Effect of Cold Atmospheric Plasma Jet and Gamma Radiation Treatments on Gingivobuccal Squamous Cell Carcinoma and Breast Adenocarcinoma Cells

Surgery, chemotherapy and radiotherapy, the conventional treatment modalities of cancer though successful are limited by presence of residual tumor cells, toxic side-effects and treatment resistance, thus raising the need for investigating other novel approaches. Here, we have used a cold atmospheric plasma (CAP) jet and assessed the in vitro efficacy in gingivobuccal squamous cell carcinoma (GB-SCC) – ITOC-03, breast adenocarcinoma—MCF7 and HEK293 cells. Cells lines were subjected to varying doses of ionizing radiation (0, 2, 4, 6, 8 Gy) and CAP jet treatment (0, 60, 180, 240, 300 s). CAP jet treatment showed time dependent increase in H₂O₂ and NO₂^? concentration. Cell viability assay showed potent effect of CAP jet on all three cell lines in comparison to radiation treatment, while helium gas treatment showed minimal inhibitory effect. Irradiated, CAP jet and helium gas treated cells showed loss of nucleic acid features, 788 cm^?1 and 1340 cm^?1 in Raman spectra, indicating DNA damage. Principal Component Analysis (PCA) showed distinct classification of CAP-treated and control cells, while Principal Component – Linear Discriminant Analysis (PC-LDA) based classification of Raman spectra showed ITOC-03 and HEK293 cells to be sensitive to CAP jet and radiation treatment in comparison to MCF7 cells. Collectively, cell viability assay and Raman spectroscopy have shown potent effect of CAP jet in GB-SCC and breast adenocarcinoma cells.

     

Order-Unity 13C Nuclear Polarization of [1-13C]Pyruvate in Seconds and the Interplay of Water and SABRE Enhancement

Signal Amplification By Reversible Exchange in SHield Enabled Alignment Transfer (SABRE-SHEATH) is investigated to achieve rapid hyperpolarization of ¹³C₁ spins of [1-¹³C]pyruvate, using parahydrogen as the source of nuclear spin order. Pyruvate exchange with an iridium polarization transfer complex can be modulated via a sensitive interplay between temperature and co-ligation of DMSO and H₂O. Order-unity ¹³C (>50 %) polarization of catalyst-bound [1-¹³C]pyruvate is achieved in less than 30 s by restricting the chemical exchange of [1-¹³C]pyruvate at lower temperatures. On the catalyst bound pyruvate, 39 % polarization is measured using a 1.4 T NMR spectrometer, and extrapolated to >50 % at the end of build-up in situ. The highest measured polarization of a 30-mM pyruvate sample, including free and bound pyruvate is 13 % when using 20 mM DMSO and 0.5 M water in CD₃OD. Efficient ¹³C polarization is also enabled by favorable relaxation dynamics in sub-microtesla magnetic fields, as indicated by fast polarization buildup rates compared to the T₁ spin-relaxation rates (e. g., ∼0.2 s⁻¹ versus ∼0.1 s⁻¹, respectively, for a 6 mM catalyst-[1-¹³C]pyruvate sample). Finally, the catalyst-bound hyperpolarized [1-¹³C]pyruvate can be released rapidly by cycling the temperature and/or by optimizing the amount of water, paving the way to future biomedical applications of hyperpolarized [1-¹³C]pyruvate produced via comparatively fast and simple SABRE-SHEATH-based approaches.     

Raman Imaging: An Impending Approach Towards Cancer Diagnosis

In accordance with the recent studies, Raman spectroscopy is well experimented as a highly sensitive analytical and imaging technique in biomedical research, mainly for various disease diagnosis including cancer. In comparison with other imaging modalities, Raman spectroscopy facilitate numerous assistances owing to its low background signal, immense spatial resolution, high chemical specificity, multiplexing capability, excellent photo stability and non-invasive detection capability. In cancer diagnosis Raman imaging intervened as a promising investigative tool to provide molecular level information to differentiate the cancerous vs non-cancerous cells, tissues and even in body fluids. Anciently, spontaneous Raman scattering is very feeble due to its low signal intensity and long acquisition time but new advanced techniques like coherent Raman scattering (CRS) and surface enhanced Raman scattering (SERS) gradually superseded these issues. So, the present review focuses on the recent developments and applications of Raman spectroscopy-based imaging techniques for cancer diagnosis.     

Scanning tunneling microscopy/spectroscopy on Au nanoparticles assembled using lauryl amine (LAM) and octadecane thiol (ODT)

In this report, we demonstrate scanning tunneling microscopy and spectroscopy on thin films of lauryl amine (LAM) and octadecane thiol (ODT) protected gold nanoparticles. We show that the zero current in the I-V curves (measure of Coulomb blockade (CB) of the nanoparticles) depends on the properties of the spacer molecule. In both the cases the gap voltage and the tunneling current at which the images are obtained are quite different which is further confirmed from the fitting performed based on the orthodox theory. The values for the capacitance and charging energy obtained from the fitting for ODT capped particles are comparable to the values obtained using spherical capacitor model. In contrast, values of these parameters were found to differ for LAM capped nanoparticles. While imaging, ODT capped nanoparticles were observed to drag along the scan direction leading to ordering of particles. Images of LAM capped gold nanoparticles show local ordering in self-assembly of particles although no evidence of large scale ordering in spatial Fourier transform was seen. These observations suggest that nanoparticles with larger CB would be imaged nonevasively in contrast to small CB systems for which tip induced effects will be dominant. In both the systems the current was found to rise faster than theoretical curves based on the orthodox theory suggesting that mechanism of charge transfer in this case may involve field emission rather than tunneling through a rectangular barrier. An attempt has been made to explain charge transfer based on Fowler-Nordheim (F-N) plots of the I-V curves.     

Synthesis,antioxidant activity,and α-glucosidase enzyme inhibition of α-aminophosphonate derivatives bearing piperazine-1,2,3-triazole moiety

A novel series of piperazine-1,2,3-triazole bearing dimethyl(((2-(4-((1H-1,2,3-triazole-4-yl)methyl)piperazin-1-yl)ethylamino)(2-hydroxyaryl)methyl)phosphonate derivatives have been prepared via copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) (Click Reaction) and Schiff base reactions. The synthesized compounds were confirmed by spectral characterization (¹H, ¹³C and ³¹P NMR, and mass). The title compounds were evaluated for in vitro alpha glucosidase enzyme inhibition and in vitro antioxidant activity using DPPH and H₂O₂ methods.     

Brønsted acid catalyzed synthesis of 2-aryl-quinazolinones via cyclization of 2-aminobenzamide with benzonitriles in PEG

A simple and efficient Brønsted acid catalyzed synthesis of 2-aryl-quinazolinones via cyclization of 2-aminobenzamides with benzonitrile in PEG under metal and ligand-free condition. All substituted benzonitriles were also well participated with the formation of the corresponding products in moderate to good yields.     

Kinetics of thermal decomposition of a synthetic K–H3O jarosite analog

The thermal decomposition kinetics of a synthetic K–H₃O jarosite analog was determined from thermogravimetric analysis at various heating rates in air. A thermal decomposition mechanism was proposed based on X-ray analysis of partially decomposed material and distinct features observed during thermal decomposition analysis. The decomposition path is complex. The material was treated as a composite of K-jarosite, H₃O-jarosite, and a “vacancy component”. The evolution of (OH)^? and SO₃ from these individual components was modeled. The decomposition is broken into subreactions according to distinct features in the thermoanalytical measurements. The subreactions are arranged sequentially and in parallel according to the evolution of the participating phases. A set of associated apparent activation energies was determined using isoconversion analysis. Kinetic triplets were assigned to each subreaction. A reasonable match with the observed decomposition was achieved by varying pre-exponential factors.     

Serendipitous Discovery of a Potent Influenza Virus A Neuraminidase Inhibitor

We have previously reported a potent neuraminidase inhibitor that comprises a carbocyclic analogue of zanamivir in which the hydrophilic glycerol side chain is replaced by the hydrophobic 3‐pentyloxy group of oseltamivir. This hybrid inhibitor showed excellent inhibitory properties in the neuraminidase inhibition assay (K_i=0.46 nM ; K_{i (zanamivir)}=0.16 nM ) and in the viral replication inhibition assay in cell culture at 10^?8 M . As part of this lead optimization, we now report a novel spirolactam that shows comparable inhibitory activity in the cell culture assay to that of our lead compound at 10^?7 M . The compound was discovered serendipitously during the attempted synthesis of the isothiourea derivative of the original candidate. The X‐ray crystal structure of the spirolactam in complex with the N8 subtype neuraminidase offers insight into the mode of inhibition.     

Self‐Assembly of DNA–Oligo(p‐phenylene‐ethynylene) Hybrid Amphiphiles into Surface‐Engineered Vesicles with Enhanced Emission

Surface‐addressable nanostructures of linearly π‐conjugated molecules play a crucial role in the emerging field of nanoelectronics. Herein, by using DNA as the hydrophilic segment, we demonstrate a solid‐phase “click” chemistry approach for the synthesis of a series of DNA–chromophore hybrid amphiphiles and report their reversible self‐assembly into surface‐engineered vesicles with enhanced emission. DNA‐directed surface addressability of the vesicles was demonstrated through the integration of gold nanoparticles onto the surface of the vesicles by sequence‐specific DNA hybridization. This system could be converted to a supramolecular light‐harvesting antenna by integrating suitable FRET acceptors onto the surface of the nanostructures. The general nature of the synthesis, surface addressability, and biocompatibility of the resulting nanostructures offer great promises for nanoelectronics, energy, and biomedical applications.