Asymmetric Hybrid Polyoxometalates: A Platform for Multifunctional Redox‐Active Nanomaterials

Access to asymmetrically functionalized polyoxometalates is a grand challenge as it could lead to new molecular nanomaterials with multiple or modular functionality. Now, a simple one‐pot synthetic approach to the isolation of an asymmetrically functionalized organic–inorganic hybrid Wells–Dawson polyoxometalate in good yield is presented. The cluster bears two organophosphonate moieties with contrasting physical properties: a chelating metal‐binding group, and a long aliphatic chain that facilitates solvent‐dependent self‐assembly into soft nanostructures. The orthogonal properties of the modular system are effectively demonstrated by controlled assembly of POM‐based redox‐active nanoparticles. This simple, high‐yielding synthetic method is a promising new approach to the preparation of multi‐functional hybrid metal oxide clusters, supermolecular systems, and soft‐nanomaterials.     

Theoretical molecular predictions and antimicrobial activities of newly synthesized molecular hybrids of norfloxacin and ciprofloxacin

Antibiotics such as norfloxacin and ciprofloxacin are used to treat numerous bacterial infections. The present research work involves the molecular prediction, synthesis, characterization and in vitro antimicrobial activities of molecular hybrids of norfloxacin and ciprofloxacin. First set of compounds involve the substitutions of various amines at third position of ciprofloxacin and norfloxacin. On the other hand, second set of molecular hybrids include the substitution of different amines at seventh position along with linker (─COCH₂─). These synthesized compounds were identified by TLC technique and well characterized by various spectroscopic techniques such as IR, NMR, and ESI-MS. Molecular prediction of these newly synthesized compounds have been carried out using the SwissADME, ADMETLab software. Their cytotoxicity parameters have also been studied using Osiris software. It was observed that almost all these molecular hybrids suitable for their drug likeness properties. Further, these newly synthesized compounds were subjected to study their antimicrobial activities in vitro. The third substituted as well as most of seventh substituted molecular hybrids have shown 10-folds increase in their antibacterial activity as compared to the standard drug ciprofloxacin. Some of these compounds have also shown their potency when subjected to study their cytotoxicity test against Escherichia coli AB 1157, proficient to prepare damage in DNA.     

Synthesis of flexible silica aerogels using methyltrimethoxysilane (MTMS) precursor

The experimental results on the synthesis of flexible and superhydrophobic silica aerogels using methyltrimethoxysilane (MTMS) precursor by a two-step (acid-base) sol-gel process followed by the supercritical drying, are reported. The effects of various sol-gel parameters on the flexibility of the aerogels have been investigated. The aerogels of different densities were obtained by varying the molar ratio of MeOH/MTMS (S) from 14 to 35, with lower densities for larger S values. It has been observed that the Young's modulus (Y) decreased from 14.11 x 10(4) to 3.43 x 10(4) N/m(2) with the decrease in the density of the aerogels from 100 to 40 kg/m(3). Simultaneously, the aerogels are superhydrophobic with a contact angle as high as 164 degrees . The superhydrophobic aerogels are thermally stable up to a temperature of 530 K, above which they become hydrophilic. The aerogels have been characterized by bulk density, percentage volume shrinkage, and porosity measurements. The microstructures of the aerogels have been studied using the transmission electron microscopy (TEM). The Young's modulus of the aerogels has been determined by an uniaxial compression test. The variation of physical properties of the aerogels has been explained by taking into consideration the hydrolysis, condensation reactions, the resulting colloidal clusters and their network formation.     

Synthesis and Characterization of <Emphasis Type="Italic">Sygyzium cumini</Emphasis> Nanoparticles for Its Protective Potential in High Glucose-Induced Cardiac Stress: a Green Approach

There exists a complex and multifactorial relationship between diabetes and cardiovascular disease. Hyperglycemia is an important factor imposing damage (glucose toxicity) on cardiac cell leading to diabetic cardiomyopathy. There are substantial clinical evidences on the adverse effects of conventional therapies in the prevention/treatment of diabetic cardiovascular complications. Currently, green-synthesized nanoparticles have emerged as a safe, efficient, and inexpensive alternative for therapeutic uses. The present study discloses the silver nanoparticle biosynthesizing capability and cardioprotective potential of Syzygium cumini seeds already reported to have antidiabetic properties. Newly generated silver nanoparticles S. cumini MSE silver nanoparticles (SmSNPs) were characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), zeta sizer, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Using methanolic extract of S. cumini seeds, an average size of 40–100-nm nanoparticles with 43.02 nm and ?19.6 mV zeta potential were synthesized. The crystalline nature of SmSNPs was identified by using XRD. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) assays revealed the antioxidative potential to be 66.87 (±0.7) % and 86.07 (±0.92) % compared to 60.29 (±0.02) % and 85.67 (±1.27) % for S. cumini MSE. In vitro study on glucose-stressed H9C2 cardiac cells showed restoration in cell size, nuclear morphology, and lipid peroxide formation upon treatment of SmSNPs. Our findings concluded that S. cumini MSE SmSNPs significantly suppress the glucose-induced cardiac stress in vitro by maintaining the cellular integrity and reducing the oxidative damages therefore establishing its therapeutic potential in diabetic cardiomyopathy.     

On the practical aspects of large-scale production of 177Lu for peptide receptor radionuclide therapy using direct neutron activation of 176Lu in a medium flux research reactor: the Indian experience

This paper accentuates on the practical aspects and intricate technicalities involved in the large-scale production of ¹⁷⁷Lu with specific activity >740 GBq mg^?1 following (n,γ)¹⁷⁷Lu route in a medium flux (~1.2 × 10¹⁴ n cm^?2 s^?1 thermal neutron) research reactor. The implication of target burn-up on the specific activity of ¹⁷⁷Lu during irradiation was discussed in detail. ¹⁷⁷Lu obtained from this route has been extensively utilized for targeted therapy in patients with neuroendocrine tumor in India. The important details available from our experience, as well as technical know-how, would be of considerable value for institutions planning to pursue ¹⁷⁷Lu production through (n,γ)¹⁷⁷Lu route.     

Solvent-Tuned Self-Assembled Nanostructures of Chiral l/d-Phenylalanine Derivatives of Protoporphyrin IX

Protoporphyrin IX is a naturally occurring amphiphilic porphyrin with a rigid hydrophobic nonpolar core and two polar propionic acid substitutions on the porphyrin ring. This molecule can be modified on the hydrophilic group, which can lead to strengthened π–π-stacking and spontaneous self-assembly into novel nanostructures. Herein, we use l- phenylalanine and d-phenylalanine to modify protoporphyrin IX, and use the two derivatives for solvophobic-controlled self-assembly. Both derivatives possess two important features: 1) the aromatic core of the porphyrin for dispersive interactions and 2) a chiral amino acid to maximize the influence of chirality on selfassembly. These derivatives lead to the formation of a variety of nanostructure morphologies, such as spheres, nanofibers, lamellar structures, and thread-like and spherical shells. Solution-based self-assembly was determined by UV/Vis, fluorescence, and circular dichroism spectroscopy, and the formed nanostructures were characterized by scanning electron microscopy (SEM). Such engineered porphyrin derivatives could have potential applications in energy transport and storage, supramolecular chemistry, materials science, and medicine.     

Rapid analysis of titer,aggregate, and intact mass of antibody therapeutics using automated multi-dimensional liquid chromatography coupled with native mass spectroscopy

Monoclonal antibodies are tetrameric complex proteins, primarily produced using mammalian cell culture. Attributes such as titer, aggregates, and intact mass analysis are monitored during process development/optimization. In the present study, a novel workflow such that the Protein-A affinity chromatography is performed in the first dimension for purification and titer estimation, whereas size exclusion chromatography is employed in the second dimension to characterize size variants using native mass spectrometry. The present workflow offers a significant advantage over the traditionally used standalone Protein-A affinity chromatography followed by size exclusion chromatography analysis in that it can monitor these four attributes in 8 min while requiring a minimal sample size (10–15 μg) and not requiring any manual peak collection. In contrast, the traditional standalone approach requires manual collection of eluted peaks in Protein-A affinity chromatography followed by buffer exchange to a mass-compatible buffer, which can take up to 2–3 h with considerable risk of sample loss, degradation, and induced modifications. As the biopharma industry moves to make analytical testing efficient, we believe that the approach proposed here would be of significant interest due to its ability to monitor multiple process and product quality attributes in a single workflow and via rapid analysis.