Highly Dispersed Gold Nanoparticles Supported on SBA-15 for Vapor Phase Aerobic Oxidation of Benzyl Alcohol.

Gold nanoparticles supported on SBA-15 are prepared by homogenous deposition-precipitation method (HDP) using urea as the precipitating agent. The structural features of the synthesized catalysts were characterized by various techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption-desorption (BET), pore size distribution (PSD), CO chemisorption and X-ray photoelectron spectroscopy (XPS). The catalytic activity and stability of the Au/SBA-15 catalysts are investigated during the vapor phase aerobic oxidation of benzyl alcohol. The BJH pore size distribution results of SBA-15 support and Au/SBA-15 catalysts reveals that the formation of mesoporous structure in all the samples. TEM results suggest that Au nanoparticles are highly dispersed over SBA-15 and long range order of hexagonal mesopores of SBA-15 is well retained even after the deposition of Au metallic nanoparticles. XPS study reveals the formation of Au (0) after chemical reduction by NaBH4. The particle size measured from CO-chemisorption and TEM analysis are well correlated with the TOF values of the reaction. Au/SBA-1 5 catalysts are found to show higher activity compare to Au/TiO2 and Au/MgO catalysts during the vapor phase oxidation of benzyl alcohol. The catalytic functionality are well substantiated with particle size measured from TEM. The crystallite size of Au in both fresh and spent catalysts were measured from X-ray diffraction.

Cobalt phthalocyanine immobilized on graphene oxide: an efficient visible-active catalyst for the photoreduction of carbon dioxide.

New graphene oxide (GO)-tethered-Co(II) phthalocyanine complex [CoPc-GO] was synthesized by a stepwise procedure and demonstrated to be an efficient, cost-effective and recyclable photocatalyst for the reduction of carbon dioxide to produce methanol as the main product. The developed GO-immobilized CoPc was characterized by X-ray diffraction (XRD), FTIR, XPS, Raman, diffusion reflection UV/Vis spectroscopy, inductively coupled plasma atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). FTIR, XPS, Raman, UV/Vis and ICP-AES along with elemental analysis data showed that Co(II) -Pc complex was successfully grafted on GO. The prepared catalyst was used for the photocatalytic reduction of carbon dioxide by using water as a solvent and triethylamine as the sacrificial donor. Methanol was obtained as the major reaction product along with the formation of minor amount of CO (0.82 %). It was found that GO-grafted CoPc exhibited higher photocatalytic activity than homogeneous CoPc, as well as GO, and showed good recoverability without significant leaching during the reaction. Quantitative determination of methanol was done by GC flame-ionization detector (FID), and verification of product was done by NMR spectroscopy. The yield of methanol after 48 h of reaction by using GO-CoPc catalyst in the presence of sacrificial donor triethylamine was found to be 3781.8881 µmol g(-1) cat., and the conversion rate was found to be 78.7893 µmol g(-1) cat. h(-1). After the photoreduction experiment, the catalyst was easily recovered by filtration and reused for the subsequent recycling experiment without significant change in the catalytic efficiency.

Catalyst-free activation of methylene chloride and alkynes by amines in a three-component coupling reaction to synthesize propargylamines.

Propargylamines are synthesized via metal-free activation of the C-halogen bond of dihalomethanes and the C-H bond of terminal alkynes in a three-component coupling without catalyst or additional base and under mild reaction conditions. The dihalomethanes are used both as solvents as well as precursors for the methylene fragment (C1) in the final product. The scope of the reaction and the influence of various reaction variables has been investigated. A plausible reaction mechanism is proposed and the involvement of various intermediates that can be generated in situ in the process is discussed. The metal-free conditions also make this protocol environmentally benign and atom economical.

ROS mediated Cu[Fe(CN)5NO] nanoparticles for triple negative breast cancer: A detailed study in preclinical mouse model.

Triple negative breast cancer (TNBC) is an aggressive form of tumor, more prevalent in younger women resulting in poor survival rate (2nd in cancer deaths) because of its asymptomatic existence. The most popular and convenient approach for the treatment of TNBC is chemotherapy which is associated with several limitations. Considering the importance of nanotechnology in health care system, in the present manuscript, we have designed and developed a simple, efficient, cost effective, and ecofriendly method for the synthesis of copper nitroprusside analogue nanoparticles (Cu[Fe(CN)5NO] which is abbreviated as CuNPANP that may be the potential anti-cancer nanomedicine for the treatment of TNBC. Copper (present in CuNPANP) is used because of its affordability, nutritional value and various biomedical applications. The CuNPANP are thoroughly characterized using several analytical techniques. The in vitro cell viability (in normal cells) and the ex vivo hemolysis assay reveal the biocompatible nature of CuNPANP. The anti-cancer activity of the CuNPANP is established in TNBC cells (MDA-MB-231 and 4T1) through several in vitro assays along with plausible mechanisms. The intraperitoneal administration of CuNPANP in orthotopic breast tumor model by transplanting 4T1 cells into the mammary fat pad of BALB/c mouse significantly inhibits the growth of breast carcinoma as well as increases the survival time of tumor-bearing mice. These results altogether potentiate the anti-cancer efficacy of CuNPANP as a smart therapeutic nanomedicine for treating TNBC in near future after bio-safety evaluation in large animals.

Heterogeneous Cu(II) -catalysed solvent-controlled selective N-arylation of cyclic amides and amines with bromo-iodoarenes.

A selective N-arylation of cyclic amides and amines in DMF and water, respectively, catalysed by Cu(II) /Al2 O3 has been achieved. This protocol has been employed for the synthesis of a library of arenes bearing a cyclic amide and an amine moiety at two ends, including a few scaffolds of therapeutic importance. The mechanism has been established based on detailed electron paramagnetic resonance (EPR) spectroscopy, X-ray photoelectron spectroscopy (XPS), UV diffuse reflectance spectroscopy (DRS) and inductively coupled plasma-mass spectrometry (ICP-MS) studies of the catalyst at different stages of the reaction. The Cu(II) /Al2 O3 catalyst was recovered and recycled for subsequent reactions.

Green chemistry approach for the synthesis and stabilization of biocompatible gold nanoparticles and their potential applications in cancer therapy.

The biological approach to synthesis of AuNPs is eco-friendly and an ideal method to develop environmentally sustainable nanoparticles alternative to existing methods. We have developed a simple, fast, clean, efficient, low-cost and eco-friendly single-step green chemistry approach for the synthesis of biocompatible gold nanoparticles (AuNPs) from chloroauric acid (HAuCl(4)) using a water extract of Eclipta Alba leaves at room temperature. The AuNPs using Eclipta extract have been formed in very short time, even in less than 10 min. The as-synthesized AuNPs were thoroughly characterized by several physico-chemical techniques. The in vitro stability of as-synthesized AuNPs was studied in different buffer solutions. A plausible mechanism for the synthesis of AuNPs by Eclipta extract has been discussed. The biocompatibility of AuNPs was observed by in vitro cell culture assays. Finally, we have designed and developed a AuNPs-based drug delivery system (DDS) (Au-DOX) containing doxorubicin (DOX), a FDA approved anticancer drug. Administration of this DDS to breast cancer cells (MCF-7 and MDA-MB-231) shows significant inhibition of breast cancer cell proliferation compared to pristine doxorubicin. Therefore we strongly believe that the use of Eclipta Alba offers large-scale production of biocompatible AuNPs that can be used as a delivery vehicle for the treatment of cancer diseases.

Cationic amphiphiles with fatty acyl chain asymmetry of coconut oil deliver genes selectively to mouse lung.

Recent structure-activity studies have revealed a dramatic influence of hydrophobic chain asymmetry in enhancing gene delivery efficacies of synthetic cationic amphiphiles (Nantz, M. H. et al. Mol. Pharmaceutics2010, 7, 786-794; Koynova, R. et al. Mol. Pharmaceutics2009, 6, 951-958). The present findings demonstrate for the first time that such a transfection enhancing influence of asymmetric hydrocarbon chains observed in pure synthetic cationic amphiphiles also works for cationic amphiphiles designed with natural, asymmetric fatty acyl chains of a food-grade oil. Herein, we demonstrate that cationic amphiphiles designed with the natural fatty acyl chain asymmetry of food-grade coconut oil are less cytotoxic and deliver genes selectively to mouse lung. Despite lauroyl chains being the major fatty acyl chains of coconut oil, both the in vitro and In vivo gene transfer efficiencies of such cationic amphiphiles were found to be remarkably superior (>4-fold) to those of their pure dilauroyl analogue. Mechanistic studies involving the technique of fluorescence resonance energy transfer (FRET) revealed higher biomembrane fusibility of the cationic liposomes of the coconut amphiphiles than that of the symmetric dilauroyl analogue. AFM study revealed pronounced fusogenic nonlamellar structures of the liposomes of coconut amphiphiles. Findings in the FRET and cellular uptake study, taken together, support the notion that the higher cellular uptake resulting from the more fusogenic nature of the liposomes of coconut amphiphiles 1 are likely to play a dominant role in making the coconut amphiphiles transfection competent.

Facile chemical synthesis of W-Ag and W-Cu nanocomposites at low temperature.

W-Ag (80.2W-19.8Ag, 70.4W-29.6Ag and 60.5W-39.5Ag) and W-Cu (79.7W-20.3Cu, 70.5W-29.5Cu and 59.8W-40.2Cu) nanocomposites in the size range of 24-30 nm have been synthesized by thermal decomposition of W(CO)6/CH3COOAg and W(CO)6/Cu(acac)2 in diphenyl ether as solvent at 220 degrees C in presence of oleic acid and hexadecyl amine and characterized. FTIR spectra have been used to explain the role of oleic acid and hexadecyl amine in the synthesis of W-Ag and W-Cu composite powders. XRD studies show that the tungsten phase is amorphous, whereas both Ag and Cu crystallize in fcc for as-synthesized W-Ag and W-Cu nanocomposites. These composite powders when annealed at 700 degrees C results in the formation of bcc tungsten and peaks corresponding to fcc silver and copper still persists. The particle size, shape and distribution of these nanocomposites of various compositions have been studied by SAXS, ESEM and TEM and found to be nearly spherical with the average diameters below 30 nm.

Anti-angiogenic vanadium pentoxide nanoparticles for the treatment of melanoma and their in vivo toxicity study.

In recent days, vanadium complexes and nanoparticles have received sustainable attention owing to their vast applications in different fields. In the present study, we report a facile approach for the synthesis of irregular dumbbell shaped vanadium pentoxide nanoparticles (V2O5 NPs: 30-60 nm) via the polyol-induced microwave irradiation process along with calcination. The as-synthesized nanoparticles were characterized using various physico-chemical techniques (e.g. XRD, TEM, FT-IR, DLS and XPS). The cell viability assay showed that V2O5 NPs could efficiently inhibit the proliferation of different cancer cells (B16F10, A549, and PANC1), depicting their anti-proliferative activity. However, V2O5 NPs did not exert significant cytotoxicity to the normal cells (CHO, HEK-293 and NRK-49F), suggesting their biocompatible nature. Interestingly, these nanoparticles inhibited the proliferation and migration of the endothelial cells (HUVECs and EA.hy926) and disrupted the blood vasculature in a chick embryo model, indicating their anti-angiogenic properties. The mechanistic study revealed that the effective internalization of V2O5 NPs generated intracellular reactive oxygen species (ROS) which in turn up-regulated p53 protein and down-regulated survivin protein in cancer cells, leading to the apoptosis process. Furthermore, the administration of V2O5 NPs to melanoma bearing C57BL6/J mice significantly increased their survivability as compared to the control untreated tumor bearing mice, exhibiting the therapeutic potential of the nanoparticles against melanoma. Additionally, the in vivo toxicity study demonstrated no toxic effect in mice upon sub-chronic exposure to V2O5 NPs. Altogether, we strongly believe that V2O5 NPs could intrinsically provide a new direction for alternative therapeutic treatment strategies for melanoma and other cancers by employing their anti-angiogenic properties in the future.

Asymmetric hydrosilylation of ketones catalyzed by magnetically recoverable and reusable copper ferrite nanoparticles.

Herein we present magnetically recoverable and reusable copper ferrite nanoparticles for asymmetric hydrosilylation of several ketones. Up to 99% enantiometric excess was obtained at room temperature using polymethylhydrosiloxane as the stoichiometric reducing agent. The copper ferrite nanoparticles were magnetically separated, and the efficiency of the catalyst remains almost unaltered up to three cycles.

Design of DNA-intercalators based copper(II) complexes, investigation of their potential anti-cancer activity and sub-chronic toxicity.

In the present paper, we synthesized and characterized four N-donor polypyridyl copper(II) complexes (C1-C4); [Cu(mono-CN-PIP)2]2+ (C1), [Cu(tri-OMe-PIP)2]2+ (C2), [Cu(di-CF3-PIP)2]2+ (C3) and [Cu(DPPZ)2]2+ (C4). The (Calf-Thymus) CT-DNA binding studies depicted that the complexes could interact with DNA via intercalative mode. All the complexes, particularly C3 and C4 attenuated the proliferation as well as migration of various cancer cells, indicating their anti-cancer and anti-metastatic activity. Additionally, chick embryo angiogenesis (CEA) assay exhibited the inhibition of vascular sprouting in presence of C3 and C4, suggesting their potential in inhibiting the blood vessel growth. Mechanistic studies revealed that the complexes induced the excessive production of cellular reactive oxygen species (ROS) leading to apoptosis through up regulation of p53 and downregulation of Bcl-xL, which might be the plausible mechanisms underlying their anti-cancer properties. To understand the feasibility of practical application of anti-cancer copper complexes C3 and C4, in vivo sub-chronic toxicity study (4 weeks) was performed in C57BL6 mice and the results exhibited almost non-toxic effects induced by these complexes in terms of haematology and serum biochemical analyses, suggesting their biocompatible nature. The current study provides the basis for future advancement of other novel biocompatible metal complexes that could be employed for the therapy of different cancers.

An efficient copper-aluminum hydrotalcite catalyst for asymmetric hydrosilylation of ketones at room temperature.

A catalyst system consisting of a copper-aluminum hydrotalcite-chiral diphosphine ligand effects asymmetric hydrosilylation of several ketones, using polymethylhydrosiloxane (PMHS) as the stoichiometric reducing agent at room temperature, with moderate-to-excellent enantioselectivities. The catalyst is recovered by simple centrifugation, and the efficiency of the catalyst remains almost unaltered even after several cycles.

Ag2[Fe(CN)5NO] Nanoparticles Exhibit Antibacterial Activity and Wound Healing Properties.

Therapeutic agents harboring both wound healing and antibacterial activities have much demand in biomedical applications. Development of such candidates with clinically approved materials adds more advantages toward these applications. Recently, silver metal complex nanomaterials have been playing a major role in medical uses especially for antibacterial activity and wound healing. In this report, we designed and synthesized silver nitroprusside complex nanoparticles (abbreviated as AgNNPs) using sodium nitroprusside and silver nitrate (both are FDA approved precursors). The nanoparticles (AgNNPs) were thoroughly characterized by various physicochemical techniques such as XRD, FTIR, TGA, DLS, EDAX, Raman, ICP-OES, HRTEM, and FESEM. The cell viability assay in normal cells (EA.hy 926 cells, NIH 3T3) using MTT reagents and CEA assay (CEA: Chick embryo angiogenesis assay) in fertilized eggs demonstrate the biocompatibility of AgNNPs. These nanoparticles show effective antibacterial activity against both Gram positive and Gram negative bacteria through membrane and DNA damage. Additionally, AgNNPs accelerate the wound healing in C57BL6 mice by altering the macrophages from M1 to M2. Considering the results together, the current study may offer the development of new silver nanocomplex nanomaterials that shows synergistic effect on antibacterial activity and wound healing (2-in-1-system). To the best of our knowledge, this is the first report for the synthesis, characterization, and biomedical applications of silver nitroprusside nanoparticles.

Chemical Characterization of an Ayurvedic Herbo-Mineral Formulation - Vasantakusumakara Rasa: A Potential Tool for Quality Assurance.

BACKGROUND: Herbo-mineral formulations of Ayurveda contain specified metals or minerals as composition, which have their beneficial effects on biological systems. These metals or minerals are transformed into non-toxic forms through meticulous procedures explained in Ayurveda. Though literature is available on quality aspects of such herbo-mineral formulations; contemporary science is raising concerns at regular intervals on such formulations. Thus, it becomes mandate to develop quality profiles of all formulations that contain metals or minerals in their composition. Considering this, it is planned to evaluate analytical profile of Vasantakusumakara Rasa. OBJECTIVE: To prepare Vasantakusumakara Rasa as per Standard operating Procedures (SoP) mentioned in classical text and to characterize it chemically using modern analytical techniques. MATERIALS AND METHODS: The drug (Vasantakusumakara Rasa) in three batches was prepared in GMP certified pharmacy. Physico-chemical analysis, Assay of elements and HPTLC were carried out as per API. XRD was conducted using Rigaku Ultima-IV X-ray diffractometer. RESULTS: The analysis shown the presence of Mercury, Tin, Gold, Silver, Iron, Zinc and Calcium etc., and HPTLC revealed presence of organic constituents from plant material. The XRD indicated the presence of cinnabar (mercury sulphide from Rasa Sindhura), cassiterite (tin oxide from Vanga Bhasma), massicot (lead oxide from Naga bhasma) and Magnetite (di-iron oxide from Loha bhasma). CONCLUSION: The physico chemical analysis reveals that VKR prepared by following classical guidelines is very effective in converting the macro elements into therapeutically effective medicines in micro form. Well prepared herbo-mineral drugs offer many advantages over plant medicines due to their longer shelf life, lesser doses, easy storing facilities, better palatability etc. The inferences and the standards laid down in this study certainly can be utilized as baseline data of standardization and QC.

Glucocorticoid receptor-mediated delivery of nano gold-withaferin conjugates for reversal of epithelial-to-mesenchymal transition and tumor regression.

AIM: To explore the potential of glucocorticoid receptor-targeted nano-gold formulation as antitumor drug sensitizing agent. MATERIALS & METHODS: Simultaneous conjugation of gold nanoparticle with thiol-modified dexamethasone, a synthetic glucocorticoid and anticancer drug withaferin A afforded stable gold nanoparticle-modifed dexamethasone-withaferin A nanoconjugate. RESULTS: This metallic nanoparticle formulation showed glucocorticoid receptor-dependent cancer cell selective cytotoxicity, inhibited growth of aggressive mouse melanoma tumor, reduced mice mortality, while reversing epithelial-to-mesenchymal transition in tumor cells. Same treatment also leads to near-complete downregulation of ABCG2 drug transporter in tumor-associated cells thus attributing it to its drug sensitizing ability. CONCLUSION: The presently synthesized nanoconjugate holds a great promise to sensitize cancer cells to chemotherapeutics and induce epithelial-to-mesenchymal transition reversal in tumor cells preventing metastasis.

Green Synthesis and Characterization of Monodispersed Gold Nanoparticles: Toxicity Study, Delivery of Doxorubicin and Its Bio-Distribution in Mouse Model.

In the present article, we report the in vitro and in vivo delivery of doxorubicin using biosynthesized gold nanoparticles (b-Au-PP). Gold nanoparticles were synthesized by a simple, fast, efficient, environmentally friendly and economical green chemistry approach using an extract of Peltophorum pterocarpum (PP) leaves. Because the biosynthesized b-Au-PP was highly stable in various physiological buffers for several weeks and biocompatible in both in vitro and in vivo systems, we designed and developed a biosynthesized gold nanoparticle (b-Au-PP)-based drug-delivery system (DDS) using doxorubicin (Dox) (b-Au-PP-Dox). Both b-Au-PP and b-Au-PP-Dox were thoroughly characterized using several analytical tools. Administration of doxorubicin-loaded DDS (b-Au-PP-Dox) resulted in a significant inhibition of the proliferation of cancer cells (A549, B16F10) in vitro and of tumor growth in an in vivo model compared to doxorubicin alone. Furthermore, we found that the cellular uptake and release of Dox in the nanoconjugated form (b-Au-PP-Dox) were faster than the uptake and release of unconjugated Dox. The in vivo toxicity study did not show any significant changes in the hematology, serum clinical biochemistry or histopathology in the C57BL6/J female mice after consecutive intraperitoneal (IP) injections over a period of seven days. To the best of our knowledge, our study is the first to report the application of a biosynthesized gold nanoparticle-based DDS for cancer therapy in an animal model, in addition to a detailed in vivo toxicity study. Together, the results demonstrate that a biosynthesized gold nanoparticle-based drug-delivery system (b-Au-PP-Dox) could be used in the near future as an alternative cost-effective treatment strategy for cancer therapy.

Copper Prussian blue analogue: investigation into multifunctional activities for biomedical applications.

We have designed and developed stable and biocompatible copper analogues of a Prussian blue (PB) nanoparticle based drug delivery system containing doxorubicin that show selective quenching of fluorescence of doxorubicin compared to PB analogues with other metals and inhibition of cancer cell proliferation, suggesting future potential multifunctional applications in biomedical sciences.

Green synthesis, characterization of gold and silver nanoparticles and their potential application for cancer therapeutics.

In the present article, we demonstrate the delivery of anti-cancer drug to the cancer cells using biosynthesized gold and silver nanoparticles (b-AuNP & b-AgNP). The nanoparticles synthesized by using Butea monosperma (BM) leaf extract are thoroughly characterized by various analytical techniques. Both b-AuNP and b-AgNP are stable in biological buffers and biocompatible towards normal endothelial cells (HUVEC, ECV-304) as well as cancer cell lines (B16F10, MCF-7, HNGC2 & A549). Administration of nanoparticle based drug delivery systems (DDSs) using doxorubicin (DOX) [b-Au-500-DOX and b-Ag-750-DOX] shows significant inhibition of cancer cell proliferation (B16F10, MCF-7) compared to pristine drug. Therefore, we strongly believe that biosynthesized nanoparticles will be useful for the development of cancer therapy using nanomedicine approach in near future.

Examples of Tumor Growth Inhibition Properties of Liposomal Formulations of pH-Sensitive Histidinylated Cationic Amphiphiles.

Herein we report on the unexpected cancer cell selective cytotoxicities of the liposomal formulations of aspartic and glutamic acid backbone-based four novel lipids with endosomal pH-sensitive head-groups and aliphatic n-hexadecyl & n-octadecyl hydrophobic tails. Surprisingly, although the formulations killed cancer cells efficiently, they were significantly less cytotoxic in non-cancerous healthy cells. Importantly, intratumoral administration of the liposomal formulations efficiently inhibited growth of melanoma in a syngeneic C57BL/6J mouse tumor model. Western Blotting experiments with the lysates of liposomes treated cancer cells revealed that liposomes of lipids 1-4 induce apoptosis selectively in cancer cells presumably by releasing cytochrome c from depolarized mitochondria and subsequent activation of caspases 3 & 9, upregulation of Bax and down regulation of Bcl-2. In summary, the present report describes for the first time tumor growth inhibition properties of the liposomal formulations of endosomal pH-sensitive histidinylated cationic lipids under both in vitro and systemic settings.

Antiangiogenic activity of mononuclear copper(II) polypyridyl complexes for the treatment of cancers.

A series of four new mononuclear copper(II) polypyridyl complexes (1-4) have been designed, developed, and thoroughly characterized by several physicochemical techniques. The CT-DNA binding properties of 1-4 have been investigated by absorption, emission spectroscopy, and viscosity measurements. All the complexes especially 1 and 4 exhibit cytotoxicity toward several cancer cell lines, suggesting their anticancer properties as observed by several in vitro assays. Additionally, the complexes show inhibition of endothelial cell (HUVECs) proliferation, indicating their antiangiogenic nature. In vivo chick embryo angiogenesis assay again confirms the antiangiogenic properties of 1 and 4. The formation of excessive intracellular ROS (H2O2 and O2(•-)) and upregulation of BAX induced by copper(II) complexes may be the plausible mechanisms behind their anticancer activities. The present study may offer a basis for the development of new transition metal complexes through suitable choice of ligands for cancer therapeutics by controlling tumor angiogenesis.