Drug-loaded polymer-coated silver nanoparticles for lung cancer theranostics.

Lung cancer is the leading cause of death in cancer across the globe. To minimize these deaths, the replacement of traditional chemotherapy with novel strategies is significant. We have developed a nanotheranostic approach using silver nanoparticles for imaging and treatment. Silver nanoparticles (AgNPs) are fabricated by chemical reduction method. The formulation of AgNPs was confirmed by different characterization techniques like stability test, UV-Visible spectroscopy, Confocal Raman Spectroscopy, and Energy-Dispersive X-ray analysis. Further, AgNPs are coated with poly lactic-co-glycolic acid (PLGA) and then loaded with paclitaxel (Pac). Then the drug-loaded PLGA-coated AgNPs were characterized for size and zeta potential measurement by zetasizer, surface morphology study by atomic force microscopy, Fourier transform infrared spectroscopy, and release kinetics study. The imaging and anticancer properties of these nanoformulations are investigated using lung cancer cell lines. The results proved that the particles are in the nanometer range with smooth surface morphology. Moreover, the drug-loaded NPs showed a sustained release of the drug for a longer period of time. Further the formulations showed imaging property with greater anticancer efficacy. Thus, the results suggest the effective use of these nanoformulation in both lung cancer imaging and treatment using a simple and efficient approach.

Probing the Impact of Tribolayers on Enhanced Wear Resistance Behavior of Carbon-Rich Molybdenum-Based Coatings.

Minimizing friction and wear is one of the continuing challenges in many mechanical industries. Recent research efforts have been focused on accelerating the antifriction and antiwear properties of hard coatings through the incorporation of self-lubricant materials or the development of new architectures. In this present study, carbon-rich MoC, MoCN, and multilayer MoC/MoCN coatings were deposited using reactive magnetron sputtering. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were used to evaluate their properties, which revealed the presence of ceramic cubic crystallites, covalent bonds between primary elements, and an excess of amorphous carbon (a-C) in all of the coatings. The multilayer architecture and possible segregation of a-C around the ceramic crystallites resulted in improved mechanical properties for all coatings, with MoC/MoCN coatings having a maximum hardness of 21 GPa and elastic modulus of 236 GPa. Friction and wear behavior are initially determined by the structural-composition-property relationships of the respective coatings; later, the tribological characteristics are altered depending on the nature of tribolayer on both mating surfaces at the contact interface. The highest wear resistance of multilayer MoC/MoCN coating (8.7 × 10-8 mm3/N m) and MoC coating (3.9 × 10-7 mm3/N m) was due to the dissipation of contact stress by the tribofilm consisting of carbon tribo products like graphitic sp2 carbon, diamond-like sp3 carbon, and pyrrolic-N. On the other hand, MoCN coating depicted a lower wear resistance due to the frequent termination of C-H bonds by N, which restricts the strong formation of tribofilms as well as poor mechanical properties.

Synthesis and Biological Assessment of Pyrrolobenzoxazine Scaffold as a Potent Antioxidant.

Reduction of mitochondrial oxidative stress-mediated diseases is an important pharmaceutical objective in recent biomedical research. In this context, a series of novel pyrrolobenzoxazines (PyBs) framework with enormous diversity (compounds 5a-w) was synthesized by employing a low-temperature greener pathway, and antioxidant property of the synthesized compounds was successfully demonstrated on preclinical model goat heart mitochondria, in vitro. Copper-ascorbate (Cu-As) was utilized as an oxidative stress generator. Out of screened PyBs, the compound possessing -OH and -OMe groups on benzene nucleus along with pyrrolobenzoxazine core moiety (compound 5w) displayed magnificent antioxidant property with a minimum effective dose of 66 µM during the biochemical assessment. The ameliorative effect of synthesized pyrrolobenzoxazine moiety on levels of biomarkers of oxidative stress, antioxidant enzyme, activities of Krebs cycle and respiratory chain enzymes, mitochondrial morphology, and Ca2+ permeability of mitochondrial membrane was investigated in the presence of Cu-As. Furthermore, the binding mode of Cu-As by compound 5w was explored successfully using isothermal titration calorimetry (ITC) analysis.

A novel tryptamine-appended rhodamine-based chemosensor for selective detection of Hg2+ present in aqueous medium and its biological applications.

A novel rhodamine-tryptamine conjugate-based fluorescent and chromogenic chemosensor (RTS) for detection of Hg2+ present in water was reported. After gradual addition of Hg2+ in aqueous methanol solution of RTS, a strong orange fluorescence and deep-pink coloration were observed. The probe showed high selectivity towards Hg2+ compared to other competitive metal ions. The 1:1 binding stoichiometry between RTS and Hg2+ was established by Job's plot analysis and mass spectroscopy. Initial studies showed that the synthesized probe RTS possessed fair non-toxicity and effectively passed through cell walls of model cell systems, viz., human neuroblastoma (SHSY5Y) cells and cervical cells (HeLa) to detect intercellular Hg2+ ions, signifying its utility in biological system. The limit of detection (LOD) was found to be 2.1 nM or 0.42 ppb by fluorescence titration. Additionally, the potential relevance of synthesized chemosensor for detecting Hg2+ ions in environmental water samples has been demonstrated. Graphical abstract ᅟ.

Development of a Ru Nanoparticle Loaded Thiol Functionalized Meso Porous Silica Modified Screen Printed Au Electrode for Electrochemical Detection and Estimation of Glucose.

Here we report the development of a glucose sensor based on electrochemical detection. The working electrode was a screen printed Au electrode, which was modified with Ru nanoparticle loaded thiol functionalized mesoporous silica. This sensor demonstrated its capability of detecting and estimating glucose concentration in aqueous medium over a wide range of concentration with high sensitivity, durability and reproducibility.

Preparation of Ru Nanocatalysts Supported on SBA-15 and Their Excellent Catalytic Activity Towards Decolorization of Various Dyes.

In this paper, we report a simple aqueous solution based chemical method for preparation Ru nanocatalysts supported on mesoporous silica SBA-15 (Ru@SBA-15) catalysts. Synthesized catalysts were characterized by powder X-ray diffraction (XRD), Optical emission spectroscopy (ICP-OES), Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscope (HRTEM) and N2 adsorption-desorption surface area and pore size analyzer, and particle size analyzer. Catalytic activity of the synthesized catalysts towards decolorization of various dyes, such as 4-nitrophenol, Methyl Orange, Congo Red, Rhodamine B, Methylene Blue and mixture of dyes was investigated in presence of excess NaBH4. Catalysis reactions were monitored by employing UV-vis spectroscopy. Catalysis reactions followed pseudo-first order rate equation. The catalyst with 2.5 wt% Ru nanoparticle exhibited excellent catalytic activity and convenient recycling. The high catalytic activity and simple preparation methodology make 2.5Ru@SBA-15 an attractive catalyst for decolorization of organic dyes.

One-Pot Synthesis of (NiFe2O4)x-(SrFe12O19)1-x Nanocomposites and Their Microwave Absorption Properties.

In this paper, we report a simple but novel aqueous solution based 'one-pot' method for preparation of (NiFe2O4)x-(SrFe12O19)1-x nanocomposites consist of hard ferrite-soft ferrite phases. A physical mixing method has also been employed to prepare nanocomposites having same compositions. The effects of synthetic methodologies on the microstructures of the nanocomposites as well as their magnetic and microwave absorption properties have been evaluated. Crystal structures and microstructures of these composites have been investigated by using X-ray diffraction, transmission electron microscope and scanning electron microscope. In the nanocomposites, prepared by both methods, presence of nanocrystalline NiFe2O4 and SrFe12O19 phases was detected. However, nanocomposites, prepared by one-pot method, possessed better homogeneous distribution of hard and soft ferrite phases than the nanocomposites, prepared by physical mixing method. Nanocomposites, prepared by one-pot method, demonstrated significant spring exchange coupling interaction between hard and soft ferrite phases and exhibited magnetically single phase behaviour. The spring exchange coupling interaction enhanced the magnetic properties (high saturation magnetization and coercivity) and microwave absorption properties of the nanocomposites, prepared by one-pot method, in comparison with the nanocomposites prepared by physical mixing method as well as pure NiFe2O4 and SrFe12O19 nanoparticles. Minimum reflection loss of the composite was ~ -17 dB (i.e., 98% absorption) at 8.2 GHz for an absorber thickness of 3.2 mm.

Preparation of TiO2 Nanoparticle Loaded MCM-41 and Study of Its Photo-Catalytic Activity Towards Decolorization of Methyl Orange.

Here we report the synthesis of TiO2 nanoparticle loaded mesoporous MCM-41 photocatalysts for degradation of methyl orange dye in aqueous medium under sunlight exposure. TiO2 loaded MCM-41 was synthesized by impregnation method. Anatase form of TiO2 nanoparticles were formed in the porous matrix of the silicate MCM-41. The synthesized materials were characterized using powder X-ray diffraction method, surface area and porosimetry analysis; diffuse reflectance analysis, particle size analysis and transmission electron microscopy. The photocatalytic property of the synthesized materials were investigated towards the degradation of methyl orange under sunlight exposure and monitored by UV-visible spectrophotometer. Synthesized catalysts showed high photocatalytic activity for the degradation of methyl orange.

Biosynthesis of fluorescent gold nanoparticles using an edible freshwater red alga, Lemanea fluviatilis (L.) C.Ag. and antioxidant activity of biomatrix loaded nanoparticles.

Biosynthesis of gold nanoparticles has been accomplished via reduction of an aqueous chloroauric acid solution with the dried biomass of an edible freshwater epilithic red alga, Lemanea fluviatilis (L.) C.Ag., as both reductant and stabilizer. The synthesized nanoparticles were characterized by UV-visible, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), and dynamic light scattering (DLS) studies. The UV-visible spectrum of the synthesized gold nanoparticles showed the surface plasmon resonance (SPR) at around 530 nm. The powder XRD pattern furnished evidence for the formation of face-centered cubic structure of gold having average crystallite size 5.9 nm. The TEM images showed the nanoparticles to be polydispersed, nearly spherical in shape and have sizes in the range 5-15 nm. The photoluminescence spectrum of the gold nanoparticles excited at 300 nm showed blue emission at around 440 nm. Gold nanoparticles loaded within the biomatrix studied using a modified 2,2-diphenyl-1-picrylhydrazyl (DPPH) method exhibited pronounced antioxidant activity.