Kharazmi University

About: Kharazmi University is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Membrane & Supply chain. The organization has 3395 authors who have published 5321 publications receiving 45645 citations. The organization is also known as: Tarbiat Moallem University of Tehran & Teacher Training University.

Definitive endoderm differentiation of human-induced pluripotent stem cells using signaling molecules and IDE1 in three-dimensional polymer scaffold.

Abstract: Human-induced pluripotent stem cells (hiPSCs) are considered to be potentially able to differentiate into all human cell lineages and thus hold promise as an unlimited source for cell replacement therapies in clinical applications. Definitive endoderm (DE) formation is the first and crucial step in the development of visceral organs such as liver, lung, pancreas and so forth. Therefore, efficient generation of DE cells ensures the efficient generation of eventual target cells used in cell therapy. In the present study, Matrigel-coated poly(lactic acid)/gelatin (PLA/gelatin) nanofibrous scaffolds were utilized to investigate the proliferation and differentiation of hiPSCs into DE cells. Analyses of DE-specific markers including Sox17, FoxA2, and Gooscoid (Gsc) genes revealed higher levels of mRNA and protein expression in the differentiated hiPSCs cells cultured on PLA/gelatin scaffolds than cells differentiated in two-dimensional (2D) culture. Our results showed that three-dimensional (3D) cultures could significantly promote DE differentiation in comparison with 2D culture. Also using small molecules such as inducer of definitive endoderm 1 (IDE1) and signaling molecules such as Activin A and Wnt3a could enhance the DE differentiation of hiPSCs with Activin A/Wnt3a being significantly more potent in both 2D and 3D cultures compared to IDE1. The results of this study may have impact in tissue engineering and cell replacement therapy of visceral organs-related diseases.

Preparation of nanostructured magnetite with plasma for degradation of a cationic textile dye by the heterogeneous Fenton process

Abstract: The surface and catalytic properties of natural magnetite were modified using plasma treatment, and were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, N 2 adsorption–desorption, and scanning electron microscopy. The results show the production of nanostructured magnetite, from its natural particles, with an average diameter in the range of 20–40 nm. The application of nanostructured magnetite in a heterogeneous Fenton process was investigated in the degradation of Basic Blue 3 (BB3) as a model pollutant in aqueous solution. The effects of operational parameters were studied with respect to decolorization efficiency. The application of a nanostructured magnetite catalyst allows the Fenton process to be operated at milder pH conditions (a pH of 5). A decolorization efficiency of 96% in the presence of plasma-treated magnetite was approximately two times higher than that of untreated magnetite. Negligible iron leaching and a simple separation of used catalyst using an external magnetite field are merits of using plasma-treated magnetite in heterogeneous Fenton process.

A quantum dot-based fluorescence sensor for sensitive and enzymeless detection of creatinine

Abstract: In this paper, we report a novel “turn-on” fluorescence sensor for selective and sensitive determination of creatinine (Crn) in human serum and urine samples, using thioglycolic acid (TGA) capped ZnS:Mn/ZnS quantum dots (QDs). TGA capped ZnS:Mn/ZnS QDs have been synthesized via a facile aqueous co-precipitation method and characterized by fluorescence, UV-vis absorption, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS) measurements and energy-dispersive X-ray spectroscopy (EDS). The fluorescence emission spectrum of TGA functionalized ZnS:Mn/ZnS QDs showed a significant increase in emission intensity in the presence of Crn. The enhancement in emission is due to passivation of the surface trap states of QDs through the binding of Crn with the QD surface, which results in the formation of new radiative electron–hole recombination centers. The interaction between Crn and QDs was investigated by some analytical techniques such as fluorescence, UV-vis spectroscopy and DLS measurements. Under the optimum conditions the probe offers a good linear relationship between 0.07 and 3.4 μM for Crn with the correlation coefficient (R2) of 0.9963 and limit of detection (LOD) and limit of quantification (LOQ) of 7.25 nM and 0.0242 μM, respectively. The method was successfully employed for the analysis of the Crn content in human serum and urine. The proposed method demonstrated several advantages such as high sensitivity, short analysis time, low cost and ease of operation.