the most harmful among the three formats. In summary, changes in the morphology of the TiO2 nanostructures change its distribution and toxicity.

Outstanding features of Cu-doped ZnS nanoclusters.

ZnS and their Cu-doped nanoclusters (NCs) were synthesized successfully using the wet chemical route with different Cu content. The crystalline structure was investigated using x-ray powder diffraction which assured the single-phase formation in cubic symmetry. High-resolution transmission electron microscope indicated the microstructure of NCs with a size ranging from 2-4 nm. A butterfly hysteresis (M-H) loop was observed at room temperature with large values of coercivity for the Cu content of x = 0.05. Photoluminescence emission spectra were recorded from 500-615 nm for pure and Cu-doped ZnS NCs at a 350 nm excitation wavelength. The sample exhibited green fluorescence bands peaking at 535, 544, 552.5, 558.2, and 560.6 nm, which confirmed the characteristic feature of Zn2+ as luminescent centers in the lattice. The additional yellow and orange emissions are due to defect levels or/and impurity centers. The dielectric constant as well as the conductivity values increased with increasing Cu content.

Management of ibuprofen in wastewater using electrospun nanofibers developed from PET and PS wastes.

Electrospinning is a promising technique for the beneficial use and recycling of plastic waste polymers using simple methodologies. In this study, plastic bottles and Styrofoam wastes have been used to develop polyethylene terephthalate (PET) and polystyrene (PS) nanofibers using electrospinning technique separately without any further purification. The effect of the concentration onto the nanofiber's morphology was studied. The fabricated nanofibers were characterized using Field Emission Scanning Electron Microscope (FE-SEM), Fourier Transformed Infrared Spectroscopy (ATR-FTIR), N2 adsorption/desorption analysis, and water contact angle (WCA). Furthermore, the prepared nanofibers were applied for the adsorption of ibuprofen (IBU) from wastewater. Some parameters that can influence the adsorption efficiency of nanofibers such as solution pH, wt.% of prepared nanofibers, drug initial concentration, and contact time were studied and optimized. The results show that the equilibrium adsorption capacity was achieved after only 10 min for 12 wt% PET nanofibers which is equivalent to 364.83 mg/g. For 12 wt% PS nanofibers, an equilibrium adsorption capacity of 328.42 mg/g was achieved in 30 min. The experimental data was fitted to five isotherm and four kinetics models to understand the complicated interaction between the nanofibers and the drug. Langmuir-Freundlich isotherm model showed the best fit for experimental data for both PET and PS nanofibers. The adsorption process was characterized by predominantly physical reaction rather than chemical adsorption for both materials. The reusability study revealed that the synthesized nanofibers maintain their ability to adsorb/desorb IBU for up to five cycles. The results obtained demonstrated that fabricated nanofibers from plastic wastes could perform promising adsorbents for the management of IBU in wastewater. However, further research is needed for the scaling-up the fabrication which is required for real-world applications.

Investigating the potential of triclinic ABSe3 (A = Li, Na, K, Rb, Cs; B = Si, Ge, Sn) perovskites as a new class of lead-free photovoltaic materials.

In recent years, chalcogenide perovskites have emerged as promising candidates with favorable structural, electrical, and optical properties for photovoltaic applications. This paper explores the structural, electronic, and optical characteristics of ABSe3 perovskites (where A = Li, Na, K, Rb, Cs; B = Si, Ge, Sn) in their triclinic crystallographic phases using density functional theory. The stability of these materials is ensured by calculating formation energies, tolerance factors (Tf), and phonon dispersion. The Eform values of all ABSe3 are negative, suggesting favorable thermodynamic stability. The Tf values range between 0.82 and 1.1, which is consistent with stable perovskites. The phonon dispersion analysis of the chalcogenide perovskites revealed no imaginary frequencies in any of the vibrational modes, confirming their stability. The electronic band structures and corresponding density of states are computed to unveil the semiconducting nature of the studied compounds. These perovskites are promising for high-performance solar cells due to their indirect bandgaps (Eg, 1.10-2.33 eV) and a small difference between these indirect and direct gaps (0.149-0.493 eV). The Eg values increase as the ionic radii of A-site elements increase (Li < Na < K < Rb < Cs). At the B-site, Si-based chalcogenides have the largest Eg values, followed by Sn-based and then Ge-based materials. Furthermore, optical properties such as the real part and imaginary part of the dielectric function, refractive index extinction coefficient, optical conductivity, absorption coefficient, reflectivity, and energy loss are predicted within the energy range of 0-50 eV. Several ABSe3 materials, particularly LiGeSe3 and NaGeSe3, demonstrated optical properties comparable to both traditional and emerging materials, suggesting their potential for effective use in solar cells.

LaCo0.2Fe0.8O3 perovskites doped with natural Ca2+ as bifunctional electrocatalysts for oxygen evolution and reduction reactions.

Perovskite oxides are promising electrocatalysts for various energy applications due to their exceptional catalytic activity, flexible architecture, and low cost. In this study, LCFO was doped with different ratios of Ca2+ from eggshells, resulting in dual-purpose electrocatalysts for oxygen reduction and evolution processes. The nanoparticles were characterized using various techniques, including Brunauer-Emmett-Teller analysis and XRD. Results clarified the relative surface area and roughness, increasing with Ca2+ doping. LCFO also demonstrated highly magnetic properties, improved charge transfer, catalytic activity, and long-term durability. The results demonstrated the perovskite's cost-effectiveness as a bifunctional electrocatalyst, and the role of Ca2+ in enhancing its properties. La0.6Ca0.4Co0.2Fe0.8O3(LCCFO-0.4) showed higher magnetic properties (M s = 13.36 emu g-1 and M r = 2.54 emu g-1). The LCFO sample showed a current density of 5.13 mA cm-2 and 3 mA cm-2 for OER and ORR respectively, at E onset 1.7 V and 0.57 V (vs. RHE). The LCFO electrochemical active surface area is 0.033 cm2.

Expression of concern: Acceleration of ammonium phosphate hydrolysis using TiO2 microspheres as a catalyst for hydrogen production.

Expression of concern for 'Acceleration of ammonium phosphate hydrolysis using TiO2 microspheres as a catalyst for hydrogen production' by Ayman H. Zaki et al., Nanoscale Adv., 2020, 2, 2080-2086, https://doi.org/10.1039/D0NA00204F.

Estimating the in vitro cytotoxicity of the newly emerged zinc oxide (ZnO) doped chromium nanoparticles using the human fetal lung fibroblast cells (WI38 cells).

Advances in nanotechnology have been increased for more smart applications and getting the highest level of benefits, recently modification of the surface characters of nanoparticles is a new trend to get the optimal benefits, one of these modification is doping of zinc oxide with chromium nanoparticles (ZnO doped Cr NPs), the present study aimed to identify the surface characters of doped ZnO and their possible cytotoxic effects. The doped NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Field emission scanning electron microscope (FESEM), and Electromagnetic Data Exchange (EDX). Human fetal lung fibroblast cells (WI38 Cells) was treated with variable concentrations of pure ZnO and ZnO doped Cr (0.01 %, 0.02 %, 0.03 % and 0.04 %) for 24 hr at 37 °C followed by the MTT assay. The cells treated with the obtained half-maximal inhibitory concentration (IC50). The supernatant and cells were collected for oxidant/anti-oxidant and molecular analysis.The observed FESEM features are in line with the reported XRD analysis confirming the hexagonal crystal symmetry of all samples. The findings revealed that pure ZnO exhibited potent cytotoxic effects followed by (0.03 % and 0.04 %). All tested NPs produce lipid peroxidation significantly (0.03 % and 0.04 %). The significant up regulation of Bcl-2-associated X protein (BAX) and apoptotic Caspase (Cas-3) transcription level were reported in ZnO and 0.03 % and 0.04 % in contrast the anti apoptitic B-cell lymphoma 2 (Bcl-2) is elevated in 0.01 % and 0.02 %. Doping of ZnO with Cr causing significant morphological changes which effect on their toxicity especially with 0.03 % and 0.04 %.

Mechanical performance and thermal stability of hardened Portland cement-recycled sludge pastes containing MnFe2O4 nanoparticles.

This study focused on investigating the possibility of using different ratios (5, 10, 15 mass%) of recycled alum sludge (RAS) as partial replacement of ordinary Portland cement (OPC), to contribute to solving the problems encountered by cement production as well as stockpiling of large quantities of water-treated sludge waste. MnFe2O4 spinel nanoparticles (NMFs) were used to elaborate the mechanical characteristics and durability of different OPC-RAS blends. The outcomes of compressive strength, bulk density, water absorption, and stability against firing tests fastened the suitability of utilization of RAS waste for replacing OPC (maximum limit 10%). The inclusion of different doses of NMFs nanoparticles (0.5, 1 and 2 mass %) within OPC-RAS pastes, motivates the configuration of hardened nanocomposites with improved physico-mechanical characteristics and stability against firing. Composite made from 90% OPC-10% RAS-0.5% NMFs presented the best characteristics and consider the optimal choice for general construction applications. Thermogravimetric analysis (TGA/DTG), X-ray diffraction analysis (XRD), and scanning electron microscope (SEM) techniques. affirmed the positive impact of NMFs particles, as they demonstrated the formation of enormous phases as ilvaite (CFSH), calcium silicate hydrates (CSHs), MnCSH, Nchwaningite [Mn2 SiO3(OH)2 H2O], [(Mn, Ca) Mn4O9⋅3H2O], calcium aluminosilicate hydrates (CASH), Glaucochroite [(Ca, Mn)2SiO4, and calcium ferrite hydrate (CFH). These hydrates boosted the robustness and degradation resistance of the hardened nanocomposites upon firing.

Electronic Structures and Electrical Properties of Cr2+-, Cu2+-, Ni2+-, and Zn2+-Doped Sodium Titanate Nanotubes.

Sodium titanate nanotubes (Na-TNTs) and their metal-doped derivatives were prepared using simple hydrothermal and metal ion-exchange methods, respectively. The as-prepared doped materials were characterized by X-ray powder diffraction, thermal gravimetric analysis, high-resolution transmission electron microscopy, field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The dielectric constant, the loss tangent, and the AC electrical conductivity of NaM-TNTs (where M = Cr, Cu, Ni, or Zn) were measured at selected frequencies (400 kHz and 2 MHz) as a function of temperature. The activation energy was calculated and reported at 400 kHz. All samples showed mixed ionic electronic conductivity. Some of the materials were used as examples for theoretically exploring structures and optoelectronic properties (density of states, reflectivity, absorption curve, refractive index, dielectric function, optical conductivity, and loss function) using density functional theory calculations. The band gaps of the materials were found to vary from 2.4 to 3.17 eV, which makes them suitable for many optoelectronic applications.

Theranostics platform of Abemaciclib using magnetite@silica@chitosan nanocomposite.

The current study was designed to synthesize a nanoformula comprising of magnetite nanoparticles (MN) with mesoporous silica (MS), which was in turn coated with chitosan (CS) and further loaded with a chemotherapeutic agent, Abemaciclib (ABE). The prepared formula, MN@MS@CS@ABE, was characterized by XRD, FTIR, HRTEM, FESEM, DLS, VSM, BET, and BJH. The ABE loading capacity and entrapment efficiency were calculated, and an in vitro drug release experiment was conducted. Cytoxicity was studied by the MTT assay. The formula was investigated as an anticancer agent versus MCF-7 cells by performing Annexin V-FITC flow cytometry and cell cycle analysis. Furthermore, we examine the formula as a contrast agent in magnetic resonance imaging (MRI). ABE loading and encapsulation efficiency were 24.2 % and 63.4 %, respectively. The formula demonstrated sustained drug release behavior for 72 h. The MTT assay revealed a higher cytotoxicity of free ABE in MCF-7 cells compared to MN@MS@CS@ABE. Flow cytometry revealed early and late phases of apoptosis and necrosis with different percentages. The formula stimulated a reduction in signal intensity in the MR T2-weighted imaging technique. In conclusion, the current study developed a nanoformula which could be a promising theranostic agent in cancer therapy and diagnosis.

Nanofibrous ε-polycaprolactone scaffolds containing Ag-doped magnetite nanoparticles: Physicochemical characterization and biological testing for wound dressing applications in vitro and in vivo.

Skin wounds can lead to numerous complications with dangerous health consequences. In this work, magnetite nanoparticles were doped with different concentrations of antimicrobial silver (Ag) ions and incorporated into the electrospun nanofibrous ε-polycaprolactone (PCL) scaffolds. Nanoparticles and scaffolds with various Ag contents were characterized using a range of physicochemical techniques. Ag entered magnetite as cations and preferentially positioned at tetrahedral sites, introducing lattice distortions and topographic irregularities. Amorphization of the structure due to accommodation of Ag expanded the lattice in the bulk and contracted it on the surface, where broadened distribution of Fe-O coordinations was detected. Promoting spin canting and diminishing the double exchange interaction through altered distribution of ferric and ferrous ions, Ag softened the magnetism of magnetite. By making the nanoparticle structure more defective, Ag modified the interface with the polymer and promoted the protrusion of the nanoparticles from the surface of the polymeric nanofibers, thus increasing their roughness and hydrophilicity, with positive repercussions on cell adhesion and growth. Both the viability of human melanocytes and the antibacterial activity against E. coli and S. aureus increased with the concentration of Ag in the magnetite phase of the scaffolds. Skin wound healing rate in rats also increased in direct proportion with the concentration of Ag in the magnetite phase, and no abnormalities in the dermal and epidermal tissues were visible on day 10 in the treatment group. These results imply an excellent potential of these composite nanofibrous scaffolds for use as wound dressings and in other reconstructive skin therapies.

Efficient water decontamination using layered double hydroxide beads nanocomposites.

Ni-Al-CO3-layered double hydroxide (LDH) with Ni:Al ratio (3:1) and their nanocomposites with alginate and chitosan beads were prepared and examined for their efficiency in removal of Cd2+ and Cu2+ ions from wastewater. Different parameters such as contact time, pH value, adsorbent weight, and heavy metal ion concentration on the removal efficiency were examined and reported. The prepared beads were examined using X-ray diffraction (XRD), TEM, SEM, and FTIR. Our results revealed a successful preparation of the LDH in rhombohedral hexognal crystal form and the alginate-LDH-chitosan beads. The optimized batch experiment conditions in ambient room temperature were found to be 2 g/L adsorbent dose, 50 mg/L initial concentration of meal, contact time of 2 h, and pH ~ 5 and 6 for removal of Cu2+ and Cd2+, respectively. The adsorption process was well fitted with Langmuir and Freundlich isotherm models (higher R2), with trivial advantage for Freundlich approach. Kinetic studies showed that the adsorption of both Cd2+ and Cu2+ followed the pseudo-second-order. The current study demonstrated that the Ni-Al-CO3 LDH and their novel alginate-chitosan-based nanocomposite could be further tailored and used as efficient adsorbents for the uptake of heavy metals from wastewater.

Acceleration of ammonium phosphate hydrolysis using TiO2 microspheres as a catalyst for hydrogen production.

Titania microspheres are considered an adequate material with low cost and easily attainable pathways, and can be utilized in photocatalytic H2 production to solve the energy crisis. Spherical porous titanium dioxide materials, with nanostructure composition, were chemically synthesized from titanate nanotubes via a simple hydrothermal technique, then added as a catalyst to accelerate the route of ammonium phosphate hydrolysis for hydrogen production. The mechanism of sphere formation from titanate nanotubes is elucidated in detail through the current study. The prepared materials were applied as a photocatalyst to facilitate the separation and transfer of photoinduced electrons, while preventing the recombination of electron-hole pairs. Experimental results show that the obtained microspheres possess significantly enhanced photocatalytic hydrogen (H2) production performance. The amount of photocatalytic hydrogen product using the microspheres is found to be ∼2.5 fold greater than that of titanate nanotubes. Analytical techniques such as field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), simulated visible solar light and X-ray diffraction (XRD) were used for the evaluation and characterization of the developed products, as well as the elucidation of the route of hydrolysis in the hydrogen production process.

Enhanced antibacterial activity of capped zinc oxide nanoparticles: A step towards the control of clinical bovine mastitis.

BACKGROUND AND AIM: Bovine mastitis is the costliest prevalent disease in the dairy sector due to the limitations of conventional treatments. Zinc oxide nanoparticles (ZnO-NPs) have been regarded as safe and economical antibacterial candidates against several microorganisms, but the tendency of these particles to aggregate is a major barrier to their application. This study aimed to enhance the antibacterial efficiency of ZnO-NPs against some bacterial agents, causing bovine mastitis. MATERIALS AND METHODS: A total of 24 milk samples out of 300 cases from Nubaria farm, Beheira Governorate, Egypt, were collected from cows with clinical mastitis. ZnO-NPs were fabricated by a sonochemical method using starch as a capping agent and by an auto-combustion reaction using glycine as a fuel. The two preparations of synthesized ZnO-NPs at different concentrations were assessed for their antimicrobial activities in vitro against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae isolated from milk of affected cows. RESULTS: Sonochemically synthesized capped ZnO-NPs were dispersed and non-agglomerated in comparison with aggregated uncapped ZnO-NPs prepared by an auto-combustion reaction. Capped dispersed ZnO-NPs showed higher antibacterial activity against S. aureus, E. coli, and K. pneumoniae than particles synthesized by the auto-combustion reaction at same concentrations. However, the zone of inhibition for dispersed and agglomerated ZnO-NPs was concentration-dependent. In addition, Gram-positive S. aureus exhibited higher resistance to ZnO-NPs synthesized by both methods than Gram-negative E. coli and K. pneumoniae. CONCLUSION: Dispersed, non-agglomerated ZnO-NPs fabricated using starch as a capping agent under sonochemical irradiation could potentially be regarded as highly effective and inexpensive antimicrobial agents against S. aureus, E. coli, and K. pneumoniae for the management of bovine mastitis.

Synthesis and multifunctionality of (CeO2-NiO) nanocomposites synthesized via sonochemical technique.

CeO2, NiO and their nanocomposite were synthesized using facile sonochemical technique. XRD assure single phase CeO2 and NiO while the nanocomposite consists of the two phases only. CeO2 nanoparticles possess cubic shape, NiO was formed in nanorods, and CeO2 decorated the NiO nanorods in the nanocomposite. The magnetic behavior of the nanocomposite lies between those of the two parents with a ferromagnetic tendency. Metal oxide nanoparticles acted as catalyst in the formation of carbon nanofibers (CNFs), while the nanocomposite leads to the production of carbon nanotubes. The photocatalyst (CeO2-NiO) achieved complete dye degradation (100%) in light for the tested dye at 50 min. The decay products were analyzed using GC mass confirming mineralization of Bb red dye.

Physico-mechanical and morphological features of zirconia substituted hydroxyapatite nano crystals.

Zirconia doped Hydroxyapatite (HAP) nanocrystals [Ca10(PO4)6-x(ZrO2)x(OH)2]; (0 ≤ x ≤ 1 step 0.2) were synthesized using simple low cost facile method. The crystalline phases were examined by X-ray diffraction (XRD). The crystallinity percentage decreased with increasing zirconia content for the as-synthesized samples. The existence of zirconia as secondary phase on the grain boundaries; as observed from scanning electron micrographs (FESEM); resulted in negative values of microstrain. The crystallite size was computed and the results showed that it increased with increasing annealing temperature. Thermo-gravimetric analysis (TGA) assured the thermal stability of the nano crystals over the temperature from room up to 1200 °C depending on the zirconia content. The corrosion rate was found to decrease around 25 times with increasing zirconia content from x = 0.0 to 1.0. Microhardness displayed both compositional and temperature dependence. For the sample (x = 0.6), annealed at 1200 °C, the former increased up to 1.2 times its original value (x = 0.0).

Preparation and characterization of nanometric Mn ferrite via different methods.

The structure and magnetic properties of MnFe(2)O(4) ferrites have been investigated using five different preparation methods, including the ceramic technique, flash combustion, co-precipitation, sol-gel and citrate methods. The characteristics of one sample prepared by different methods have been studied to select the better method, i.e. the one that is the simplest and does not require an elaborate instrumental set-up. The results indicated that the citrate method gives the lowest value for the lattice parameter and particle size (14.1 nm), while the highest values are obtained with the ceramic method. The smallest nanosizes were obtained in the citrate and flash methods (14.1 and 40.7 nm, respectively).