Fabrication and Characterization of a Biomaterial Based on Extracellular-Vesicle Functionalized Graphene Oxide

Mesenchymal stem cell (MSC) derived extracellular vesicles (EV) are emerging as acellular therapeutics for solid organ injury and as carriers for drug delivery. Graphene-based materials are novel two-dimensional crystal structure-based materials with unique characteristics of stiffness, strength and elasticity that are being explored for various structural and biological applications. We fabricated a biomaterial that would capture desirable properties of both graphene and stem cell derived EV. Metabolically engineered EV that express azide groups were cross-linked with alkyne-functionalized graphene oxide (GO) via a copper catalyzed alkyne-azide cycloaddition (CuAAC) reaction. The crosslinking between EV and GO was accomplished without the need for ligand expression on the metal. Scanning electron and fluorescence microscopy demonstrated excellent cross-linking between EV and GO. Biological effects were assessed by phagocytosis studies and cell viability studies. The uptake of GO or sonicated GO (sGO) resulted in a durable pro-inflammatory immune response. Cell studies further showed that crosslinked GO-EV scaffolds exhibited cell-type dependent cytotoxicity on liver cancer cells whereas there was minimal impact on healthy hepatocyte proliferation. In vitro, neither GO-EV nor sGO-EV induced DNA strand breaks. In vivo studies in zebrafish revealed gross developmental malformations but treatment-induced mortality was only seen with the highest doses of GO-EV and sGO-EV. With these advantages, this engineered biomaterial combining the versatility of graphene with the therapeutic effects of MSC-EV has potential for applications in tissue engineering and regenerative medicine

A water soluble Al3+ selective colorimetric and fluorescent turn-on chemosensor and its application in living cell imaging

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A ratiometric fluorescent chemosensor for iron: discrimination of Fe2+ and Fe3+ and living cell application

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Fluoride selective chemosensor derived from vitamin B₆ cofactor pyridoxal

619-625An easy-to-prepare and non-cytotoxic Schiff base receptor (L) is synthesized by condensation of pyridoxal with aniline. The anion sensing ability of L is explored by naked-eye, UV-vis and fluorescence methods. The receptor L shows a high selectivity and sensitivity for the sensing of fluoride anion among the other tested competitive anions. The sensor L shows both naked-eye detectable color change and significant ‘turn-on’ fluorescence at 550 nm in the presence of F- with the detection limit as low as 0.4 mM. The fluoride recognition by L is supported by 1H NMR and DFT data. The detection of cytoplasmic fluoride was tested in human cancer cell HeLa through fluorescence imaging

Efficient and Convenient Methods for Synthesis of Some Phthalazine Derivatives and Their Evaluation of Cytotoxicity

<div><p></p><p>A systematic study of the reaction of 1,4-dihydrazinophthalazine (DHPH) with 1,3-dicarbonyls [<i>viz.</i>, acetylacetone (acac), dibenzoylmethane (bzbz), and 1-benzoylacetone (bzac)] varying the reaction conditions was carried out to obtain the phthalazine derivatives (<b>1</b>–<b>4</b>). One-pot reaction of DHPH with acac led to the formation of two compounds <b>1</b> and <b>2</b>, with various factors such as the presence of the acid or base, amount of the acac, time of reflux, and the temperature. The reaction conditions of DHPH with bzbz or bzac are sort of different to isolate the products <b>3</b> and <b>4</b>, respectively. The derivatives (<b>1</b>–<b>4</b>) have been characterized by elemental analyses, ¹H NMR, and electrospray ionization–mass spectrometry (ESIMS) and the cytotoxic activity of the compounds <b>1</b>–<b>4</b> was evaluated on HeLa cell line.</p> <p>[Supplementary materials are available for this article. Go to the publisher's online edition of <i>Synthetic Communications</i>® for the following free supplemental resource(s): Full experimental and spectral details.]</p> </div

Ruthenium(II) complexes of pyrrol-azo ligands: cytotoxicity, interaction with calf thymus DNA and bovine serum albumin

Two ruthenium(II) complexes of newly designed pyrrol-azo ligands(L) and bipyridine(bpy) formulated as [Ru(L)(bpy)2]ClO4, where HL1 = (4-chloro-phenyl)-(1H-pyrrol-2-yl)-diazene (1) complex 1 and HL2 = (4-nitro-phenyl)-(1H-pyrrol-2-yl)-diazene for 2, were isolated in pure form. The complexes were characterized by physicochemical and spectroscopic methods. The electrochemical behavior of the complexes showed the Ru(III)/Ru(II) couple at different potentials with quasi-reversible voltammograms. The study of cytotoxicity effects of 1 and 2 on human breast cancer cells (MCF 7, MDA-MB 231) and cervical cancer cell (HeLa) taking Cisplatin as a positive reference showed that 1 exhibited higher cytotoxicity against cancer cell lines than 2, but less activity than Cisplatin. The interaction of 1 with calf thymus DNA (CT-DNA) using absorption, emission spectral studies, viscosity-measurement, and electrochemical techniques has been used to determine the binding constant Kb and the linear Stern\u2013Volmer quenching constant KSV. The results indicate that 1 strongly interacts with CT-DNA in groove binding mode. The interaction of bovine serum albumin (BSA) with 1 was also investigated with the help of spectroscopic tools. Absorption spectroscopy proved the formation of a BSA-[Ru(L1)(bpy)2]ClO4 complex