Publications by authors named "Shokoofeh Maghari"

5 Publications

  • Page 1 of 1

Modifying Superparamagnetic Iron Oxide and Silica Nanoparticles Surfaces for Efficient (MA)LDI-MS Analyses of Peptides and Proteins.

Rapid Commun Mass Spectrom 2021 Oct 18:e9212. Epub 2021 Oct 18.

Department of Phytochemistry, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Tehran, Iran.

Rationale: Surface functionalization is considered as the foundation of developing nanomaterial applications in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analyses. However, the surface properties of nanostructures can influence their interaction with analyte and consequently mass data. In the present study, functionalized nanoparticles (NPs) were used for MALDI-MS and laser desorption/ionization mass spectrometry (LDI-MS) experiments in order to evaluate the effect of the surface properties of NPs on tailoring the intensity of mass signals.

Methods: Regarding the LDI-MS analyses, the surface of superparamagnetic iron oxide nanoparticles (SPIONs) was coated with nitrosonium tetrafluoroborate, citric acid, nitrodopamin, and gallic acid. Additionally, the SPIONs were applied as a matrix for analyzing three small peptides. In the MALDI-MS analyses, silica NPs were selected as co-matrix and functionalized with cysteine, sulfobetaine, and amine alkoxysilanes. Then, the silica NPs were utilized as additives in the MALDI-MS samples of four proteins in a mass range between ~2000 and 60000 Da.

Results: The results of LDI-MS analyses demonstrated more than one order enhancement in the signal intensity of analytes based on the amount of electrostatic interaction and laser energy absorption by the surface ligands. However, those of MALDI-MS experiments indicated a significant signal improvement when achieving the colloidal stability of silica NPs in the matrix solution.

Conclusions: Based on the results, the surface properties of NPs affected the (MA)LDI-MS analyses indispensably. Finally, the functionalization of SPIONs represented a new model for the future development of NPs with both affinity and enhanced ionization abilities in mass spectrometry.
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http://dx.doi.org/10.1002/rcm.9212DOI Listing
October 2021

Enantioseparation of mandelic acid on vancomycin column: Experimental and docking study.

Chirality 2020 11 14;32(11):1289-1298. Epub 2020 Aug 14.

Medicinal Plants and Drug Research Institute, Shahid Beheshti University, Evin, Tehran, Iran.

So far, no detailed view has been expressed regarding the interactions between vancomycin and racemic compounds including mandelic acid. In the current study, a chiral stationary phase was prepared by using 3-aminopropyltriethoxysilane and succinic anhydride to graft carboxylated silica microspheres and subsequently by activating the carboxylic acid group for vancomycin immobilization. Characterization by elemental analysis, Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance, and thermogravimetric analysis demonstrated effective functionalization of the silica surface. R and S enantiomers of mandelic acid were separated by the synthetic vancomycin column. Finally, the interaction between vancomycin and R/S mandelic acid enantiomers was simulated by Auto-dock Vina. The binding energies of interactions between R and S enantiomers and vancomycin chiral stationary phase were different. In the most probable interaction, the difference in mandelic acid binding energy was approximately 0.2 kcal/mol. In addition, circular dichroism spectra of vancomycin interacting with R and S enantiomers showed different patterns. Therefore, R and S mandelic acid enantiomers may occupy various binding pockets and interact with different vancomycin functions. These observations emphasized the different retention of R and S mandelic acid enantiomers in vancomycin chiral column.
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http://dx.doi.org/10.1002/chir.23273DOI Listing
November 2020

A click tyrosine zwitterionic stationary phases for hydrophilic interaction liquid chromatography.

J Chromatogr A 2020 Jun 13;1621:461045. Epub 2020 Mar 13.

Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, G.C., Evin, Tehran, Iran. Electronic address:

New zwitterionic (ZIC) stationary phases (SPs) are synthesized with the click and conventional bonding of tyrosine to silica gel. Infrared spectra and elemental analysis demonstrate the successful click and conventional bonding of this ZIC group on silica particles by the surface coverage including 2.36 and 0.75 µm m, respectively. Given the above-mentioned explanation, the present study evaluated the retention mechanism and chromatographic manners of polar compounds on these new materials under hydrophilic interaction liquid chromatography (HILIC) conditions. Based on the results, the Click-Tyrosine Stationary Phase provided good HILIC characteristics when it was applied to separate phenolic compounds, amino acids, alkaloids, and nucleobases compared to bare silica gel SP and even conventional tyrosine SPs. Further, this new Click-Tyrosine-SP represented appropriate HILIC features and column efficiency (the theoretical plate number was up to 50,000 plates m for thebaine). Furthermore, the study investigated the effect of solute polarity (the number of the hydroxyl group of phenolic compounds) and hydrophobicity (the number of the side chain of aliphatic amino acids) on retention behaviors. Finally, some important factors were studied as the potential variables for guiding the retention behavior of the polar compound in HILIC condition including solvent composition, salt concentration, and the buffer pH of the mobile phase.
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http://dx.doi.org/10.1016/j.chroma.2020.461045DOI Listing
June 2020

Bypassing Protein Corona Issue on Active Targeting: Zwitterionic Coatings Dictate Specific Interactions of Targeting Moieties and Cell Receptors.

ACS Appl Mater Interfaces 2016 Sep 25;8(35):22808-18. Epub 2016 Aug 25.

Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences , Tehran, Iran.

Surface functionalization strategies for targeting nanoparticles (NP) to specific organs, cells, or organelles, is the foundation for new applications of nanomedicine to drug delivery and biomedical imaging. Interaction of NPs with biological media leads to the formation of a biomolecular layer at the surface of NPs so-called as "protein corona". This corona layer can shield active molecules at the surface of NPs and cause mistargeting or unintended scavenging by the liver, kidney, or spleen. To overcome this corona issue, we have designed biotin-cysteine conjugated silica NPs (biotin was employed as a targeting molecule and cysteine was used as a zwitterionic ligand) to inhibit corona-induced mistargeting and thus significantly enhance the active targeting capability of NPs in complex biological media. To probe the targeting yield of our engineered NPs, we employed both modified silicon wafer substrates with streptavidin (i.e., biotin receptor) to simulate a target and a cell-based model platform using tumor cell lines that overexpress biotin receptors. In both cases, after incubation with human plasma (thus forming a protein corona), cellular uptake/substrate attachment of the targeted NPs with zwitterionic coatings were significantly higher than the same NPs without zwitterionic coating. Our results demonstrated that NPs with a zwitterionic surface can considerably facilitate targeting yield of NPs and provide a promising new type of nanocarriers in biological applications.
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http://dx.doi.org/10.1021/acsami.6b05099DOI Listing
September 2016

Synthesis of functionalized pseudopeptides through five-component sequential Ugi/nucleophilic reaction of N-substituted 2-alkynamides with hydrazides.

J Org Chem 2013 Jul 20;78(13):6450-6. Epub 2013 Jun 20.

Peptide Chemistry Research Center, K. N. Toosi University of Technology, P.O. Box 15875-4416 Tehran, Iran.

Five-component sequential Ugi/nucleophilic addition reaction of aromatic aldehydes, primary amines, propiolic acid, isocyanides, and hydrazides has been developed in order to access polyfunctional pseudopeptides. The reaction may proceed through formation of N-substituted 2-alkynamides as intermediates. This process is found to be mild and operationally simple with broad substrate scope.
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http://dx.doi.org/10.1021/jo4003294DOI Listing
July 2013
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