The fabrication of bifunctional supramolecular glycolipid-based nanocomposite gel: insights into electrocatalytic performance with effective selectivity towards gold.

Recovery, recycling, and reuse of metal waste have been re-intensified in the current era to build a sustainable future. In this context, gel nanocomposites were formulated by in situ reduction of gold within the low molecular weight gel matrix of synthetic glycolipid amphiphiles without using any external reducing/stabilizing agents. This strategy aroused the interest in formulating gel nanocomposites with preferential uptake of gold. The exclusive advantages owned by gold nanoparticle (GNP) embedded hydrogel offer an alternative to decorate the electrode surface without physical deposition/plating of the catalyst. Formation of GNP within the gel matrix was confirmed by the SPR peak in the UV-Visible spectrum. The particle size of 5-7 nm with zeta potential value in the range of -30.5 to -41.4 mV displayed good stability of nanoparticles in the gel matrix. Due to the encapsulation of nanoparticles within supramolecular assemblies of gel, a noteworthy increase in viscoelastic strength was observed, whereas the gelation behavior, melting temperature, and original fibrillar morphology of hydrogel remained intact. This hybrid gel exhibited good ionic conductivity (2.36 × 10-5 S cm-1) with appreciable ionic transport, remarkable oxygen reduction reaction (ORR) augmentation in reduction potential from 0 V to -0.12 V vs. Ag/AgCl as reference electrode, and excellent thermal stability in a wide temperature range. This green and efficient approach can pave the way for creating GNP-embedded hierarchical architecture that can act as bifunctional electrolyte/electrocatalyst material.

Integrating Ultrasmall Pd NPs into Core-Shell Imidazolate Frameworks for Photocatalytic Hydrogen and MeOH Production.

The construction of photoactive units in the proximity of a stable framework support is one of the promising strategies for uplifting photocatalysis. In this work, the ultrasmall Pd NPs implanted onto core-shell (CS) metal organic frameworks (MOFs), i.e., CS@Pd nanoarchitectures with tailored electronic and structural properties are reported. The all-in-one heterogeneous catalyst CS@Pd3 improves the surface functionalities and exhibits an outstanding hydrogen evolution reaction (HER) activity rate of 12.7 mmol g-1 h-1, which is 10-folds higher than the pristine frameworks with an apparent quantum efficiency (AQE) of 9.02%. The bifunctional CS@Pd shows intriguing results when subjected to photocatalytic CO2 reduction with an impressive rate of 71 µmol g-1 h-1 of MeOH under visible-light irradiation at ambient conditions. Spectroscopic data reveal efficient charge migrations and an extended lifetime of 2.4 ns, favoring efficient photocatalysis. The microscopic study affirms the formation of well-ordered CS morphology with precise decoration of Pd NPs over the CS networks. The significance of active Pd and Co sites is addressed by congruent charge-transfer kinetics and computational density functional theory calculations of CS@Pd, which validate the experimental findings with their synergistic involvement in improved photocatalytic activity. This present work provides a facile and competent avenue for the systematic construction of MOF-based CS heterostructures with active Pd NPs.

Silver nitroprusside nanoparticles for breast cancer therapy: in vitro and in vivo approach.

The advancement of nanotechnology has led to the experimental development of cancer therapeutics, which may overcome the shortcomings of commercially available drugs and facilitate improved clinical outcomes. Recently, several metal nanoparticles, especially silver, have been evaluated by scientists globally as useful chemotherapeutic agents due to their multi-functionality and well-recognized biological activity. Herein, we developed silver nitroprusside nanoparticles (abbreviated as AgNNPs) with slight modifications in the reaction conditions and demonstrated their application for breast cancer therapy using in vitro assays and in vivo experiments in a mouse model. Initially, the modified AgNNPs were thoroughly characterized using several analytical techniques. AgNNPs were found to be biocompatible according to in vitro experiments in normal cell lines (HEK-293 and EA.hy926), which was further validated by a hemolysis assay (ex vivo experiment) using mouse red blood cells. In contrast, the cell viability assay using the MTT reagent showed the cytotoxic nature of the AgNNPs against several cancer cell lines (MDA-MB-231, 4T1, B16F10, and PANC-1). Their detailed anticancer activity was investigated using 4T1 (mouse specific) and MDA-MB-231 (human specific) cells through various in vitro assays. The nanoparticles inhibited the formation of blood vessels in the chick embryo model, highlighting their anti-angiogenic behavior. Furthermore, the administration of AgNNPs significantly inhibited orthotopic breast tumor growth (4T1; BALB/c mice) and increased the survivability of the tumor-bearing mice. Also, we demonstrated the plausible molecular mechanisms for the anti-cancer activity of AgNNPs through various in vitro assays and in vivo experiments. Overall, the results support that AgNNPs can be used as an alternative generalized nanomedicine for the treatment of breast and other cancers after proper biosafety evaluation in near future.

Supramolecular Glycolipid-Based Hydro-/Organogels with Enzymatic Bioactive Release Ability by Tuning the Chain Length and Headgroup Size.

Designing of supramolecular hydro-/organogels having desired properties, biocompatibility, and stimuli responsiveness is a challenging task. Herein, the gelation ability of amphiphilic glycolipid-based gelators in a wide range of solvents is explored. The structure-function relationship was established by varying the chain length and polar headgroup size of amphiphilic gelators. The prepared hydro-/organogels were characterized by employing several techniques such as differential scanning calorimetry (DSC), rheology, field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), etc. The thermal stability of hydro-/organogels increased with an increase in chain length. Rheological analysis depicted that variation in chain length and headgroup size of amphiphilic gelators significantly affected the gel strength and stability. The self-assembled morphology of hydro-/organogel samples revealed the compact entangled fibrillar network structures. After comparing the energy-minimized molecular length with the d-spacing value obtained by XRD, interdigitated bilayer packing in the gel network was established. The bioactive encapsulation and enzymatic release study of hydro-/organogels portrayed their potential application in the biomedical field. To our delight, glycolipid 16M (C16 chain length) formed a molecular hydrogel with injectable and thixotropic behaviors. High critical strain value, thixotropy, injectability, thermoreversibility, and faster bioactive release for the 16M-W hydrogel proved crucial to predict its future applications. Overall, glycolipid amphiphiles designed by upholding proper hydrophilic-lipophilic balance can form multifunctional supramolecular hydrogels with excellent implementation in the drug delivery system.

Technoeconomic Investigation of Amine-Grafted Zeolites and Their Kinetics for CO2 Capture.

Solid adsorbents with precise surface structural chemistry and porosity are of immense interest to decode the structure-property relationships and maintain an energy-intensive path while achieving high activity and durability. In this work, we reported a series of amine-modified zeolites and their CO2 capture efficiencies. The amine impregnated molecular zeolite compounds were characterized and systematically investigated for CO2 adsorption capacity through thermogravimetric analysis for the occurrence of atmospheric pure CO2 gas at 75 °C with diethylenetriamine (DETA), ethylenediamine (EDA), monoethanolamine (MEA), and triethanolamine (TEA)-loaded zeolite 13X, 4A, and 5A adsorbents. The kinetics of the adsorption study indicated that the adsorption capacity for CO2 adsorption was improved with amine loading up to a certain concentration over 13X-DETA-40, showing an adsorption capacity of 1.054 mmol of CO2 per gram of zeolite in a very short amount of time. The result was especially promising in terms of the initial adsorption capacity of zeolite, which adsorbed approximately 0.8 mmol/g zeolite within the first two minutes of experimentation. A detailed flow chart that includes a brief look into the process adopted for adsorption was included. Lagergren pseudo-first- and pseudo-second-order models of 40 wt % DETA zeolite 13X gave CO2 adsorption capacities of 1.055 and 1.058 mmol/g and also activation energies of 86 and 76 kJ/mol, respectively. The CO2 adsorption capacity of 13X-DETA-40 in a lab-scale reactor was found to be 1.69 mmol/g. A technoeconomic study was conducted for the solid amine zeolites to understand the investment per ton of CO2 adsorbed. This study was used as a basis to improve cost estimates from a microscale to a lab-scale reactor. The cost of investment for 13X-DETA-40 was reduced by 84% from $49,830/ton CO2 adsorbed in a microscale reactor to $7,690/ton of CO2 adsorbed in a lab-scale reactor.

Unsaturation and Polar Head Effect on Gelation, Bioactive Release, and Cr/Cu Removal Ability of Glycolipids.

Designing of multifunctional soft and smart materials from natural sources is a useful strategy for producing safer chemicals having potential applications in biomedical research and pharmaceutical industries. Herein, eight glycolipids with variation in unsaturation of hydrophobic tail and polar headgroup size were designed. The effect of unsaturation in the tail group and headgroup size on gelation ability, and mechanical and thermal stability of glycolipid hydro/organogels was studied to understand structure and property relationship. Glycolipids are functional amphiphilic molecules having potential applications in the field of drug delivery and metal removal. The encapsulation capacity and kinetic release behavior of hydrophobic/hydrophilic bioactives like curcumin/riboflavin from the hydrophobic/hydrophilic pockets of glycolipids hydro/organogels was examined. A significant observation was that the glucamine moiety of the glycolipid headgroup plays a vital role in removal of Cr and Cu from oil/water biphasic systems. Typical functions of the glycolipid hydrogels are metal chelation and enzyme-triggered release behavior, enabled them as promising material for Cr, Cu removal from edible oils and controlled release of water soluble/insoluble bioactives.

Acute and subacute oral toxicity of copper oxide nanoparticles in female albino Wistar rats.

The extensive use of copper oxide nanoparticles (CuO-NPs) in various industries and their wide range of applications have led to their accumulation in different ecological niches of the environment. This excess exposure raises the concern about its potential toxic effects on various organisms including humans. However, the hazardous potential of CuO-NPs in the literature is elusive, and it is essential to study its toxicity in different biological models. Hence, we have conducted single acute dose (2000 mg/kg) and multiple dose subacute (30, 300 and 1000 mg/kg daily for 28 days) oral toxicity studies of CuO-NPs in female albino Wistar rats following OECD guidelines 420 and 407 respectively. Blood analysis, tissue aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acetylcholinesterase, superoxide dismutase, catalase, lipid malondialdehyde and reduced glutathione assays, and histopathology of the tissues were carried out. The higher dose treatments of the acute and subacute study caused significant alterations in biochemical and antioxidant parameters of the liver, kidney and brain tissues of the rat. In addition, histopathological evaluation of these three organs of treated rats showed significantly high abnormalities in their histoarchitecture when compared to control rats. We infer from the results that the toxicity observed in the liver, kidney and brain of treated rats could be due to the increased generation of reactive oxygen species by CuO-NPs.

Application of Spectroscopic and Chromatographic Methods for Chemical Characterization of an Ayurvedic Herbo-Mineral Preparation: Maha Yograja Guggulu.

Rasa Shastra is an exclusive branch of ayurveda that uses processed metals and minerals in various combinations. Though the formulations are time tested, safety and quality concerns are being raised since the past two decades. In view of this, it becomes mandatory to generate quality control profiles of such formulations by following available parameters. Considering this, we attempted to develop standard manufacturing procedures of Maha Yogaraja Guggulu and generate preliminary physicochemical profiles using inductively coupled plasma mass spectrometry, X-ray diffraction, and high-performance thin-layer chromatography. The results from high-performance thin-layer chromatography revealed presence of organic constituents from plant material. X-ray diffraction indicated that the prepared drug contained cinnabar (mercury sulfide; Rasa sindhura), cassiterite (tin oxide; Vanga bhasma), litharge (lead oxide; Naga bhasma), and iron dioxide and magnetite (di-iron oxide; Loha and Mandura bhasma). The observations of the present study are preliminary and first of its kind that may be considered as baseline data for future studies.

Chitosan-Thiobarbituric Acid: A Superadsorbent for Mercury.

In the present investigation, chitosan (CH) was supramolecularly cross-linked with thiobarbituric acid to form CT. CT was well characterized by UV, scanning electron microscopy-energy-dispersive X-ray analysis, Fourier transform infrared, NMR, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction analyses, and its adsorption potential for elemental mercury (Hg0), inorganic mercury (Hg2+), and methyl mercury (CH3Hg+) was investigated. Adsorption experiments were conducted to optimize the parameters for removal of the mercury species under study, and the data were analyzed using Langmuir, Freundlich, and Temkin adsorption isotherm models. CT was found to have high adsorption capacities of 1357.69, 2504.86, and 2475.38 mg/g for Hg0, Hg2+, and CH3Hg+, respectively. The adsorbent CT could be reused up to three cycles by eluting elemental mercury using 0.01 N thiourea, inorganic mercury using 0.01 N perchloric acid, and methyl mercury with 0.2 N NaCl.

Mercury based drug in ancient India: The red sulfide of mercury in nanoscale.

Mercury is one of the elements which had attracted the attention of the chemists and physicians of ancient India and China. Among the various metal based drugs which utilize mercury, we became interested in the red sulfide of mercury which is known in ancient Indian literature as rasasindur (alias rasasindura, rasasindoor, rasasinduram, sindur, or sindoor) and is used extensively in various ailments and diseases. Following various physico-chemical characterizations it is concluded that rasasindur is chemically pure α-HgS with Hg:S ratio as 1:1. Analysis of rasasindur vide Transmission Electron Microscopy (TEM) showed that the particles are in nanoscale. Bio-chemical studies of rasasindur were also demonstrated. It interacts with Bovine Serum Albumin (BSA) with an association constant of (9.76 ± 0.56) × 103 M-1 and behaves as a protease inhibitor by inhibiting the proteolysis of BSA by trypsin. It also showed mild antioxidant properties.

The chaperone-like activity of α-synuclein attenuates aggregation of its alternatively spliced isoform, 112-synuclein in vitro: plausible cross-talk between isoforms in protein aggregation.

Abnormal oligomerization and aggregation of α-synuclein (α-syn/WT-syn) has been shown to be a precipitating factor in the pathophysiology of Parkinson's disease (PD). Earlier observations on the induced-alternative splicing of α-syn by Parkinsonism mimetics as well as identification of region specific abnormalities in the transcript levels of 112-synuclein (112-syn) in diseased subjects underscores the role of 112-syn in the pathophysiology of PD. In the present study, we sought to identify the aggregation potential of 112-syn in the presence or absence of WT-syn to predict its plausible role in protein aggregation events. Results demonstrate that unlike WT-syn, lack of 28 aa in the C-terminus results in the loss of chaperone-like activity with a concomitant gain in vulnerability to heat-induced aggregation and time-dependent fibrillation. The effects were dose and time-dependent and a significant aggregation of 112-syn was evident at as low as 45 °C following 10 min of incubation. The heat-induced aggregates were found to be ill-defined structures and weakly positive towards Thioflavin-T (ThT) staining as compared to clearly distinguishable ThT positive extended fibrils resulting upon 24 h of incubation at 37 °C. Further, the chaperone-like activity of WT-syn significantly attenuated heat-induced aggregation of 112-syn in a dose and time-dependent manner. On contrary, WT-syn synergistically enhanced fibrillation of 112-syn. Overall, the present findings highlight a plausible cross-talk between isoforms of α-syn and the relative abundance of these isoforms may dictate the nature and fate of protein aggregates.

Opacification of intraocular lenses implanted during infancy: a clinicopathologic study of 4 explanted intraocular lenses.

OBJECTIVE: To report the clinicopathologic features of 4 opacified, single-piece, hydrophilic, acrylic intraocular lenses (IOLs) explanted from children who had undergone IOL implantation during infancy. DESIGN: Observational case series. PARTICIPANTS: Four IOLs explanted from 4 eyes of 3 children for visually significant opacification were included in the study. METHODS: The clinical details of each case were obtained to look for possible risk factors for IOL opacification. The explanted IOLs were subjected to gross examination, staining by alizarin red 1% for calcium, scanning electron microscopy, and energy-dispersive x-ray spectroscopy (EDS). Levels of calcium and phosphorous were analyzed in the serum of all cases and in the aqueous humor of 1 case. MAIN OUTCOME MEASURES: Morphologic features and composition of deposits. RESULTS: Two cases had congenital cataract while one case was after bilateral lens sparing vitrectomy for retinopathy of prematurity. All underwent surgery during infancy with implantation of an IOL. The IOLs were explanted 8 months after surgery from 4 eyes of 3 children at the age of 17, 25, and 26. All the children received a single-piece hydrophilic acrylic IOL. The IOLs were in situ for an average duration of 13.86 months. The deposits were in the shape of a bicycle wheel on 3 IOLs and looked like fish eggs on 1 IOL. All deposits stained bright orange with alizarin red. On EDS, the deposits were found to be composed of calcium, phosphate, and silicone. CONCLUSIONS: The morphologic features and composition of IOL deposits in 2 cases were similar to those of earlier reports in adults. The hydrophilic nature of the IOL material, sulcus implantation, and postoperative inflammation may be possible risk factors for opacification. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Biochemical and biophysical characterization of collagens of marine sponge, Ircinia fusca (Porifera: Demospongiae: Irciniidae).

Collagens were isolated and partially characterized from the marine demosponge, Ircinia fusca from Gulf of Mannar (GoM), India, with an aim to develop potentially applicable collagens from unused and under-used resources. The yield of insoluble, salt soluble and acid soluble forms of collagens was 31.71 ± 1.59, 20.69 ± 1.03, and 17.38 ± 0.87 mg/g dry weight, respectively. Trichrome staining, Scanning & Transmission Electron microscopic (SEM & TEM) studies confirmed the presence of collagen in the isolated, terminally globular irciniid filaments. The partially purified (gel filtration chromatography), non-fibrillar collagens appeared as basement type collagenous sheets under light microscopy whereas the purified fibrillar collagens appeared as fibrils with a repeated band periodicity of 67 nm under Atomic Force Microscope (AFM). The non-fibrillar and fibrillar collagens were seen to have affinity for anti-collagen type IV and type I antibodies raised against human collagens, respectively. The macromolecules, i.e., total protein, carbohydrate and lipid contents within the tissues were also quantified. The present information on the three characteristic irciniid collagens (filamentous, fibrillar and non-fibrillar) could assist the future attempts to unravel the therapeutically important, safer collagens from marine sponges for their use in pharmaceutical and cosmeceutical industries.

Photocatalytic degradation of monocrotophos pesticide--an endocrine disruptor by magnesium doped titania.

Mg-doped TiO(2) with different Mg concentrations were prepared using sol-gel method and characterized by XRD, UV-visible, XPS, SEM and FT-IR. The XRD results revealed that Mg(2+) goes into the TiO(2) lattice. SEM images of the doped and pure TiO(2) indicated that there is a smaller particle size for the doped catalyst compared to that of the pure TiO(2). UV-visible absorption spectra indicated that upon doping with Mg(2+) ion, the catalyst exhibits absorption in visible region. FT-IR and XPS spectra demonstrated that the presence of Mg(2+) ion in the TiO(2) lattice as substitutional dopant. Photocatalytic activity of doped TiO(2) has been evaluated by degradation of the monocrotophos (MCP) pesticide. The effect of solution pH, catalyst dosage and initial concentration of MCP on the photocatalytic activity of Mg-doped TiO(2) with different loadings was studied. It was observed that the rate of degradation of MCP over Mg-doped TiO(2) is better than Pure TiO(2) and Degussa P-25.