Anser Ali

Facile synthesis, cytotoxicity and bioimaging of Fe3+ selective fluorescent chemosensor

The designing and development of fluorescent chemosensors have recently been intensively explored for sensitive and specific detection of environmentally and biologically relevant metal ions in aqueous solution and living cells. Herein, we report the photophysical results of alanine substituted rhodamine B derivative 3 having specific binding affinity toward Fe(3+) with micro molar concentration level. Through fluorescence titration at 599nm, we were confirmed that ligand 3 exhibited ratiometric fluorescence response with remarkable enhancement in emission intensity by complexation between 3 and Fe(3+) while it appeared no emission in case of the competitive ions (Sc(3+), Yb(3+), In(3+), Ce(3+), Sm(3+), Cr(3+), Sn(2+), Pb(2+), Ni(2+), Co(2+), Cu(2+), Ba(2+), Ca(2+), Mg(2+), Ag(+), Cs(+), Cu(+), K(+)) in aqueous/methanol (60:40, v/v) at neutral pH. However, the fluorescence as well as colorimetric response of ligand-iron complex solution was quenched by addition of KCN which snatches the Fe(3+) from complex and turn off the sensor confirming the recognition process was reversible. Furthermore, bioimaging studies against L-929 cells (mouse fibroblast cells) and BHK-21 (hamster kidney fibroblast), through confocal fluorescence microscopic experiment indicated that ligand showed good permeability and minimum toxicity against the tested cell lines.

Controlling conductivity of carbon film for L-929 cell biocompatibility using magnetron sputtering plasmas

As a material of current interest compatible with many living organisms, carbon has received considerable attention for applications in medicine. To improve and investigate the performance and applications of diamond-like carbon (DLC) films for implantable bio-organs, it is important to optimize the synthesis process from the original deposition conditions to control the characterization of DLC. Simultaneously, it is necessary to develop new techniques and processes that yield DLC films with stronger adhesion to the substrate and better biocompatibility. This work investigates the suitability of sputtering plasmas for application of carbon film biocompatibility in cell growth. This work also reports an approach to the study of the biomedical response of the well-characterized carbon films deposited by a DC unbalanced magnetron sputtering system (UBMS). Conductive carbon films are prepared at a working pressure of 3 mTorr, and their properties are studied under different operating conditions by varying the target power density. In the present work, we have used L-929 cells as the biomaterial. The influence of L-929 cells on the carbon films fabricated using closed field UBMS is studied. The data reveal that the change in L-929 cell growth with 1-5 days proliferation is caused by the decreasing electrical resistivity with increasing sp2 bonding structure.

Influence of plasma-activated compounds on melanogenesis and tyrosinase activity

Many organic chemists around the world synthesize medicinal compounds or extract multiple compounds from plants in order to increase the activity and quality of medicines. In this work, we synthesized new eugenol derivatives (ED) and then treated them with an N2 feeding gas atmospheric pressure plasma jet (APPJ) to increase their utility. We studied the tyrosinase-inhibition activity (activity test) and structural changes (circular dichroism) of tyrosinase with ED and plasma activated eugenol derivatives (PAED) in a cell-free environment. Later, we used docking studies to determine the possible interaction sites of ED and PAED compounds with tyrosinase enzyme. Moreover, we studied the possible effect of ED and PAED on melanin synthesis and its mechanism in melanoma (B16F10) cells. Additionally, we investigated the structural changes that occurred in activated ED after plasma treatment using nuclear magnetic resonance (NMR). Hence, this study provides a new perspective on PAED for the field of plasma medicine.

Synthesis, cytotoxicity and bioimaging of a novel Hg2+ selective fluorogenic chemosensor

A rhodamine B derivative 2 with a terminal mercapto thiadiazole moiety was successfully synthesized and applied for selective recognition of Hg2+ in aqueous–acetonitrile (1 : 1, v/v, pH 7) solution by employing its photophysical properties. Low toxicity and precise cell-permeability of the ligand were used to probe in vitro intracellular mercury contamination using L-929 cells (mouse fibroblast cells) and BHK-21 (hamster kidney fibroblast) through a confocal fluorescence microscopic experiment and bio-imaging results showed the equal applicability of the ligand toward both tested cell lines. Meanwhile, it exhibited distinct Hg2+ induced increment in the fluorescence and absorption intensities with induction of an apparent colorimetric change from colorless to reddish pink, providing naked eye mercury detection based on the metal-promoted intramolecular electronic rearrangement in the probe molecule. The probe responds selectively to Hg2+ over various competitive cations (Sc3+, Yb3+, In3+, Ce3+, Sm3+, Cr3+, Sn2+, Pb2+, Fe2+, Ni2+, Co2+, Cu2+, Ba2+, Ca2+, Mg2+, Ag+, Cs+, Cu+, and K+) with marked fluorogenic response and selective colorimetric changes with high sensitivity of 30 nM. We expect that the proposed method will serve as a practical tool for environmental sample analysis and biological studies.

A Novel Approach to Inactivate the Clinical Isolates of Trichophytonmentagrophytes and Trichophyton rubrum by Using Non-Thermal Plasma

In this study, we propose a novel approach that uses non-thermal plasma to inactivate dermatophytes, and we evaluate the antifungal activity of the proposed method using an In vitro infected skin model with clinical isolates of dermatophytes. For this study, a floating electrode-dielectric barrier discharge (FE-DBD) plasma jet was the source for non-thermal plasma, and we investigated its antifungal activity on Trichophyton mentagrophytes (T. mentagrophytes) and Trichophyton rubrum (T. rubrum), two clinical isolates of dermatophytes. These two strains are the most frequently isolated from skin, hair, and nail infections for use in an infected skin model. The results of this study confirm that the FE-DBD plasma jet has statistically significant antifungal activity in saline and in an infected skin model, and after plasma treatment; we also observed a significant inhibition of the growth of the conidia and hypha for both strains in the infected skin mimicking model. In addition, we found a time-dependent correlation between the intracellular reactive species and the fungal cell viabilities after exposure to plasma. These results indicate FE-DBD plasma can inactivate clinically isolated dermatophyte species and suggest that non-thermal plasma may be an effective tool for use in supportive and/or alternative treatments for dermatophytosis.

Optical Properties of Some Novel 2,5-Disubstituted 1,3,4-Oxadiazole Derivatives and their Application as an Efficient Cell Staining Azo Dyes

AbstractA series of six 2,5-disubstituted 1,3,4-oxadiazole derivatives with various length of conjugation have been synthesized and their optical properties including UV-visible absorption spectra, fluorescence emission spectra, molar absorption co-efficient, Stokes shift and the relative fluorescence quantum yield were measured in a variety of organic solvents. Correlation of the absorption spectra and fluorescence emission response of the 2,5-disubstituted 1,3,4-oxadiazole derivatives with the substituent effect revealed that the optical response can easily be tuned toward red shift by increasing conjugation length. The synthesized compounds were further employed in bioimaging assay in order to investigate their potential as an efficient cell staining agent using L-929 cells under confocal fluorescence microscope which showed scrupulous cell permeability and no toxicity as assessed by MTT assay.