Presence Of Oleic Acid Research Articles

Effect of temperature, water content and free fatty acid on reverse micelle formation of phospholipids in vegetable oil

The self-assembly of phospholipids in oil, specifically lecithin in rapeseed oil, was investigated by combining experimental and computational methods The influence of temperature, water, and free fatty acids on the onset of lecithin aggregation in the rapeseed oil was determined using the 7,7,8,8 -tetracyanoquinodimethane dye (TCNQ) solubilization method and the size and shape of the self-assembled lecithin structures were investigated by small-angle X-ray scattering and cryogenic transmission electron microscopy. In the absence of excess water in the system (0.03wt-% water in oil), stable cylindrical lecithin reverse micelles were observed above the critical micelle concentration (CMC). Comparing the aggregation response in room temperature and at 70°C revealed that CMC decreased with increasing temperature. Furthermore, already a modest amount of added water (0.3wt-% water in oil) was sufficient to induce the formation of lamellar lecithin structures, that phase separated from the oil. In low water content, oleic acid suppressed the formation of lecithin reverse micelles whereas in the presence of more water, the oleic acid stabilized the reverse micelles. Consequently, more water was needed to induce phase separation in the presence of oleic acid. Molecular dynamics simulations indicated that the stabilizing effect of oleic acid resulted from oleic acid enhancing phospholipid solubilization in the oil by forming a solvating shell around the phosphate head group. The findings showed that the response of the mixed surfactant system is a delicate interplay of the different components and variables. The significance of the observations is that multiple parameters need to be controlled for desired system response, for example towards vegetable oil purification or phospholipid based microemulsions.

From Colloidal Monodisperse Nickel Nanoparticles to Well-Defined Ni/Al2O3 Model Catalysts.

In the past few decades, advances in colloidal nanoparticle synthesis have created new possibilities for the preparation of supported model catalysts. However, effective removal of surfactants is a prerequisite to evaluate the catalytic properties of these catalysts in any reaction of interest. Here we report on the colloidal preparation of surfactant-free Ni/Al2O3 model catalysts. Monodisperse Ni nanoparticles (NPs) with mean particle size ranging from 4 to 9 nm were synthesized via thermal decomposition of a zerovalent precursor in the presence of oleic acid. Five weight percent Ni/Al2O3 catalysts were produced by direct deposition of the presynthesized NPs on an alumina support, followed by thermal activation (oxidation-reduction cycle) for complete surfactant removal and surface cleaning. Structural and morphological characteristics of the nanoscale catalysts are described in detail following the propagation of the bulk and surface Ni species at the different treatment stages. Powder X-ray diffraction, electron microscopy, and temperature-programmed reduction experiments as well as infrared spectroscopy of CO adsorption and magnetic measurements were conducted. The applied thermal treatments are proven to be fully adequate for complete surfactant removal while preserving the metal particle size and the size distribution at the level attained by the colloidal synthesis. Compared with standard impregnated Ni/Al2O3 catalysts, the current model materials display narrowed Ni particle size distributions and increased reducibility with a higher fraction of the metallic nickel atoms exposed at the catalyst surface.

Antimicrobial activity of ethyl acetate extract of <i>Citrullus lanatus</i> seeds

Purpose: To determine the antimicrobial activity and chemical constituents of ethyl acetate extract of Citrullus lanatus seeds.Methods: Antimicrobial activity of the ethyl acetate extract of the seeds of C. lanatus was evaluated against Staphylococus aureus ATCC 25923, Escherichia coli ATCC 25922, Bacillus subtilis NCTC8236, Pseudomonas aeruginosa ATCC 10145 and Candida albicans ATCC 24433 using standard microbiological method. Chemical constituents of the extract were determined with Gas chromatography and mass spectrometry (GC MS) systems.Results: An oily, yellowish orange coloured extract with a yield of 18.7 % was obtained. The extract inhibited the growth of all test microorganisms at minimum inhibitory concentration range of 0.313 -2.5 mg/mL and minimum bactericidal concentration of 0.313-5 mg/mL. GC MS profile of the extract showed the presence of oleic acid (31.22 %), saturated fatty acid (23.85 %) and gamma tocopherol (8.79 %). Other organic compounds accounted for 36.16 % of the extractConclusion: Ethyl acetate extract of the seeds of Citrullus lanatus has antimicrobial effect against some Gram positive and Gram negative bacteria as well as C. albicans. Twenty-one compounds including fatty acids, hexamethyl-2-ethylacridine, gamma tocopherol and methylphthalate have been identified in the seeds.Keywords: Citrulluslanatus seeds, ethyl acetate extract, antimicrobial activity

UV and Temperature-Sensing Based on NaGdF4:Yb3+:Er3+@SiO2-Eu(tta)3.

A multifunctional nanosystem was synthesized to be used as a dual sensor of UV light and temperature. NaGdF4:Yb3+:Er3+ upconverting nanoparticles (UCNPs) were synthesized and coated with a silica shell to which a europium(III) complex was incorporated. The synthesis of NaGdF4 UCNPs was performed via thermal decomposition of lanthanide ion fluoride precursors in the presence of oleic acid. To achieve sufficient water dispersibility, the surface of the hydrophobic oleate-capped UCNPs in the hexagonal phase was modified by a silica coating through a modified Stöber process through a reverse microemulsion method. An Eu(tta)3 (tta: thenoyltrifluoroacetonate) complex was prepared in situ at the silica shell. A dual-mode nanothermometer was obtained from a near infrared to visible upconversion fluorescence signal of Er3+ ions together with UV-excited downshifting emission from the Eu3+ complex. Measurements were recorded near the physiological temperature range (293–323 K), revealing excellent linearity (R2 > 0.99) and relatively high thermal sensitivities (≥1.5%·K–1). The Eu(tta)3 complex present in the silica shell was tested as the UV sensor because of the Eu3+ luminescence dependence on UV-light exposure time.

Monodisperse Iron Oxide Nanoparticles by Thermal Decomposition: Elucidating Particle Formation by Second-Resolved in Situ Small-Angle X-ray Scattering.

The synthesis of iron oxide nanoparticles (NPs) by thermal decomposition of iron precursors using oleic acid as surfactant has evolved to a state-of-the-art method to produce monodisperse, spherical NPs. The principles behind such monodisperse syntheses are well-known: the key is a separation between burst nucleation and growth phase, whereas the size of the population is set by the precursor-to-surfactant ratio. Here we follow the thermal decomposition of iron pentacarbonyl in the presence of oleic acid via in situ X-ray scattering. This method allows reaction kinetics and precursor states to be followed with high time resolution and statistical significance. Our investigation demonstrates that the final particle size is directly related to a phase of inorganic cluster formation that takes place between precursor decomposition and particle nucleation. The size and concentration of clusters were shown to be dependent on precursor-to-surfactant ratio and heating rate, which in turn led to differences in the onset of nucleation and concentration of nuclei after the burst nucleation phase. This first direct observation of prenucleation formation of inorganic and micellar structures in iron oxide nanoparticle synthesis by thermal decomposition likely has implications for synthesis of other NPs by similar routes.

Characterization and Chemical Stability of Hydrophilic and Hydrophobic Magnetic Nanoparticles

Magnetic nanoparticles can improve the efficiency of phase separation time in multi-stage operations when a magnetic field is present. As such operations involve contact with aqueous and/or organic solutions, hydrophilic magnetic nanoparticles synthesized through the co-precipitation method were functionalized with oleic acid to attain hydrophobic magnetic nanoparticles. Both nanoparticles were characterized morphologically, chemically and magnetically. The results revealed that the particles (size ≈ 10 nm) consisted of an iron oxide mixture of magnetite and maghemite. The functionalization with oleic acid was effective in converting them into hydrophobic nanoparticles. Both particles were ferro/ferrimagnetic and the presence of oleic acid did not interfere significantly in the saturation magnetization value. The chemical stability of both nanoparticles were also evaluated, as an attempt of simulating broad industrial conditions to which the nanoparticles may be subjected; the hydrophilic nanoparticles were resistant at pH ≥ 4, while the hydrophobic nanoparticles were stable at pH ≥ 3.

PHYTOCHEMICAL STUDIES AND ANTIMICROBIAL COMPOUNDS FROM FRUIT OF THESPESIA POPULNEA

Objectives: To study the phytochemical analysis and antimicrobial compounds from fruits of Thespesia populnea.Methods: The determination of antimicrobial activity of fruit extract was done by agar well diffusion method. Active compounds were extracted bydifferent solvent extraction methods. The presence of active compounds was confirmed by ultraviolet-visible spectrophotometry, Fourier transforminfrared spectroscopy and gas chromatography-mass spectrometry analysis (GC-MS).Results: The active extract was identified by the GC-MS analysis and it was revealed that the presence of oleic acid, pentadecanoic acid, andN-hexadecanoic acid.Conclusion: This method adopted and extracted purified active metabolites and can be fruitfully employed for obtaining novel antibiotic compounds to treat human pathogenic bacterial and fungal diseases.Keywords: Thespesia populnea (L.), Gas chromatography-mass spectrometry, Fourier transform infrared spectroscopy, Antimicrobial, Phytochemical.

Eicosapentaenoic acid (EPA) promotes differentiation of human brown precursor cells into metabolically active classical brown adipocytes via Gq/11 signaling

Eicosapentaenoic acid (EPA) supplementation exerts a plethora of health benefits. Previously, we demonstrated that EPA promotes brown adipogenesis by mediating G‐coupled protein receptor 120 (GPR120) activation in rodent brown precursor cells. The aim of this study is to establish the role of EPA in regulating brown adipogenesis in human classical brown precursor cells. The immortalized human brown precursor cells were employed to induce differentiation in the presence of oleic acid, palmitic acid, and EPA. EPA treatment significantly increased brown‐specific gene expressions including Ucp1, Prdm16, Cidea, DiO2, UCP1 protein expressions and oxygen consumption rate. To further investigate the role of GPR120, a receptor family involved in Gq/11 subtype, human brown precursor cells were treated with either GPR120‐specific agonist cdpA or a potent Gq/11 inhibitor (YM‐254890) during differentiation. GPR120 agonism significantly promoted EPA‐mediated brown adipogenesis, while inhibition of Gq/11 signaling completely abrogated brown adipogenesis. Consistently, the genetic deletion of GRR120 by CRISPR/Cas9 abrogated EPA‐mediated brown adipogenic effects. Collectively, these results demonstrate that EPA supplementation mediates Gq/11 signaling of GPR120 leading to augmentation of brown adipogenesis in human brown precursor cells.Support or Funding InformationNIH 1P20GM104320

Economically attractive route for the preparation of high quality magnetic nanoparticles by the thermal decomposition of iron(III) acetylacetonate

The thermal decomposition (TD) methods are among the most successful in obtaining magnetic nanoparticles with a high degree of control of size and narrow particle size distribution. Here we investigated the TD of iron(III) acetylacetonate in the presence of oleic acid, oleylamine, and a series of alcohols in order to disclose their role and also investigate economically attractive alternatives for the synthesis of iron oxide nanoparticles without compromising their size and shape control. We have found that some affordable and reasonably less priced alcohols, such as 1,2-octanediol and cyclohexanol, may replace the commonly used and expensive 1,2-hexadecanediol, providing an economically attractive route for the synthesis of high quality magnetic nanoparticles. The relative cost for the preparation of Fe3O4 NPs is reduced to only 21% and 9% of the original cost when using 1,2-octanediol and cyclohexanol, respectively.

Photoluminescence and self-assembly of cesium lead halide perovskite nanocrystals: Effects of chain length of organic amines and reaction temperature

All-inorganic halide perovskites have become one of the most prospective materials for lightening and display technology due to their color-tunable and narrow-band emission. Herein, we have systematically studied the effects of organic amines with different hydrocarbon chain length on the optical properties and morphology as well as the crystal structure of colloidal CsPbBr3 nanocrystals (NCs), which were synthesized in the presence of oleic acid (OA) and organic amines by using a simple hot-injection approach. The hydrocarbon chain length has shown an independent correlation to the morphology and crystal structure of the as-obtained CsPbBr3 NCs at 160°C, but their optical properties can be affected to some extent. The photoluminescence quantum yields (PLQYs) of the CsPbBr3 NCs synthesized in the presence of organic amines with long carbon chain length are generally in the range of 55–80% for different reaction time, but the PLQYs of less than 20% are obtained for the products synthesized in the presence of octylamine (OTAm) with short carbon chain length. The effects of the reaction temperature on the optical properties, size and crystal structure of the CsPbBr3 NCs synthesized in the presence of cetylamine (CTAm) are studied. Interestingly, some nanoplates also appear in these CsPbBr3 NCs obtained at relatively low temperatures (120 and 140°C), which have a strong tendency to self-assemble into face-to-face nanostructures. Such a similar self-assembly behavior is also observed in the product synthesized in the presence of oleylamine (OLAm), but only flat nanoplates are observed in the products in the presence of OTAm at 120°C. The results indicate that the lower reaction temperature and hydrocarbon chain length of the organic ligands play a significant role in the self-assembly of CsPbBr3 NCs. This work opens up an alternative approach to controllable-synthesis of perovskite NCs through varying the carbon chain length of organic surfactants, and enlightens the fabrication of different nanostructures via self-assembly methods for further optoelectronic applications.

Development and Optimisation of Spironolactone Nanoparticles for Enhanced Dissolution Rates and Stability

Stable solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) formulations to enhance the dissolution rates of poorly soluble drug spironolactone (SP) were being developed. Probe ultra-sonication method was used to prepare SLNs and NLCs. All NLCs contained stearic acid (solid lipid carrier) and oleic acid (liquid lipid content), whereas, SLNs were prepared and optimised by using the solid lipid only. The particles were characterised in terms of particle size analysis, thermal behaviour, morphology, stability and in vitro release. The zeta sizer data revealed that the increase in the concentration of oleic acid in the formulations reduced the mean particle size and the zeta potential. The increase in concentration of oleic acid from 0 to 30% (w/w) resulted in a higher entrapment efficiency. All nanoparticles were almost spherically shaped with an average particle size of about ∼170 nm. The DSC traces revealed that the presence of oleic acid in the NLC formulations resulted in a shift in the melting endotherms to a higher temperature. This could be attributed to a good long-term stability of the nanoparticles. The stability results showed that the particle size remained smaller in NLC compared to that of SLN formulations after 6 months at various temperatures. The dissolution study showed about a 5.1- to 7.2-fold increase in the release of the drug in 2 h compared to the raw drug. Comparing all nanoparticle formulations indicated that the NLC composition with a ratio of 70:30 (solid:liquid lipid) is the most suitable formulation with desired drug dissolution rates, entrapment efficiency and physical stability.

English

The present study aimed to evaluate some agronomical, physical and nutritional characteristics of seeds of three species of Cucurbitaceous, namely Citrulus lanatus, Lagenaria siceraria and Cucumeropsis edulus. Agronomic experiments were investigated over a two-year period during which, some agronomic performances of the tested varieties were evaluated. The physical characteristics of the collected fruits were also determined. The nutritional composition of the seeds, in particular their moisture, oils and proteins contents were then evaluated. Finally, the physicochemical characteristics, such as acidity, peroxide index, saponification index and the composition of fatty acids present in the oils extracted from seeds were performed. Results show that the species of C. lanatus and L. siceraria germinated respectively five and seven days after sowing. The flowering was observed 36 and 42 days, respectively, after sowing while the fructification appeared 44 and 58 days after sowing. According to results obtained during the two years of experimentation, the three species of Cucurbitaceous investigated in the present study could be ranged in short-cycle species (C. lanatus and L. siceraria) and long cycle species (C. edulus). Moreover, C. lanatus could be classified as the most productive as compared to others species of Cucurbitaceous plants investigated in the present study. C. edulus seeds are the longest (1.76 and 1.83 cm) in opposition to the seeds from C. lanatus (1.33 and 1.49 cm). Results of physicochemical analyses revealed the presence of fat (49.5 - 51.9%), with a high protein contents (18.46 - 31.41%). The composition of the fatty acids detected in oils extracted from seeds showed a strong concentration of linoleic acid (66.65%) and the presence of oleic acid (13.76%). The high unsaturated fatty acids proportion detected in oils from L. siceraria seeds was 80.40%. The saturated fatty acids detected were C16:0 and C18:0; and were more concentrated in the species of C. lanatus. Key words: Cucurbitaceous, Citrullus lanatus, Lagenaria siceraria, Cucumeropsis edulis, oil, seeds, Benin.

Size‐controlled synthesis of silver nanoparticles from silver mirror reaction in toluene

Size-controlled silver nanoparticles (Ag NPs) with a size of 2–15 nm have been synthesised from silver (Ag) mirror reaction in toluene, which refers to reduction of Ag precursor (Ag–dodecylamine complexes solution) by acetaldehyde (CH3CHO) in the presence of oleic acid (OLA). In this synthesis, the size of Ag NPs was finely tuned by just varying the Ag precursor concentrations (cAg). The addition of OLA can play an important role in stabilising the emerging Ag nuclei. With the OLA/Ag molar ratio at 3:1, the adsorption layer of enough OLA on the surface of the emerging Ag nuclei prevented the direct contact between Ag+ ions and Ag nuclei, and Ag nuclei grew up to their final size by the aggregation mechanism.

Synthesis of Zn,La-catalysts for biodiesel production from edible and acid soybean oil

Mixed oxides are widely used as catalyst in biodiesel production. The synthesis of these materials is mostly performed through co-precipitation using a basic solution as precipitating agent. The presence of residual alkali metals in the catalyst is a problem. The use of non-edible raw materials is a challenging issue in biodiesel production. The effect of precipitating agent (NaOH/Na2CO3, urea and (NH4)2CO3/NH4OH), calcination temperature (450 and 750 °C), and Zn/La molar ratio in the catalytic performance of Zn,La-mixed oxides for edible and non-edible soybean oil methanolysis was studied. ZnO promoted biodiesel production and lanthanum oxide carbonate and carbonate hydroxide phases are more effective for transesterification reaction than lanthanum oxide. The catalytic results for the transesterification of edible soybean oil could be correlated to catalyst basicity. The esterification of oleic acid added to edible soybean oil was favored by La species. In the presence of oleic acid, FAME yield could not be correlated to acid-basic sites density and the lanthanum oxide carbonate and carbonate hydroxide species deactivated more than lanthanum oxide. The best performance for the methanolysis of soybean oil containing 10% of oleic acid (95%) was obtained by the catalyst prepared using urea as coprecipitation agent and calcined at 750 °C.

Facile Synthesis of BaTiO3 Nanocubes with the Use of Anatase TiO2 Nanorods as a Precursor to Titanium Hydroxide

AbstractWe report a solvothermal method for the facile and reproducible synthesis of BaTiO3 nanocubes by employing anatase TiO2 nanorods as a precursor to titanium hydroxide. The TiO2 nanorods were, in turn, synthesized in advance through another solvothermal process. We could obtain high‐quality BaTiO3 nanocubes by reacting the TiO2 nanorods with Ba(NO3)2 under solvothermal conditions in the presence of oleic acid and acetic acid as dual capping agents, followed by a purification process involving chemical washing and physical filtration. The addition of acetic acid alongside oleic acid was critical to the formation of well‐defined {100} facets on the nanocrystals and also increased batch‐to‐batch reproducibility without the use of a glove box or similar air‐free experimental design. Using this method, BaTiO3 nanocubes crystallized in the cubic phase could be readily obtained with an average edge length around 8 nm.

Magnetic boron specific chelating microsphere by dispersion polymerisation for boron adsorption

Magnetic poly(glycidylmethacrylate) microspheres were prepared by dispersion polymerisation in the presence of oleic acid coated Fe3O4 nanoparticles and modified by N-methyl-D-glucamine for the fabrication of magnetic boron specific chelating microspheres. The structure and properties of obtained microspheres were analysed by scanning electron microscopy, Fourier transform infrared spectroscopy and vibrating sample magnetometer. The utility efficiency of monomer reached 60% under an optimum dropwise feeding process. The magnetic microspheres are ∼1 μm in size, and superparamagnetic nanoparticles have a saturation magnetisation of 17.1 emu g− 1 and a Fe3O4 content of 28 wt.%. The resultant boron specific chelating sorbent presents an adsorption capacity of 0.43 mmol g− 1 in the optimum conditions. Fast separation by magnetic field makes the prepared microspheres useful for the purification of boron contaminated water. These microspheres will exhibit strong potential in the treatment of boron contaminated water by rapid cost efficient separation under external magnetic field.

Synthesis of Metal Ion-Doped TiO2 Nanoparticles Using Two-Phase Method and Their Photocatalytic Activity Under Visible Light Irradiation.

In this study, TiO2 and metal ion-doped TiO2 nanoparticles were successfully synthesized by solvothermal reaction of titanium butoxide precursor in the presence of oleic acid, oleylamine and vapor water and they were characterized by XRD, Raman, TEM and DRS. We also investigated the photocatalytic activity of these oxides for the decomposition of Rhodamine B. From XRD and Raman results, doping of the metal ion in the crystal lattice did not change the high crystallinity of the TiO2 structure, and all the metal ions were incorporated into the structures of titania as well as replaced titanium ion or located at interstitial site. The absorption band shifted to a higher wavelength on the metal ion-doped TiO2 samples compared to the pure TiO2 sample. The Ce ion- doped TiO2 catalysts showed the higher photocatalytic activity compared to the pure TiO2 and a commercial P-25 catalysts and 1% Ce-doped TiO2 showed the highest photocatalytic activity.

Restrained Phosphatidylcholine Synthesis in a Cellular Model of Down's Syndrome is Associated with the Overexpression of Dyrk1A.

Aberrant formation of the cerebral cortex could be attributed to the lack of suitable substrates that direct the migration of neurons. Previous work carried out at our laboratory has shown that oleic acid is a neurotrophic factor. In order to characterize the effect of oleic acid in a cellular model of Down's syndrome (DS), here, we used immortalized cell lines derived from the cortex of trisomy Ts16 and euploid mice. We report that in the plasma membrane of euploid cells, an increase in phosphatidylcholine concentrations occurs in the presence of oleic acid. However, in trisomic cells, oleic acid failed to increase phosphatidylcholine incorporation into the plasma membrane. Gene expression analysis of trisomic cells revealed that the phosphatidylcholine biosynthetic pathway was deregulated. Taken together, these results suggest that the overdose of specific genes in trisomic lines delays differentiation in the presence of oleic acid. The dual-specificity tyrosine (Y) phosphorylation-regulated kinase 1A (DYRK1A) gene is located on human chromosome 21. DYRK1A contributes to intellectual disability and the early onset of Alzheimer's disease in DS patients. Here, we explored the potential role of Dyrk1A in the reduction of phosphatidylcholine concentrations in trisomic cells in the presence of oleic acid. The downregulation of Dyrk1A by small interfering RNA (siRNA) in trisomic cells returned phosphatidylcholine concentrations up to similar levels to those of euploid cells in the presence of oleic acid. Thus, our results highlight the role of Dyrk1A in brain development through the modulation of phosphatidylcholine location, levels and synthesis.

Developing Magnetic Particle Imaging (MPI) tracers for in vivo tissue-targeted applications

Event Abstract Back to Event Developing Magnetic Particle Imaging (MPI) tracers for in vivo tissue-targeted applications Hamed Arami1, Haydin Bradshaw1, Eric Teeman1, Alyssa Troksa1 and Kannan M. Krishnan1 1 University of Washington, Department of Materials Science and Engineering, United States Introduction: Magnetic particle imaging (MPI) is a real-time, quantitative and clinically safe imaging technique, potentially applicable for future clinical applications such as cancer imaging, cardiovascular imaging or stem cell labeling and tracking[1],[2]. MPI performance (i.e. spatial resolution and sensitivity) is highly dependent on nanoparticles (NPs) size distribution, magnetization and environment[3],[4]. Therefore, NPs MPI signal is different after distribution into tissues or binding to the cells. Here, using in vitro and in vivo studies, we present the potential capabilities of MPI for tissue targeted imaging applications such as cancer and atherosclerosis imaging. Materials and Methods: Monodispersed iron oxide nanoparticles (NPs) optimized for MPI were synthesized by thermal decomposition of iron oleate in the presence of oleic acid and transferred to water according to our previous reports[5]-[9]. Nanoparticles were functionalized using PMAO-PEG co-polymers and different PEG derivatives such as NH2-PEG-NH2 and NH2-PEG-SH (MWs: 2-20kDa). Cy5.5 near infra-red fluorescent (NIRF) molecules were conjugated to the NPs for multimodal (MPI/NIRF) imaging. For targeting experiments, the relevant targeting peptides (e.g. lactoferrin for targeting the C6 glioma xenografts in mice) were conjugated to the NPs[10]. All NPs formulations were characterized using dynamic light scattering (DLS), Zeta potential measurements, vibrating sample magnetometer (VSM) and transmission electron microscope (TEM). The biodistribution, pharmacokinetics and delivery of the NPs to organs and tissues (e.g. tumors and heart lesions) were evaluated using different groups of mice with brain or prostate cancers or aorta atherosclerosis. A home-built magnetic particle spectrometer (MPS) was used to evaluate the MPI performance of the NPs in tissues[4]. MPI, magnetic resonance imaging (MRI) and NIRF (IVIS) were used to monitor the biodistribution of the NPs in mice. Histology (H & E and Prussian Blue staining) were used to investigate tissue distribution and side-effects of the NPs. Results and Discussions: First, we used two preliminary experimental models to predict the MPI performance of the tracers in a tissue equivalent environment and an acidic lysosome-like solution[4],[7]. Then, for imaging of the reticuloendothelial system (RES) organs, cancers or heart lesions, we introduced functional groups (e.g. amine, -NH2) to the surface of the optimized NPs and used them as conjugation sites for bonding of the NIRF molecules (Cy5.5) and specific targeting peptides[8],[10]. We investigated the biodistribution (Fig. 1) of these NPs after their intravenous injection and evaluated their MPI performance after their accumulation in RES organs (e.g. liver and spleen) and other targeted tissues[5],[6]. Also, blood samples were collected by retro-orbital blood drawing and used for pharmacokinetic studies and evaluation of the NPs blood half-life. Our results show that MPI can be used as a potential whole-body imaging technique for a wide range of biomedical imaging applications. Also, NIRF has a high tracer mass sensitivity and reveals more details of microstructural distribution of these optimized MPI tracers in organs and tissues (e.g. cancers and heart lesions)[11]. Histology results showed no apparent side-effects due to accumulation of the NPs in organs. Fig.1. Multimodal MPI/NIRF/MRI imaging of the mice enabled us to map the biodistribution of the MPI tracers[5]. Conclusions: MPS and MPI enabled us to track our optimized MPI tracers in organs and targeted tissues effectively. Additional imaging modalities (NIRF and MRI) helped us to study the targeting ability, biodistribution and pharmacokinetics of the NPs in mice more accurately. These results pave the ways for future applications of MPI in pre-clinical tissue-targeted magnetic imaging and diagnostic applications. This work was supported by NIH grants 1RO1EB013689-01/NIBIB, 2R42EB013520-02A1 and 1R41EB013520-01.

Resveratrol Ameliorates Alcoholic Fatty Liver by Inducing Autophagy.

Alcoholic fatty liver (AFL) is early stage of alcoholic liver disease, which can progress to steatohepatitis, fibrosis, and cirrhosis if alcohol consumption is continued. The pathogenesis of AFL is associated with excessive lipid accumulation in hepatocytes. Resveratrol (RES), a dietary polyphenol found in red wines and grapes, has been shown to have a hepatoprotective effect. Autophagy is a crucial physiological process in cellular catabolism that involves the regulation of lipid droplets. Autophagy maintains a balance between protein synthesis, degradation and self-recycling. In the present study, we evaluated the protective effects of RES (10[Formula: see text]mg/kg, 30[Formula: see text]mg/kg, 100[Formula: see text]mg/kg) on AFL mice fed with an ethanol Lieber-DeCarli liquid diet, and HepG2 cells in the presence of oleic acid and alcohol to investigate whether resveratrol could induce autophagy to attenuate lipid accumulation. The results showed that RES (30[Formula: see text]mg/kg and 100[Formula: see text]mg/kg) treatment significantly attenuated hepatic steatosis and lowered the activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), low density lipoprotein cholesterol (LDL-C). H&E staining showed that RES reduced hepatic lipid accumulation. Transmission electron microscopy (TEM) images showed that RES treatment increased the number of autophagosomes and promoted the formation of autophagy. Western blot analysis showed that RES treatment increased the levels of microtubule-associated protein light chain3- II (LC3-II) and Beclin1, decreased expression of p62 protein. In addition, in vitro studies also demonstrated that RES led to the formation of acidic vesicular organelles (AVOs), however, 3-Methyladenine (3-MA), a specific inhibitor of autophagy, obviously inhibited the above effects of RES. In conclusion, RES has protective effects on alcoholic hepatic steatosis, and the potential mechanism might be involved in inducing autophagy.