Expression, purification, characterization, and cytotoxic evaluation of the ML1-STxB fusion protein.

Targeted delivery of a toxin substance to cancer cells is one of the most recent cancer treatment options. Mistletoe Lectin-1 (ML1) in Viscum album L. is a Ribosome-inactivating proteins with anticancer properties. Therefore, it appears that a recombinant protein with selective permeability can be generated by fusing ML1 protein with Shiga toxin B, which can bind to Gb3 receptor that is abundantly expressed on cancer cells. In this study, we sought to produce and purify a fusion protein containing ML1 fused to STxB and evaluate its cytotoxic activities. The ML1-STxB fusion protein coding sequence was cloned into the pET28a plasmid, then was transformed into E. coli BL21-DE3 cells. Following induction of protein expression, Ni-NTA affinity chromatography was used to purify the protein. Using SDS-PAGE and western blotting, the expression and purification processes were validated. On the SkBr3 cell line, the cytotoxic effects of the recombinant proteins were evaluated. On SDS-PAGE and western blotting membrane, analysis of purified proteins revealed a band of approximately 41 kDa for rML1-STxB. Ultimately, statistical analysis demonstrated that rML1-STxB exerted significant cytotoxic effects on SkBr3 cells at 18.09 and 22.52 ng/L. The production, purification, and encapsulation of rML1-STxB fusion protein with potential cancer cell-specific toxicity were successful. However, additional research must be conducted on the cytotoxic effects of this fusion protein on other malignant cell lines and in vivo cancer models.

Skull, mandible and hyoid apparatus in the Indian grey mongoose (Herpestes edwardsii): A comprehensive anatomical study.

Mongooses are small carnivores residing in different regions of Asia. The Indian grey mongoose (Herpestes edwardsii) is one of the species mostly found in Iran. The skull gives the head of animal species' phylogenetic appearance and protects vital organs such as the brain and eyes. Our study aimed to enrich the current data pool by providing a morphological and morphometric description of the Indian grey mongoose's skull, mandible and hyoid apparatus. The present work was conducted on ten skulls and mandibles of the mongoose to describe the skull's anatomy and mandible grossly and radiographically. The radiographic characteristics of the Indian grey mongoose skull and mandible were demonstrated in lateral and dorsoventral projections. They were studied anatomically, and the measurements of morphometric characteristics were performed. Unpaired t-tests were used to investigate the sexual dimorphism regarding skull measurements between sexes. This study showed that the neuro-cranium area was extensive in the Indian grey mongoose skull, and the orbit was utterly bony. The presence of a two-part tympanic bulla and the absence of a distinct jugular process are also significant. In terms of the morphometric characteristics, there were significant differences between males and females, especially in the total length of the skull. Morphologically, the anatomy of the skull, mandible and hyoid apparatus is similar in male and female mongooses and follows the species' behavioural and nutritional characteristics. Some of these characteristics are different from other carnivores, especially dogs.

Selective spectrofluorimetric determination of sulfide ion using manganese doped ZnS quantum dots as luminescent probe.

This work reports a spectrofluorimetric method for selective and sensitive determination of sulfide ion in aqueous solution. The ultra-small zinc sulfide quantum dots (QDs) doped with manganese (ZnS:Mn) were synthesized by using a simple and fast procedure based on the co-precipitation of nanoparticles in aqueous solution in the presence of 2-mercaptoethanol, as capping agent. The nanoparticles have exhibited two strong fluorescent emissions at about 424 and 594 nm. Luminescent surface-capped ZnS:Mn QDs, with particle size below 5 nm, have been applied for determination of sulfide anions in water samples. Under the optimum conditions, the fluorescence intensity of ZnS:Mn QDs is linearly proportional to the sulfide ion concentration in the range 1.2×10(-6) to 2.6×10(-5) mol L(-1) with a detection limit as 3.3×10(-7) mol L(-1). The relative standard deviation for five replicate measurements (for 8.0×10(-6) mol L(-1) of S(2-)) was obtained to be 2.6%. It was founded that the interference of the other anions was negligible on the quantitive determination of sulfide ion.

Photoluminescence emission of nanoporous anodic aluminum oxide films prepared in phosphoric acid.

The photoluminescence emission of nanoporous anodic aluminum oxide films formed in phosphoric acid is studied in order to explore their defect-based subband electronic structure. Different excitation wavelengths are used to identify most of the details of the subband states. The films are produced under different anodizing conditions to optimize their emission in the visible range. Scanning electron microscopy investigations confirm pore formation in the produced layers. Gaussian analysis of the emission data indicates that subband states change with anodizing parameters, and various point defects can be formed both in the bulk and on the surface of these nanoporous layers during anodizing.

Synthesis and characterizations of ultra-small ZnS and Zn(1-x)Fe(x)S quantum dots in aqueous media and spectroscopic study of their interactions with bovine serum albumin.

This work reports a new experimental methodology for the synthesis of ultra small zinc sulfide and iron doped zinc sulfide quantum dots in aqueous media. The nanoparticles were obtained using a simple procedure based on the precipitation of ZnS in aqueous solution in the presence of 2-mercaptoethanol as a capping agent, at room temperature. The effect of Fe(3+) ion concentration as dopant on the optical properties of ZnS was studied. The size of quantum dots was determined to be about 1nm, using scanning tunneling microscopy. The synthesized nanoparticles were characterized by X-ray diffraction, UV-Vis absorption and photoluminescence emission spectroscopies. The presence and amount of iron impurity in the structure of Zn((1-x))Fe(x)S nanocrystals were confirmed by atomic absorption spectrometry. A blue shift in band-gap of ZnS was observed upon increasing incorporation of Fe(3+) ion in the iron doped zinc sulfide quantum dots. The photoluminescence investigations showed that, in the case of iron doped ZnS nanoparticles, the emission band of pure ZnS nanoparticles at 427nm shifts to 442nm with appearance of a new sharp emission band around 532nm. The X-ray diffraction analysis indicated that the iron doped nanoparticles are crystalline, with cubic zinc blend structure, having particle diameters of 1.7±022nm. Finally, the interaction of the synthesized nanoparticles with bovine serum albumin was investigated at pH 7.2. The UV-Vis absorption and fluorescence spectroscopic methods were applied to compare the optical properties of pure and iron doped ZnS quantum dots upon interaction with BSA. It was proved that, in both cases, the fluorescence quenching of BSA by the quantum dots is mainly a result of the formation of QDs-BSA complex in solution. In the steady-state fluorescence studies, the interaction parameters including binding constants (K(a)), number of binding sites (n), quenching constants ( [Formula: see text] ), and bimolecular quenching rate constants (k(q)) were determined at three different temperatures and the results were then used to evaluate the corresponding thermodynamic parameters ΔH, ΔS and ΔG.