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The Ca10(PO4)6(OH)2/Li-BioMOFs resin nanocomposites were prepared and introduced as a new dental resin nanocomposite. Ca10(PO4)6(OH)2/Li-BioMOFs resin nanocomposites were synthesized with individual mechanical properties in the presence of lecithin as a biostabilizer. The hydrothermal synthesis of hydroxyapatite (HAp) nanostructures occurred in the presence of Glycyrrhiza glabra (liquorice) root juice that acts not only as a green capping agent but also as a reductant compound with a high steric hindrance agent. Results showed that the mechanical properties of nano-Ca10(PO4)6(OH)2 structures with a concentration of 60 ppm Li-BioMOF were increased by ∼132.5 MPa and 11.5 GPa for the flexural and Young's modulus, respectively. Based on the optical absorption ultraviolet-visible spectrum, the HAp nanocrystallites had a direct bandgap energy of 4.2 eV. The structural, morphological, and mechanical properties of the as-prepared nanoparticles were characterized with the FT-IR (Fourier-transform infra-red), UV-Vis (ultraviolet visible) spectrums, X-ray diffraction, SEM (scanning electron microscopy), and TEM (transmission electron microscopy) images, and atomic force microscopy (AFM). It is suggested that HAp structures loaded on the Li-BioMOFs are as a suitable and novel substrate which can be considered as a promising biomaterial in dental resin nanocomposites significantly improved the strength and modulus. For the first time Ca10(PO4)6(OH)2/Li-MOFs were synthesised as dental resin nanocomposites with hydrothermal approach. Glycyrrhiza glabra (Liquorice) root juice acts not only as green capping agent but also act as reducing agent. Li-BioMOFsasa suitable substrate improve the hydroxyapatite mechanical properties. Li-BioMOFssubstrates for Ca10(PO4)6(OH)2 nanostructures were synthesised in the presence of lecithin as bio stabiliser. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the protective effects of zinc nanoparticles against cisplatin-induced testicular toxicity in mice. Zinc nanoparticles were produced by microwave-assisted synthesis using Lavandula vera extract as reducing agent. Single doses of cisplatin (7 mg/kg, intraperitoneally) and ZnSO4 (10 mg/kg, orally), and various doses of zinc nanoparticles (10 − 50 mg/kg, orally) and vitamin E (100 mg/kg, interaperitoneally) were administered. The protective role of zinc nanoparticles was determined biochemically and histologically. Gradual reduction in malondialdehyde levels and elevation in glutathione levels and in the activities of superoxide dismutase and catalase upon administration of zinc nanoparticles were observed. The pathology of mice treated with cisplatin/vitamin E and cisplatin/zinc nanoparticles were apparently equal, but vitamin E treatment was more effective in lowering oxidative stress markers than zinc nanoparticles. These findings suggest that co-administration of zinc nanoparticles with cisplatin could prevent adverse effects on the male reproductive system via their potential antioxidant properties. [ABSTRACT FROM AUTHOR]

This study was designed to describe the oral acute and subacute toxicities and underlying toxicological mechanisms of biogenic Zn NPs in mice. The Zn NPs were prepared by a green microwave-assisted synthesis method in the presence of Lavandula vera leaf extract. Determination of median lethal dose (LD50) of Zn NPs and the subacute toxicity after 14 days of exposure was performed as a measurement of substance toxicity through general toxicological, hematological, serum, and histopathological investigations. The western blotting was used to determine the cleaved-caspase-3 expression in the sampled tissues. Flame atomic absorption spectrophotometer (AAS) was applied to estimate the Zn levels in tissues. The SEM analyses revealed that the biogenic Zn NPs were spherical-shaped with the size range of 30–80 nm. The LD50 value above 5 g/kg indicated that biogenic Zn NPs could be classified as non-toxic chemicals. In subacute toxicity, no significant differences were found in the body weight as well as hematological and oxidative stress (OS) biomarkers after exposure to Zn NPs at the dose of 1 g/kg in comparison to the control. The AAS results indicated that Zn NPs were mainly distributed in the testis, liver, and brain. The findings of histology images of Zn NPs at the dose of 1 g/kg were similar to those of the control. Furthermore, no significant differences were observed in cleaved-caspase-3 expression after exposure to Zn NPs at the dose of 5 g/kg. The results demonstrated that changes in the OS were not related to caspase pathway and the no-observed-adverse-effect level (NOAEL) dose of biogenic Zn NPs in 14-days subacute toxicity study was lower than 1 g/kg. [ABSTRACT FROM AUTHOR]

The main aim of this study was to synthesize the superparamagnetic nanoparticles coated by alginate/chitosan/β-cyclodextrin to purify α-amylase. Isolated bacteria were identified by morphological, biochemical and taxonomic molecular studies. FTIR- spectrometer, VSM, X-ray instruments and Malvern Zetasizer were used to characterize nanoparticles characteristics. The morphological structures and the elemental composition of the nanoparticles were studied by using FESEM and EDS, respectively. The molecular weight of enzyme was determined using SDS-PAGE, and the enzyme activity detected by zymographic analysis. FTIR studies showed the presence of Fe–O–Fe in the Fe3O4 and verified the interaction between chitosan, β-cyclodextrin and alginate. The saturation magnetization for superparamagnetic and coated superparamagnetic nanoparticles was indicated 39 and 1.9 emu g−1, respectively. The maximum intensity of the XRD peak indicated the presence of the Fe3O4. FESEM and EDS analysis showed that the nanoparticles were regular and spherical in shape and corresponded to the Fe and O elements. Enzyme purification by synthesized nanoparticles was achieved 13.84 U mg−1; purification fold of 3.50. The molecular weight of α-amylase was about 22 kDa. The highest activity of α-amylase was observed at 70 °C, pH 9.3 and Ca2+-independent. As a conclusion, the coated superparamagnetic nanoparticles showed more applications in enzyme purification comparing to the conventional methods. [ABSTRACT FROM AUTHOR]

Microbial enzymes of extremophilic origin serve as a vital source of stable industrial enzymes. The present study focused on overproduction of a thermoalkalophilic lipase produced by Bacillus atrophaeus FSHM2 through UV-induced random mutagenesis (5-45 min exposure to UV light) and factorial experimental design augmented to response surface methodology. Firstly, a UV-induced mutant (designated as UV-45) was developed after the exposure of wild strain to UV irradiation for 45 min which was able to secrete 3484.8 U/L lipase. Afterward, Plackett-Burman experimental approach augmented to central composite design was employed to optimize medium components (olive oil, maltose, glucose, sucrose, yeast extract, tryptone, urea, (NH4)2SO4, NaCl, CaCl2, and ZnSO4) for lipase production by the UV-45 mutant strain. The maximum lipase production of 5505.3 U/L were predicted in medium containing 5% of olive oil, 0.69% of glucose, 0.69% of sucrose, 2.5% of maltose, yeast extract (0.7 g/L), urea (0.44 g/L), (NH4)2SO4 (2.44 g/L), tryptone (1.19 g/L), NaCl (1.61 g/L), CaCl2 (3.81 g/L), and ZnSO4 (1.42 g/L). A mean value of 5161.3 ± 83.3 U/L of lipolytic activity was acquired from real experiments. To sum up, the lipolytic activity of wild type strain (1720.4 U/L) increased by 3-fold after UV-induced mutagenesis and medium components optimization (5161.3 U/L). [ABSTRACT FROM AUTHOR]

The present study was designed to isolate and identify an extremely halophilic lipase-producing bacterial strain, purify and characterize the related enzyme and evaluate its application for ethyl and methyl valerate synthesis. Among four halophilic isolates, the lipolytic ability of one isolate (identified asBacillus atrophaeusFSHM2) was confirmed. The enzyme (designated asBaL) was purified using three sequential steps of ethanol precipitation and dialysis, Q-Sepharose XL anion-exchange chromatography and SP Sepharose cation-exchange chromatography with a final yield of 9.9% and a purification factor of 31.8. The purifiedBaL (Mw∼85 kDa) was most active at 70 °C and pH 9 in the presence of 4 M NaCl and retained 58.7% of its initial activity after 150 min of incubation at 80 °C. The enzyme was inhibited by Cd2+(35.6 ± 1.7%) but activated by Ca2+(132.4 ± 2.2%). Evaluation ofBaL's stability in the presence of organic solvents showed that xylene (25%) enhanced the relative activity of the enzyme to 334.2 ± 0.6% after 1 h of incubation. The results of esterification studies using the purifiedBaL revealed that maximum ethyl valerate (88.5%) and methyl valerate (67.5%) synthesis occurred in the organic solvent medium (xylene) after 48 h of incubation at 50 °C. [ABSTRACT FROM PUBLISHER]

In this investigation, Fe3O4magnetic nanoparticles (MNPs) were prepared by the alkalinization of an aqueous medium containing ferrous sulfate and ferric chloride. In the next step, a Fe3O4–AgCl magnetic nanocomposite was fabricated by the drop-by-drop addition of silver nitrate solution into a NaCl solution containing Fe3O4MNPs. All prepared nanoparticles were characterized by transition electron microscopy (TEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). Both particle types varied in size from 2.5 to 20 nm, with an average size of 7.5 nm for Fe3O4MNPs and 12.5 nm for Fe3O4–AgCl nanocomposites. The antibacterial effect of the Fe3O4MNPs and fabricated Fe3O4–AgCl nanocomposites againstEscherichia coli(ATCC 35218) were investigated by conventional serial agar dilution method using the Müller–Hinton Agar medium. The minimum inhibitory concentration was 4 mg mL−1for Fe3O4MNPs and 2 mg mL−1for the Fe3O4–AgCl magnetic nanocomposites. Time-kill course assays showed that the Fe3O4–AgCl magnetic nanocomposites successfully killed all inoculated bacterial cells during an exposure time of 60 min. The antibacterial activity of recycled Fe3O4–AgCl magnetic nanocomposites over four 60 min cycles of antibacterial treatment was further tested againstE. coliby the colony-forming unit (CFU) method. The antibacterial efficiency of the nanocomposites was constant over two cycles of antibacterial testing. [ABSTRACT FROM AUTHOR]

In this study, different positively charged niosomal formulations containing sorbitan esters, cholesterol and cetyl trimethyl ammonium bromide were prepared by film hydration method for the entrapment of autoclaved Leishmania major (ALM). Size distribution pattern and stability of niosomes were investigated by laser light scattering method and ALM encapsulation per cent was measured by the bicinchoninic acid method. Finally, the selected formulation was used for the induction of the immune response against cutaneous leishmaniasis in BALB/c mice. Size distribution curves of all the formulations followed a log-normal pattern and the mean volume diameter was in the range 7.57-15.80 µm. The mean volume diameters were significantly increased by adding Tween to Span formulations ( p < 0.05). The percentage of ALM entrapped in all formulations varied between 14.88%% and 36.65%%. In contrast to ALM, in vivo studies showed that the niosomes containing ALM have a moderate effect in the prevention of cutaneous leishmaniasis in BALB/c mice. [ABSTRACT FROM AUTHOR]