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Sample records for preparing polymer-cushioned lipid

  1. Lipid bilayers on nano-templates

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    Noy, Aleksandr; Artyukhin, Alexander B.; Bakajin, Olgica; Stoeve, Pieter

    2009-08-04

    A lipid bilayer on a nano-template comprising a nanotube or nanowire and a lipid bilayer around the nanotube or nanowire. One embodiment provides a method of fabricating a lipid bilayer on a nano-template comprising the steps of providing a nanotube or nanowire and forming a lipid bilayer around the polymer cushion. One embodiment provides a protein pore in the lipid bilayer. In one embodiment the protein pore is sensitive to specific agents

  2. Preparation of artificial plasma membrane mimicking vesicles with lipid asymmetry.

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    Qingqing Lin

    Full Text Available Lipid asymmetry, the difference in lipid distribution across the lipid bilayer, is one of the most important features of eukaryotic cellular membranes. However, commonly used model membrane vesicles cannot provide control of lipid distribution between inner and outer leaflets. We recently developed methods to prepare asymmetric model membrane vesicles, but facile incorporation of a highly controlled level of cholesterol was not possible. In this study, using hydroxypropyl-α-cyclodextrin based lipid exchange, a simple method was devised to prepare large unilamellar model membrane vesicles that closely resemble mammalian plasma membranes in terms of their lipid composition and asymmetry (sphingomyelin (SM and/or phosphatidylcholine (PC outside/phosphatidylethanolamine (PE and phosphatidylserine (PS inside, and in which cholesterol content can be readily varied between 0 and 50 mol%. We call these model membranes "artificial plasma membrane mimicking" ("PMm" vesicles. Asymmetry was confirmed by both chemical labeling and measurement of the amount of externally-exposed anionic lipid. These vesicles should be superior and more realistic model membranes for studies of lipid-lipid and lipid-protein interaction in a lipid environment that resembles that of mammalian plasma membranes.

  3. Preparation of artificial plasma membrane mimicking vesicles with lipid asymmetry.

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    Lin, Qingqing; London, Erwin

    2014-01-01

    Lipid asymmetry, the difference in lipid distribution across the lipid bilayer, is one of the most important features of eukaryotic cellular membranes. However, commonly used model membrane vesicles cannot provide control of lipid distribution between inner and outer leaflets. We recently developed methods to prepare asymmetric model membrane vesicles, but facile incorporation of a highly controlled level of cholesterol was not possible. In this study, using hydroxypropyl-α-cyclodextrin based lipid exchange, a simple method was devised to prepare large unilamellar model membrane vesicles that closely resemble mammalian plasma membranes in terms of their lipid composition and asymmetry (sphingomyelin (SM) and/or phosphatidylcholine (PC) outside/phosphatidylethanolamine (PE) and phosphatidylserine (PS) inside), and in which cholesterol content can be readily varied between 0 and 50 mol%. We call these model membranes "artificial plasma membrane mimicking" ("PMm") vesicles. Asymmetry was confirmed by both chemical labeling and measurement of the amount of externally-exposed anionic lipid. These vesicles should be superior and more realistic model membranes for studies of lipid-lipid and lipid-protein interaction in a lipid environment that resembles that of mammalian plasma membranes.

  4. Single-component solid lipid nanocarriers prepared with ultra-long chain amphiphilic lipids

    DEFF Research Database (Denmark)

    Wei, Wei; Lu, Xiaonan; Wang, Zegao

    2017-01-01

    HYPOTHESIS: Synthetic sugar alcohol mono-behenates with high melting points, surface activity and resistance to enzymatic lipolysis, are expected to form stable single-component solid lipid nanocarriers (SC-SLNs). The preparation methods and the polar head group of the molecules should affect...... the smallest mean size (∼100nm with PdI of 0.26). In addition, they displayed high entrapment efficiency of fenofibrate (95%) and long term drug release. Nanocarriers prepared by emulsification-diffusion method entrapped fenofibrate into lipid bilayers. In contrast, Nanocarriers prepared by melting......-probe sonication method had a micelle structure with fenofibrate incorporated into a lipid monolayer. This study provides an insight into the systematic development of novel amphiphilic lipids for solid lipid-based drug delivery system....

  5. Improved characterization of EV preparations based on protein to lipid ratio and lipid properties.

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    Xabier Osteikoetxea

    Full Text Available In recent years the study of extracellular vesicles has gathered much scientific and clinical interest. As the field is expanding, it is becoming clear that better methods for characterization and quantification of extracellular vesicles as well as better standards to compare studies are warranted. The goal of the present work was to find improved parameters to characterize extracellular vesicle preparations. Here we introduce a simple 96 well plate-based total lipid assay for determination of lipid content and protein to lipid ratios of extracellular vesicle preparations from various myeloid and lymphoid cell lines as well as blood plasma. These preparations included apoptotic bodies, microvesicles/microparticles, and exosomes isolated by size-based fractionation. We also investigated lipid bilayer order of extracellular vesicle subpopulations using Di-4-ANEPPDHQ lipid probe, and lipid composition using affinity reagents to clustered cholesterol (monoclonal anti-cholesterol antibody and ganglioside GM1 (cholera toxin subunit B. We have consistently found different protein to lipid ratios characteristic for the investigated extracellular vesicle subpopulations which were substantially altered in the case of vesicular damage or protein contamination. Spectral ratiometric imaging and flow cytometric analysis also revealed marked differences between the various vesicle populations in their lipid order and their clustered membrane cholesterol and GM1 content. Our study introduces for the first time a simple and readily available lipid assay to complement the widely used protein assays in order to better characterize extracellular vesicle preparations. Besides differentiating extracellular vesicle subpopulations, the novel parameters introduced in this work (protein to lipid ratio, lipid bilayer order, and lipid composition, may prove useful for quality control of extracellular vesicle related basic and clinical studies.

  6. Lipids in pharmaceutical and cosmetic preparations

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    González Rodríguez, María Luisa

    2000-04-01

    Full Text Available In this paper, a review of the applications of lipids in the pharmaceutical field has been reported. In a first stage, different lipids used as excipients in cosmetics and medicines have been described. Many vegetable oils are used in this sense: almond oil, apricot oil, avocado oil, borage oil, coffee oil, safflower oil, etc.; from de animal source, fish oil and bird oil can be employed as excipients in cosmetical formulations. Fats and waxes may be also used for this purpose. A broad range of phospholipids are suitable for use in cosmetics, pharmaceuticals and diagnosis. These substances are used as vehicle for therapeutic substances, such as liposomes. Finally, a study of lipids, as a function of their biological activity, as active substances for the elaboration of pharmaceuticals, cosmetics or nutritional supplements, was carried out. Carotenoids, retinoids, tocopherols are used for their antioxidant properties, that are important to health and diagnostic medicine.En el presente trabajo se ha llevado a cabo una revisión sobre las aplicaciones de los lípidos en el campo famacéutico. En un primer apartado, se describieron los diferentes lípidos utilizados como excipientes en cosmética y medicina. En este sentido, se utilizan muchos aceites vegetales, como el aceite de almendra, albaricoque, aguacate, borraja, café, cártamo, etc.; a partir de fuente animal, pueden emplearse como excipientes en formulaciones cosméticas los aceites de pescados y de aves. También se utilizan con este propósito las grasas y las ceras. Así mismo se revisan los fosfolípidos empleados en cosmética y en diagnosis, que actúan como vehículos transportadores de sustancias activas, como los liposomas. Finalmente, se llevó a cabo un estudio de los lípidos, en función de su actividad biológica, como sustancias activas que forman parte de la elaboración de formulaciones cosméticas, farmacéuticas o suplementos nutricionales. Los carotenoides, retinoides

  7. Peptide-Loaded Solid Lipid Nanoparticles Prepared through Coacervation Technique

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    Marina Gallarate

    2011-01-01

    Full Text Available Stearic acid solid lipid nanoparticles were prepared according to a new technique, called coacervation. The main goal of this experimental work was the entrapment of peptide drugs into SLN, which is a difficult task, since their chemical characteristics (molecular weight, hydrophilicity, and stability hamper peptide-containing formulations. Insulin and leuprolide, chosen as model peptide drugs, were encapsulated within nanoparticles after hydrophobic ion pairing with anionic surfactants. Peptide integrity was maintained after encapsulation, and nanoparticles can act in vitro as a sustained release system for peptide.

  8. Lipid oxidation in omega-3 emulsions prepared with milk proteins

    DEFF Research Database (Denmark)

    Horn, Anna Frisenfeldt; Nielsen, Nina Skall; Andersen, Ulf

    components. In these three studies different parameters that are expected to change the properties and structure of the proteins at the interface were investigated. The first study compares 70% emulsions with either sodium caseinate or whey protein isolate at two pH values with and without iron addition....... The properties of the emulsifier used and the structure at the interface are therefore expected to be of great importance for oxidation in emulsions. This presentation will include results from mainly three different studies of lipid oxidation in omega-3 emulsions prepared with milk proteins and protein....... The second study evaluates the effect of two different high pressure homogenizers on oxidation in 10% emulsions with the same emulsifiers as in the first study. Finally, the third study considers the effect of changing pH on oxidation in emulsions prepared with different whey protein components. Results...

  9. Preparation and Characterization of Minoxidil Loaded Nanostructured Lipid Carriers.

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    Wang, Wenxi; Chen, Lina; Huang, Xinyan; Shao, Anna

    2017-02-01

    Nanostructured lipid carriers (NLCs) are interesting delivery systems for enhancing the penetration of an active substance through the skin after topical administration. The present paper described the development of a novel NLCs for minoxidil (MXD) topical delivery. Stearic acid and oleic acid that showed the highest solubility for MXD were selected as solid lipid and liquid lipid, respectively, and the NLCs were prepared by hot high pressure homogenization method. The minoxidil loaded NLCs prepared accordingly to the optimal formulation exhibited spherical shape with a mean diameter of 281.4 ± 7.4 nm, polydispersity of 0.207 ± 0.009, zeta potential of -32.90 ± 1.23 mV, drug entrapment efficiency of 92.48 ± 0.31%, and drug loading of 13.85 ± 0.47%. Storage stability studies demonstrated that the particle size and entrapment efficiency of the MXD-NLCs were not changed during 3 months both at 4°C and room temperature. Moreover, the release of MXD from the NLCs was faster than drug release from SLNs. In vitro skin permeability test demonstrated that MXD-NLCs had a more pronounced permeation and retention profile than MXD-SLNs. Furthermore, no erythema was observed after administration of MXD-NLCs. All these results indicated that the developed MXD-NLCs could be a promising and effective nanocarrier for topical delivery of MXD.

  10. Multiscale Modeling of Supported Lipid Bilayers

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    Hoopes, Matthew I.; Xing, Chenyue; Faller, Roland

    Cell membranes consist of a multitude of lipid molecules that serve as a framework for the even greater variety of membrane associated proteins [1-4]. As this highly complex (nonequilibrium) system cannot easily be understood and studied in a controlled way, a wide variety of model systems have been devised to understand the dynamics, structure, and thermodynamics in biological membranes. One such model system is a supported lipid bilayer (SLB), a two-dimensional membrane suspended on a surface. SLBs have been realized to be manageable experimentally while reproducing many of the key features of real biological membranes [5,6]. One of the main advantages of supported bilayers is the physical stability due to the solid support that enables a wide range of surface characterization techniques not available to free or unsupported membranes. As SLBs maintain some of the crucial structural and dynamic properties of biological membranes, they provide an important bridge to natural systems. In order to mimic cell membranes reliably, certain structural and dynamic features have to be reliably reproduced in the artificially constructed lipid bilayers. SLBs should display lateral mobility as in living cells, because many membrane activities involve transport, recruitment, or assembly of specific components. It is also critical for membranes to exhibit the correct thermodynamic phase, namely, a fluid lipid bilayer, to respond to environmental stress such as temperature and pressure changes [7]. There are several ways to fabricate supported lipid bilayers (SLBs) on planar substrates. One can use vesicle fusion on solid substrates [5,8-10] as well as Langmuir-Blodgett deposition [11,12]. Proteoliposome adsorption and subsequent membrane formation on a mica surface was first demonstrated by Brian and McConnell [13]. Because of its simplicity and reproducibility, this is one of the most common approaches to prepare supported membranes. A diverse range of different solid substrates

  11. Preparation and characterization of Biochanin A loaded solid lipid nanoparticles

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    Chunlei Tao

    2012-01-01

    Full Text Available Biochanin A, the predominant isoflavones found in plants, had proved its human health benefits. The purpose of this research was to study whether Biochanin A (BCA loaded solid lipid nanoparticles (SLN could improve solution and prolong the half-life of BCA. BCA-SLN was prepared by emulsion evaporation and low temperature solidification technique, and freeze-dried powders were developed to improve stability. The mean particle sizes, zeta potential, entrapment efficiency (EE, and drug loading capacity (DL of BCA was 176.0 nm, −18.7 ± 0.26, 97.15 ± 0.28%, and 6.38 ± 0.04%, respectively. The results of differential scanning calorimetry (DSC and X-ray diffraction analysis (XRD indicated that the BCA was wrapped and absorbed in the nanoparticles. The solution of preparation is much higher than the untreated BCA. Results of stability of SLN showed a relatively short-term stability after storage at 4°C and 25°C for 15 days. Drug release of untreated BCA and BCA-SLN was fit into the Biexponential equations and Weibull equations, respectively, and SLN showed sustained release properties. But after freeze-dried, stability was improved, and the EE and DL had a slightly decrease. The mean particle size was slightly increased, but the structure was not changed. In conclusion, SLN systems can represent an effective strategy to change the poor aqueous solubility and prolong the half-time of BCA.

  12. Lipid mixtures prepared with well-defined synthetic ceramides closely mimic the unique stratum corneum lipid phase behavior.

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    de Jager, Miranda W; Gooris, Gert S; Ponec, Maria; Bouwstra, Joke A

    2005-12-01

    Lipid lamellae present in the outermost layer of the skin, the stratum corneum, form the main barrier for the diffusion of molecules through the skin. The presence of a unique 13 nm lamellar phase and its high crystallinity are characteristic for the stratum corneum lipid phase behavior. In the present study, small-angle and wide-angle X-ray diffraction were used to examine the organization in lipid mixtures prepared with a unique set of well-defined synthetic ceramides, varying from each other in head group architecture and acyl chain length. The results show that equimolar mixtures of cholesterol, free fatty acids, and synthetic ceramides (resembling the composition of pig ceramides) closely resemble the lamellar and lateral stratum corneum lipid organization, both at room and higher temperatures. Exclusion of several ceramide classes from the mixture does not affect the lipid organization. However, complete substitution of ceramide 1 (acylceramide with a sphingosine base) with ceramide 9 (acylceramide with a phytosphingosine base) reduces the formation of the long periodicity lamellar phase. This indicates that the head group architecture of acylceramides affects the lipid organization. In conclusion, lipid mixtures prepared with well-defined synthetic ceramides offer an attractive tool with which to unravel the importance of the molecular structure of individual ceramides for proper lipid organization.

  13. Preparation and characteristics of lipid nanoemulsion formulations loaded with doxorubicin

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    Jiang SP

    2013-08-01

    Full Text Available Sai-Ping Jiang,1,2,* Sai-Nan He,3,* Yun-Long Li,2,3 Da-Lin Feng,2 Xiao-Yang Lu,1 Yong-Zhong Du,2 He-Yong Yu,3 Fu-Qiang Hu,2 Hong Yuan2 1Department of Pharmacy, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 2College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 3Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China *These authors contributed equally to this work Purpose: Safe and effective lipid nanoemulsion (LNE formulations for the antitumor delivery of doxorubicin is designed. Methods: LNEs composed of medium-chain triglyceride, soybean oil, lecithin, and doxorubicin are prepared by a solvent-diffusion method in an aqueous system. The effects of lipid material composition and polyethylene glycol (PEGylation on the size, drug encapsulation efficiency, and stability of LNEs are investigated. Based on in-vitro cytotoxicity and cellular uptake tests of A549 (human lung carcinoma cells, in-vivo biodistribution, antitumor activity, and cardiac toxicity are further examined using nude mouse bearing A549 tumor. Results: The LNE size decreases from 126.4 ± 8.7 nm to 44.5 ± 9.3 nm with increased weight ratio of medium-chain triglyceride to soybean oil from 1:4 to 3:2, whereas the encapsulation efficiency of doxorubicin is slightly reduced from 79.2% ± 2.1% to 71.2% ± 2.9%. The PEGylation of LNE by 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(PEG2000] (DSPE-PEG 2000 does not significantly change the size and drug encapsulation efficiency. Three-month storage at room temperature and lyophilization process does not affect the drug encapsulation efficiency, whereas the size slightly increases to almost 100 nm. The in-vitro drug-release profiles of LNEs suggest that the present formulation can prolong drug release for 48 hours. LNEs can be internalized into tumor cells in vitro and efficiently accumulate in tumor tissues in vivo by passive targeting

  14. Novel preparation of intercellular lipid models of the stratum corneum containing stereoactive ceramide.

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    Watanabe, Hiroshi; Obata, Yasuko; Onuki, Yoshinori; Ishida, Kenya; Takayama, Kozo

    2010-03-01

    The microstructure formed by intercellular lipids in the stratum corneum is important for the barrier function of the skin. However, the correlation between lipid composition and microstructure has not yet been clarified. To elucidate the microstructure of intercellular lipids in the stratum corneum, an intercellular lipid model was prepared from ceramide 5 (CER5), cholesterol (CHOL), and palmitic acid (PA), considering the nonuniformity of the lipid components of the stratum corneum. A response surface method incorporating thin-plate spline interpolation (RSM-S) was employed to prepare the CER5/CHOL/PA lipid bilayers. Fluorescence anisotropy of the CER5/CHOL/PA bilayers showed four distinct clusters based on Kohonen's self-organizing maps (SOM). At the centroid formulation of those clusters, the microstructures of CER5/CHOL/PA bilayers were determined using synchrotron X-ray scattering. Three kinds of lamellar structures and two kinds of lateral packing-namely, hexagonal and orthorhombic-were formed. The microstructure of the CER5/CHOL/PA bilayers was likely to be intrinsic to the intercellular lipids in the stratum corneum. In conclusion, the CER5/CHOL/PA bilayers prepared based on RSM-S and SOM were useful as models of the intercellular lipids in the stratum corneum.

  15. Preparation and characterization of n-dodecyl-ferulate-loaded solid lipid nanoparticles (SLN).

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    Souto, E B; Anselmi, C; Centini, M; Müller, R H

    2005-05-13

    Solid lipid nanoparticles (SLN) containing a novel potential sunscreen n-dodecyl-ferulate (ester of ferulic acid) were developed. The preparation and stability parameters of n-dodecyl-ferulate-loaded SLN have been investigated concerning particle size, surface electrical charge (zeta potential) and matrix crystallinity. The chemical stability of n-dodecyl-ferulate at high temperatures was also assessed by thermal gravimetry analysis. For the selection of the appropriated lipid matrix, chemically different lipids were melted with 4% (m/m) of active and lipid nanoparticles were prepared by the so-called high pressure homogenization technique. n-Dodecyl-ferulate-loaded SLN prepared with cetyl palmitate showed the lowest mean particle size and polydispersity index, as well as the highest physical stability during storage time of 21 days at 4, 20 and 40 degrees C. These colloidal dispersions containing the sunscreen also exhibited the common melting behaviour of aqueous SLN dispersions.

  16. Amphotericin B lipid preparations: what are the differences?

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    Adler-Moore, J P; Proffitt, R T

    2008-05-01

    To reduce the in-vivo toxicity of the broad-spectrum antifungal drug amphotericin B, various lipid formulations of amphotericin B, ranging from lipid complexes to small unilamellar liposomes, have been developed and subsequently commercialized. These structurally diverse formulations differ in their serum pharmacokinetics as well as their tissue localisation, tissue retention and toxicity. These differences can affect the choice of formulation for a given infection, the time of initiation of treatment, and the dosing regimen. Although preclinical studies have shown similarities in the in-vitro and in-vivo antifungal activity of the formulations with comparable dosing, their acute and chronic toxicity profiles are not the same, and this has a significant impact on their therapeutic indices, especially in high-risk, immunosuppressed patients. With the recent introduction of new antifungal drugs to treat the increasing numbers of infected patients, the amphotericin B lipid formulations are now being studied to evaluate their potential in combination drug regimens. With proven efficacy demonstrated during the past decade, it is expected that amphotericin B lipid formulations will remain an important part of antifungal drug therapy.

  17. Stabilization of polymer lipid complexes prepared with lipids of lactic acid bacteria upon preservation and internalization into eukaryotic cells.

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    Alves, P; Hugo, A A; Szymanowski, F; Tymczyszyn, E E; Pérez, P F; Coelho, J F J; Simões, P N; Gómez-Zavaglia, A

    2014-11-01

    The physicochemical characterization of polymer liposome complexes (PLCs) prepared with lipids of lactic acid bacteria and poly(N,N-dimethylaminoethyl methacrylate) covalently bound to cholesterol (CHO-PDMAEMA) was carried out in an integrated approach, including their stability upon preservation and incorporation into eukaryotic cells. PLCs were prepared with different polymer:lipid molar ratios (0, 0.05 and 0.10). Zeta potential, particle size distribution and polydispersity index were determined. The optimal polymer:lipid ratio and the stability of both bare liposomes and PLCs were evaluated at 37 °C and at different pHs, as well as after storage at 4 °C, -80 °C and freeze-drying in the presence or absence of trehalose 250 mM. Internalization of PLCs by eukaryotic cells was assessed to give a complete picture of the system. Incorporation of CHO-PDMAEMA onto bacterial lipids (ratio 0.05 and 0.10) led to stabilization at 37 °C and pH 7. A slight decrease of pH led to their strong destabilization. Bacteria PLCs showed to be more stable than lecithin (LEC) PLCs (used for comparison) upon preservation at 4 and -80 °C. The harmful nature of the preservation processes led to a strong decrease in the stability of PLCs, bacterial formulations being more stable than LEC PLCs. The addition of trehalose to the suspension of liposomes stabilized LEC PLC and did not have effect on bacterial PLCs. In vitro studies on Raw 264.7 and Caco-2/TC7 cells demonstrated an efficient incorporation of PLCs into the cells. Preparations with higher stability were the ones that showed a better cell-uptake. The nature of the lipid composition is determinant for the stability of PLCs. Lipids from lactic acid bacteria are composed of glycolipids and phospholipids like cardiolipin and phosphatidylglycerol. The presence of negatively charged lipids strongly improves the interaction with the positively charged CHO-PDMAEMA, thus stabilizing liposomes. In addition, glycolipids and

  18. Hydrogel Micro-/Nanosphere Coated by a Lipid Bilayer: Preparation and Microscopic Probing

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    Sarah Rahni

    2017-02-01

    Full Text Available The result of polymeric nanogels and lipid vesicles interaction—lipobeads—can be considered as multipurpose containers for future therapeutic applications, such as targeted anticancer chemotherapy with superior tumor response and minimum side effects. In this work, micrometer sized lipobeads were synthesized by two methods: (i mixing separately prepared microgels made of poly(N-isopropylacrylamide (PNIPA and phospholipid vesicles of micrometer or nanometer size and (ii polymerization within the lipid vesicles. For the first time, a high vacuum scanning electron microscopy was shown to be suitable for a quick validation of the structural organization of wet lipobeads and their constituents without special sample preparation. In particular, the structural difference of microgels prepared by thermal and UV-polymerization in different solvents was revealed and three types of giant liposomes were recognized under high vacuum in conjunction with their size, composition, and method of preparation. Importantly, the substructure of the hydrogel core and multi- and unilamellar constructions of the peripheral lipid part were explicitly distinguished on the SEM images of lipobeads, justifying the spontaneous formation of a lipid bilayer on the surface of microgels and evidencing an energetically favorable structural organization of the hydrogel/lipid bilayer assembly. This key property can facilitate lipobeads’ preparation and decrease technological expenses on their scaled production. The comparison of the SEM imaging with the scanning confocal and atomic force microscopies data are also presented in the discussion.

  19. Lipid rafts prepared by different methods contain different connexin channels, but gap junctions are not lipid rafts.

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    Locke, Darren; Liu, Jade; Harris, Andrew L

    2005-10-04

    Cell extraction with cold nonionic detergents or alkaline carbonate prepares an insoluble membrane fraction whose buoyant density permits its flotation in discontinuous sucrose gradients. These lipid "rafts" are implicated in protein sorting and are attractive candidates as platforms that coordinate signal transduction pathways with intracellular substrates. Gap junctions form a direct molecular signaling pathway by end-to-end apposition of hemichannels containing one (homomeric) or more (heteromeric) connexin isoforms. Residency of channels composed of Cx26 and/or Cx32 in lipid rafts was assessed by membrane insolubility in alkaline carbonate or different concentrations of Triton X100, Nonidet P40 and Brij-58 nonionic detergents. Using Triton X100, insoluble raft membranes contained homomeric Cx32 channels, but Cx26-containing channels only when low detergent concentrations were used. Results were similar using Nonidet P40, except that Cx26-containing channels were excluded from raft membranes at all detergent concentrations. In contrast, homomeric Cx26 channels were enriched within Brij-58-insoluble rafts, whereas Cx32-containing channels partitioned between raft and nonraft membranes. Immunofluorescence microscopy showed prominent colocalization only of nonjunctional connexin channels with raft plasma membrane; junctional plaques were not lipid rafts. Rafts prepared by different extraction methods had considerable quantitative and qualitative differences in their lipid compositions. That functionally different nonjunctional connexin channels partition among rafts with distinct lipid compositions suggests that unpaired Cx26 and/or Cx32 channels exist in membrane domains of slightly different physicochemical character. Rafts may be involved in trafficking of plasma membrane connexin channels to gap junctions.

  20. Preparation and characteristics of nanostructured lipid carriers for control-releasing progesterone by melt-emulsification.

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    Yuan, Hong; Wang, Lei-Lei; Du, Yong-Zhong; You, Jian; Hu, Fu-Qiang; Zeng, Su

    2007-11-15

    Nanostructured lipid carriers (NLC) made from mixtures of solid and spatially incompatible liquid lipids were prepared by melt-emulsification. Their drug loading capacity and releasing properties of progesterone were compared with those of solid lipid nanoparticles (SLN), and the NLC prepared by solvent diffusion method. Monostearin (MS) and stearic acid (SA) were used as solid lipid, whilst the oleic acid (OA) was used as liquid lipid. Properties of carriers such as the particle size and its distribution, drug loading, drug encapsulation efficiency and drug release behavior were investigated. As a result, the drug encapsulation efficiencies were improved by adding the liquid lipid into the solid lipid of nanoparticles. The drug release behavior could be adjusted by the addition of liquid lipid, and the NLC with higher OA content showed the faster rate of drug releasing. NLC had higher efficiency of encapsulation and slower rate of drug release than those of NLC prepared by solvent diffusion method. On the other hand, the NLC with higher drug loading was obtained, though the drug encapsulation efficiency was decreased slightly due to the increase of the amount of drug. The NLC modified with polyethylene glycol (PEG) was also prepared by using polyethylene glycol monostearate (PEG-SA). It was observed that the incorporation of PEG-SA reduced the drug encapsulation efficiency, but increased the rate of drug release. A sample with almost complete drug release in 24h was obtained by modifying with 1.30mol% PEG-SA. It indicated that the modified NLC was a potential drug delivery system for oral administration.

  1. Stimulation pattern dependent contractions of myocardial preparations after lipid diets.

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    Günther, J; Oppelt, F; Storch, E; Thamm, E

    1986-01-01

    Lipid diets modify the electro-mechanical coupling. To characterize the regulation of the supply of Ca for the activation of the contraction the influence of the stimulation pattern on the development of tension was investigated after diets containing cholesterol (Ch), rape oil (RO) and cholesterol-oil (ChO). The sequence of increasing inotropic states produced was compared with a control group (C). In ChO high resting potentiation, low postextrastimulatory potentiation (PEP) and a delayed Ca supply for interpolated extra contractions (EC) are typical features. The positive inotropic effect of rising extracellular Ca grows parallel to the sequence of the inotropic states. The maximum rate of contraction and relaxation correlates linearly with the tension development. Some of the results are similar in RO. In both groups a more pronounced involvement of the sarcoplasmic reticulum in the Ca regulation should be responsible for the effects. Especially in C the Ca loading effect of paired stimulation shortens the latent period and increases the rate of contraction and relaxation. In Ch the highest values of PEP are reached. These results reflect the involvement of a high sarcolemmal fraction of Ca in the activation.

  2. Facilitated preparation of bioconjugatable zwitterionic quantum dots using dual-lipid encapsulation.

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    Shrake, Robert; Demillo, Violeta G; Ahmadiantehrani, Mojtaba; Zhu, Xiaoshan; Publicover, Nelson G; Hunter, Kenneth W

    2015-01-01

    Zwitterionic quantum dots prepared through incorporated zwitterionic ligands on quantum dot surfaces, are being paid significant attention in biomedical applications because of their excellent colloidal stability across a wide pH and ionic strength range, antifouling surface, good biocompatibility, etc. In this work, we report a dual-lipid encapsulation approach to prepare bioconjugatable zwitterionic quantum dots using amidosulfobetaine-16 lipids, dipalmitoyl-sn-glycero-3-phosphoethanolamine lipids with functional head groups, and CuInS2/ZnS quantum dots in a tetrahydrofuran/methanol/water solvent system with sonication. Amidosulfobetaine-16 is a zwitterionic lipid and dipalmitoyl-sn-glycero-3-phosphoethanolamine, with its functional head, provides bioconjugation capability. Under sonication, tetrahydrofuran/methanol containing amidosulfobetaine-16, dipalmitoyl-sn-glycero-3-phosphoethanolamine, and hydrophobic quantum dots are dispersed in water to form droplets. Highly water-soluble tetrahydrofuran/methanol in droplets is further displaced by water, which induces the lipid self-assembling on hydrophobic surface of quantum dots and thus forms water soluble zwitterionic quantum dots. The prepared zwitterionic quantum dots maintain colloidal stability in aqueous solutions with high salinity and over a wide pH range. They are also able to be conjugated with biomolecules for bioassay with minimal nonspecific binding.

  3. Preparation of ultra-fine powders from polysaccharide-coated solid lipid nanoparticles and nanostructured lipid carriers by innovative nano spray drying technology.

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    Wang, Taoran; Hu, Qiaobin; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao

    2016-09-10

    In this study, five polysaccharides were applied as natural polymeric coating materials to prepare solid lipid nanoparticles (SLN) and nanostructure lipid carriers (NLC), and then the obtained lipid colloidal particles were transformed to solid powders by the innovative nano spray drying technology. The feasibility and suitability of this new technology to generate ultra-fine lipid powder particles were evaluated and the formulation was optimized. The spray dried SLN powder exhibited the aggregated and irregular shape and dimension, but small, uniform, well-separated spherical powder particles of was obtained from NLC. The optimal formulation of NLC was prepared by a 20-30% oleic acid content with carrageenan or pectin as coating material. Therefore, nano spray drying technology has a potential application to produce uniform, spherical, and sub-microscale lipid powder particles when the formulation of lipid delivery system is appropriately designed. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Preparation, characterization, and optimization of primaquine-loaded solid lipid nanoparticles

    CSIR Research Space (South Africa)

    Omwoyo, WN

    2014-08-01

    Full Text Available . The aim of this work was to design, synthesize, and characterize PQ-loaded solid lipid nanoparticles (SLNs) (PQ-SLNs) as a potential drug-delivery system. SLNs were prepared by a modified solvent emulsification evaporation method based on a water...

  5. Incorporation of ovalbumin into ISCOMs and related colloidal particles prepared by the lipid film hydration method.

    Science.gov (United States)

    Demana, Patrick H; Davies, Nigel M; Berger, Bianca; Rades, Thomas

    2004-07-08

    The aim of this study was to investigate the incorporation of a model antigen, fluorescently labelled ovalbumin (FITC-OVA), into various colloidal particles including immune stimulating complexes (ISCOMs), liposomes, ring and worm-like micelles, lamellae and lipidic/layered structures that are formed from various combinations of the triterpene saponin Quil A, cholesterol and phosphatidylethanolamine (PE) following hydration of PE/cholesterol lipid films with aqueous solutions of Quil A. Colloidal dispersions of these three components were also prepared by the dialysis method for comparison. FITC-OVA was conjugated with palmitic acid (P) and PE to produce P-FITC-OVA and PE-FITC-OVA, respectively. Both P-FITC-OVA and PE-FITC-OVA could be incorporated in all colloidal structures whereas FITC-OVA was incorporated only into liposomes. The incorporation of PE-FITC-OVA into all colloidal structures was significantly higher than P-FITC-OVA (P < 0.05). The degree of incorporation of protein was in the order: ring and worm-like micelles < liposomes and lipidic/layered structures < ISCOMs and lamellae. The incorporation of protein into the various particles prepared by the lipid film hydration method was similar to those for colloidal particles prepared by the dialysis method (provided both methods lead to the formation of the same colloidal structures). In the case of different colloidal structures arising due to the preparation method, differences in encapsulation efficiency were found (P < 0.05) for formulations with the same polar lipid composition. This study demonstrates that the various colloidal particles formed as a result of hydrating PE/cholesterol lipid films with different amounts of Quil A are capable of incorporating antigen, provided it is amphipathic. Some of these colloidal particles may be used as effective vaccine delivery systems.

  6. Optimization of solid lipid nanoparticles prepared by a single emulsification-solvent evaporation method

    Directory of Open Access Journals (Sweden)

    Deep Pooja

    2016-03-01

    Full Text Available This data article contains the data related to the research article “Characterization, biorecognitive activity and stability of WGA grafted lipid nanostructures for the controlled delivery of rifampicin” (Pooja et al. 2015 [1]. In the present study, SLN were prepared by a single emulsification-solvent evaporation method and the various steps of SLN preparation are shown in a flow chart. The preparation of SLN was optimized for various formulation variables including type and quantity of lipid, surfactant, amount of co-surfactant and volume of organic phase. Similarly, effect of variables related to homogezation, sonication and stirring processes, on the size and surface potential of SLN was determined and optimized.

  7. Preparation and use of lipid microemulsions as nutritional supplements for culturing mammalian cells.

    Science.gov (United States)

    Darfler, F J

    1990-08-01

    Cells grown in vitro generally have a requirement for an exogenous source of lipid. This requirement is often met by the addition of serum, lipoproteins, or lipids complexed to albumin. To overcome the disadvantages of using lipoproteins or albumin for culturing cells in serum-free media, a method has been devised to provide necessary lipids. This report describes the preparation and use of protein-free lipid microemulsions suitable for use in tissue culture. The microemulsions are prepared from purified, synthetic lipids to produce a homogeneous, water-soluble, stable suspension that can be sterile-filtered. The best results were obtained using a sonicate of cholesterol oleate, dipalmitoyl phosphatidylcholine, dilinoleoyl phosphatidylcholine, dimyristoyl phosphatidylglycerol, cholesterol, sphingomyelin, alpha-tocopherol, alpha-tocopherol acetate, and Tween 80. Using Chinese hamster ovary (CHO) cells in a protein-free medium, cell growth was 222% vs. control (no microemulsion) in a 5-d assay. Inclusion of the microemulsion to protein-free media also increased the growth rate of murine hybridomas, H9 transformed T lymphoblasts, and human skin keratinocytes.

  8. Preparation, characterization and evaluation of breviscapine lipid emulsions coated with monooleate-PEG-COOH.

    Science.gov (United States)

    Xiong, Fei; Xiong, Chen; Yao, Juan; Chen, Xinmei; Gu, Ning

    2011-12-15

    Series of monooleate-modified PEG with active carboxylic terminus on the other end (MO-PEG-COOH) were used to modify the lipid emulsions surface to prepare a sterically stabilized lipid emulsions for carrying Traditional Chinese Medicine - breviscapine. Based on the research of relationship between polymer structure and prolonged circulation activity, we developed an optimized formulation and a technological method to prepare the sterile and stable MO-PEG(10,000)-COOH (Bre-LE-PEG(10,000)) coated breviscapine lipid emulsions (Bre-LE) for intravenous administration. Follow the optimum preparation, the average particle size, polydispersity index, zeta potential, Ke value and content of final product were determined to be (207.1±8.5)nm, 0.197±0.005, (-33.6±2.0)mV, (21.1±2.3)% and (95.0±1.8)% respectively (n=3). The characteristics, stability and safety of Bre-LE-PEG(10,000) were also studied with Bre-LE as a control. Increased plasma concentration by surface modification of the lipid emulsions may enhance the pharmacological activity of breviscapine to promote blood circulation.

  9. Preparation of ibuprofen/lipid composite microparticles by supercritical fluid technique

    Institute of Scientific and Technical Information of China (English)

    Xia WANG; Hui CHEN; Yanni GUO; Yuzhong SU; Hongtao WANG; Jun LI

    2008-01-01

    Using the CO2-and N2-assisted atomization processes, the production of ibuprofen/lipid composite microparticles is investigated, in which the lipid includes myristic acid and tripalmitin. The produced composite particles show similar morphology to that of the pure lipids obtained by the same process. In the case of the N2-assisted process, the average size of composite part-icles is slightly larger than that of the pure lipid particles due to the difficulty of solidification when using N2. In the case of the CO2-assisted process, the average size of com-posite particles is slightly smaller than that of the pure myr-istic acid particles, but slightly larger than that of the pure tripalmitin particles. The dissolution study reveals that the drug release from the ibuprofen/myristic acid particles is enhanced in comparison with that of the unprocessed ibu-profen. For the particles produced by the N2-assisted pro-cess, the X-ray diffraction (XRD) patterns clearly indicate the encapsulation of ibuprofen into myristic acid. The obtained ibuprofen/tripalmitin composite particles with 5% or 20% of ibuprofen (in mass) evidently show the con-trolled drug release: only about 20% of the drug is released in 500 min from the ibuprofen/tripalmitin composite part-icles consisting of 20% ibuprofen prepared by the CO2-assisted process, and the same release is obtained from the ibuprofen/tripalmitin composite particles containing 5% ibuprofen prepared by the N2-assisted process.

  10. Influence of the preparation route on the supramolecular organization of lipids in a vesicular system

    DEFF Research Database (Denmark)

    Elizondo, Elisa; Larsen, Jannik; Hatzakis, Nikos

    2012-01-01

    A confocal fluorescence microscopy-based assay was used for studying the influence of the preparation route on the supramolecular organization of lipids in a vesicular system. In this work, vesicles composed of cholesterol and CTAB (1/1 mol %) or cholesterol and DOPC (2/8 mol %) and incorporating...... two membrane dyes were prepared by either a compressed fluid (CF)-based method (DELOS-susp) or a conventional film hydration procedure. They were subsequently immobilized and imaged individually using a confocal fluorescence microscope. Two integrated fluorescence intensities, I(dye1) and I(dye2...

  11. Preparation, characterization and scale-up of sesamol loaded solid lipid nanoparticles

    Directory of Open Access Journals (Sweden)

    Vandita Kakkar

    2012-01-01

    Full Text Available Sesamol loaded solid lipid nanoparticles (SSLNs were prepared with the aim of minimizing its distribution to tissues and achieving its targeting to the brain. Three scale-up batches (100x1 L of S-SLNs were prepared using a microemulsification technique and all parameters were statistically compared with the small batch (1x;10 mL. S-SLNs with a particle size of less than 106 nm with a spherical shape (transmission electron microscopy were successfully prepared with a total drug content and entrapment efficiency of 94.26±2.71% and 72.57±5.20%, respectively. Differential scanning calorimetry and infrared spectroscopy confirmed the formation of lipidic nanoparticles while powder X-ray diffraction revealed their amorphous profile. S-SLNs were found to be stable for three months at 5±3°C in accordance with International Conference on Harmonisation guidelines. The SLN preparation process was successfully scaled-up to a 100x batch on a laboratory scale. The procedure was easy to perform and allowed reproducible SLN dispersions to be obtained.

  12. Preparation and characterization of tetrandrine-phospholipid complex loaded lipid nanocapsules as potential oral carriers

    Directory of Open Access Journals (Sweden)

    Zhao YQ

    2013-10-01

    Full Text Available Yi-qing Zhao, Li-ping Wang, Chao Ma, Kun Zhao, Ying Liu, Nian-ping FengSchool of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of ChinaBackground: Tetrandrine is an active constituent that is extracted from the root tuber of the Chinese herb Stephania tetrandra S. Moore. It has shown various pharmacological effects, such as antitumor activity, multidrug resistance reversal, and hepatic fibrosis resistance. In clinical applications, it has been used to treat hypertension, pneumosilicosis, and lung cancer. However, the poor water solubility of tetrandrine has limited its application. In this study, a newly emerging oral drug carrier of phospholipid complex loaded lipid nanocapsules was developed to improve the oral bioavailability of tetrandrine.Methods: The phospholipid complex was prepared with the solvent-evaporation method to enhance the liposolubility of tetrandrine. The formation of the phospholipid complex was confirmed with a solubility study, infrared spectroscopy, and a differential scanning calorimetry (DSC analysis. The tetrandrine-phospholipid complex loaded lipid nanocapsules (TPC-LNCs were prepared using the phase inversion method. Lyophilization was performed with mannitol (10% as a cryoprotectant. TPC-LNCs were characterized according to their particle size, zeta potential, encapsulation efficiency, morphology by transmission electron microscopy, and crystallinity by DSC. In addition, the in vitro release of tetrandrine from TPC-LNCs was examined to potentially illustrate the in vivo release behavior. The in vivo bioavailability of TPC-LNCs was studied and compared to tetrandrine tablets in rats.Results: The liposolubility of tetrandrine in n-octanol improved from 8.34 µg/mL to 35.64 µg/mL in the tetrandrine-phospholipid complex. The prepared TPC-LNCs were spherical-shaped particles with a small size of 40 nm and a high encapsulation efficiency of 93.9%. DSC measurements revealed

  13. Preparation and characterization of fenofibrate-loaded nanostructured lipid carriers for oral bioavailability enhancement.

    Science.gov (United States)

    Tran, Tuan Hiep; Ramasamy, Thiruganesh; Truong, Duy Hieu; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

    2014-12-01

    The aim of this study is to investigate the potential of nanostructured lipid carriers (NLCs) in improving the oral bioavailability of a lipid lowering agent, fenofibrate (FEN). FEN-loaded NLCs (FEN-NLCs) were prepared by hot homogenization followed by an ultrasonication method using Compritol 888 ATO as a solid lipid, Labrafil M 1944CS as a liquid lipid, and soya lecithin and Tween 80 as emulsifiers. NLCs were characterized in terms of particle size and zeta potential, surface morphology, encapsulation efficiency, and physical state properties. Bioavailability studies were carried out in rats by oral administration of FEN-NLC. NLCs exhibited a spherical shape with a small particle size (84.9 ± 4.9 nm). The drug entrapment efficiency was 99% with a loading capacity of 9.93 ± 0.01% (w/w). Biphasic drug release manner with a burst release initially, followed by prolonged release was depicted for in vitro drug release studies. After oral administration of the FEN-NLC, drug concentration in plasma and AUCt-∞ was fourfold higher, respectively, compared to the free FEN suspension. According to these results, FEN-NLC could be a potential delivery system for improvement of loading capacity and control of drug release, thus prolonging drug action time in the body and enhancing the bioavailability.

  14. Development of olmesartan medoxomil lipid-based nanoparticles and nanosuspension: preparation, characterization and comparative pharmacokinetic evaluation.

    Science.gov (United States)

    B, Arun; D, Narendar; Veerabrahma, Kishan

    2017-03-14

    The aim was to enhance the oral bioavailability of olmesartan medoxomil (OM) by preparing solid lipid nanoparticles (SLNs) and comparing with nanosuspension (OM-NS). OM-SLNs and OM-NS were prepared by known methods. Prepared SLNs were evaluated for physical characters and in vivo pharmacokinetic (PK) performance in rats. OM-NS showed more than four-fold increase in the solubility. During DSC and XRD studies, drug incorporated in SLNs was found to be in amorphous form. The relative bioavailability of OM-SLN and OM-NS was 7.21- and 3.52-fold when compared with that of coarse suspension. Further, OM-SLNs also increased the oral bioavailability by two-fold over that of OM-NS.

  15. Preparation, Characterization and Evaluation of Quetiapine Fumarate Solid Lipid Nanoparticles to Improve the Oral Bioavailability

    Directory of Open Access Journals (Sweden)

    Arjun Narala

    2013-01-01

    Full Text Available Quetiapine fumarate is an antipsychotic drug with poor oral bioavailability (9% due to first-pass metabolism. Present work is an attempt to improve oral bioavailability of quetiapine fumarate by incorporating in solid lipid nanoparticles (SLN. Six quetiapine fumarate SLN formulations were developed using three different lipids by hot homogenisation followed by ultrasonication. The drug excipient compatibility was studied by differential scanning calorimetry (DSC. Stable quetiapine fumarate SLNs having a mean particle size of 200–250 nm with entrapment efficiency varying in between 80% and 92% were developed. The physical stability of optimized formulation F3 was checked at room temperature for 2 months. Comparative bioavailability studies were conducted in male Wistar rats after oral administration of quetiapine fumarate suspension and SLN formulation. The relative bioavailability of quetiapine fumarate from optimized SLN preparation was increased by 3.71 times when compared with the reference quetiapine fumarate suspension. The obtained results are indicative of SLNs as potential lipid carriers for improving the bioavailability of quetiapine fumarate by minimizing first-pass metabolism.

  16. Preparation and evaluation of solid lipid nanoparticles based nanogel for dermal delivery of meloxicam.

    Science.gov (United States)

    Khurana, S; Bedi, P M S; Jain, N K

    2013-01-01

    The aim of the current investigation was to prepare and investigate the potential of solid lipid nanoparticles based gel (SLN-gel) for the dermal delivery of meloxicam (MLX). The meloxicam loaded SLN (MLX-SLN) gel was developed and characterized by means of photon correlation spectroscopy, rheometry, and differential scanning calorimetry to determine the physicochemical properties. The behavior of SLN gel on rat skin was evaluated in vitro using Franz diffusion cells to determine the skin permeation and penetration characteristics, in vivo on mice to determine the skin tolerance by histopathological examinations. The anti-inflammatory potential of SLN gel was assessed by carrageenan induced rat paw edema test. Biophysical studies including differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were undertaken to study the interaction between the SLN gel and skin. MLX-SLN gel with nanometric particle size exhibited the controlled release abilities and simultaneously the potential to transport the drug to various skin layers. SLN gel displayed viscoelastic properties with predominantly elastic behavior and exhibited plastic flow. Biophysical studies elucidated the interaction between the SLN gel and stratum corneum (SC) lipids, and proposed the lipid bilayer fluidization as the possible mechanism for the increased penetration of meloxicam into skin. The nano-gel system showed marked anti-inflammatory activity and excellent skin tolerability. It can be concluded that SLN gel may be a promising delivery system for MLX in the treatment of inflammatory disorders.

  17. Preparation and Characterization of Catalase-Loaded Solid Lipid Nanoparticles Protecting Enzyme against Proteolysis

    Directory of Open Access Journals (Sweden)

    Ce Qi

    2011-07-01

    Full Text Available Catalase-loaded solid lipid nanoparticles (SLNs were prepared by the double emulsion method (w/o/w and solvent evaporation techniques, using acetone/methylene chloride (1:1 as an organic solvent, lecithin and triglyceride as oil phase and Poloxmer 188 as a surfactant. The optimized SLN was prepared by lecithin: triglyceride ratio (5%, 20-second + 30-second sonication, and 2% Poloxmer 188. The mean particle size of SLN was 296.0 ± 7.0 nm, polydispersity index range and zeta potential were 0.322–0.354 and −36.4 ± 0.6, respectively, and the encapsulation efficiency reached its maximum of 77.9 ± 1.56. Catalase distributed between the solid lipid and inner aqueous phase and gradually released from Poloxmer coated SLNs up to 20% within 20 h. Catalase-loaded SLN remained at 30% of H2O2-degrading activity after being incubated with Proteinase K for 24 h, while free catalase lost activity within 1 h.

  18. Preparation and evaluation of novel octylmethoxycinnamate-loaded solid lipid nanoparticles.

    Science.gov (United States)

    Liu, X-h; Liang, X-z; Fang, X; Zhang, W-P

    2015-08-01

    Octylmethoxycinnamate (OMC)-loaded solid lipid nanoparticles (SLNs) were prepared by ultrasonic emulsification method. Effects of process variables and formulation composition were investigated on particle size and polydispersity index (PI), and the UV absorbance. Effect of OMC concentration on entrapment efficiency (EE) was also studied. The optimal formulation was characterized and evaluated by environment emission scanning electron microscopy (ESEM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). In addition, the degradations of OMC from SLNs and OMC conventional emulsion were compared. The composition of optimal formulation was determined as 5% (w/w) of solid lipid, 7% (w/w) of emulsifier and 9% of loaded OMC, resulting in a particle size of 392.8 nm, and EE of 88.73%, LD of 38.05% under the preparation condition of 6 min of sonication, 400 W of sonication power. ESEM study showed spherical particles with smooth surface. DSC studies indicated OMC encapsulation within the nanoparticle matrix. The characteristic peaks for OMC-SLNs stood at 1710, 1604, 1513, 1465 and 830.3 cm(-1) . The degradation rate of OMC was decreased when using SLNs formulations compared to conventional emulsion. Hence, the developed SLNs can be used as sunscreen carrier for improve the stability. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  19. Preparation, in vitro release, and pharmacokinetics in rabbits of lyophilized injection of sorafenib solid lipid nanoparticles

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    Zhang H

    2012-06-01

    Full Text Available Hong Zhang, Fu-Ming Zhang, Shi-Jun YanDepartment of Pharmacy, Renmin Hospital of Wuhan University, Wuhan, People’s Republic of ChinaAbstract: Sorafenib solid lipid nanoparticles (S-SLN were prepared by emulsion evaporation–solidification at low temperature. Morphology was examined by transmission electron microscope. Particle size and zeta potential were determined by laser granularity equipment. Encapsulation efficiency (EE was detected by Sephadex gel chromatography and high-performance liquid chromatography (HPLC. The in vitro release profile of S-SLN was studied with dialysis technology. The lyophilized injection of S-SLN was prepared by freeze drying and analyzed by differential scanning calorimetry. The plasma concentration of sorafenib in blood was determined by HPLC. The solid lipid nanoparticles assumed a spherical shape with an even distribution of diameter and particle size 108.23 ± 7.01 nm (n = 3. The polydispersity index, zeta potential, and EE were determined to be 0.25 ± 0.02, -16.37 ± 0.65 mV, and 93.49% ± 1.87%, respectively (n = 3. The in vitro release accorded with the Weibull distribution model. An equal volume of 15% (w/v mannitol performed better as the protective agent for a lyophilized injection of S-SLN with a new material phase formation. The pharmacokinetic processes of sorafenib solution and lyophilized injection of S-SLN in vivo were in accordance with the two-compartment and one-compartment models, respectively. S-SLN nanoparticles are thus considered a promising drug-delivery system.Keywords: sorafenib, solid lipid nanoparticles, material phase analysis, HPLC, release profile, pharmacokinetics

  20. Preparation and characterization of solid lipid nanoparticles loaded with frankincense and myrrh oil

    Directory of Open Access Journals (Sweden)

    Shi F

    2012-04-01

    Full Text Available Feng Shi, Ji-Hui Zhao, Ying Liu, Zhi Wang, Yong-Tai Zhang, Nian-Ping FengSchool of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of ChinaAbstract: The aim of the present study was to prepare solid lipid nanoparticles (SLNs for the oral delivery of frankincense and myrrh essential oils (FMO. Aqueous dispersions of SLNs were successfully prepared by a high-pressure homogenization method using Compritol 888 ATO as the solid lipid and soybean lecithin and Tween 80 as the surfactants. The properties of the SLNs such as particle size, zeta potential (ZP, and drug encapsulation efficiency (EE were investigated. The morphology of SLNs was observed by transmission electron microscopy (TEM. The crystallinity of the formulation was analyzed by differential scanning calorimetry (DSC and X-ray diffraction (XRD. In addition, drug evaporation release and antitumor activity were also studied. Round SLNs with a mean size of 113.3 ± 3.6 nm, a ZP of -16.8 ± 0.4 mV, and an EE of 80.60% ± 1.11% were obtained. DSC and XRD measurements revealed that less ordered structures were formed in the inner cores of the SLN particles. Evaporation loss of the active components in FMO could be reduced in the SLNs. Furthermore, the SLN formulation increased the antitumor efficacy of FMO in H22-bearing Kunming mice. Hence, the presented SLNs can be used as drug carriers for hydrophobic oil drugs extracted from traditional Chinese medicines.Keywords: solid lipid nanoparticles, frankincense oil, myrrh oil, evaporation release, antitumor activity, traditional Chinese medicine

  1. Preparation and evaluation of chitosan/ellagic acid/erythrocyte membrane lipid hemostatic composite sponge

    Institute of Scientific and Technical Information of China (English)

    贺庆; 敖强; 王臻; 刘伟强; 龚锴; 公衍道; 张秀芳

    2013-01-01

    BACKGROUND: Some previous studies have indicated that the hemostatic effect of chitosan is limited when dealing with severe injuries. Therefore, the procoagulant activity of chitosan-based hemostatic agents needs to be enhanced. OBJECTIVE: To prepare a novel chitosan/el agic acid/erythrocyte membrane lipid composite sponge and to evaluate its procoagulant activity and cytotoxicity.METHODS: Chitosan sponge and chitosan acetate sponge were prepared by freeze-drying method. Then chitosan/el agic acid/erythrocyte membrane lipid composite sponge was prepared by electrostatic adsorption method. Procoagulant activity of the chitosan, chitosan acetate, and chitosan/el agic acid/erythrocyte membrane lipid sponges was evaluated by the plasma recalcification time method. Hemostatic effect of these sponges was evaluated in the Sprague Dawley rat liver bleeding model, and the cytotoxicity to L929 cel line was evaluated. RESULTS AND CONCLUSION: The plasma recalcification time, bleeding time and blood loss of the chitosan/el agic acid/erythrocyte membrane lipid composite sponge group were significantly lower than those of the chitosan sponge and chitosan acetate sponge groups (P < 0.01). Cel culture experiment showed that the chitosan/el agic acid/erythrocyte membrane lipid composite sponge did not have cytotoxicity. The results indicate that the chitosan/el agic acid/erythrocyte membrane lipid composite sponge has the enhanced procoagulant activity and non-cytotoxicity.%  背景:部分文献报道壳聚糖对严重创伤的止血效果有限,因此以壳聚糖为基础止血剂的促凝血活性还有待进一步增强。目的:制备一种新型的壳聚糖/鞣花酸/红细胞膜脂复合海绵,评价其促凝血活性和细胞毒性。方法:通过冻干法制备壳聚糖海绵和壳聚糖乙酸盐海绵,然后再通过静电吸附法制备壳聚糖/鞣花酸/红细胞膜脂复合海绵。血浆复钙时间法观察3种海绵的促凝血活性,并检测3

  2. Profiling the Triacylglyceride Contents in Bat Integumentary Lipids by Preparative Thin Layer Chromatography and MALDI-TOF Mass Spectrometry

    Science.gov (United States)

    Pannkuk, Evan L.; Risch, Thomas S.; Savary, Brett J.

    2013-01-01

    The mammalian integument includes sebaceous glands that secrete an oily material onto the skin surface. Sebum production is part of the innate immune system that is protective against pathogenic microbes. Abnormal sebum production and chemical composition are also a clinical symptom of specific skin diseases. Sebum contains a complex mixture of lipids, including triacylglycerides, which is species-specific. The broad chemical properties exhibited by diverse lipid classes hinder the specific determination of sebum composition. Analytical techniques for lipids typically require chemical derivatizations that are labor-intensive and increase sample preparation costs. This paper describes how to extract lipids from mammalian integument, separate broad lipid classes by thin-layer chromatography, and profile the triacylglyceride contents using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This robust method enables a direct determination of the triacylglyceride profiles among species and individuals, and it can be readily applied to any taxonomic group of mammals. PMID:24056580

  3. Profiling the triacylglyceride contents in bat integumentary lipids by preparative thin layer chromatography and MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Pannkuk, Evan L; Risch, Thomas S; Savary, Brett J

    2013-09-05

    The mammalian integument includes sebaceous glands that secrete an oily material onto the skin surface. Sebum production is part of the innate immune system that is protective against pathogenic microbes. Abnormal sebum production and chemical composition are also a clinical symptom of specific skin diseases. Sebum contains a complex mixture of lipids, including triacylglycerides, which is species-specific. The broad chemical properties exhibited by diverse lipid classes hinder the specific determination of sebum composition. Analytical techniques for lipids typically require chemical derivatizations that are labor-intensive and increase sample preparation costs. This paper describes how to extract lipids from mammalian integument, separate broad lipid classes by thin-layer chromatography, and profile the triacylglyceride contents using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This robust method enables a direct determination of the triacylglyceride profiles among species and individuals, and it can be readily applied to any taxonomic group of mammals.

  4. Preparation and evaluation of ofloxacin-loaded palmitic acid solid lipid nanoparticles

    Directory of Open Access Journals (Sweden)

    Shuyu Xie

    2011-03-01

    Full Text Available Shuyu Xie, Luyan Zhu, Zhao Dong, Yan Wang, Xiaofang Wang, WenZhong ZhouDepartment of Preventive Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of ChinaAbstract: The purpose of this study was to use solid lipid nanoparticles (SLN to improve the pharmacological activity of ofloxacin. Ofloxacin-loaded SLN were prepared using palmitic acid as lipid matrix and poly vinyl alcohol (PVA as emulsifier by a hot homogenization and ultrasonication method. The physicochemical characteristics of SLN were investigated by optical microscope, scanning electron microscopy, and photon correlation spectroscopy. Pharmacokinetics was studied after oral administration in mice. In vitro antibacterial activity and in vivo antibacterial efficacy of the SLN were investigated using minimal inhibitory concentrations (MIC and a mouse protection model. The results demonstrated that the encapsulation efficiency, loading capacity, diameter, polydispersivity index, and zeta potential of the nanoparticles were 41.36% ± 1.50%, 4.40% ± 0.16%, 156.33 ± 7.51 nm, 0.26 ± 0.04, and –22.70 ± 1.40 mv, respectively. The SLN showed sustained release and enhanced antibacterial activity in vitro. Pharmacokinetic results demonstrated that SLN increased the bioavailability of ofloxacin by 2.27-fold, and extended the mean residence time of the drug from 10.50 to 43.44 hours. Single oral administrations of ofloxacin-loaded nanoparticles at 3 drug doses, 5 mg/kg, 10 mg/kg, and 20 mg/kg, all produced higher survival rates of lethal infected mice compared with native ofloxacin. These results indicate that SLN might be a promising delivery system to enhance the pharmacological activity of ofloxacin.Keywords: ofloxacin, pharmacological activity, solid lipid nanoparticles, antibacterial activity

  5. Preparation and In Vitro Evaluation of Glycyrrhetinic Acid-Modified Curcumin-Loaded Nanostructured Lipid Carriers

    Directory of Open Access Journals (Sweden)

    Yang Chu

    2014-02-01

    Full Text Available Curcumin, a phenolic antioxidant compound derived from the rhizome of the turmeric plant Curcuma longa, has proven to be a modulator of intracellular signaling pathways that control cancer cell growth, inflammation, invasion and apoptosis, revealing its anticancer potential. In this study, a Glycyrrhetinic Acid-Modified Curcumin-Loaded Nanostructured Lipid Carrier (Cur-GA-PEG-NLC was prepared by the film ultrasound method to improve the tumor-targeting ability. The drug content was detected by an UV spectrophotometry method. The encapsulation efficiency of curcumin in the nanostructured lipid carriers (NLCs was determined using a mini-column centrifugation method. The encapsulation efficiency for various Cur-GA-PEG-NLC was within the range of 90.06%–95.31% and particle size was between 123.1 nm and 132.7 nm. An in vitro MTT assay showed that Cur-GA10%-PEG-NLC had significantly high cellular uptake and cytotoxicity against HepG2 cells compared with other groups.

  6. Preparation, characterization, pharmacokinetics and tissue distribution of solid lipid nanoparticles loaded with tetrandrine.

    Science.gov (United States)

    Li, Su; Ji, Zhaoshuai; Zou, Meijuan; Nie, Xin; Shi, Yijie; Cheng, Gang

    2011-09-01

    Tetrandrine (TET) is a poorly water-soluble bisbenzylisoquinoline alkaloid. In this study, TET solid lipid nanoparticles (SLNs) were prepared by a melt-emulsification and ultrasonication technique. Precirol(®) ATO 5, glyceryl monostearate, and stearic acid were used as the lipid matrix for the SLNs, while Lipoid E80, Pluronic F68, and sodium deoxycholate were used as emulsifying and stabilizing agents. The physicochemical characteristics of the TET-SLNs were investigated when it was found that the mean particle size and zeta potential of the TET-SLNs were 134 ± 1.3 nm and -53.8 ± 1.7 mV, respectively, and the entrapment efficiency (EE) was 89.57% ± 0.39%. Differential scanning calorimetry indicated that TET was in an amorphous state in SLNs. TET-SLNs exhibited a higher release rate at a lower pH and a lower release rate at a higher pH. The release pattern of the TET-SLNs followed the Weibull model. The pharmacokinetics of TET-SLNs after intravenous administration to male rats was studied. TET-SLN resulted in a higher plasma concentration and lower clearance. The biodistribution study indicated that TET-SLN showed a high uptake in reticuloendothelial system organs. In conclusion, TET-SLNs with a small particle size, and high EE, can be produced by the method described in this study. The SLN system is a promising approach for the intravenous delivery of tetrandrine.

  7. Preparation and characterization of ketoprofen-loaded solid lipid nanoparticles made from beeswax and carnauba wax.

    Science.gov (United States)

    Kheradmandnia, Soheila; Vasheghani-Farahani, Ebrahim; Nosrati, Mohsen; Atyabi, Fatemeh

    2010-12-01

    Solid lipid nanoparticles (SLNs) have been proposed as suitable colloidal carriers for delivery of drugs with limited solubility. Ketoprofen as a model drug was incorporated into SLNs prepared from a mixture of beeswax and carnauba wax using Tween 80 and egg lecithin as emulsifiers. The characteristics of the SLNs with various lipid and surfactant composition were investigated. The mean particle size of drug-loaded SLNs decreased upon mixing with Tween 80 and egg lecithin as well as upon increasing total surfactant concentration. SLNs of 75 ± 4 nm with a polydispersity index of 0.2 ± 0.02 were obtained using 1% (vol/vol) mixed surfactant at a ratio of 60:40 Tween 80 to egg lecithin. The zeta potential of these SLNs varied in the range of -15 to -17 (mV), suggesting the presence of similar interface properties. High drug entrapment efficiency of 97% revealed the ability of SLNs to incorporate a poorly water-soluble drug such as ketoprofen. Differential scanning calorimetry thermograms and high-performance liquid chromatographic analysis indicated the stability of nanoparticles with negligible drug leakage after 45 days of storage. It was also found that nanoparticles with more beeswax content in their core exhibited faster drug release as compared with those containing more carnauba wax in their structure.

  8. Preparation of microcrystals in lipidic cubic phase for serial femtosecond crystallography.

    Science.gov (United States)

    Liu, Wei; Ishchenko, Andrii; Cherezov, Vadim

    2014-09-01

    We have recently established a procedure for serial femtosecond crystallography (SFX) in lipidic cubic phase (LCP) for protein structure determination at X-ray free-electron lasers (XFELs). LCP-SFX uses the gel-like LCP as a matrix for growth and delivery of membrane protein microcrystals for crystallographic data collection. LCP is a liquid-crystalline mesophase composed of lipids and water. It provides a membrane-mimicking environment that stabilizes membrane proteins and supports their crystallization. Here we describe detailed procedures for the preparation and characterization of microcrystals for LCP-SFX applications. The advantages of LCP-SFX over traditional crystallographic methods include the capability of collecting room-temperature high-resolution data with minimal effects of radiation damage from sub-10-μm crystals of membrane and soluble proteins that are difficult to crystallize, while eliminating the need for crystal harvesting and cryo-cooling. Compared with SFX methods for microcrystals in solution using liquid injectors, LCP-SFX reduces protein consumption by 2-3 orders of magnitude for data collection at currently available XFELs. The whole procedure typically takes 3-5 d, including the time required for the crystals to grow.

  9. Preparation of calcium chloride-loaded solid lipid particles and heat-triggered calcium ion release

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Huangying; Kim, Jin-Chul [Kangwon National University, Chunchon (Korea, Republic of)

    2015-08-15

    CaCl{sub 2}-loaded solid lipid particles (SLPs) were prepared by a melt/emulsification/solidification method. CaCl{sub 2} microparticles (1-5 μm) could be obtained in a mortar with aid of the dispersant (Tween 80/Span80 (35/65, w/w)) when the ratio of CaCl{sub 2} to dispersant was 2 : 0.1 (w/w). SLP was prepared by dispersing 0.42 g of micronized CaCl{sub 2} particles in 2 g of molten PBSA, emulsifying the mixture at 85 .deg. C in 40 ml of Tween 20 solution (0.5% w/v), and quenching the emulsion in an ice bath. The diameter of CaCl{sub 2}-loaded SLP was 10-150 μm. The unenveloped CaCl{sub 2} could be removed by dialysis and the specific loading of CaCl{sub 2} in SLP was 0.036mg/mg. An EDS spectrum of CaCl{sub 2}-loaded SLP, which was dialyzed, showed that the unenveloped CaCl{sub 2} was completely removed. Any excipients (dispersant, Tween 20, CaCl{sub 2}) had little effect on the melting point of SLPs. No appreciable amount of Ca2+ was released in 20-50 .deg. C for 22 h. But the release degree at 60 .deg. C was significant (about 2.3%) during the same period. The matrix of the lipid particle was in a liquid state at 60 .deg. C, so CaCl{sub 2} particles could move freely and contact the surrounding water, leading to the release. At 70 .deg. C, the release degree at a given time was a few times higher than that obtained at 60 .deg. C.

  10. The preparation of magnetically guided lipid based nanoemulsions using self-emulsifying technology

    Energy Technology Data Exchange (ETDEWEB)

    Bakandritsos, Aristides; Bouropoulos, Nikolaos [Department of Materials Science, University of Patras, 26504 Rio, Patras (Greece); Zboril, Radek [Nanomaterial Research Centre, Palacky University, Svobody 26, 77146 Olomouc (Czech Republic); Kallinteri, Paraskevi; Favretto, Marco E [Medway School of Pharmacy, Universities of Kent/Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB (United Kingdom); Parker, Terry L [School of Biomedical Science, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Mullertz, Anette [Bioneer, FARMA, Faculty of Pharmaceutical Sciences, University of Copenhagen (Denmark); Fatouros, Dimitrios G, E-mail: abakan@upatras.gr, E-mail: zboril@prfnw.upol.cz, E-mail: dimitris.fatouros@port.ac.uk [School of Pharmacy and Biomedical Sciences, University of Portsmouth, St Michael' s Building, White Swan Road, Portsmouth PO1 2DT (United Kingdom)

    2010-02-05

    This paper reports an easy and highly reproducible preparation route, using self-emulsifying technology, for an orally administered high quality magnetically responsive drug delivery system. Hydrophobic iron oxide nanoparticles of about 5 nm in diameter were prepared and incorporated into the lipid core of the produced oil droplets of a self-nanoemulsifying drug delivery system (MagC{sub 18}/SNEDDS). The produced nanoemulsion exhibits colloidal stability at high ionic strengths and temperatures. The observed value of the saturation magnetization at 2 K is {approx}4.1 emu g{sup -1}. The nanoemulsion displayed the magnetic properties of a non-interacting assembly of superparamagnetic particles and a low blocking temperature. Moreover the effect of MagC{sub 18}/SNEDDS on biological systems in vitro was investigated in rodent fibroblasts (3T3 cells). The cytotoxicity studies show that none of the formulations tested affected cell activity significantly over the 24 h incubation. Such systems might have a potential use for oral delivery of poorly soluble compounds by extending the residence time of the formulation in the small intestine resulting in increased drug absorption values.

  11. Docetaxel-loaded solid lipid nanoparticles: preparation, characterization, in vitro, and in vivo evaluations.

    Science.gov (United States)

    Mosallaei, Navid; Jaafari, Mahmoud Reza; Hanafi-Bojd, Mohammad Yahya; Golmohammadzadeh, Shiva; Malaekeh-Nikouei, Bizhan

    2013-06-01

    The aim of the present study was to prepare, characterize, and evaluate solid lipid nanoparticles (SLNs) containing docetaxel (DTX) to improve the efficacy of this chemotherapeutic agent. SLNs containing DTX (SLN-DTX) were prepared by microemulsion and probe sonication techniques. In vitro cytotoxicity of SLN-DTX compared with Taxotere® (TXT) was evaluated on colorectal (C-26) and malignant melanoma (A-375) cell lines. Cellular uptake experiment was also carried out on C-26 cells. In in vivo tests, tumor inhibitory efficacy and survival were compared with TXT on C-26-implanted BALB/c mice. SLN-DTX particle size was 180 nm and PDI of 0.2 with spherical shape. Encapsulation efficacy was more than 98%. SLN-DTX at concentration of 100 μM caused 100% and 99.9% viability reduction in C-26 and A-375 after 48 and 72 h, respectively. The half maximal inhibitory concentration (IC50 ) of SLN-DTX on C-26 and A-375 was respectively 0.769 and 28.132 μM after 24 h. DTX cell uptake from SLN-DTX was remarkably higher than TXT. SLN-DTX showed better tumor inhibitory efficacy and survival at a dose of 10 mg/kg versus 10 and 20 mg/kg TXT. In conclusion, the results of the present study showed that the efficacy of SLN-DTX was better than TXT in cell-uptake and in vivo experiments.

  12. The preparation of magnetically guided lipid based nanoemulsions using self-emulsifying technology

    Science.gov (United States)

    Bakandritsos, Aristides; Zboril, Radek; Bouropoulos, Nikolaos; Kallinteri, Paraskevi; Favretto, Marco E.; Parker, Terry L.; Mullertz, Anette; Fatouros, Dimitrios G.

    2010-02-01

    This paper reports an easy and highly reproducible preparation route, using self-emulsifying technology, for an orally administered high quality magnetically responsive drug delivery system. Hydrophobic iron oxide nanoparticles of about 5 nm in diameter were prepared and incorporated into the lipid core of the produced oil droplets of a self-nanoemulsifying drug delivery system (MagC18/SNEDDS). The produced nanoemulsion exhibits colloidal stability at high ionic strengths and temperatures. The observed value of the saturation magnetization at 2 K is ≈4.1 emu g-1. The nanoemulsion displayed the magnetic properties of a non-interacting assembly of superparamagnetic particles and a low blocking temperature. Moreover the effect of MagC18/SNEDDS on biological systems in vitro was investigated in rodent fibroblasts (3T3 cells). The cytotoxicity studies show that none of the formulations tested affected cell activity significantly over the 24 h incubation. Such systems might have a potential use for oral delivery of poorly soluble compounds by extending the residence time of the formulation in the small intestine resulting in increased drug absorption values.

  13. Diclofenac sodium-loaded solid lipid nanoparticles prepared by emulsion/solvent evaporation method

    Energy Technology Data Exchange (ETDEWEB)

    Liu Dongfei; Jiang Sunmin [Nanjing Medical University, School of Pharmacy (China); Shen Hong [Nanjing Brain Hospital Affiliated to Nanjing Medical University, Neuro-Psychiatric Institute (China); Qin Shan; Liu Juanjuan; Zhang Qing; Li Rui, E-mail: chongloutougao@gmail.com; Xu Qunwei, E-mail: qunweixu@163.com [Nanjing Medical University, School of Pharmacy (China)

    2011-06-15

    The preparation of solid lipid nanoparticles (SLNs) suffers from the drawback of poor incorporation of water-soluble drugs. The aim of this study was therefore to assess various formulation and process parameters to enhance the incorporation of a water-soluble drug (diclofenac sodium, DS) into SLNs prepared by the emulsion/solvent evaporation method. Results showed that the entrapment efficiency (EE) of DS was increased to approximately 100% by lowering the pH of dispersed phase. The EE of DS-loaded SLNs (DS-SLNs) had been improved by the existence of cosurfactants and increment of PVA concentration. Stabilizers and their combination with PEG 400 in the dispersed phase also resulted in higher EE and drug loading (DL). EE increased and DL decreased as the phospholipid/DS ratio became greater, while the amount of DS had an opposite effect. Ethanol turned out to be the ideal solvent making DS-SLNs. EE and DL of DS-SLNs were not affected by either the stirring speed or the viscosity of aqueous and dispersed phase. According to the investigations, drug solubility in dispersion medium played the most important role in improving EE.

  14. Naringenin-loaded solid lipid nanoparticles: preparation, controlled delivery, cellular uptake, and pulmonary pharmacokinetics

    Directory of Open Access Journals (Sweden)

    Ji P

    2016-03-01

    Full Text Available Peng Ji, Tong Yu, Ying Liu, Jie Jiang, Jie Xu, Ying Zhao, Yanna Hao, Yang Qiu, Wenming Zhao, Chao WuCollege of Pharmacy, Liaoning Medical University, Jinzhou, Liaoning Province, People’s Republic of ChinaAbstract: Naringenin (NRG, a flavonoid compound, had been reported to exhibit extensive pharmacological effects, but its water solubility and oral bioavailability are only ~46±6 µg/mL and 5.8%, respectively. The purpose of this study is to design and develop NRG-loaded solid lipid nanoparticles (NRG-SLNs to provide prolonged and sustained drug release, with improved stability, involving nontoxic nanocarriers, and increase the bioavailability by means of pulmonary administration. Initially, a group contribution method was used to screen the best solid lipid matrix for the preparation of SLNs. NRG-SLNs were prepared by an emulsification and low-temperature solidification method and optimized using an orthogonal experiment approach. The morphology was examined by transmission electron microscopy, and the particle size and zeta potential were determined by photon correlation spectroscopy. The total drug content of NRG-SLNs was measured by high-performance liquid chromatography, and the encapsulation efficiency (EE was determined by Sephadex gel-50 chromatography and high-performance liquid chromatography. The in vitro NRG release studies were carried out using a dialysis bag. The best cryoprotectant to prepare NRG-SLN lyophilized powder for future structural characterization was selected using differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The short-term stability, 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl-tetrazolium bromide (MTT assay, cellular uptake, and pharmacokinetics in rats were studied after pulmonary administration of NRG-SLN lyophilized powder. Glycerol monostearate was selected to prepare SLNs, and the optimal formulation of NRG-SLNs was spherical in shape, with a particle

  15. Preparation, characterization and evaluation of moisturizing and UV protecting effects of topical solid lipid nanoparticles

    Directory of Open Access Journals (Sweden)

    Shiva Golmohammadzadeh

    2012-12-01

    Full Text Available Solid lipid nanoparticles (SLN were recently proposed as carriers for various pharmaceutical and cosmetic actives. These lipid nanoparticles can act as moisturizers and physical sunscreens on their own. Therefore, the full potential of these carriers has yet to be determined. The present study was aimed to determine and compare moisturizing and UV-protecting effects of different solid lipid nanoparticles (SLN prepared by different solid lipids including Glyceryl monostearate (GMS, Precirol® (P and cetyl palmitate (CP as carrier systems of moisturizers and sunscreens. The influence of the size and matrix crystallinity of the solid lipids on the occlusive factor, skin hydration and UV-protection were evaluated by in vitro and in vivo methods. The SLN were prepared by high-shear homogenization and ultrasound methods. Size, zeta potential and morphological characteristics of the samples were assessed by transmission electron microscopy (TEM and thermotropic properties with differential scanning calorimetry (DSC technique. Results of the assessments showed that SLN-CP significantly increases skin hydration and UV-protection, compared to SLN-GMS and SLN-P. It was demonstrated that the size of SLN, crystallinity index of solid lipid in SLN and probably other mechanisms besides the occlusive factor can influence skin hydration and UV-protection indices. Furthermore, findings of the assessments demonstrated significant difference between in vitro and in vivo assessments regarding occlusive factor and moisturizing effects. Findings of the present study indicate that the SLN-CP could be a promising carrier for sunscreens and moisturizers.Nanopartículas lipídicas sólidas (NLS foram, recentemente, propostas como carreadores de vários ativos cosméticos e farmacêuticos. Essas nanopartículas lipídicas podem atuar como hidratantes e protetores solares físicos por si só. Assim sendo, determinou-se o potencial desses carreadores. Os objetivos do

  16. Naringenin-loaded solid lipid nanoparticles: preparation, controlled delivery, cellular uptake, and pulmonary pharmacokinetics.

    Science.gov (United States)

    Ji, Peng; Yu, Tong; Liu, Ying; Jiang, Jie; Xu, Jie; Zhao, Ying; Hao, Yanna; Qiu, Yang; Zhao, Wenming; Wu, Chao

    2016-01-01

    Naringenin (NRG), a flavonoid compound, had been reported to exhibit extensive pharmacological effects, but its water solubility and oral bioavailability are only~46±6 µg/mL and 5.8%, respectively. The purpose of this study is to design and develop NRG-loaded solid lipid nanoparticles (NRG-SLNs) to provide prolonged and sustained drug release, with improved stability, involving nontoxic nanocarriers, and increase the bioavailability by means of pulmonary administration. Initially, a group contribution method was used to screen the best solid lipid matrix for the preparation of SLNs. NRG-SLNs were prepared by an emulsification and low-temperature solidification method and optimized using an orthogonal experiment approach. The morphology was examined by transmission electron microscopy, and the particle size and zeta potential were determined by photon correlation spectroscopy. The total drug content of NRG-SLNs was measured by high-performance liquid chromatography, and the encapsulation efficiency (EE) was determined by Sephadex gel-50 chromatography and high-performance liquid chromatography. The in vitro NRG release studies were carried out using a dialysis bag. The best cryoprotectant to prepare NRG-SLN lyophilized powder for future structural characterization was selected using differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The short-term stability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay, cellular uptake, and pharmacokinetics in rats were studied after pulmonary administration of NRG-SLN lyophilized powder. Glycerol monostearate was selected to prepare SLNs, and the optimal formulation of NRG-SLNs was spherical in shape, with a particle size of 98 nm, a polydispersity index of 0.258, a zeta potential of -31.4 mV, a total drug content of 9.76 mg, an EE of 79.11%, and a cumulative drug release of 80% in 48 hours with a sustained profile. In addition, 5% mannitol (w

  17. Preparation and in vivo toxicity study of solid lipid microparticles as carrier for pulmonary administration.

    Science.gov (United States)

    Sanna, Vanna; Kirschvink, Nathalie; Gustin, Pascal; Gavini, Elisabetta; Roland, Isabelle; Delattre, Luc; Evrard, Brigitte

    2004-03-10

    The purpose of this research was to investigate the effects of processing conditions on the characteristics of solid lipid microparticles (SLM) with a potential application as carriers for pulmonary administration. Compritol (5.0% wt/wt) SLM dispersions were prepared by rotor-stator homogenization, at different surfactant concentrations and emulsification times. The SLM were characterized, in terms of morphology and size, after lyophilization and sterilization by autoclaving process. In vivo assessment was carried out in rats by intratracheal instillation of either placebo or SLM dispersion, and by bronchoalveolar lavage for cytological analysis. Mean particle size of 4 to 5 microm was achieved using 0.3% and 0.4% (wt/wt) of emulsifier (Poloxamer 188) and emulsification times of 2 and 5 minutes. The particles showed spherical shape and smooth surface. The morphology of microparticles, the size, and the size distribution were not substantially modified after lyophilization and sterilization. Total cell counts showed no significant differences between placebo and SLM 0.5% or 2.5% groups. Regarding cytology, percentage of polymorphonuclear neutrophils and macrophages did not significantly differ between groups. These results suggest that a single intratracheal administration of the SLMs does not induce a significant inflammatory airway response in rats and that the SLMs might be a potential carrier for encapsulated drug via the pulmonary route.

  18. Preparation, characterisation and antibacterial activity of a florfenicol-loaded solid lipid nanoparticle suspension.

    Science.gov (United States)

    Wang, Ting; Chen, Xiaojin; Lu, Mengmeng; Li, Xihe; Zhou, WenZhong

    2015-12-01

    A florfenicol-loaded solid lipid nanoparticle (FFC-SLN) suspension was prepared by hot homogenisation and ultrasonic technique. The suspension was characterised for its release profile, stability, toxicity, and the physicochemical properties of the nanoparticles. Antibacterial activity of the suspension was evaluated in vitro and in vivo. The results showed that the mean diameter, polydispersity index and zeta potential of the nanoparticles were 253 ± 3 nm, 0.409 ± 0.022 and 47.5 ± 0.21 mV, respectively. In vitro release profile showed the FFC-SLN suspension had sustained release effect. The minimum inhibition concentration values of the FFC-SLN suspension were 6 and 3 µg/mL against Staphylococcus aureus and Escherichia coli respectively, compared with 3.5 and 2 µg/mL of native florfenicol. The suspension was relatively stable at 4°C and less stable at room temperature during 9 months storage. Although the nanoparticle carriers exhibited cytotoxicity in cell cultures, the LD50 of the lyophilised dry power of the suspension was higher than 5 g/kg body weight. Mortality protection against E. coli lethal infection in mice showed that the nanoparticle suspension had much better efficacy (6/10) than native drug (1/10). These results indicate that FFC-SLN suspension could be a promising formulation in veterinary medicine.

  19. Bevacizumab loaded solid lipid nanoparticles prepared by the coacervation technique: preliminary in vitro studies

    Science.gov (United States)

    Battaglia, Luigi; Gallarate, Marina; Peira, Elena; Chirio, Daniela; Solazzi, Ilaria; Giordano, Susanna Marzia Adele; Gigliotti, Casimiro Luca; Riganti, Chiara; Dianzani, Chiara

    2015-06-01

    Glioblastoma, the most common primary brain tumor in adults, has an inauspicious prognosis, given that overcoming the blood-brain barrier is the major obstacle to the pharmacological treatment of brain tumors. As neoangiogenesis plays a key role in glioblastoma growth, the US Food and Drug Administration approved bevacizumab (BVZ), an antivascular endothelial growth factor antibody for the treatment of recurrent glioblastoma in patients whose the initial therapy has failed. In this experimental work, BVZ was entrapped in solid lipid nanoparticles (SLNs) prepared by the fatty-acid coacervation technique, thanks to the formation of a hydrophobic ion pair. BVZ activity, which was evaluated by means of four different in vitro tests on HUVEC cells, increased by 100- to 200-fold when delivered in SLNs. Moreover, SLNs can enhance the permeation of fluorescently labelled BVZ through an hCMEC/D3 cell monolayer—an in vitro model of the blood brain barrier. These results are promising, even if further in vivo studies are required to evaluate the effective potential of BVZ-loaded SLNs in glioblastoma treatment.

  20. Preparation and characterization of vinpocetine loaded nanostructured lipid carriers (NLC) for improved oral bioavailability.

    Science.gov (United States)

    Zhuang, Chun-Yang; Li, Ning; Wang, Mi; Zhang, Xiao-Ning; Pan, Wei-San; Peng, Jun-Jie; Pan, Yu-Sheng; Tang, Xin

    2010-07-15

    The purpose of this study is to develop an optimized nanostructured lipid carriers (NLC) formulation for vinpocetine (VIN), and to estimate the potential of NLC as oral delivery system for poorly water-soluble drug. In this work, VIN-loaded NLC (VIN-NLC) was prepared by a high pressure homogenization method. The VIN-NLC showed spherical morphology with smooth surface under transmission electron microscope (TEM) and scanning electron microscopic (SEM) analysis. The average encapsulation efficiency was 94.9+/-0.4%. The crystallization of drug in NLC was investigated by powder X-ray diffraction and differential scanning calorimetry (DSC). The drug was in an amorphous state in the NLC matrix. In the in vitro release study, VIN-NLC showed a sustained release profile of VIN and no obviously burst release was observed. The oral bioavailability study of VIN was carried out using Wistar rats. The relative bioavailability of VIN-NLC was 322% compared with VIN suspension. In conclusion, the NLC formulation remarkably improved the oral bioavailability of VIN and demonstrated a promising perspective for oral delivery of poorly water-soluble drugs. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  1. Effect of cholinergic ligands on the lipids of acetylcholine receptor-rich membrane preparations from Torpedo californica

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Carrion, M.; Raftery, M.A.; Thomas, J.K.; Sator, V.

    1976-01-01

    Ion permeation, triggered by ligand-receptor interaction, is associated with the primary events of membrane depolarization at the neuromuscular junction and synaptic connections. To explore the possible sites of ion permeation, the long-lived fluorescent probe pyrene (fluorescence lifetime approximately 400 nsec) has been inserted into the lipid phase of acetylcholine receptor-rich membrane (AcChR-M) preparations from Torpedo californica. The pyrene probe is susceptible to both fluidity and permeability changes in the lipid bilayer. These changes are detected by variations in the rate of decay of the excited singlet state of pyrene after pulsation with a 10-nsec ruby laser flash. Variations of these lifetimes in the membrane preparations alone or in the presence of quenchers show that binding of cholinergic agonists and antagonists, neurotoxins, and local anesthetics to AcChR-M produces varying effects on the properties of the pyrene probe in the lipid phase. It is concluded that binding of cholinergic ligands to the receptor does not significantly alter the fluidity or permeability of the lipids in the bilayer in contact with pyrene. On the other hand, local anesthetics do affect these properties.

  2. Synthesis of an end-group functionalized polyethylene glycol-lipid conjugate for preparation of polymer-grafted liposomes.

    Science.gov (United States)

    Zalipsky, S

    1993-01-01

    Synthesis of a distearoylphosphatidylethanolamine-polyethylene glycol (DSPE-PEG) conjugate, bearing a hydrazide group at the unattached end of the polymer chain, was achieved using a new heterobifunctional polymeric reagent. The heterobifunctional PEG derivative carrying on one end a reactive succinimidyl carbonate (SC) group and at the other terminal a tert-butyloxycarbonyl (Boc) protected hydrazide group was prepared by an efficient four step process from readily available PEG-2000. The SC-end group of the polymer reacted readily with the amino group of DSPE forming a stable urethane attachment between lipid and PEG. Acidolytic removal of the Boc group yielded a hydrazide-PEG-lipid conjugate suitable for preparation of polymer-grafted liposomes. Taking advantage of the well-documented chemical versatility of hydrazide groups, various biologically relevant ligands can be linked to this type of functionalized liposomes.

  3. Preparation of tripterine nanostructured lipid carriers and their absorption in rat intestine.

    Science.gov (United States)

    Zhou, Lei; Chen, Yan; Zhang, Zhenhai; He, Junjie; Du, Meng; Wu, Qingqing

    2012-04-01

    The purpose of this study was to develop an optimized nanostructured lipid carrier formulation (NLC) for tripterine, and to estimate the potential of NLCs as oral delivery system. Tripterine-loaded NLCs were prepared by the solvent evaporation method. The average drug entrapment efficiency, particle size and zeta potential of the optimized tripterine-loaded NLCs were 78.64 +/- 0.37%, 109.6 +/- 5.8 nm and -29.8 +/- 1.3 mV, respectively. The tripterine-loaded NLCs showed spherical morphology with smooth surface under the transmission electron microscope (TEM). The crystallization of drug in NLC was investigated by differential scanning calorimetry (DSC). The drug was in an amorphous state in the NLC matrix. According to the in vitro release study, the tripterine-loaded NLCs showed a delayed release profile of tripterine. The rat intestinal perfusion model was used to study the absorption of tripterine solution and tripterine-loaded NLCs. The Peff* (effective permeability) of tripterine-loaded NLCs in the duodenum, jejunum, ileum and colon was approximately 2.1, 2.7, 1.1, 1.2-fold higher than that of tripterine solution, respectively. The 10% ABS (percent absorption of 10 cm of intestine) of tripterine-loaded NLCs in the duodenum, jejunum, ileum and colon was approximately 2.2, 2.3, 1.2, 1.3-fold higher than that of tripterine solution, respectively. The intestinal toxicity of tripterine formulated in the NLCs was investigated and compared with the tripterine solution by the MTT assay with Caco-2 cell models. According to the result, the tripterine-loaded NLCs could greatly decrease the cytotoxicity of the drug. In conclusion, the NLC formulation remarkably improved the absorption of tripterine and showed a better biocompatibility.

  4. Preparation and Delivery of Protein Microcrystals in Lipidic Cubic Phase for Serial Femtosecond Crystallography.

    Science.gov (United States)

    Ishchenko, Andrii; Cherezov, Vadim; Liu, Wei

    2016-09-20

    Membrane proteins (MPs) are essential components of cellular membranes and primary drug targets. Rational drug design relies on precise structural information, typically obtained by crystallography; however MPs are difficult to crystallize. Recent progress in MP structural determination has benefited greatly from the development of lipidic cubic phase (LCP) crystallization methods, which typically yield well-diffracting, but often small crystals that suffer from radiation damage during traditional crystallographic data collection at synchrotron sources. The development of new-generation X-ray free-electron laser (XFEL) sources that produce extremely bright femtosecond pulses has enabled room temperature data collection from microcrystals with no or negligible radiation damage. Our recent efforts in combining LCP technology with serial femtosecond crystallography (LCP-SFX) have resulted in high-resolution structures of several human G protein-coupled receptors, which represent a notoriously difficult target for structure determination. In the LCP-SFX technique, LCP is recruited as a matrix for both growth and delivery of MP microcrystals to the intersection of the injector stream with an XFEL beam for crystallographic data collection. It has been demonstrated that LCP-SFX can substantially improve the diffraction resolution when only sub-10 µm crystals are available, or when the use of smaller crystals at room temperature can overcome various problems associated with larger cryocooled crystals, such as accumulation of defects, high mosaicity and cryocooling artifacts. Future advancements in X-ray sources and detector technologies should make serial crystallography highly attractive and practicable for implementation not only at XFELs, but also at more accessible synchrotron beamlines. Here we present detailed visual protocols for the preparation, characterization and delivery of microcrystals in LCP for serial crystallography experiments. These protocols include

  5. HEPATIC INTRACELLULAR OSMIOPHILIC DROPLETS : Effect of Lipid Solvents during Tissue Preparation.

    Science.gov (United States)

    Ashworth, C T; Leonard, J S; Eigenbrodt, E H; Wrightsman, F J

    1966-11-01

    Lipid solvent extraction of aldehyde-fixed hepatic tissue of rats caused disappearance of all intravascular and hepatocellular osmiophilic droplets normally present, thus indicating their lipid content. Intramitochondrial dense granules and osmiophilic droplets in lysosomes also disappeared after this treatment. Lipid solvents extracted 43.8 to 92.6% of the radioactivity from aldehyde-fixed rat liver with C(14)-labeled lipids. Only 0.7 to 5.8% of the radioactivity was extracted when the hepatic proteins were labeled. When tissue was fixed with OsO(4), the lipid solvents extracted only 0.7 to 7.2% of the radioactivity from lipid-labeled liver and only 0 to 0.7% when proteins were labeled. Thin layer chromatography of the lipid solvents used in extraction of formaldehyde-fixed tissue revealed that triglyceride, phospholipid, and cholesterol and other lipid classes had been removed. However, acetone extracted less phospholipids than did ethanol or methanol-chloroform. During fat absorption the number and size of osmiophilic droplets increased in the nongranular endoplasmic reticulum. In animals fasted up to 5 days, 250-A osmiophilic particles were still present in the Golgi vesicles, other cytoplasmic vesicles, and in the space of Disse. These were considered possibly to represent lipoprotein being synthesized in the liver cell and secreted into the blood.

  6. Preparation, characterization, and optimization of primaquine-loaded solid lipid nanoparticles

    Directory of Open Access Journals (Sweden)

    Omwoyo WN

    2014-08-01

    Full Text Available Wesley Nyaigoti Omwoyo,1,2 Bernhards Ogutu,3,4 Florence Oloo,3,5 Hulda Swai,6 Lonji Kalombo,6 Paula Melariri,6 Geoffrey Maroa Mahanga,2 Jeremiah Waweru Gathirwa3,4 1Department of Chemistry, Maasai Mara University, Narok, Kenya; 2Department of Chemistry, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya; 3Center for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya; 4Kenya Medical Research Institute, Nairobi, Kenya; 5Department of Chemical Sciences and Technology, Technical University of Kenya, Nairobi, Kenya; 6Department of Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa Abstract: Primaquine (PQ is one of the most widely used antimalarial drugs and is the only available drug that combats the relapsing form of malaria. PQ use in higher doses is limited by severe tissue toxicity including hematological- and gastrointestinal-related side effects. Nanoformulation of drugs in an appropriate drug carrier system has been extensively studied and shown to have the potential to improve bioavailability, thereby enhancing activity, reducing dose frequency, and subsequently reducing toxicity. The aim of this work was to design, synthesize, and characterize PQ-loaded solid lipid nanoparticles (SLNs (PQ-SLNs as a potential drug-delivery system. SLNs were prepared by a modified solvent emulsification evaporation method based on a water-in-oil-in-water (w/o/w double emulsion. The mean particle size, zeta potential, drug loading, and encapsulation efficiency of the PQ-SLNs were 236 nm, +23 mV, 14%, and 75%, respectively. The zeta potential of the SLNs changed dramatically, from -6.54 mV to +23.0 mV, by binding positively charged chitosan as surface modifier. A spherical morphology of PQ-SLNs was seen by scanning electron microscope. In vitro, release profile depicted a steady drug release over 72 hours. Differential scanning calorimeter thermograms demonstrated presence

  7. CHANGES IN LIPID PARAMETERS AND ANTROPOMETRIC INDICATORS OF DIETING DURING THE PERIOD OF INTENSIVE PREPARATIONS OF TOP ATHLETES

    Directory of Open Access Journals (Sweden)

    Ljubiša Lilić

    2009-12-01

    Full Text Available Physical exercise is a planned and repeated exercise aiming to maintain and improve one or more aspects of physical condition. Increased sympathetic-adrenal activity and reduction of insulin concentration are the main stimuli of lipolysis during physical activity.The aim of this study was to investigate acute and chronic effects of intensive aerobic training program on lipid profile and antropometric parameters in young healthy soccer players.Fifteen healthy male (soccer players, average age 21.4±3.6 were included in this study. Soccer players had a minimum of 6 months continuous training that consisted of three training sessions per week. They did not smoke, take drugs or drink alcohol during the examination period. A balanced diet (60% carbohydrates, 25% lipids and 15% proteins was recommended by a nutritionist as a standard diet during the preparations period. This consisted of three repetitions of 20-min running sessions, with two 3-min breaks in-between. Target load was obtained at 120–140 bpm heart rate. Anthropometric estimation comprized determination of body fat % by impendansometer Omron BF306, body height (BH, body weight (BW, waist circumference (WC, waist/hip ratio (WHR and determination of body mass index (BMI=BW/BH2. Blood samples were taken prior to and 5-10 min after completion of exercise. Biochemical investigation comprized spectrophotometric determination of total cholesterol (TC, triglicerides (TG, HDL-C and low-density lipoprotein cholesterol (LDL-C. There was a significant reduction of body fat content % after 6 months of intensive physical preparation (p<0.05, but not of BMI and BW. There were no signifficant changes in waist circumference and WHR values at the end of physical preparation compared to the values from the beginning. There were not significant changes in TC and TG levels at the end of 6 months preparations; however significant changes in lipid fractions were present. There was a significant decrease in

  8. Preparation, characterization, and in vitro and in vivo evaluation of lovastatin solid lipid nanoparticles

    OpenAIRE

    Suresh, Gande; Manjunath, Kopparam; Venkateswarlu, Vobalaboina; Satyanarayana, Vemula

    2007-01-01

    The purpose of this research was to study whether the bioavailability of lovastatin could be improved by administering lovastatin solid lipid nanoparticles (SLN) duodenally to rats. Lovastatin SLN were developed using triglycerides by hot homogenization followed by ultrasonication. Particle size and zeta potential were measured by photon correlation spectroscopy. The solid state of the drug in the SLN and lipid modification were characterized. Bioavailability studies were conducted in male Wi...

  9. Optimization of {beta}-carotene loaded solid lipid nanoparticles preparation using a high shear homogenization technique

    Energy Technology Data Exchange (ETDEWEB)

    Triplett, Michael D., E-mail: triplettm@battelle.or [Battelle Memorial Institute, Health and Life Sciences Global Business (United States); Rathman, James F. [The Ohio State University, Department of Chemical and Biomolecular Engineering (United States)

    2009-04-15

    Using statistical experimental design methodologies, the solid lipid nanoparticle design space was found to be more robust than previously shown in literature. Formulation and high shear homogenization process effects on solid lipid nanoparticle size distribution, stability, drug loading, and drug release have been investigated. Experimentation indicated stearic acid as the optimal lipid, sodium taurocholate as the optimal cosurfactant, an optimum lecithin to sodium taurocholate ratio of 3:1, and an inverse relationship between mixing time and speed and nanoparticle size and polydispersity. Having defined the base solid lipid nanoparticle system, {beta}-carotene was incorporated into stearic acid nanoparticles to investigate the effects of introducing a drug into the base solid lipid nanoparticle system. The presence of {beta}-carotene produced a significant effect on the optimal formulation and process conditions, but the design space was found to be robust enough to accommodate the drug. {beta}-Carotene entrapment efficiency averaged 40%. {beta}-Carotene was retained in the nanoparticles for 1 month. As demonstrated herein, solid lipid nanoparticle technology can be sufficiently robust from a design standpoint to become commercially viable.

  10. A comparison of two common sample preparation techniques for lipid and fatty acid analysis in three different coral morphotypes reveals quantitative and qualitative differences.

    Science.gov (United States)

    Conlan, Jessica A; Rocker, Melissa M; Francis, David S

    2017-01-01

    Lipids are involved in a host of biochemical and physiological processes in corals. Therefore, changes in lipid composition reflect changes in the ecology, nutrition, and health of corals. As such, accurate lipid extraction, quantification, and identification is critical to obtain comprehensive insight into a coral's condition. However, discrepancies exist in sample preparation methodology globally, and it is currently unknown whether these techniques generate analogous results. This study compared the two most common sample preparation techniques for lipid analysis in corals: (1) tissue isolation by air-spraying and (2) crushing the coral in toto. Samples derived from each preparation technique were subsequently analysed to quantify lipids and their constituent classes and fatty acids in four common, scleractinian coral species representing three distinct morphotypes (Acropora millepora, Montipora crassotuberculata, Porites cylindrica, and Pocillopora damicornis). Results revealed substantial amounts of organic material, including lipids, retained in the skeletons of all species following air-spraying, causing a marked underestimation of total lipid concentration using this method. Moreover, lipid class and fatty acid compositions between the denuded skeleton and sprayed tissue were substantially different. In particular, the majority of the total triacylglycerol and total fatty acid concentrations were retained in the skeleton (55-69% and 56-64%, respectively). As such, the isolated, sprayed tissue cannot serve as a reliable proxy for lipid quantification or identification in the coral holobiont. The in toto crushing method is therefore recommended for coral sample preparation prior to lipid analysis to capture the lipid profile of the entire holobiont, permitting accurate diagnoses of coral condition.

  11. Formulation design, preparation, and in vitro and in vivo characterizations of β-Elemene- loaded nanostructured lipid carriers

    Directory of Open Access Journals (Sweden)

    Shi F

    2013-07-01

    Full Text Available Feng Shi,1 Gang Yang,1 Juan Ren,2 Teng Guo,1 Yan Du,1 Nianping Feng1 1Department of Pharmaceutics, School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China; 2Department of Traditional Chinese Medicine, Changhai Hospital, Shanghai, People's Republic of China Abstract: In the present study, nanostructured lipid carriers (NLCs were prepared and optimized for the intravenous delivery of β-Elemene (β-E. Aqueous dispersions of NLCs were successfully prepared by high-pressure homogenization method using glycerol monostearate as the solid lipid and a mixture of Maisine 35-1 and Labrafil M1944 CS as the liquid lipid. The results revealed that the morphology of the NLCs was spheroidal. The particle size, zeta potential, and entrapment efficiency (EE for the optimized formulation were observed as 138.9 nm, –20.2 mV, and 82.11%, respectively. X-ray diffraction analysis revealed the formation of less ordered structures in the inner core of the NLC particles. Moreover, the β-E-loaded NLCs were also less irritating and less toxic compared to Elemene injection. In addition, β-E-NLCs showed a significantly higher bioavailability and anti-tumor efficacy than Elemene injection. Taken together, our data indicate that the β-E-NLCs described in this study are well-suited for the intravenous delivery of β-E. Keywords: nanostructured lipid carriers, high-pressure homogenization, β-Elemene, venous irritation, anti-tumor efficacy

  12. Thymoquinone-loaded nanostructured lipid carriers: preparation, gastroprotection, in vitro toxicity, and pharmacokinetic properties after extravascular administration.

    Science.gov (United States)

    Abdelwahab, Siddig Ibrahim; Sheikh, Bassem Yousef; Taha, Manal Mohamed Elhassan; How, Chee Wun; Abdullah, Rasedee; Yagoub, Umar; El-Sunousi, Rashad; Eid, Eltayeb E M

    2013-01-01

    Nanostructured lipid carriers (NLCs), composed of solid and liquid lipids, and surfactants are potentially good colloidal drug carriers. Thymoquinone is the main bioactive compound of Nigella sativa. In this study, the preparation, gastroprotective effects, and pharmacokinetic (PK) properties of thymoquinone (TQ)-loaded NLCs (TQNLCs) were evaluated. TQNLCs were prepared using hydrogenated palm oil (Softisan® 154), olive oil, and phosphatidylcholine for the lipid phase and sorbitol, polysorbate 80, thimerosal, and double distilled water for the liquid lipid material. A morphological assessment of TQNLCs was performed using various methods. Analysis of the ulcer index, hydrogen concentration, mucus content, and biochemical and histochemical studies confirmed that the loading of TQ into the NLCs significantly improved the gastroprotective activity of this natural compound against the formation of ethanol-induced ulcers. The safety of TQNLC was tested on WRL68 liver normal cells with cisplatin as a positive control. The average diameter of the TQNLCs was 75 ± 2.4 nm. The particles had negative zeta potential values of -31 ± 0.1 mV and a single melting peak of 55.85°C. Immunohistochemical methods revealed that TQNLCs inhibited the formation of ethanol-induced ulcers through the modulation of heat shock protein-70 (Hsp70). Acute hepatotoxic effects of the TQNLCs were not observed in rats or normal human liver cells (WRL-68). After validation, PK studies in rabbits showed that the PK properties of TQ were improved and indicated that the drug behaves linearly. The Tmax, Cmax, and elimination half-life of TQ were found to be 3.96 ± 0.19 hours, 4811.33 ± 55.52 ng/mL, and 4.4933 ± 0.015 hours, respectively, indicating that TQ is suitable for extravascular administration. NLCs could be a promising vehicle for the oral delivery of TQ and improve its gastroprotective properties.

  13. Uncovering the lipidic basis for the preparation of functional nicotinic acetylcholine receptor detergent complexes for structural studies.

    Science.gov (United States)

    Quesada, Orestes; González-Freire, Carol; Ferrer, María Carla; Colón-Sáez, José O; Fernández-García, Emily; Mercado, Juan; Dávila, Alejandro; Morales, Reginald; Lasalde-Dominicci, José A

    2016-09-19

    This study compares the lipid composition, including individual phospholipid molecular species of solubilized nAChR detergent complexes (nAChR-DCs) with those of the bulk lipids from their source, Torpedo californica (Tc) electric tissue. This lipidomic analysis revealed seventy-seven (77) phospholipid species in the Tc tissue. Analysis of affinity-purified nAChR-DCs prepared with C-12 to C-16 phospholipid analog detergents alkylphosphocholine (FC) and lysofoscholine (LFC) demonstrated that nAChR-DCs prepared with FC12, LFC14, and LFC16 contained >60 phospholipids/nAChR, which was more than twice of those prepared with FC14, FC16, and LFC12. Significantly, all the nAChR-DCs lacked ethanolamine and anionic phospholipids, contained only four cholesterol molecules, and a limited number of phospholipid molecular species per nAChR. Upon incorporation into oocytes, FC12 produce significant functionality, whereas LFC14 and LFC16 nAChR-DCs displayed an increased functionality as compared to the crude Tc membrane. All three nAChR-DCs displayed different degrees of alterations in macroscopic activation and desensitization kinetics.

  14. Nonlinear Response of Strong Nonlinear System Arisen in Polymer Cushion

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2013-01-01

    Full Text Available A dynamic model is proposed for a polymer foam-based nonlinear cushioning system. An accurate analytical solution for the nonlinear free vibration of the system is derived by applying He's variational iteration method, and conditions for resonance are obtained, which should be avoided in the cushioning design.

  15. Preparation and Optimization of Triptolide-Loaded Solid Lipid Nanoparticles for Oral Delivery with Reduced Gastric Irritation

    Directory of Open Access Journals (Sweden)

    Xiangliang Yang

    2013-10-01

    Full Text Available Triptolide (TP often causes adverse reactions in the gastrointestinal tract when it is administered orally. This study aimed to prepare and optimize triptolide-loaded solid lipid nanoparticles (TP-SLN with reduced gastric irritation. The microemulsion technique was used to formulate TP-SLN employing a five-level central composite design (CCD that was developed for exploring the optimum levels of three independent variables on particle size, encapsulation efficiency (EE and drug loading (DL. Quadratic polynomial models were generated to predict and evaluate the three independent variables with respect to the three responses. The optimized TP-SLN was predicted to comprise fraction of lipid of 49.73%, surfactant to co-surfactant ratio of 3.25, and lipid to drug ratio of 55.27, which showed particle size of 179.8 ± 5.7 nm, EE of 56.5 ± 0.18% and DL of 1.02 ± 0.003% that were in good agreement with predicted values. In addition, the optimized nanoparticles manifested a sustained-release pattern in vitro and were stable during 3 h of incubation in simulated gastric fluids without significant size change and the majority (91% of the drug was protected. Furthermore, the nanoparticles did not show obvious gastric irritation caused by oral administration of TP in rats.

  16. Alendronate Sodium as Enteric Coated Solid Lipid Nanoparticles; Preparation, Optimization, and In Vivo Evaluation to Enhance Its Oral Bioavailability.

    Directory of Open Access Journals (Sweden)

    Khaled Mohamed Hosny

    Full Text Available Treatment of osteoporosis with alendronate sodium has several challenges. The first challenge is the low bioavailability. The second main challenge is side effects, which include oesophageal ulceration. The aim of this research was to reformulate alendronate sodium as enteric coated solid lipid nanoparticles in order to enhance its bioavailability, and preventing the free alendronate sodium from coming into direct contact with the gastrointestinal mucosa, and thereby reducing the possibility of side effects. Enteric coated solid lipid nanoparticles were prepared according to the Box-Behnken design employing Design expert® software, and characterized for size, morphology, and entrapment efficiency. The optimized formula was coated with an Eudragit S100 and evaluated for drug release in acidic and basic media, stability studies and pharmacokinetic evaluations on rabbits. The results indicated that, using Derringer's desirability functional tool for optimization, the highest entrapment efficiency value of 74.3% and the smallest size value of 98 nm were predicted under optimum conditions with a desirability value of 0.917. The optimized nanoparticles released alendronate sodium only at an alkaline pH. The pharmacokinetic evaluation revealed that alendronate sodium bioavailability was enhanced by more than 7.4-fold in rabbits. In conclusion, enteric coated solid lipid nanoparticles is a promising formula for the delivery of alendronate sodium, eliminating its oesophageal side effects and enhancing its bioavailability.

  17. Solid lipid nanoparticles (SLN)--based hydrogels as potential carriers for oral transmucosal delivery of risperidone: preparation and characterization studies.

    Science.gov (United States)

    Silva, A C; Amaral, M H; González-Mira, E; Santos, D; Ferreira, D

    2012-05-01

    Two different solid lipid nanoparticles (SLN)-based hydrogels (HGs) formulations were developed as potential mucoadhesive systems for risperidone (RISP) oral transmucosal delivery. The suitability of the prepared semi-solid formulations for application on oral mucosa was assessed by means of rheological and textural analysis, during 30 days. Plastic flows with thixotropy and high adhesiveness were obtained for all the tested systems, which predict their success for the oral transmucosal application proposed. The SLN remained within the colloidal range after HGs preparation. However, after 30 days of storage, a particle size increase was detected in one type of the HGs formulations. In vitro drug release studies revealed a more pronounced RISP release after SLN hydrogel entrapment, when compared to the dispersions alone. In addition, a pH-dependent release was observed as well. The predicted in vivo RISP release mechanism was Fickian diffusion alone or combined with erosion.

  18. Use of dynamic membranes for the preparation of vitamin E-loaded lipid particles: An alternative to prevent fouling observed in classical cross-flow emulsification

    NARCIS (Netherlands)

    Lauoini, A.; Charcosset, C.; Fessi, H.; Schroën, C.G.P.H.

    2014-01-01

    Solid lipid particles (SLP) were introduced at the beginning of the 1990s as an alternative to encapsulation systems such as emulsions and liposomes used in cosmetic and pharmaceutical preparations. The present paper investigated for the first time the preparation of SLP based on premix emulsificati

  19. Thymoquinone-loaded nanostructured lipid carriers: preparation, gastroprotection, in vitro toxicity, and pharmacokinetic properties after extravascular administration

    Directory of Open Access Journals (Sweden)

    Abdelwahab SI

    2013-06-01

    Full Text Available Siddig Ibrahim Abdelwahab,1 Bassem Yousef Sheikh,2 Manal Mohamed Elhassan Taha,1 Chee Wun How,3 Rasedee Abdullah,3 Umar Yagoub,1 Rashad El-Sunousi,1 Eltayeb EM Eid31Medical Research Centre, Jazan University, Jazan, Saudi Arabia; 2Department of Surgery, College of Medicine, Taibah University, Medina, Saudi Arabia; 3Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, University Putra Malaysia, Serdang, MalaysiaBackground: Nanostructured lipid carriers (NLCs, composed of solid and liquid lipids, and surfactants are potentially good colloidal drug carriers. Thymoquinone is the main bioactive compound of Nigella sativa. In this study, the preparation, gastroprotective effects, and pharmacokinetic (PK properties of thymoquinone (TQ-loaded NLCs (TQNLCs were evaluated.Method: TQNLCs were prepared using hydrogenated palm oil (Softisan® 154, olive oil, and phosphatidylcholine for the lipid phase and sorbitol, polysorbate 80, thimerosal, and double distilled water for the liquid lipid material. A morphological assessment of TQNLCs was performed using various methods. Analysis of the ulcer index, hydrogen concentration, mucus content, and biochemical and histochemical studies confirmed that the loading of TQ into the NLCs significantly improved the gastroprotective activity of this natural compound against the formation of ethanol-induced ulcers. The safety of TQNLC was tested on WRL68 liver normal cells with cisplatin as a positive control.Results: The average diameter of the TQNLCs was 75 ± 2.4 nm. The particles had negative zeta potential values of −31 ± 0.1 mV and a single melting peak of 55.85°C. Immunohistochemical methods revealed that TQNLCs inhibited the formation of ethanol-induced ulcers through the modulation of heat shock protein-70 (Hsp70. Acute hepatotoxic effects of the TQNLCs were not observed in rats or normal human liver cells (WRL-68. After validation, PK studies in rabbits showed that the PK properties of TQ

  20. Pyrolytic characteristics of biodiesel prepared from lipids accumulated in diatom cells with growth regulation.

    Science.gov (United States)

    Cheng, Jun; Feng, Jia; Ge, Tingting; Yang, Weijuan; Zhou, Junhu; Cen, Kefa

    2015-08-01

    Dynamic compositions of lipids accumulated in two diatoms Chaetoceros gracilis and Nitzschia closterium cultured with nitrogen and silicon deprivation were studied. It was found that short-chain fatty acids (C14-C16) content was much higher than long-chain fatty acids (C18-C20) content in lipids of two diatoms. The pyrolytic characteristics of biodiesel made from two diatoms and two plant seeds were compared by thermogravimetric analysis. The highest activation energy of 46.68 kJ mol(-1) and the minimum solid residue of 25.18% were obtained in the pyrolysis of biodiesel made from C. gracilis cells, which were cultured with 0.5 mmol L(-1) of nitrogen (no silicon) and accumulated the minimum polyunsaturated fatty acid (C20:5). The pyrolysis residue percentage of C. gracilis biodiesel was lower than that of N. closterium biodiesel and higher than those of plant (Cormus wilsoniana and Pistacia chinensis) biodiesels.

  1. Preparation, characterization and biocompatibility studies on risperidone-loaded solid lipid nanoparticles (SLN): high pressure homogenization versus ultrasound.

    Science.gov (United States)

    Silva, A C; González-Mira, E; García, M L; Egea, M A; Fonseca, J; Silva, R; Santos, D; Souto, E B; Ferreira, D

    2011-08-01

    The suitability of solid lipid nanoparticles (SLN) for the encapsulation of risperidone (RISP), an antipsychotic lipophilic drug, was assessed for oral administration. The hot high pressure homogenization (HPH) and the ultrasound (US) technique were used as production methods for SLN. All the studies on the SLN formulations were done in parallel, in order to compare the results and conclude about the advantages and limitations of both techniques. The particle sizes were in the nanometer range for all prepared SLN formulations and the zeta potential absolute values were high, predicting good long-term stability. Optical analyses demonstrated the achievement of stable colloidal dispersions. Physicochemical characterization of dispersions and bulk lipids, performed by differential scanning calorimetry (DSC) and X-ray assays, support prediction of occurrence of drug incorporation in the SLN and good long term stability of the systems. The toxicity of SLN with Caco-2 cells and the existence of contaminations derived from the production equipments were assessed by the (4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) assay. The results showed 90% of cell viability after SLN exposure, with no significant differences within all prepared formulations (p > 0.05). From this study, we conclude that SLN can be considered as efficient carriers for RISP encapsulation. Moreover, HPH and US revealed to be both effective methods for SLN production.

  2. Preparation of drug-loaded polymeric nanoparticles and evaluation of the antioxidant activity against lipid peroxidation.

    Science.gov (United States)

    Pohlmann, Adriana R; Schaffazick, Scheila Rezende; Creczynski-Pasa, Tânia B; Guterres, Sílvia S

    2010-01-01

    Antioxidants have been found to be effective as prophylatic and therapeutic agents for different diseases such as diabetes, cancer, and neurodegenerative disorders. However, antioxidant substances can present poor solubility in water, inefficient permeability, gastrointestinal degradation, first-pass effect, and/or instability during storage. These drawbacks can be potentially circumvented by encapsulating the susceptible antioxidants. Polymeric nanoparticles (nanocapsules or nanospheres) have been used to improve the drug efficacy and release. Our group has shown that the in vitro antioxidant effect of melatonin against lipid peroxidation in microsomes and liposomes can be improved by encapsulation of the antioxidant drug in polymeric nanoparticles.

  3. A comparison of pseudo-ternary diagrams of aqueous mixtures of Quil A, cholesterol and phospholipid prepared by lipid-film hydration and dialysis.

    Science.gov (United States)

    Demana, P H; Davies, N M; Berger, B; Vosgerau, U; Rades, T

    2004-05-01

    Pseudo-ternary diagrams for Quil A, phospholipid (phosphatidylcholine (PC) or phosphatidylethanolamine (PE)) and cholesterol were established in order to identify combinations that result in the formation of immune-stimulating complex (ISCOM) matrices and other colloidal structures produced by these three components in aqueous systems following lipid-film hydration or dialysis (methods that can be used to produce ISCOMs). In addition, the effect of equilibration time (1 month at 4 degrees C) on the structures formed by the various combinations of the three components was investigated. Depending on the ratio of Quil A, cholesterol and phospholipid, different colloidal particles, including ISCOM matrices, liposomes and ring-like micelles, were found irrespective of the preparation method used. In contrast, worm-like micelles were only observed in systems prepared by lipid-film hydration. For samples prepared by dialysis, ISCOM matrices were predominantly found near the Quil A apex of the pseudo-ternary diagram (> 50% Quil A). On the other hand, for samples prepared by lipid-film hydration, ISCOM matrices were predominantly found near the phospholipid apex of the pseudo-ternary diagram (> 50% phospholipid). The regions in the pseudo-ternary diagrams in which ISCOM matrices were observed increased following an extended equilibration time, particularly for samples prepared by lipid-film hydration. Differences were also observed between pseudoternary diagrams prepared using either PE or PC as phospholipids.

  4. Solvent-free melting techniques for the preparation of lipid-based solid oral formulations.

    Science.gov (United States)

    Becker, Karin; Salar-Behzadi, Sharareh; Zimmer, Andreas

    2015-05-01

    Lipid excipients are applied for numerous purposes such as taste masking, controlled release, improvement of swallowability and moisture protection. Several melting techniques have evolved in the last decades. Common examples are melt coating, melt granulation and melt extrusion. The required equipment ranges from ordinary glass beakers for lab scale up to large machines such as fluid bed coaters, spray dryers or extruders. This allows for upscaling to pilot or production scale. Solvent free melt processing provides a cost-effective, time-saving and eco-friendly method for the food and pharmaceutical industries. This review intends to give a critical overview of the published literature on experiences, formulations and challenges and to show possibilities for future developments in this promising field. Moreover, it should serve as a guide for selecting the best excipients and manufacturing techniques for the development of a product with specific properties using solvent free melt processing.

  5. Differential scanning calorimetry studies on sunscreen loaded solid lipid nanoparticles prepared by the phase inversion temperature method.

    Science.gov (United States)

    Montenegro, L; Sarpietro, M G; Ottimo, S; Puglisi, G; Castelli, F

    2011-08-30

    Solid lipid nanoparticles (SLN) are regarded as interesting carriers to improve sunscreens' safety and effectiveness. In this work, surfactant effects on the physico-chemical properties of SLN loading two of the most widely used UV-filters, octylmethoxycinnamate (OMC) and butylmethoxydibenzoylmethane (BMBM), were evaluated and the interactions between SLN components and loaded UV-filters were investigated by differential scanning calorimetry (DSC). All the SLN showed a mean size ranging from 30 to 95 nm, and a single peak in size distribution. The use of isoceth-20 or oleth-20 as primary surfactants did not provide SLN with suitable physico-chemical properties since: (a) OMC loaded SLN proved unstable; (b) BMBM could not be loaded. OMC or BMBM loaded SLN prepared using ceteth-20 as primary surfactant were stable but their loading capacity lowered when both sunscreens were loaded simultaneously. DSC analyses showed that OMC distributed inside the SLN and caused a decrease of the lipid matrix molecules cooperativity while BMBM did not affect SLN calorimetric behaviour. When OMC and BMBM were loaded together into these SLN, an interaction between BMBM and OMC occurred. These results suggest that the interactions between sunscreens and between sunscreens and SLN components deserve further investigation to evaluate their effect on UV-filter-loaded SLN effectiveness. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Solid Lipid Nanoparticle Formulations of Docetaxel Prepared with High Melting Point Triglycerides: In Vitro and in Vivo Evaluation

    Science.gov (United States)

    2015-01-01

    Docetaxel (DCX) is a second generation taxane. It is approved by the U.S. Food and Drug Administration for the treatment of various types of cancer, including breast, non-small cell lung, and head and neck cancers. However, side effects, including those related to Tween 80, an excipient in current DCX formulations, can be severe. In the present study, we developed a novel solid lipid nanoparticle (SLN) composition of DCX. Trimyristin was selected from a list of high melting point triglycerides as the core lipid component of the SLNs, based on the rate at which the DCX was released from the SLNs and the stability of the SLNs. The trimyristin-based, PEGylated DCX-incorporated SLNs (DCX-SLNs) showed significantly higher cytotoxicity against various human and murine cancer cells in culture, as compared to DCX solubilized in a Tween 80/ethanol solution. Moreover, in a mouse model with pre-established tumors, the new DCX-SLNs were significantly more effective than DCX solubilized in a Tween 80/ethanol solution in inhibiting tumor growth without toxicity, likely because the DCX-SLNs increased the concentration of DCX in tumor tissues, but decreased the levels of DCX in major organs such as liver, spleen, heart, lung, and kidney. DCX-incorporated SLNs prepared with one or more high-melting point triglycerides may represent an improved DCX formulation. PMID:24621456

  7. Preparation and characterization of vinculin-targeted polymer–lipid nanoparticle as intracellular delivery vehicle

    Directory of Open Access Journals (Sweden)

    Wang J

    2012-12-01

    Full Text Available Junping Wang,* Ceren Örnek-Ballanco,* Jiahua Xu, Weiguo Yang, Xiaojun YuDepartment of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, USA*These authors contributed equally to this workAbstract: Intracellular delivery vehicles have been extensively investigated as these can serve as an effective tool in studying the cellular mechanism, by delivering functional protein to specific locations of the cells. In the current study, a polymer–lipid nanoparticle (PLN system was developed as an intracellular delivery vehicle specifically targeting vinculin, a focal adhesion protein associated with cellular adhesive structures, such as focal adhesions and adherens junctions. The PLNs possessed an average size of 106 nm and had a positively charged surface. With a lower encapsulation efficiency 32% compared with poly(lactic-co-glycolic acid (PLGA nanoparticles (46%, the PLNs showed the sustained release profile of model drug BSA, while PLGA nanoparticles demonstrated an initial burst-release property. Cell-uptake experiments using mouse embryonic fibroblasts cultured in fibrin–fibronectin gels observed, under confocal microscope, that the anti-vinculin conjugated PLNs could successfully ship the cargo to the cytoplasm of fibroblasts, adhered to fibronectin–fibrin. With the use of cationic lipid, the unconjugated PLNs were shown to have high gene transfection efficiency. Furthermore, the unconjugated PLNs had nuclear-targeting capability in the absence of nuclear-localization signals. Therefore, the PLNs could be manipulated easily via different type of targeting ligands and could potentially be used as a powerful tool for cellular mechanism study, by delivering drugs to specific cellular organelles.Keywords: 3D gel, PLGA, targeting

  8. Preparation and characterization of decyl-terminated silicon nanoparticles encapsulated in lipid nanocapsules.

    Science.gov (United States)

    Pan, Guo-Hui; Barras, Alexandre; Boussekey, Luc; Qu, Xuesong; Addad, Ahmed; Boukherroub, Rabah

    2013-10-15

    In this Article, we report on the encapsulation of decyl-modified silicon nanoparticles (decyl-SiNPs) into ∼80 nm lipid nanocapsules (LNCs). The decyl-SiNPs were produced by thermal hydrosilylation of hydride-terminated SiNPs (H-SiNPs) liberated from porous silicon. Various techniques, including Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), UV-vis absorption, dynamic light scattering (DLS), and photoluminescence (PL), were used to characterize their size, shape, colloidal, and optical properties. The results indicate that these nanocapsules feature controllable size, good dispersity, high loading rate of SiNPs, colloidal stability in various media, and bright PL. The PL of decyl-SiNPs loaded LNCs was stable upon heating to 80 °C, but was sensitive to basic solutions due to proton-gated emission of the SiNPs arranged at the LNCs interface between the oil phase and the hydrophilic polyethylene glycol moieties of the surfactant. These luminescent nanocapsules are therefore promising candidates as cellular probes for fluorescence imaging. In addition, it was found that TEM imaging of small-sized decyl-SiNPs could be greatly improved by preliminary negative staining of TEM grids with phosphotungstic acid.

  9. Preparation and assessment cytotoxic and hemolytic activities of Complexes from “Chelating Kojic–Lipid Conjugate”

    Directory of Open Access Journals (Sweden)

    Antônio S. C. Carvalho

    2012-06-01

    Full Text Available Complex bis (2-Oleicoyloxymethyl-5-hydroxy-gamma-pyrone copper (II and tris (2-Oleicoyloxymethyl-5-hydroxy-gamma-pyrone iron (III were prepared in ethanol using the structure "chelator conjugate kojic -lipid". This ester was obtained from kojic acid by improving their lipophilicity of obtaining metalobioactives with application in Medicinal Bioinorganic Chemistry. Through the technique ATR/FTIR, the values ​​of the infrared kojic acid has been updated and it was possible to characterize      the complex 1567m, 1511w (Cu (II←[O=C]2, and 1540m, 1519m (Fe(III←[O=C]3. These compounds no showed cytotoxic potential against B16 (melanoma and ACP02 (gastric adenocarcinoma (IC50> 5 μg mL-1 and low hemolytic activity (EC50> 250 μg mL-1.The preparation of these new molecules by structural modification techniques and these interesting biological results confirm the continuity of this studies related to these coordination complexes to glimpse the possibility of obtaining other derivatives/ analogues with significant biological potential of this metallo-bioactive.

  10. Preparation of double-layer microcapsules coated by a synthesized lipid and their controlled release; Gosei shishitsu wo hifukushita nijumaku microcapsule no chosei to sono joho tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Goto, M.; Nakashio, F. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Iwama, M.; Yoshizawa, H.; Ijichi, K.; Uemura, Y.; Hatate, Y. [Kagoshima University, Kagoshima (Japan). Faculty of Engineering

    1996-07-10

    A double layer micro capsule composed of nylon and polystyrene has been prepared by a combined process of interracial polymerization and solvent evaporation. The release rate of sodium ions as a core material was investigated with the microcapsules coated by a synthesized lipid. The permeation rate drastically changed corresponding to the phase transition temperature of the bilayer membranes composed of the lipid. The permeability of the core material above the phase transition temperature was 1-order of magnitude higher than that below the temperature. A functional microcapsule in which a core material is controlled by a membrane structure can be prepared by coating the micro capsule with a synthesized lipid. 5 refs., 3 figs.

  11. Solid lipid nanoparticles containing 7-ethyl-10-hydroxycamptothecin (SN38): Preparation, characterization, in vitro, and in vivo evaluations.

    Science.gov (United States)

    Mosallaei, Navid; Mahmoudi, Asma; Ghandehari, Hamidreza; Yellepeddi, Venkata Kashyap; Jaafari, Mahmoud Reza; Malaekeh-Nikouei, Bizhan

    2016-07-01

    7-Ethyl-10-hydroxycamptothecin (SN38) is a biologically active metabolite of irinotecan. Due to the variability of irinotecan metabolism rate to SN38, and poor solubility of this compound in pharmaceutically acceptable solvents, SN38 has not been successfully used in the clinic. In the present study, we prepared solid lipid nanoparticle (SLN) formulations containing SN38 and evaluated the in vitro and in vivo efficacy of these nanoparticles. SLNs and PEGylated SLNs containing SN38 (SLN-SN38 and PEG-SLN-SN38) were prepared using ultrasonication technique. Nanoparticles were characterized for size, zeta potential, and drug encapsulation efficiency. In vitro cytotoxicity of these compounds was evaluated in two colorectal carcinoma cell lines, namely C-26 and HT-116. In vivo antitumor efficacy of the formulations was evaluated in C-26 xenograft tumor mice models. Mice survival was also explored through 60days post IV injection. Mean size of SLN-SN38 and PEG-SLN-SN38 was around 103 and 131nm, respectively. Polydispersity index (PDI) for all the formulations was around 0.2 and zeta potential was negative (-5 to -15mV). Nearly 90% of the drug was encapsulated in SLNs. SLN-SN38 and PEG-SLN-SN38 compared to irinotecan were significantly more toxic to C-26 and HT-116 cell lines after 48h of exposure. Calculation of IC50 suggests higher sensitivity of HT-116 cells than C-26 cells to SLN-SN38 and PEG-SLN-SN38. Tumor inhibitory efficacy presented the highest efficacy in SLN-SN38. However, both SLN-SN38 and PEG-SLN-SN38 carriers showed higher efficiency to inhibit tumors compared to irinotecan (25mg/kg).

  12. Solid lipid nanoparticles co-loaded with simazine and atrazine: preparation, characterization, and evaluation of herbicidal activity.

    Science.gov (United States)

    de Oliveira, Jhones Luiz; Campos, Estefânia Vangelie Ramos; Gonçalves da Silva, Camila Morais; Pasquoto, Tatiane; Lima, Renata; Fraceto, Leonardo Fernandes

    2015-01-21

    Solid lipid nanoparticles (SLN) containing the herbicides atrazine and simazine were prepared and characterized, and in vitro evaluation was made of the release kinetics, herbicidal activity, and cytotoxicity. The stability of the nanoparticles was investigated over a period of 120 days, via analyses of particle size, ζ potential, polydispersion, pH, and encapsulation efficiency. SLN showed good physicochemical stability and high encapsulation efficiencies. Release kinetics tests showed that use of SLN modified the release profiles of the herbicides in water. Herbicidal activity assays performed with pre- and postemergence treatment of the target species Raphanus raphanistrum showed the effectiveness of the formulations of nanoparticles containing herbicides. Assays with nontarget organisms (Zea mays) showed that the formulations did not affect plant growth. The results of cytotoxicity assays indicated that the presence of SLN acted to reduce the toxicity of the herbicides. The new nanoparticle formulations enable the use of smaller quantities of herbicide and therefore offer a more environmentally friendly method of controlling weeds in agriculture.

  13. Preparation of oridonin-loaded solid lipid nanoparticles and studies on them in vitro and in vivo

    Science.gov (United States)

    Zhang, Dianrui; Tan, Tianwei; Gao, Lei

    2006-12-01

    Oridonin, a lipophilic Chinese medicine, has very low oral bioavailability due to its poor solubility. Solid lipid nanoparticle (SLN) delivery systems of oridonin have been formed using stearic acid, soybean lecithin and pluronic F68 in our studies to overcome this problem. Emulsion evaporation-solidification at low temperature was used to prepare SLN dispersions. The particle size and morphology were examined by transmission electron microscopy (TEM), and the zeta potential was measured by a television micro-electrophoresis apparatus. Process and formulation variables have been studied and optimized on the basis of entrapment efficiency. Differential scanning calorimetry (DSC) and powder x-ray diffraction (PXRD) studies were performed to characterize the state of the drug. In vitro release studies were performed in phosphate-buffer solution (PBS) (pH 7.4). The tissue distribution in mice and the pharmacokinetics in rabbits were studied to evaluate the tissue targeted property of SLNs. Stable SLN formulations of oridonin having a mean size range of 15-35 nm and mean zeta potential -45.07 mV were developed. More than 40% oridonin was entrapped in SLNs. DSC and PXRD analysis showed that oridonin is dispersed in SLNs in an amorphous state. The release pattern of the drug was analysed and found to follow the Higuchi equations. In vivo studies demonstrated that oridonin-loaded SLNs obviously increased the concentration of oridonin in liver, lung and spleen, while its distribution in heart and kidney decreased.

  14. Preparation of oridonin-loaded solid lipid nanoparticles and studies on them in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Dianrui [College of Life Science and Technology, Beijing University of Chemical Technology, 15 Bei Sanhuan Donglu, Beijing 100029 (China); Tan Tianwei [College of Life Science and Technology, Beijing University of Chemical Technology, 15 Bei Sanhuan Donglu, Beijing 100029 (China); Gao Lei [Department of Pharmaceutics, College of Pharmacy, Shandong University, 44 Wenhua Xilu, Jinan 250012 (China)

    2006-12-14

    Oridonin, a lipophilic Chinese medicine, has very low oral bioavailability due to its poor solubility. Solid lipid nanoparticle (SLN) delivery systems of oridonin have been formed using stearic acid, soybean lecithin and pluronic F{sub 68} in our studies to overcome this problem. Emulsion evaporation-solidification at low temperature was used to prepare SLN dispersions. The particle size and morphology were examined by transmission electron microscopy (TEM), and the zeta potential was measured by a television micro-electrophoresis apparatus. Process and formulation variables have been studied and optimized on the basis of entrapment efficiency. Differential scanning calorimetry (DSC) and powder x-ray diffraction (PXRD) studies were performed to characterize the state of the drug. In vitro release studies were performed in phosphate-buffer solution (PBS) (pH 7.4). The tissue distribution in mice and the pharmacokinetics in rabbits were studied to evaluate the tissue targeted property of SLNs. Stable SLN formulations of oridonin having a mean size range of 15-35 nm and mean zeta potential -45.07 mV were developed. More than 40% oridonin was entrapped in SLNs. DSC and PXRD analysis showed that oridonin is dispersed in SLNs in an amorphous state. The release pattern of the drug was analysed and found to follow the Higuchi equations. In vivo studies demonstrated that oridonin-loaded SLNs obviously increased the concentration of oridonin in liver, lung and spleen, while its distribution in heart and kidney decreased.

  15. Hydrolysis of erythrocyte membrane phospholipids by a preparation of phospholipase C from Clostridium Welchii. Deactivation of (Ca-2+, Mg-2+)-ATPase and its reactivation by added lipids.

    Science.gov (United States)

    Coleman, R; Bramley, T A

    1975-04-08

    1. Haemoglobin-free erythrocyte ghosts were prepared in 40 imosM bicarbonate buffer, pH 7.4, containing 1 mM EDTA (40 imosM/l mM EDTA). The ghost preparation was highly permeable on preparation but partially resealed on incubation in media containing Ca-2+. 2. A partially purified preparation of phospholipase C from Clostridum welchii caused an increase in observed Mg-2+-ATPase activity, reflecting a change in the permeability of the ghost to substrate. The phospholipase did not decrease Mg-2+-ATPase even at the highest levels tested. Mg-2+-ATPase activity could therefore be used as a permeability indicatior in these experiments. 3. Both (Ca-2+, Mg-2+)-ATPase activities of the ghosts were progressively lost as a result of the phospholipid hydrolysis induced by phospholipase C. 4. When a haemolysin in the commercial preparation was destroyed by heat-treatment, deactivation of the (Ca-2+, Mg-2+)-ATPase and (Na+, K+, Mg-2+)-ATPases were still observed but permeability changes were greatly reduced. 5. The products of phospholipase action were not inhibitory to the Ca-2+, Mg-2+)-ATPase. 6. Lysolecithin brought about a reactivation of the (Ca-2+, Mg-2+)-ATPase which was superimposed upon permeability changes in the preparation. 7. Reactivation of the (Ca-2+, Mg-2+)-ATPase was brought about by a nonlytic, mixed lipid preparation without significant effect upon permeability. 8. Human erythrocyte (Ca-2+, Mg-2+)-ATPase therefore appears to be an enzyme which responds to perturbation of the lipid environment in the membrane and is a "lipid-dependant" enzyme.

  16. Synthetic surfactant- and cross-linker-free preparation of highly stable lipid-polymer hybrid nanoparticles as potential oral delivery vehicles.

    Science.gov (United States)

    Wang, Taoran; Xue, Jingyi; Hu, Qiaobin; Zhou, Mingyong; Chang, Chao; Luo, Yangchao

    2017-06-05

    The toxicity associated with concentrated synthetic surfactants and the poor stability at gastrointestinal condition are two major constraints for practical applications of solid lipid nanoparticles (SLN) as oral delivery vehicles. In this study, a synthetic surfactant-free and cross-linker-free method was developed to fabricate effective, safe, and ultra-stable lipid-polymer hybrid nanoparticles (LPN). Bovine serum albumin (BSA) and dextran varying in molecular weights were first conjugated through Maillard reaction and the conjugates were exploited to emulsify solid lipid by a solvent diffusion and sonication method. The multilayer structure was formed by self-assembly of BSA-dextran micelles to envelope solid lipid via a pH- and heating-induced facile process with simultaneous surface deposition of pectin. The efficiency of different BSA-dextran conjugates was systematically studied to prepare LPN with the smallest size, the most homogeneous distribution and the greatest stability. The molecular interactions were characterized by Fourier transform infrared and fluorescence spectroscopies. Both nano spray drying and freeze-drying methods were tested to produce spherical and uniform pectin-coated LPN powders that were able to re-assemble nanoscale structure when redispersed in water. The results demonstrated the promise of a synthetic surfactant- and cross-linker-free technique to prepare highly stable pectin-coated LPN from all natural biomaterials as potential oral delivery vehicles.

  17. Preparation and Characterization of Loperamide-Loaded Dynasan 114 Solid Lipid Nanoparticles for Increased Oral Absorption In the Treatment of Diarrhea

    OpenAIRE

    Wei, Lili; Yang, Yunfang; Shi, Kun; Wu, Jun; Zhao, Wei; Mo, Jingxin

    2016-01-01

    The aim of the project was to assemble two optimum solid lipid nanoparticle (SLN) formulations for oral delivery of loperamide (LPM) to treat different types of diarrhea, and to evaluate their release profiles in vitro and pharmacokinetic properties in vivo. In this work, glyceryl trimyristate (Dynasan 114) nanoparticles containing the drug LPM and sodium cholate as a stabilizer were prepared using a modified solvent evaporation technique. Two LPM-loaded SLNs, namely LPM-SLN-1 (LPM-SLN with a...

  18. Preparation and characterization of loperamide-loaded Dynasan 114 solid lipid nanoparticles for increased oral absorption in the treatment of diarrhea

    OpenAIRE

    Lili Wei; Yunfang Yang; Kun Shi; Jun Wu; Wei Zhao; Jingxin Mo

    2016-01-01

    The aim of the project was to assemble two optimum solid lipid nanoparticle (SLN) formulations for oral delivery of loperamide (LPM) to treat different types of diarrhea, and to evaluate their release profiles in vitro and pharmacokinetic properties in vivo. In this work, glyceryl trimyristate (Dynasan 114) nanoparticles containing the drug LPM and sodium cholate as a stabilizer were prepared using a modified solvent evaporation technique. Two LPM-loaded SLNs, namely LPM-SLN-1 (LPM-SLN with a...

  19. Profiling the Triacylglyceride Contents in Bat Integumentary Lipids by Preparative Thin Layer Chromatography and MALDI-TOF Mass Spectrometry

    OpenAIRE

    2013-01-01

    The mammalian integument includes sebaceous glands that secrete an oily material onto the skin surface. Sebum production is part of the innate immune system that is protective against pathogenic microbes. Abnormal sebum production and chemical composition are also a clinical symptom of specific skin diseases. Sebum contains a complex mixture of lipids, including triacylglycerides, which is species-specific. The broad chemical properties exhibited by diverse lipid classes hinder the specific d...

  20. Characterization and in vivo evaluation of novel lipid-chlorambucil nanospheres prepared using a mixture of emulsifiers for parenteral administration.

    Science.gov (United States)

    Song, Honglin; Nie, Shufang; Yang, Xinggang; Li, Ning; Xu, Hongtao; Zheng, Liangyuan; Pan, Weisan

    2010-11-09

    The purpose of the study was to develop and evaluate different lipid-based formulations for parenteral administration, as potential novel carrier systems for lipophilic drugs, and to turn an unstable drug such as chlorambucil into a useful one. A two-stage, high-pressure homogenizer was used to yield a very fine monodispersed lipid nanosphere. The strategy of combining egg yolk phospholipid and nonionic emulsifier (Lutrol F 68 and Tween 80) as an emulsifier mixture was adopted to increase safety and tolerance. The final lipid nanospheres, in a lipophilic mixture consisting of three components, monostearin, medium-chain triglycerides and soya oil, were evaluated for physicochemical properties, such as particle size, surface morphology, drug-entrapment efficiency, drug-loading capacity, lyophilization and in vivo drug-release behavior. A monodispersed lipid nanosphere with a mean particle size ranging from 90 to 150 nm was achieved. The optimized injectable cryoprotectants for lipid nanosphere were sucrose (7.5%) and mannitol (7.5%), which can stabilize the particle size (LD50) at approximately 129 nm after reconstitution. The results show that the formulation can effectively administer anticancer drugs and thus improve patient quality of life. The novel lipid nanosphere complex developed is a useful anticancer drug delivery vehicle for parenteral administration. The formulation strategy has the potential for the development of further methods of drug delivery for a wide variety of anticancer drugs.

  1. Preparation and characterization of loperamide-loaded Dynasan 114 solid lipid nanoparticles for increased oral absorption in the treatment of diarrhea

    Directory of Open Access Journals (Sweden)

    Lili Wei

    2016-09-01

    Full Text Available The aim of the project was to assemble two optimum solid lipid nanoparticle (SLN formulations for oral delivery of loperamide (LPM to treat different types of diarrhea, and to evaluate their release profiles in vitro and pharmacokinetic properties in vivo. In this work, glyceryl trimyristate (Dynasan 114 nanoparticles containing the drug LPM and sodium cholate as a stabilizer were prepared using a modified solvent evaporation technique. Two LPM-loaded SLNs, namely LPM-SLN-1 (LPM-SLN with a high ratio rate of lipid to drug and LPM-SLN-2 (LPM-SLN with a low ratio rate of lipid to drug, were prepared by the solvent evaporation method. A change in the lipid concentration affects the characteristics of LPM-SLNs. The average sizes of the LPM-SLNs were 303 ± 18 nm and 519 ± 36 nm, separately, as analyzed by dynamic light scattering (DLS. The LPM-SLNs were found to be round with a smooth surface, as observed using a transmission electron microscope (TEM and a scanning electron microscope (SEM. The average encapsulation efficiencies were 87 ± 3.78% w/w and 84 ± 5.17%, accordingly. In the in vitro release experiments, LPM-SLNs showed a continuous release profile of LPM without any burst release. The oral bioavailability of LPM-SLNs was analyzed using Wistar rats. The relative bioavailabilities of LPM-SLNs were 227% and 153%, respectively, as compared that of the LPM tablet. There was no difference in the Tmax between LPM-SLN-2 and the LPM tablet. In conclusion, LPM-SLN-1 significantly improved the oral bioavailability of LPM, while LPM-SLN-2 having the same swift action as the LPM tablet. These results demonstrate the potential of LPM-SLNs in the oral delivery of LPM to treat different types of diarrhea.

  2. Preparation and Characterization of Loperamide-Loaded Dynasan 114 Solid Lipid Nanoparticles for Increased Oral Absorption In the Treatment of Diarrhea

    Science.gov (United States)

    Wei, Lili; Yang, Yunfang; Shi, Kun; Wu, Jun; Zhao, Wei; Mo, Jingxin

    2016-01-01

    The aim of the project was to assemble two optimum solid lipid nanoparticle (SLN) formulations for oral delivery of loperamide (LPM) to treat different types of diarrhea, and to evaluate their release profiles in vitro and pharmacokinetic properties in vivo. In this work, glyceryl trimyristate (Dynasan 114) nanoparticles containing the drug LPM and sodium cholate as a stabilizer were prepared using a modified solvent evaporation technique. Two LPM-loaded SLNs, namely LPM-SLN-1 (LPM-SLN with a high ratio rate of lipid to drug) and LPM-SLN-2 (LPM-SLN with a low ratio rate of lipid to drug), were prepared by the solvent evaporation method. A change in the lipid concentration affects the characteristics of LPM-SLNs. The average sizes of the LPM-SLNs were 303 ± 18 nm and 519 ± 36 nm, separately, as analyzed by dynamic light scattering. The LPM-SLNs were found to be round with a smooth surface, as observed using a transmission electron microscope and a scanning electron microscope. The average encapsulation efficiencies were 87 ± 3.78% w/w and 84 ± 5.17%, accordingly. In the in vitro release experiments, LPM-SLNs showed a continuous release profile of LPM without any burst release. The oral bioavailability of LPM-SLNs was analyzed using Wistar rats. The relative bioavailabilities of LPM-SLNs were 227 and 153%, respectively, as compared that of the LPM tablet. There was no difference in the Tmax between LPM-SLN-2 and the LPM tablet. In conclusion, LPM-SLN-1 significantly improved the oral bioavailability of LPM, while LPM-SLN-2 having the same swift action as the LPM tablet. These results demonstrate the potential of LPM-SLNs in the oral delivery of LPM to treat different types of diarrhea. PMID:27708583

  3. Pseudo-ternary phase diagrams of aqueous mixtures of Quil A, cholesterol and phospholipid prepared by the lipid-film hydration method.

    Science.gov (United States)

    Demana, Patrick H; Davies, Nigel M; Vosgerau, Uwe; Rades, Thomas

    2004-02-11

    Pseudo-ternary phase diagrams of the polar lipids Quil A, cholesterol (Chol) and phosphatidylcholine (PC) in aqueous mixtures prepared by the lipid film hydration method (where dried lipid film of phospholipids and cholesterol are hydrated by an aqueous solution of Quil A) were investigated in terms of the types of particulate structures formed therein. Negative staining transmission electron microscopy and polarized light microscopy were used to characterize the colloidal and coarse dispersed particles present in the systems. Pseudo-ternary phase diagrams were established for lipid mixtures hydrated in water and in Tris buffer (pH 7.4). The effect of equilibration time was also studied with respect to systems hydrated in water where the samples were stored for 2 months at 4 degrees C. Depending on the mass ratio of Quil A, Chol and PC in the systems, various colloidal particles including ISCOM matrices, liposomes, ring-like micelles and worm-like micelles were observed. Other colloidal particles were also observed as minor structures in the presence of these predominant colloids including helices, layered structures and lamellae (hexagonal pattern of ring-like micelles). In terms of the conditions which appeared to promote the formation of ISCOM matrices, the area of the phase diagrams associated with systems containing these structures increased in the order: hydrated in water/short equilibration period

  4. Scalable preparation of poly(ethylene glycol)-grafted siRNA-loaded lipid nanoparticles using a commercially available fluidic device and tangential flow filtration.

    Science.gov (United States)

    Sakurai, Yu; Hada, Tomoya; Harashima, Hideyoshi

    While a number of siRNA delivery systems have been developed, the methods used in their preparation are not suitable for large-scale production. We herein report on methodology for the large-scale preparation of liposomal siRNA using a fluidic device and tangential flow filtration (TFF). A number of studies have appeared on the use of fluidic devices for preparing and purifying liposomes, but no systematic information regarding appropriate membrane type of commercially available apparatus is available. The findings reported herein indicate that, under optimized conditions, a microfluidic device and TFF can be used to produce siRNA lipid nanoparticles with the same characteristics as traditional ones'. The in vivo silencing efficiency of these lipid nanoparticles in the liver was comparable to laboratory-produced nanoparticles. In addition, con-focal laser scanning microscopy analyses revealed that they accumulated in the liver accumulation at the same levels as particles produced by batch-type and continuous-type procedures. This methodology has the potential to contribute to the advancement of this process from basic research to clinical studies of liposomal DDS.

  5. Evaluation of micro-colorimetric lipid determination method with samples prepared using sonication and accelerated solvent extraction methods

    Science.gov (United States)

    Two common laboratory extraction techniques were evaluated for routine use with the micro-colorimetric lipid determination method developed by Van Handel (1985) [E. Van Handel, J. Am. Mosq. Control Assoc. 1(1985) 302] and recently validated for small samples by Inouye and Lotufo ...

  6. Preparation of Curcumin Solid Lipid Nanoparticles by Microemulsion Method%微乳法制备姜黄素固体脂质纳米粒

    Institute of Scientific and Technical Information of China (English)

    李楠; 李锡晶; 王倩

    2015-01-01

    目的:制备姜黄素固体脂质纳米粒。方法:微乳法制备姜黄素固体脂质纳米粒。采用伪三元相图法优选微乳三相因素,确定优化条件后,将热微乳分散于冷水中制备固体脂质纳米粒。单因素试验初筛各因素(乳化剂、脂质材料、脂质用量、药脂比、冷水相温度和微乳保温温度)后,以包封率为指标进行正交试验优化处方,并进行验证试验。结果:65℃下由硬脂酸(油相)、聚山梨酯80(乳化剂)、乙醇(助乳化剂)组成三相,乳化剂与助乳化剂比为1∶4所制得的微乳最佳。固体脂质纳米粒的优化处方为姜黄素投药量为50 mg、硬脂酸的用量为0.5 g、冷水相温度为2℃、微乳保温温度为65℃;所得固体脂质纳米粒的包封率为87.73%、载药量为7.72%、粒径为(156.9±2.2)nm、多分散系数为0.480,平均Zeta电位为-24.8 mV(RSD<2%,n=3)。结论:采用微乳法制备固体脂质纳米粒操作简便、可行。%OBJECTIVE:To prepare the curcumin solid lipid nanoparticles. METHODS:Microemulsion method was adopted to prepare curcumin solid lipid nanoparticles (SLN) and pseudo-ternary phase diagrams was conducted to optimize the preferable three-phase microemulsion factors. The optimal conditions were determined,and then hot microemulsion was dispersed in cold wa-ter to prepare SLN. After the preliminary screening of the factors (emulsifiers,lipid materials,amount of lipids,drug-to-lipid ra-tio,cold water phase temperature and the holding temperature of microemulsion)by single-factor test,with the index of encapsula-tion efficiency,the orthogonal test was conducted to optimize the formulation,followed by the verification test. RESULTS:The best microemulsion was produced at 65 ℃ with three phases consisting of stearic acid(oil phase),polysorbate 80(emulsifier)and ethanol (co-emulsifier) and the Km ratio of 1∶4. The optimal conditions for SLN were as

  7. Preparation

    Directory of Open Access Journals (Sweden)

    M.M. Dardir

    2014-03-01

    Full Text Available Some hexanamide-mono and di-linoleniate esters were prepared by the reaction of linolenic acid and hexanamide (derived from the reaction of hexanoic acid and diethanolamine. The chemical structure for the newly prepared hexanamide-mono and di-linoleniate esters were elucidated using elemental analysis, (FTIR, H 1NMR and chemical ionization mass spectra (CI/Ms spectroscopic techniques. The results of the spectroscopic analysis indicated that they were prepared through the right method and they have high purity. The new prepared esters have high biodegradability and lower toxicity (environmentally friendly so they were evaluated as a synthetic-based mud (ester-based mud for oil-well drilling fluids. The evaluation included study of the rheological properties, filtration and thermal properties of the ester based-muds formulated with the newly prepared esters compared to the reference commercial synthetic-based mud.

  8. Effects of poly (lactic-co-glycolic acid) as a co-emulsifier on the preparation and hypoglycaemic activity of insulin-loaded solid lipid nanoparticles.

    Science.gov (United States)

    Wang, S L; Xie, S Y; Zhu, L Y; Wang, F H; Zhou, W Z

    2009-12-01

    Poly (lactic-co-glycolic acid) (PLGA) was used as a co-emulsifier in the preparation of insulin-loaded solid lipid nanoparticles (SLN) with hydrogenated castor oil as lipid matrix and lecithin as surfactant by double-emulsion technique. The effects of PLGA on the preparation and hypoglycaemic activity of insulin-loaded SLN were studied. The results showed that with the supplement of PLGA, the encapsulation efficiency and loading capacity were increased significantly from 79.08 +/- 1.62 to 85.57 +/- 3.21% and 1.58 +/- 0.03 to 1.71 +/- 0.06%, whereas the surface charge and particle size were changed insignificantly from -25.87 +/- 2.65 to -22.67 +/- 1.19 mv and 431.0 +/- 16.1 to 397.0 +/- 68.0 nm, respectively. In vivo studies demonstrated that PLGA increased the sustained hypoglycaemic activity from 12 to 36 h and 24 to 120 h in normal and steptozotocin-induced diabetic mice after a single intramuscular injection of the insulin-loaded SLN. These results demonstrated that PLGA could enhance the entrapment of insulin in the nanoparticles, and more importantly, prolong the time of hypoglycaemic activity of the insulin-loaded SLN.

  9. Preparation and Characterization of Three Tilmicosin-loaded Lipid Nanoparticles: Physicochemical Properties and in-vitro Antibacterial Activities

    Science.gov (United States)

    Al-Qushawi, Alwan; Rassouli, Ali; Atyabi, Fatemeh; Peighambari, Seyed Mostafa; Esfandyari-Manesh, Mehdi; Shams, Gholam Reza; Yazdani, Azam

    2016-01-01

    Tilmicosin (TLM) is an important antibiotic in veterinary medicine with low bioavailability and safety. This study aimed to formulate and evaluate physicochemical properties, storage stability after lyophilization, and antibacterial activity of three TLM-loaded lipid nanoparticles (TLM-LNPs) including solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), and lipid-core nanocapsules (LNCs). Physicochemical parameters such as particle size-mean diameter, polydispersity index, zeta potential, drug encapsulation efficiency (EE), loading capacity, and morphology of the formulations were evaluated and the effects of various cryoprotectants during lyophilization and storage for 8 weeks were also studied. The profiles of TLM release and the antibacterial activities of these TLM-LNPs suspensions (against Escherichia coli and Staphylococcus aureus) were tested in comparison with their corresponding powders. TLM-LNPs suspensions were in nano-scale range with mean diameters of 186.3 ± 1.5, 149.6 ± 3.0, and 85.0 ± 1.0nm, and also EE, 69.1, 86.3, and 94.3% for TLM- SLNs, TLM-NLCs, and TLM- LNCs respectively. TLM-LNCs gave the best results with significantly low particle size and high EE (p<0.05). Mannitol was the most effective cryoprotectant for lyophilization and storage of TLM-LNPs. The drug release profiles were biphasic and the release times were longer at pH 7.4 where TLM-NLCs and TLM-LNCs powders showed longer release times. In microbiological tests, S. aureus was about 4 times more sensitive than E. coli to TLM-LNPs with minimum inhibitory concentration ranges of 0.5-1.0 and 2-4 µg/mL respectively, and TLM-LNCs exhibited the best antibacterial activities. In conclusion, TLM-LNP formulations especially TLM-LNCs and TLM-NLCs are promising carriers for TLM with better drug encapsulation capacity, release behavior, and antibacterial activity. PMID:28261309

  10. Lipidomics reveals multiple pathway effects of a multi-components preparation on lipid biochemistry in ApoE*3Leiden.CETP mice.

    Directory of Open Access Journals (Sweden)

    Heng Wei

    Full Text Available BACKGROUND: Causes and consequences of the complex changes in lipids occurring in the metabolic syndrome are only partly understood. Several interconnected processes are deteriorating, which implies that multi-target approaches might be more successful than strategies based on a limited number of surrogate markers. Preparations from Chinese Medicine (CM systems have been handed down with documented clinical features similar as metabolic syndrome, which might help developing new intervention for metabolic syndrome. The progress in systems biology and specific animal models created possibilities to assess the effects of such preparations. Here we report the plasma and liver lipidomics results of the intervention effects of a preparation SUB885C in apolipoprotein E3 Leiden cholesteryl ester transfer protein (ApoE*3Leiden.CETP mice. SUB885C was developed according to the principles of CM for treatment of metabolic syndrome. The cannabinoid receptor type 1 blocker rimonabant was included as a general control for the evaluation of weight and metabolic responses. METHODOLOGY/PRINCIPAL FINDINGS: ApoE*3Leiden.CETP mice with mild hypercholesterolemia were divided into SUB885C-, rimonabant- and non-treated control groups. SUB885C caused no weight loss, but significantly reduced plasma cholesterol (-49%, p<0.001, CETP levels (-31%, p<0.001, CETP activity (-74%, p<0.001 and increased HDL-C (39%, p<0.05. It influenced lipidomics classes of cholesterol esters and triglycerides the most. Rimonabant induced a weight loss (-9%, p<0.05, but only a moderate improvement of lipid profiles. In vitro, SUB885C extract caused adipolysis stimulation and adipogenesis inhibition in 3T3-L1 cells. CONCLUSIONS: SUB885C, a multi-components preparation, is able to produce anti-atherogenic changes in lipids of the ApoE*3Leiden.CETP mice, which are comparable to those obtained with compounds belonging to known drugs (e.g. rimonabant, atorvastatin, niacin. This study successfully

  11. 氯霉素固体脂质纳米粒的制备及质量评价%Preparation and Quality Evaluation of Chloramphenicol Solid Lipid Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    聂绩; 黄华

    2011-01-01

    目的:制备氯霉素固体脂质纳米粒(CAP-SLN)并考察其质量.方法:选取CAP与甘油棕榈酸硬脂酸酯(PrecirolATO 5)比例(药脂比)、泊洛沙姆含量、乳化温度和初乳-分散相的体积比为考察因素,包封率和载药量为评价指标,设计正交试验并优化处方.利用乳化蒸发-低温固化法制备CAP-SLN;同时以粒径、Zeta电位、包封率、栽药量、稳定性及体外释放度为指标评价其质量.结果:最佳制备处方药脂比为1:10,泊洛沙姆含量为2%,乳化温度为70℃,初乳-分散相的体积比为1:7.所制纳米粒平均粒径为227姗,Zeta电位为-30.5mV,平均包封率为65.9%,平均载药量为6.59%;于4℃环境中考察30d,其包封率、粒径无显著变化,25℃环境中包封率显著降低、粒径明显增大;在前4h内有明显突释现象,药物累积释放率达58.86%,48h时累积释放率达85.09%,体外释药行为符合Weibull方程.结论:该制荆处方设计和工艺方法可行,制剂质量符合要求,可达到缓释效果.%OBJECTIVE: To prepare Chloramphenicol solid lipid nanoparticles (CAP-SLN) and to study the quality of it.METHODS: The preparation technilogy of CAP-SLN was optimized by orthogonal test with the entrapment efficiency and drug loading amount as index and with proportion of CAP to Precirol ATO 5 (drug-to-lipid ratio), amount of poloxamer, emulsifying temperature, volume ratio of emulsion-disperse phase as factors. CAP-SLN was prepared by emulsification evaporation-low temperature solidification technique. The quality of preparation was evaluated with particle size, Zeta potential, drug-loading amount, stability and in vitro drug release rate as index. RESULTS: The optimal formulation was as follows: drug-to-lipid ratio of 1: 10, the weight of poloxamer of 2%, emulsifying temperature of 70 ℃, drug-to-lipid of 1: 7. The mean diameter of CAP-SLN was 227 nm.The zeta potential was -30.5 mV. The entrapment efficacy was 65.9%. The average drug

  12. Isolation of fucoxanthin from Sargassum thunbergii and preparation of microcapsules based on palm stearin solid lipid core

    Science.gov (United States)

    Wang, Xuanxuan; Li, Hongyan; Wang, Fangqin; Xia, Guixue; Liu, Hongjun; Cheng, Xiaojie; Kong, Ming; Liu, Ya; Feng, Chao; Chen, Xiguang; Wang, Ying

    2017-03-01

    The objective of this study was to isolate fucoxanthin from Sargassum thunbergii and develop microcapsules with palm stearin as the solid lipid core for stability and efficient oral delivery of fucoxanthin. The microcapsules had smooth surfaces with the volume weighted mean diameter ( d 4.3) of 19.19 μm. Encapsulation efficiency and loading capacity of microcapsules with fucoxanthin were 98.3% and 0.04%, respectively. Moreover, the fucoxanthin in microcapsules presented higher stability than free fucoxanthin against light, humidity and temperature. Especially, the retention rates of fucoxanthin encapsulated in microcapsules reached 97.20% at 4°C, 92.60% at 25°C, 92.32% with the relative humidity of 33% and 92.60% in the dark. The cumulative amount of fucoxanthin released from microcapsules was 22.92% in simulated gastric fluid (SGF) and 56.55% in simulated intestinal fluid (SIF).

  13. Statistical evaluation of fatty acid profile and cholesterol content in fish (common carp) lipids obtained by different sample preparation procedures.

    Science.gov (United States)

    Spiric, Aurelija; Trbovic, Dejana; Vranic, Danijela; Djinovic, Jasna; Petronijevic, Radivoj; Matekalo-Sverak, Vesna

    2010-07-01

    Studies performed on lipid extraction from animal and fish tissues do not provide information on its influence on fatty acid composition of the extracted lipids as well as on cholesterol content. Data presented in this paper indicate the impact of extraction procedures on fatty acid profile of fish lipids extracted by the modified Soxhlet and ASE (accelerated solvent extraction) procedure. Cholesterol was also determined by direct saponification method, too. Student's paired t-test used for comparison of the total fat content in carp fish population obtained by two extraction methods shows that differences between values of the total fat content determined by ASE and modified Soxhlet method are not statistically significant. Values obtained by three different methods (direct saponification, ASE and modified Soxhlet method), used for determination of cholesterol content in carp, were compared by one-way analysis of variance (ANOVA). The obtained results show that modified Soxhlet method gives results which differ significantly from the results obtained by direct saponification and ASE method. However the results obtained by direct saponification and ASE method do not differ significantly from each other. The highest quantities for cholesterol (37.65 to 65.44 mg/100 g) in the analyzed fish muscle were obtained by applying direct saponification method, as less destructive one, followed by ASE (34.16 to 52.60 mg/100 g) and modified Soxhlet extraction method (10.73 to 30.83 mg/100 g). Modified Soxhlet method for extraction of fish lipids gives higher values for n-6 fatty acids than ASE method (t(paired)=3.22 t(c)=2.36), while there is no statistically significant difference in the n-3 content levels between the methods (t(paired)=1.31). The UNSFA/SFA ratio obtained by using modified Soxhlet method is also higher than the ratio obtained using ASE method (t(paired)=4.88 t(c)=2.36). Results of Principal Component Analysis (PCA) showed that the highest positive impact to

  14. Isolation of fucoxanthin from Sargassum thunbergii and preparation of microcapsules based on palm stearin solid lipid core

    Science.gov (United States)

    Wang, Xuanxuan; Li, Hongyan; Wang, Fangqin; Xia, Guixue; Liu, Hongjun; Cheng, Xiaojie; Kong, Ming; Liu, Ya; Feng, Chao; Chen, Xiguang; Wang, Ying

    2017-01-01

    The objective of this study was to isolate fucoxanthin from Sargassum thunbergii and develop microcapsules with palm stearin as the solid lipid core for stability and efficient oral delivery of fucoxanthin. The microcapsules had smooth surfaces with the volume weighted mean diameter (d 4.3) of 19.19 μm. Encapsulation efficiency and loading capacity of microcapsules with fucoxanthin were 98.3% and 0.04%, respectively. Moreover, the fucoxanthin in microcapsules presented higher stability than free fucoxanthin against light, humidity and temperature. Especially, the retention rates of fucoxanthin encapsulated in microcapsules reached 97.20% at 4°C, 92.60% at 25°C, 92.32% with the relative humidity of 33% and 92.60% in the dark. The cumulative amount of fucoxanthin released from microcapsules was 22.92% in simulated gastric fluid (SGF) and 56.55% in simulated intestinal fluid (SIF).

  15. Cellular uptake of beta-carotene from protein stabilized solid lipid nano-particles prepared by homogenization-evaporation method

    Science.gov (United States)

    Using a homogenization-evaporation method, beta-carotene (BC) loaded nano-particles were prepared with different ratios of food-grade sodium caseinate (SC), whey protein isolate (WPI), or soy protein isolate (SPI) to BC and evaluated for their physiochemical stability, in vitro cytotoxicity, and cel...

  16. Increased acylated plasma ghrelin, but improved lipid profiles 24-h after consumption of carob pulp preparation rich in dietary fibre and polyphenols.

    Science.gov (United States)

    Gruendel, Sindy; Garcia, Ada L; Otto, Baerbel; Wagner, Karen; Bidlingmaier, Martin; Burget, Lukas; Weickert, Martin O; Dongowski, Gerhard; Speth, Maria; Katz, Norbert; Koebnick, Corinna

    2007-12-01

    We have recently shown that a polyphenol-rich insoluble dietary fibre preparation from carob pulp (Ceratonia siliqua L; carob fibre) decreased postprandial acylated ghrelin, TAG and NEFA during an acute liquid meal challenge test. However, delayed effects of carob fibre consumption are unknown. Therefore, a randomized controlled crossover study in nineteen healthy volunteers consuming foods with or without 50 g carob fibre was conducted. On the subsequent day (day 2), glucose, TAG, total and acylated ghrelin as well as insulin, NEFA and leptin were assessed at baseline and at timed intervals for 300 min after ingestion of standardized bread. Consumption of carob fibre-enriched foods did not affect fasting concentrations of glucose, TAG, total ghrelin, NEFA, insulin and leptin. Fasting acylated ghrelin was increased on the day subsequent to carob fibre consumption compared with control (P = 0.046). After consumption of the standard bread on day 2, glucose response (P = 0.029) was increased, and TAG (P = 0.033) and NEFA (P carob fibre consumption the previous day. In conclusion, an increase in total and acylated plasma ghrelin accompanied by enhanced lipid metabolism after carob fibre consumption suggests higher lipid utilization and suppressed lipolysis on the day subsequent to carob fibre consumption. However, elevated glucose levels after carob fibre consumption need to be addressed in future studies.

  17. 微乳法制备阿昔洛韦固体脂质纳米粒%Preparation of aciclovir solid lipid nanoparticles based on the microemulsion technique

    Institute of Scientific and Technical Information of China (English)

    杜丽娜; 李淼; 李欣; 屈国乐; 金义光

    2011-01-01

    目的:用微乳法制备眼用阿昔洛韦(aciclovir,ACV)固体脂质纳米粒(SLN).方法:分别以硬脂酸、单硬脂酸甘油酯为油相,以大豆磷脂和吐温80、吐温20为乳化剂,以乙醇、甘油、胆酸钠、十二烷基硫酸钠(SLS)为助乳化剂制备微乳,微乳分散于水中形成SLN.分别考察处方组成和制备工艺对SLN混浊度和稳定性的影响.用微乳法制备的ACV-SLN经冷冻干燥后,观察其重建效果.用原子力显微镜观察ACV-SLN表面的精细结构.结果:使用注射器滴入法和优选处方可以快速制得粒径<150 nm的含1.0%脂质的ACV-SLN混悬液,10 d内保持稳定.ACV-SLN混悬液经冷冻干燥后可重建.结论:微乳法制备ACV-SLN,简单快捷,不需使用有机溶剂(如二氯甲烷、氯仿等)和复杂设备,适合SLN的研究和小规模制备.%Objective: To prepare the aciclovir (ACV) solid lipid nanoparticles (SLN) for eye use based on the microemulsion technique. Methods: Stearic acid, glycerol monostearate were selected as oil phase, tween 80, tween 20 and soy lecithin as emulsifier,and ethanol, glycerol, sodium cholate, sodium lauric sulfate as co-emulsifier respectively to prepare the oil-in-water microemulsions.Microemulsions dispersed into water and then SLNs were generated. Influences of formulation components and preparation procedures on turbidity and stability of SLN were investigated to optimize the best formula and preparation methods. ACV-SLNs prepared by the microemulsion methods were lyophilized, and its reconstruction effect was evaluated. The fine structure ofACV-SLN surface was observed by atomic force microscope (AFM). Results: ACV-SLN suspensions containing 1.0% lipid with the diameter less than 150 nm were rapidly prepared by dropping method with an injector and the optimal formula, which were stable within 10 d. ACV-SLN suspensions could be reconstituted with water after lyophilized. Conclusion: The preparation of ACV-SLN with microemulsion technique is

  18. Developments in Preparation of Lipid-Soluble Catechins Compounds%脂溶性儿茶素类化合物的制备研究进展

    Institute of Scientific and Technical Information of China (English)

    朱晋萱; 金青哲; 张士康; 朱跃进

    2012-01-01

    Catechin compounds is one kind of polyphenol antioxidant that possess a great physiological aetivties. In this paper, progress of lipid-soluble catechins' preparation that use molecules modification were reviewed. Chemical method is mainly using carbonyl chlorides and catechin compounds in reaction under the role of chemical catalyst to prepare lipid-soluble catechins. But acylation reaction happened at different locus. The carbon chain length of acyl donors generally is more than 8. Enzymatic modification is mainly using fatty acid or fatty acid ester with catechins under the role of lipase, then direct esterification or ester exchange happened to get lipid-soluble catechins. Alkyl is bonded in catchin compounds, thus solubility in oil system of the catechin compounds is raising, and expand the application fields.%儿茶素类化合物是一类具有多种生理活性的多酚类抗氧化剂.本文综述了国内外利用分子修饰法制备脂溶性儿茶素类化合物的进展。化学法主要利用酰氯在化学催化剂作用下反应制备脂溶性儿茶素.但是酰化反应发生的位点有所不同.总的来说酰基供体碳链长度一般大于等于8;酶法主要利用脂肪酶使脂肪酸或脂肪酸酯通过直接酯化或酯交换反应制备脂溶性儿茶素.在儿茶素及其化合物上键合烷基.由此提高了儿茶素类化合物在油脂体系中的溶解度,拓展了其应用领域。

  19. Carob pulp preparation rich in insoluble dietary fiber and polyphenols enhances lipid oxidation and lowers postprandial acylated ghrelin in humans.

    Science.gov (United States)

    Gruendel, Sindy; Garcia, Ada L; Otto, Baerbel; Mueller, Corinna; Steiniger, Jochen; Weickert, Martin O; Speth, Maria; Katz, Norbert; Koebnick, Corinna

    2006-06-01

    Ghrelin is an orexigenic hormone that may affect substrate utilization in humans. Ghrelin is influenced by macronutrients, but the effects of insoluble dietary fiber and polyphenols are unknown. We investigated the effects of a polyphenol-rich insoluble dietary fiber preparation from carob pulp (carob fiber) on postprandial ghrelin responses and substrate utilization. Dose-dependent effects of the consumption of carob fiber were investigated in a randomized, single-blind, crossover study in 20 healthy subjects, aged 22-62 y. Plasma total and acylated ghrelin, triglycerides, and serum insulin and nonesterified fatty acids (NEFA) levels were repeatedly assessed before and after ingestion of an isocaloric standardized liquid meal with 0, 5, 10, or 20 g of carob fiber over a 300-min period. The respiratory quotient (RQ) was determined after consumption of 0 or 20 g of carob fiber. Carob fiber intake lowered acylated ghrelin to 49.1%, triglycerides to 97.2%, and NEFA to 67.2% compared with the control meal (P fiber-enriched liquid meal. Postprandial energy expenditure was increased by 42.3% and RQ was reduced by 99.9% after a liquid meal with carob fiber compared with a control meal (P pulp preparation, an insoluble dietary fiber rich in polyphenols, decreases postprandial responses of acylated ghrelin, triglycerides, and NEFA and alters RQ, suggesting a change toward increased fatty acid oxidation. These results indicate that carob fiber might exert beneficial effects in energy intake and body weight.

  20. Preparation, Properties and Preclinical Pharmacokinetics of Low Molecular Weight Heparin-modified Isoliquiritigenin-loaded Solid Lipid Nanoparticle

    Science.gov (United States)

    Zhang, Xiaoyun; Qiao, Hua; Chen, Ying; Li, Lin; Xia, Huxiong; Shi, Yanbin

    2016-01-01

    Low molecular weight heparin-modified isoliquiritigenin-loaded solid lipid nanoparticle (LMWH-ISL-SLN) was developed for injective application. The morphological observation, particle diameter and zeta potential of LMWH-ISL-SLN were characterized using transmission electron microscopy (TEM) and a Malvern Zetasizer. Its entrapment efficiency (EE) and drug loading (DL) were determined by ultracentrifuge. The in-vitro release experiments were performed by dialysis technique. The cytotoxic effects of LMWH-ISL-SLN on Hep-G2 cell lines were determined using an MTT assay. Pharmacokinetic and tissue distribution studies were conducted in kunming mice after intravenous administration of LMWH-ISL-SLN. The average drug entrapment efficiency for LMWH-ISL-SLN was (99.80 ± 3.27)%, drug loading was (18.68 ± 1.51)%, mean particle size was (217.53 ± 4.86) nm and zeta potential was (–18.24 ± 2.47) mV. The in-vitro release experiments demonstrated isoliquiritigenin release from LMWH-ISL-SLN was in line with Weibull’s distribution law. Hemolysis test and dose-related toxic effects proved that LMWH-ISL-SLN was a safe and non toxic product when given by intravenous injection. The pharmacokinetics results of LMWH-ISL-SLN showed that the area under the concentration-time curve (AUC0→∞)of LMWH-ISL-SLN was greater than that for the isoliquiritigenin solution in plasma. Tissue distribution study indicated that ISL were mainly distributed in the liver and lung. In conclusion, low molecular weight heparin-modified SLN system is a promising carrier for the intravenous delivery of ISL. PMID:27980562

  1. 伊曲康唑固体脂质纳米粒的制备%Study on Preparation of Itraconazole Solid Lipid Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    丁艳; 武夏明; 黄桂华

    2012-01-01

    Objective: To prepared itraconazole solid lipid nanoparticles ( ITZ-SLN ) and investigate the physicochemical properties. Method: ITZ-SLN was prepared by emulsification -low temperature solidification method. Based on the results of the single factor test with the amount of adjuvants and itraconazole as the indices, the formula and the preparation conditions were optimized by orthogonal experiments using the entrapment efficiency as the evaluation index. The entrapment efficiency was determined by low temperature - ultracentrifugation. An electron microscope was used to observe the morphology of ITZ -SLN. A laser particle size analyzer was applied to stud)' the particle diameter and ^ potential of ITZ-SLN in suspension. Result: The amount of lipid, surfactant and itraconazole showed different extent of influence on the entrapment efficiency of ITZ-SLN. ITZ-SLN prepared with the optimized formulation was spherical shape with the mean diameter ( da( ) of ( 118.2 ± 15. 00 ) nm and the ^ potential of ( - 37. 06 ± 0. 53 ) mV. The average entrapment efficiency was ( 92. 11 ± 1.60 ) %. Conclusion: The emulsification-low temperature solidification method is feasible for the preparation of ITZ-SLN.%目的:制备伊曲康唑固体脂质纳米粒,并考察其理化性质.方法:采用乳化-低温固化法制备伊曲康唑固体脂质纳米粒(ITZ-SLN);在脂质、表面活性剂等辅料和主药用量的单因素考察基础上,以包封率为评价指标,采用正交试验设计,优化处方组成和制备工艺;用低温超速离心法测定包封率,透射电镜观察形态,激光粒径分析仪测定粒径和ξ电位.结果:脂质、表面活性剂和主药的用量对ITZ-SLN包封率均有不同程度的影响.以优化处方制备的伊曲康唑固体脂质纳米粒为类球形实体,粒径分布比较均匀,平均粒径为dav=(118.2±15.00)nm,ξ电位(-37.06±0.53)mV,包封率(92.11±1.60)%.结论:乳化-低温固化法制备伊曲康唑固体脂质纳米粒工艺可行.

  2. A nanosystem for water-insoluble drugs prepared by a new technology, nanoparticulation using a solid lipid and supercritical fluid.

    Science.gov (United States)

    Park, Joo Won; Yun, Jeong Min; Lee, Eun Seong; Youn, Yu Seok; Kim, Kab Sig; Oh, Young Taik; Oh, Kyung Teak

    2013-11-01

    While the number and diversity of lead compounds has increased with the development of science technologies, ca. 90 % of new chemical entities under development have shown low aqueous solubility, classified as class II or IV of the biopharmaceutics classification system (BCS). The low aqueous solubility hinders their clinical translations due to low bioavailability and dissolution-limited absorption of orally-administered drugs. Several technologies have been employed to improve the solubility of poorly water-soluble drugs. In this paper, a new method of nanoparticulation using fat and a supercritical fluid (NUFS) for the formulation of hydrophobic drugs was applied to solve the low solubility problem. A typical BCS class II drug, itraconazole, was selected and formulated with hydroxypropyl methylcellulose, emulsification, and anticoagulating agents for NUFS. The non-spherical itraconazole nanoparticles prepared by NUFS were ~300-500 nm in size with a ~15-fold improved dissolution rate compared to non-nanoparticles of itraconazole (i.e., raw itraconazole). In addition, a high drug content of ~46 % by weight and a drug loading efficiency greater than 85 % were achieved. Therefore, the new technology for nano-platforms could be a promising solution for solubilization of poorly water-soluble drugs, resulting in improved bioavailability.

  3. Stratum corneum lipids liposomes for the topical delivery of 5-aminolevulinic acid in photodynamic therapy of skin cancer: preparation and in vitro permeation study

    Directory of Open Access Journals (Sweden)

    Bentley M Vitória LB

    2001-08-01

    Full Text Available Abstract Background Photodynamic therapy (PDT using 5-aminolevulinic acid (5-ALA is a skin cancer therapy that still has limitations due to the low penetration of this drug into the skin. We have proposed in this work a delivery system for 5-ALA based on liposomes having lipid composition similar to the mammalian stratum corneum (SCLLs in order to optimize its skin delivery in Photodynamic Therapy (PDT of skin cancers. Methods SCLLs were obtained by reverse phase evaporation technique and size distribution of the vesicles was determinated by photon correlation spectroscopy. In vitro permeation profile was characterized using hairless mouse skin mounted in modified Franz diffusion cell. Results Size exclusion chromatography on gel filtration confirmed vesicle formation. SCLLs obtained by presented a degree of encapsulation of 5-ALA around 5.7%. A distribution of vesicle size centering at around 500 nm and 400 nm respectively for SCLLs and SCLLs containing 5-ALA was found. In vitro 5-ALA permeation study showed that SCLLs preparations presented higher skin retention significantly (p Conclusions The in vitro delivery performance provided by SCLLs lead to consider this systems adequate for the 5-ALA-PDT of skin cancer, since SCLLs have delivered 5-ALA to the target skin layers (viable epidermis + dermis to be treated by topical PDT of skin cancer.

  4. 构树黄酮固体脂质纳米粒的制备%The preparation of flavonoids-loaded solid lipid nanoparticles from broussonetia papyrifera

    Institute of Scientific and Technical Information of China (English)

    熊燕飞; 吕波; 李政政; 舒思敏; 郑浩

    2011-01-01

    Flavonoids have significant free radical scavenging,antioxidant,anti-aging effect.In this study,stearic acid and lecithin were used as the carrier.The method of emulsion evaporation-solidification at low temperature was used to prepare flavonoids-loaded solid lipid nanoparticles from broussonetia papyrifera.When the ratio between stearic acid and phosphatidylcholine was 75:20,the effect was the best when PEG400 was used as approach emulsifier and stabilizer.The encapsulation efficiency was 82.67% and the drug loading was 33.73%.The average particle size of SLN was 461.3nm.%黄酮类化合物具有显著的清除体内自由基、抗氧化、抗衰老等作用。以硬脂酸、卵磷脂为载体,采用乳化蒸发-低温固化法制备构树黄酮固体脂质纳米粒(SLN)。结果表明,采用PEG400作助乳化剂和稳定剂,硬脂酸、卵磷脂配比为75:20时效果最佳。所得SLN的包封率为82.67%,载药量为33.73%,平均粒径为461.3nm。

  5. Characteristics of structured lipid prepared by lipase-catalyzed acidolysis of roasted sesame oil and caprylic acid in a bench-scale continuous packed bed reactor.

    Science.gov (United States)

    Kim, Byung Hee; Akoh, Casimir C

    2006-07-12

    Structured lipid (SL) was prepared from roasted sesame oil and caprylic acid (CA) by Rhizomucor miehei lipase-catalyzed acidolysis in a bench-scale continuous packed bed reactor. Total incorporation and acyl migration of CA in the SL were 42.5 and 3.1 mol %, respectively, and the half-life of the lipase was 19.2 days. The SL displayed different physical and chemical properties, less saturated dark brown color, lower viscosity, lower melting and crystallization temperature ranges, higher melting and crystallization enthalpies, higher smoke point, higher saponification value, and lower iodine value, in comparison to those of unmodified sesame oil. The oxidative stability of purified SL was lower than that of sesame oil. There were no differences in the contents of unsaponifiables including tocopherols and phytosterols. However, total sesame lignans content was decreased in SL due to the loss of sesamol when compared to sesame oil. Most of the 70 volatiles present in roasted sesame oil were removed from SL during short-path distillation of SL. These results indicate that the characteristics of SL are different from those of original sesame oil in several aspects except for the contents of tocopherols and phytosterols.

  6. Lipid Profile

    Science.gov (United States)

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Lipid Profile Share this page: Was this page helpful? Also ... as: Lipid Panel; Coronary Risk Panel Formal name: Lipid Profile Related tests: Cholesterol ; HDL Cholesterol ; LDL Cholesterol ; Triglycerides ; ...

  7. Preparation of Etoposide Solid Lipid Nanoparticles%依托泊苷固体脂质纳米粒的研制

    Institute of Scientific and Technical Information of China (English)

    于莲; 赵向男; 崔丹; 杜妍

    2011-01-01

    OBJECTIVE: To prepare Etoposide-loaded solid lipid nanoparticles (ET-SLN) and to investigate the physical and chemical properties. METHODS: Emulsion-ultrasonic dispersion method was used to prepare ET-SLN. The formula was optimized by orthogonal test with amount of glycerin monostearate (A), soy lecithin (B), poloxamer 188 (C), etoposide (D) as factors using encapsulation coefficency as index. The particle size, Zeta potential, encapsulation efficiency and in vitro release of the ET-SLN were investigated. RESULTS: Amounts of A, B, C, D were 0.020 mg, 0.010 mg, 0.015 mg, 0.015 mg. The average particle size was (83 ± 0.5) nm with Zeta potential of (- 23 ± 0.3) mV. The encapsulation coefficency was 81.2%. In vitro release test showed a significant sustained release for 48 h. CONCLUSION: Prepared ET-SLN is in line with requirements of pharmaceutics.%目的:制备依托泊苷固体脂质纳米粒(ET-SLN)并考察其药剂学性质.方法:采用乳化-超声分散法制备ET-SLN,以单硬脂酸甘油酯(A)、大豆磷脂(B)、泊洛沙姆188(C)、依托泊苷(D)的处方用量为考察因素,包封率为指标设计正交试验,筛选最优处方.考察纳米粒的粒径、表面电位、包封率、体外释放情况等.结果:A、B、C、D分别为0.020、0.010、0.015、0.015 mg;所制纳米粒平均粒径(83±0.5) nm,表面电位(-23±0.3)mV,包封率81.2%,可持续48h缓释.结论:所制ET-SLN符合药剂学性质要求.

  8. 布洛芬固体脂质微颗粒的制备及其晶体构型研究%Preparation and Crystal Modification of Ibuprofen-Loaded Solid Lipid Microparticles

    Institute of Scientific and Technical Information of China (English)

    龙春霞; 章莉娟; 钱宇

    2006-01-01

    An emulsion-congealing technique is used to prepare solid lipid microparticles (SLM) containing ibuprofen with glyceryl behenate, tripalmitin and beewax as excipients. The difference of the solubility parameters between the excipients and ibuprofen are used to analyze their compatibility. Both the solubility parameter analysis and the experimental results show that glyceryl behenate is the best among the three excipients. The solid particles disperse well in aqueous phase when the drug loading reaches 10% (relative to lipid only). Glycerides exhibit marked polymorphism and their rapid rates of crystallization accelerate the formation of metastable crystal modification. The metastable crystal modification characterizes high drug loading capacity but less stability. Increasing the content of lipophilic drug in a lipid matrix facilitates the transformation of excipients to more stable polymorphic forms.

  9. Apolipoprotein C-II and lipoprotein lipase show a temporal and geographic correlation with surfactant lipid synthesis in preparation for birth

    Directory of Open Access Journals (Sweden)

    Gérard-Hudon Marie-Christine

    2010-11-01

    Full Text Available Abstract Background Fatty acids are precursors in the synthesis of surfactant phospholipids. Recently, we showed expression of apolipoprotein C-II (apoC-II, the essential cofactor of lipoprotein lipase (LPL, in the fetal mouse lung and found the protein on the day of the surge of surfactant synthesis (gestation day 17.5 in secretory granule-like structures in the distal epithelium. In the present study, we will answer the following questions: Does apoC-II protein localization change according to the stage of lung development, thus according to the need in surfactant? Are LPL molecules translocated to the luminal surface of capillaries? Do the sites of apoC-II and LPL gene expression change according to the stage of lung development and to protein localization? Results The present study investigated whether the sites of apoC-II and LPL mRNA and protein accumulation are regulated in the mouse lung between gestation day 15 and postnatal day 10. The major sites of apoC-II and LPL gene expression changed over time and were found mainly in the distal epithelium at the end of gestation but not after birth. Accumulation of apoC-II in secretory granule-like structures was not systematically observed, but was found in the distal epithelium only at the end of gestation and soon after birth, mainly in epithelia with no or small lumina. A noticeable increase in surfactant lipid content was measured before the end of gestation day 18, which correlates temporally with the presence of apoC-II in secretory granules in distal epithelium with no or small lumina but not with large lumina. LPL was detected in capillaries at all the developmental times studied. Conclusions This study demonstrates that apoC-II and LPL mRNAs correlate temporally and geographically with surfactant lipid synthesis in preparation for birth and suggests that fatty acid recruitment from the circulation by apoC-II-activated LPL is regionally modulated by apoC-II secretion. We propose a model

  10. Preparation and Characterization of Liranaftate Solid Lipid Nanoparticles%利拉萘酯固体脂质纳米粒的构建及表征

    Institute of Scientific and Technical Information of China (English)

    张海龙; 刘海乐; 兰天; 丁劲松

    2012-01-01

    Solid lipid nanoparticles (SLN) loaded with liranaftate were prepared by emulsion solvent diffusion method with glyceryl monostearate and cholesterin as matrix material. The formulation was optimized through orthogonal design. The mean particle size of the liranaftate SLN was (145.3±6.1)nm with the entrapment efficiency of (75.8±0.7) % and drug loading of (4.82±0.03) %. The results of differential scanning calorimetry (DSC) showed that liranaftate was entrapped in the SLN as amorphous form. The results of preliminary stability test showed that the liranaftate SLN stored at 4℃ for 30 d could maintain stable. The results of in vitro transdermal test showed that the skin deposition ratio of liranaftate SLN gel was about 100 times of the commercial cream (Zefnart).%以单硬脂酸甘油酯和胆固醇为脂质材料,采用乳化溶剂扩散法制备利拉萘酯固体脂质纳米粒,并采用正交设计优化处方.结果表明,所得优化制品平均粒径为(145.3±6.1)nm,包封率为(75.8±0.7)%,载药量为(4.82±0.03)%,DSC分析提示药物可能以无定形状态存在于载体中.稳定性初步研究显示制品在4℃条件放置30 d可维持稳定.体外透皮试验表明,利拉萘酯固体脂质纳米粒凝胶的皮肤滞留比约为市售乳膏(Zefnart)的100倍.

  11. Preparation and in vitro and in vivo characterization of cyclosporin A-loaded, PEGylated chitosan-modified, lipid-based nanoparticles.

    Science.gov (United States)

    Zhang, Ling; Zhao, Zhi-Liang; Wei, Xiao-Hong; Liu, Jin-Hua

    2013-01-01

    A new cyclosporin A-loaded, PEGylated chitosan-modified lipid-based nanoparticle was developed to improve upon the formulation of cyclosporin A. PEGylated chitosan, synthesized in three steps using mild reaction conditions, was used to modify the nanoparticles. Cyclosporin A-loaded, PEGylated chitosan-modified nanoparticles were prepared using an emulsification/solvent evaporation method. The drug content and encapsulation efficiency of the cyclosporin A-loaded, PEGylated chitosan-modified nanoparticles were measured by high-performance liquid chromatography. The average size of the nanoparticles was determined by transmission electron microscopy and dynamic light scattering. The pharmacokinetic behavior of the nanoparticles was investigated in rabbits after intravenous injection. Cyclosporin A concentrations in a whole blood sample were analyzed by high-performance liquid chromatography using tamoxifen as the internal standard. The pharmacokinetic parameters were calculated using the 3p87 software program. Fourier transform infrared spectroscopy and nuclear magnetic resonance confirmed the structure of PEGylated chitosan. The drug content and encapsulation efficiency of the cyclosporin A-loaded, PEGylated chitosan-modified nanoparticles were 37.04% and 69.22%, respectively. The average size of the nanoparticles was 89.4 nm. The nanoparticles released 30% cyclosporin A-loaded in 48 hours in vitro, with no initial burst release. The mode of release in vitro was prone to bulk erosion. The in vivo results showed the biological half-life of the elimination phase (t(1/2β)) of the nanoparticles was 21 times longer than that of the cyclosporin A solution, and the area under the curve for the nanoparticles was 25.8 times greater than that of the cyclosporin A solution. Modification of PEGylated chitosan prolonged the retention time of the nanoparticles in the circulatory system and improved the bioavailability of cyclosporin A.

  12. Preparation and Evaluation of Gambogenic Acid Solid Lipid Nanoparticles%新藤黄酸固体脂质纳米粒的制备与质量评价

    Institute of Scientific and Technical Information of China (English)

    陈延杰; 陈卫东

    2011-01-01

    目的 制备新藤黄酸固体脂质纳米粒并进行质量考察.方法 采用正交试验设计优化处方,以高温乳化-低温固化的方法制备新藤黄酸固体脂质纳米粒.并对其包封率、形态等进行研究.结果 所制得的新藤黄酸固体脂质纳米粒外观形态圆整,粒度分布均匀,平均粒径为163.3 nm,包封率为(60.1±1.1)%.结论 高温乳化-低温固化的方法适用于新藤黄酸-固体脂质纳米粒的制备.%Objective To investigate the preparation and evaluation of gambogenic acid solid lipid nanoparticles. Methods The formulation was optimized through orthogonal design. Gambogenic acid solid lipid nanoparticles were prepared by the method of emulsification evaporation - solidification at low temperature. The encapsulation efficiency and appearance of solid lipid nanoparticles were studied. Results The mean particle size was found to be 163. 3 nm with a narrow particles distribution of polydispersity index. The drug entrapment efficiency approached (60. 1 ±1. 1)%. Conclusion The method of emulsification evaporation - solidification at low temperature was appropriate for the preparation of gambogenic acid loaded solid lipid nanoparticles.

  13. 结构脂的构效关系及酶法制备的研究进展%Research progress of structure-function relationship of structured lipids and enzymatic preparation

    Institute of Scientific and Technical Information of China (English)

    刘宁; 汪勇; 赵强忠; 赵谋明

    2012-01-01

    结构脂具有天然油脂的风味和物理特性,由于对人体具有特殊的生理功能和营养价值而倍受关注。本文基于结构脂的构效关系,对脂肪酶催化分子设计制备结构脂的研究现状进行了综述,系统介绍了人乳替代品、类可可脂、甘油二酯和单甘酯等热门结构脂的研究进展。%The structured lipids,which have similar flavor and physical characteristics as natural lipids,are attracting interestings due to their special physiological functions and nutritional values.Based on the relationship between structure and function,the applications of lipase-catalyzed molecular design on the preparation of structured lipids were summarized,especially certain types of structured lipids,such as human milk fat substitute,cocoa butter,diacylglycerols,monoacylglycerols,and so on.

  14. A spin label study of perturbation effects of N-(1-methyldodecyl)-N, N, N-trimethylammonium bromide and N-(1-methyldodecyl)-N, N-dimethylamine oxide on model membranes prepared from Escherichia coli-isolated lipids.

    Science.gov (United States)

    Sersen, F; Leitmanová, A; Devínsky, F; Lacko, I; Balgavý, P

    1989-04-01

    Interaction of bactericidal surfactants N-(1-methyldodecyl)-N, N, N-trimethylammonium bromide (2-ATDBr) and N-(1-methyldodecyl)-N, N-dimethylamine oxide (2-ATDNO) with phospholipid membranes prepared from Escherichia coli -- isolated lipids was studied by ESR spectroscopy using m-doxyl stearic acid (m-DSA, m = 5, 12, 16) and N-cetyl-N, N-dimethyl-N-tempoylammonium bromide spin labels located in different membrane depths. 2-ATDBr was found to be a more potent membrane perturbant than 2-ATDNO both at equal membrane and sample concentrations; this is in compliance with the respective antimicrobial activities of these agents. Using the statistical model of hydrocarbon chains in lipid bilayers, the probabilities of the formation of gauche conformations and the effective energy differences between the trans and gauche conformations were calculated from m-DSA order parameters for two different bilayer regions. Based on these parameters, a molecular model of the location of surfactant molecules in bilayer has been formulated. It has been suggested that at low concentrations the surfactant molecules are located in structural defects between lipid clusters in the bilayer. After filling up these defects, the surfactant molecules penetrate into the clusters between lipid molecules, expand the bilayer laterally and increase the amount of gauche conformations in the hydrocarbon chains in the hydrophobic core of the bilayer.

  15. RF Microalgal lipid content characterization

    Science.gov (United States)

    Ahmad, Mahmoud Al; Al-Zuhair, Sulaiman; Taher, Hanifa; Hilal-Alnaqbi, Ali

    2014-05-01

    Most conventional techniques for the determination of microalgae lipid content are time consuming and in most cases are indirect and require excessive sample preparations. This work presents a new technique that utilizes radio frequency (RF) for rapid lipid quantification, without the need for sample preparation. Tests showed that a shift in the resonance frequency of a RF open-ended coaxial resonator and a gradual increase in its resonance magnitude may occur as the lipids content of microalgae cells increases. These response parameters can be then calibrated against actual cellular lipid contents and used for rapid determination of the cellular lipids. The average duration of lipid quantification using the proposed technique was of about 1 minute, which is significantly less than all other conventional techniques, and was achieved without the need for any time consuming treatment steps.

  16. Preparation of Paclitaxel-loaded Solid Lipid Nanoparticles in Microchannels and Formulation Optimization%微通道内载紫杉醇固体脂质纳米粒制备及工艺优化

    Institute of Scientific and Technical Information of China (English)

    丁清; 洪伟勇; 贠军贤; 杨根生

    2012-01-01

    目的:制备载紫杉醇固体脂质纳米粒。方法:微通道内采用溶剂扩散法制备脂质纳米粒,并通过正交优化制备工艺。结果:制备的纳米粒稳定性良好,平均粒径为(129.87±2.91)nm,包封率为(3.11±0.06)%,载药率为(43.67±0.24)%。结论:本研究制备的载药固体脂质纳米粒载药特性与重复性良好。%Objective: To prepare paclitaxel loaded solid lipid nanoparticles(SLNs) with proper physicochemical property by rectangular microchannels.Methods: Paclitaxel loaded solid lipid nanoparticles(PTX-SLNs) was prepared by solvent diffusion method in rectangular microchannels.Orthogonal design was utilized to optimize prescription.Result: PTX-SLNs prepared with optimized prescription demonstrated good stability.The encapsulation efficiency and drug loading of PTX-SLNs were(43.67±0.24) % and(3.11±0.06) % respectively,the average size was(129.87±2.91) nm.Conclusion: PTX-SLNs has a good medicine characteristics and reproducibility.

  17. 丹参酮ⅡA 固体脂质纳米粒的制备及质量评价%Preparation and quality evaluation of tanshinonesⅡA solid lipid nanoparticles

    Institute of Scientific and Technical Information of China (English)

    瞿继兰; 刘志东; 郭秀君; 庞晓晨; 韩真真

    2014-01-01

    [目的]以山嵛酸甘油酯和单硬脂酸甘油酯为载体材料制备丹参酮 IIA 固体脂质纳米粒(TA-SLN)并评价其质量。[方法]采用乳化固化法制备 TA-SLN,以包封率为指标,通过单因素考察法对处方进行优化,激光粒径测定仪测定其粒径、电位,并用差示扫描量热仪(DSC)表征其性质。[结果]制备的 TA-SLN 平均粒径为(110±4) nm,Zeta 电位为-34.4 mV,包封率为79.08%。DSC 表明其理化性质稳定可靠。[结论]采用乳化固化法制备的 TA-SLN 粒径和包封率较适宜,理化性质稳定,为开发其新制剂奠定了实验基础。%Objective] To prepare tanshinonesⅡA-loaded solid lipid nanoparticles with docosanoic acid glyceride and glyceryl monos-tearate as its lipid matrix and investigate its quality. [Methods] TanshinonesⅡA-loaded solid lipid nanoparticles were prepared by emul-sion evaporation-solidification. With encapsulation efficiency as index, through the single factor the formulation was optimized, using laser particle size analyzer its particle size was measured, Using potential and use DSC its properties was characterized. [Results] The obtained solid lipid nanoparticles had an average size of (110±4) nm, zeta potential was -38.5 mV and the entrapment efficiency was 79.08%. DSC showed that its physical and chemical properties were stable and reliable. [Conclusion] The solid lipid nanoparticles prepared by the emulsion evaporation-solidification have an appropriate size, the encapsulation efficiency and stable physical and chemical properties have provided an experimental foundation for the development of the new formulation.

  18. 索拉非尼固体脂质纳米粒冻干粉制备及体外释药特性研究%Preparation and in Vitro Release of Lyophilized Powder of Sorafenib Solid Lipid Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    张洪; 张福明; 闫士君

    2013-01-01

    目的 制备索拉非尼固体脂质纳米粒,并考察其理化性质及体外释药特性.方法 采用乳化蒸发-低温固化法制备索拉非尼固体脂质纳米粒,透射电镜观察形态,激光粒度仪测定粒径和Zeta电位,葡聚糖凝胶法和HPLC测定其包封率,透析法考察其体外释药特性,冷冻干燥法制备索拉非尼固体脂质纳米粒冻干粉,差示扫描量热分析其物相状态.结果 制得索拉非尼固体脂质纳米粒为类球形实体,粒径分布比较均匀,平均粒径为(108.2±7.0)nm,多分散指数为(0.250±0.022),Zeta电位为(-16.4±0.7)mV;测得3批样品的平均包封率为(73.49±1.87)%;体外释放符合Weibull模型;等体积15%甘露醇作冻干保护剂效果较好;DSC分析证明纳米粒已形成.结论 乳化蒸发-低温固化法适用于索拉非尼固体脂质纳米粒的制备,所制纳米粒各项物理指标稳定,具有明显缓释作用.%OBJECTIVE To prepare sorafenib solid lipid nanoparticles and investigate its physicochemical properties and in vitro release profile. METHODS Sorafenib solid lipid nanoparticles were prepared by emulsion evaporation-solidification at low temperature. The morphology was examined by transmission electron microscope. The particle size and Zeta potential were determined by laser granularity equipment. The encapsulation efficiency was detected by Sephadex gel chromatography and HPLC. The in vitro release profile of sorafenib solid lipid nanoparticles was studied using dialysis technology. The lyophilized powder of sorafenib solid lipid nanoparticles was prepared by refrigerated air dryer and its material phase was analyzed by DSC. RESULTS The sorafenib solid lipid nanoparticles assumed spherical shape. The distribution of diameter was even with average particle size of ( 108. 2 ±7. 0) nm. The PDI and Zeta potential were (0.250 ±0.022) and ( - 16. 4 ±0.7) mV, respectively. The average encapsulation efficiency was (73.49 ± 1. 87) %. The release

  19. Multi criteria decision making to select the best method for the preparation of solid lipid nanoparticles of rasagiline mesylate using analytic hierarchy process

    Directory of Open Access Journals (Sweden)

    Viveksarathi Kunasekaran

    2014-01-01

    Full Text Available The objective of this study was to select best method for the development of rasagiline mesylate (RM loaded nanoscale solid lipid particles using analytic hierarchy process (AHP. Improper method selection may lead to waste of time, loss of material and financial resources. One of the possibilities to overcome these difficulties, AHP was employed to find the suitable method. In the AHP, a decision of hierarchy was constructed with a goal, criteria, sub-criteria, and alternatives. After constructing the AHP, the expert choice software was used to compute the overall priority of criteria, sub-criteria and alternatives. The best alternative selected was based on the highest priority. Nanoscale solid lipid particles of RM was formulated by the selected microemulsion method (M4 and it shows the particle size, polydispersity index and zeta potential were within acceptable limits. Drug content and entrapment efficiency of the RM-solid lipid nanoparticles were 97.26% and 86.57%, respectively. This study concludes that the AHP was viable and effective tool for selecting a most suitable method for the fabrication of RM loaded nanoscale solid lipid particles.

  20. Lipidomics reveals multiple pathway effects of a multi-components preparation on lipid biochemistry in ApoE*3Leiden.CETP mice

    NARCIS (Netherlands)

    Wei, H.; Hu, C.; Wang, M.; Hoek, A.M. van den; Reijmers, T.H.; Wopereis, S.; Bouwman, J.; Ramaker, R.; Korthout, H.A.A.J.; Vennik, M.; Hankemeier, T.; Havekes, L.M.; Witkamp, R.F.; Verheij, E.R.; Xu, G.; Greef, J. van der

    2012-01-01

    Background: Causes and consequences of the complex changes in lipids occurring in the metabolic syndrome are only partly understood. Several interconnected processes are deteriorating, which implies that multi-target approaches might be more successful than strategies based on a limited number of su

  1. Multi criteria decision making to select the best method for the preparation of solid lipid nanoparticles of rasagiline mesylate using analytic hierarchy process.

    Science.gov (United States)

    Kunasekaran, Viveksarathi; Krishnamoorthy, Kannan

    2014-07-01

    The objective of this study was to select best method for the development of rasagiline mesylate (RM) loaded nanoscale solid lipid particles using analytic hierarchy process (AHP). Improper method selection may lead to waste of time, loss of material and financial resources. One of the possibilities to overcome these difficulties, AHP was employed to find the suitable method. In the AHP, a decision of hierarchy was constructed with a goal, criteria, sub-criteria, and alternatives. After constructing the AHP, the expert choice software was used to compute the overall priority of criteria, sub-criteria and alternatives. The best alternative selected was based on the highest priority. Nanoscale solid lipid particles of RM was formulated by the selected microemulsion method (M4) and it shows the particle size, polydispersity index and zeta potential were within acceptable limits. Drug content and entrapment efficiency of the RM-solid lipid nanoparticles were 97.26% and 86.57%, respectively. This study concludes that the AHP was viable and effective tool for selecting a most suitable method for the fabrication of RM loaded nanoscale solid lipid particles.

  2. Lipidomics reveals multiple pathway effects of a multi-components preparation on lipid biochemistry in ApoE*3Leiden.CETP mice

    NARCIS (Netherlands)

    Wei, H.; Hu, C.; Wang, M.; Hoek, van den A.M.; Reijmers, T.H.; Wopereis, S.; Bouwman, J.; Ramaker, R.; Korthout, H.A.A.J.; Vennik, M.; Hankemeier, T.; Havekes, L.M.; Witkamp, R.F.; Verheij, E.R.; Xu, G.; Greef, van der J.

    2012-01-01

    BACKGROUND: Causes and consequences of the complex changes in lipids occurring in the metabolic syndrome are only partly understood. Several interconnected processes are deteriorating, which implies that multi-target approaches might be more successful than strategies based on a limited number of su

  3. Lipidomics reveals multiple pathway effects of a multi-components preparation on lipid biochemistry in ApoE*3Leiden.CETP mice

    NARCIS (Netherlands)

    Wei, H.; Hu, C.; Wang, M.; Hoek, A.M. van den; Reijmers, T.H.; Wopereis, S.; Bouwman, J.; Ramaker, R.; Korthout, H.A.A.J.; Vennik, M.; Hankemeier, T.; Havekes, L.M.; Witkamp, R.F.; Verheij, E.R.; Xu, G.; Greef, J. van der

    2012-01-01

    Background: Causes and consequences of the complex changes in lipids occurring in the metabolic syndrome are only partly understood. Several interconnected processes are deteriorating, which implies that multi-target approaches might be more successful than strategies based on a limited number of su

  4. Dimethyl carbonate-mediated lipid extraction and lipase-catalyzed in situ transesterification for simultaneous preparation of fatty acid methyl esters and glycerol carbonate from Chlorella sp. KR-1 biomass.

    Science.gov (United States)

    Jo, Yoon Ju; Lee, Ok Kyung; Lee, Eun Yeol

    2014-04-01

    Fatty acid methyl esters (FAMEs) and glycerol carbonate were simultaneously prepared from Chlorella sp. KR-1 containing 40.9% (w/w) lipid using a reactive extraction method with dimethyl carbonate (DMC). DMC was used as lipid extraction agent, acyl acceptor for transesterification of the extracted triglycerides, substrate for glycerol carbonate synthesis from glycerol, and reaction medium for the solvent-free reaction system. For 1g of biomass, 367.31 mg of FAMEs and 16.73 mg of glycerol carbonate were obtained under the optimized conditions: DMC to biomass ratio of 10:1 (v/w), water content of 0.5% (v/v), and Novozyme 435 to biomass ratio of 20% (w/w) at 70°C for 24h. The amount of residual glycerol was only in the range of 1-2.5mg. Compared to conventional method, the cost of FAME production with the proposed technique could be reduced by combining lipid extraction with transesterification and omitting the extraction solvent recovery process.

  5. [Mexidol preparation influence upon lipids peroxide oxidation and oral fluid antioxidant system activity in patients with chronic generalized parodontitis and arterial hypertension].

    Science.gov (United States)

    Kazarina, L N; Vdovina, L V; Dubrovskaia, E N

    2010-01-01

    Results of laboratory investigations of the estimation of peroxide oxidation of lipids and antioxidant protection in the oral fluid of the patients with chronic generalizating parodontitis and arterial hypertension with using mexidol. It was shown that the normalization of parameters of the primary and second products of peroxidation with mexidol action, antioxidant protection of oral liquid increased that was favorably reflected in structures and functions of cell.

  6. Lipid somersaults

    DEFF Research Database (Denmark)

    Günther-Pomorski, Thomas; Menon, Anant K.

    2016-01-01

    Membrane lipids diffuse rapidly in the plane of the membrane but their ability to flip spontaneously across a membrane bilayer is hampered by a significant energy barrier. Thus spontaneous flip-flop of polar lipids across membranes is very slow, even though it must occur rapidly to support divers...

  7. 川芎嗪棕榈酸酯亚微乳的制备及其药动学与脑靶向性的评价%Preparation of tetramethylpyrazine palmitate lipid emulsion and its pharmacokinetics and brain targeting performance

    Institute of Scientific and Technical Information of China (English)

    李茜; 王珍珍; 于小月; 曹然; 王银艳; 毛声俊

    2013-01-01

    OBJECTIVE To prepare the 2-Hydroxymethyl-3,5,6-trimethyl pyrazine palmitate (HTMPP) lipid emulsion and investigate the pharmacokinetics and its brain targeting performance in mice.METHODS HTMPP lipid emulsion was prepared by high-pressure homogeneous technique.Central composite design surface methodology was applied to optimize the lipid emulsion formulation.The concentration of drug in mice plasma and brain was determined by HPLC,and the parameters were calculated with DAS 2.0.RESULTS The mean diameter of lipid emulsion was 253.2 ± 0.26 nm.The pharmacokinetic parameters of HTMPP lipid emulsion were 18.58 min for t1/2 and 745.96 mg·L-1 ·min-1 for AUC(0-∞) in plasma,and in brain,the AUC(0-∞) was 632.31 mg·L-1 ·min-1.The pharmacokinetic parameters of tetramethylpyrazine phosphate (TMPP) injection were 10.16 min for t1/2 and 522.03 mg· L-1 · min-1 for AUC(0-∞) in plasma,and in brain,the AUC(0-∞) was 440.89 mg· L-1· min-1.CONCLUSION Compared with TMPP injection,the prepared HTMPP lipid emulsion prolonged the t1/2 and improved the brain targeting ability by determining the concentration of HTMP.%目的 制备2-羟甲基-3,5,6-三甲基吡嗪棕榈酸酯(HTMPP)亚微乳,并考察其在小鼠体内的药动学及脑靶向性.方法 采用星点设计-效应面法优选处方,高压均质法制备HTMPP亚微乳,HPLC法测定2-羟甲基-3,5,6-三甲基吡嗪(HTMP)的含量,DAS 2.0软件计算药动学参数.结果 制备的亚微乳平均粒径为253.2±0.26 nm,HTMPP亚微乳在血浆中的t1/2为18.58 min,为磷酸川芎嗪(TMPP)注射液的1.83倍,AUC(0-∞)为745.96 mg· L-1·min-1,为TMPP注射液的1.43倍(P<0.01);其在脑中的AUC(0-∞)为632.31 mg· L-1·min-1,为TMPP注射液的1.43倍(P<0.01).结论 以HTMP计,HTMPP亚微乳与TMPP注射液相比,生物半衰期显著延长,具有较强的脑靶向性.

  8. Lipid Ion Channels

    CERN Document Server

    Heimburg, Thomas

    2010-01-01

    The interpretation electrical phenomena in biomembranes is usually based on the assumption that the experimentally found discrete ion conduction events are due to a particular class of proteins called ion channels while the lipid membrane is considered being an inert electrical insulator. The particular protein structure is thought to be related to ion specificity, specific recognition of drugs by receptors and to macroscopic phenomena as nerve pulse propagation. However, lipid membranes in their chain melting regime are known to be highly permeable to ions, water and small molecules, and are therefore not always inert. In voltage-clamp experiments one finds quantized conduction events through protein-free membranes in their melting regime similar to or even undistinguishable from those attributed to proteins. This constitutes a conceptual problem for the interpretation of electrophysiological data obtained from biological membrane preparations. Here, we review the experimental evidence for lipid ion channels...

  9. 固体脂质体纳米粒制备方法的研究进展%Advances in the preparation methods of solid lipid nanoparticles

    Institute of Scientific and Technical Information of China (English)

    冯炜玮; 陈志伟

    2011-01-01

    @@ 固体脂质纳米粒(solid lipid nanoparticles,SLN)又称固体脂质体,是一种室温下为固态的天然或合成的脂质体或类脂纳米粒子.SLN的研究始于20世纪90年代,是一种以硬脂酸、卵磷脂、三酰甘油等脂类原料为基质,将药物包裹于类脂核中制成50~1000nm粒径的固体脂质粒子给药体系.

  10. Simultaneous extraction and cleanup of high-lipid organs from white sturgeon (Acipenser transmontanus) for multiple legacy and emerging organic contaminants using QuEChERS sample preparation.

    Science.gov (United States)

    Morrison, Shane A; Sieve, Kristal K; Ratajczak, Robert E; Bringolf, Robert B; Belden, Jason B

    2016-01-01

    The objective of this research was to utilize the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method to extract a broad range of persistent organic pollutants from sturgeon organs (liver and gonad) as indicators of exposure. The analyte list was prioritized to include carcinogenic polyaromatic hydrocarbons (PAHs), the most commonly occurring polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), persistent bioaccumulative and toxic chemicals (PBTs), and emergent contaminants of concern (ECCs) as indicators of human sewage exposure. White sturgeon (Acipenser transmontanus) were selected for this study to support a larger ecotoxicological study to monitor contaminants as an assessment of fish health. Organ tissues contained high lipid content with percentages of 15% and 34% for liver and gonad, respectively. Overall recoveries from fortified sturgeon tissues were high, 71-98% for PAHs, 60-107% for PBDEs and PCBs, 86-107% for PBT chemicals, and 88-107% for ECCs with the exception of octinoxate (28%) from liver tissues. Analyte recovery trends decreased as analyte lipophilicity and molecular weight increased. These recoveries demonstrate that extraction using QuEChERS can be used for screening of the most common bioaccumulating organic compounds in high lipid fish tissue using a single extraction and analysis.

  11. Effects of green tea extract and α-tocopherol on the lipid oxidation rate of omega-3 oils, incorporated into table spreads, prepared using multiple emulsion technology.

    Science.gov (United States)

    Dwyer, Sandra P O'; O'Beirne, David; Ní Eidhin, Deirdre; O'Kennedy, Brendan T

    2012-12-01

    This study examined the effectiveness of fat and water soluble antioxidants on the oxidative stability of omega (ω)-3 rich table spreads, produced using novel multiple emulsion technology. Table spreads were produced by dispersing an oil-in-water (O/W) emulsion (500 g/kg 85 camelina/15 fish oil blend) in a hardstock/rapeseed oil blend, using sodium caseinate and polyglycerol polyricinoleate as emulsifiers. The O/W and oil-in-water-in-oil (O/W/O) emulsions contained either a water soluble antioxidant (green tea extract [GTE]), an oil soluble antioxidant (α-Tocopherol), or both. Spreads containing α-Tocopherol had the highest lipid hydroperoxide values, whereas spreads containing GTE had the lowest (P spreads. By the end of storage, none of the spreads had significantly different G' values. Firmness (Newtons) of all spreads generally increased during storage (P Food Technologists®

  12. Preparation of Solid Lipid Nanoparticles Loaded with Ibuprofen%布洛芬固体脂质纳米粒的制备

    Institute of Scientific and Technical Information of China (English)

    吴冬冬; 伟忠民; 逄秀娟; 余克富

    2009-01-01

    目的 制备布洛芬固体脂质纳米粒(solid lipid nanoparticles,SLN)并优化其处方.方法 采用乳化分散-超声法制备布洛芬SLN,以包封率为评价指标,进行正交实验筛选最优处方.结果 通过正交筛选,得到的最优处方为布洛芬0.05 g、F-68 0.35 g、正丁醇2 mL、卵磷脂0.15 g、单硬脂酸甘油脂0.05 g.结论 用该工艺和处方制备的布洛芬SLN符合制剂学性质要求.

  13. Effect of different dietary concentrations of brown marine algae (Sargassum dentifebium prepared by different methods on plasma and yolk lipid profiles, yolk total carotene and lutein plus zeaxanthin of laying hens

    Directory of Open Access Journals (Sweden)

    Ahmed A. El-Deek

    2012-10-01

    Full Text Available The effect of different concentrations (0%, 3% and 6% of brown marine algae (BMA, Sargassum dentifebium prepared according to different methods (sun-dried, SBMA; boiled, BBMA; autoclaved, ABMA on plasma and yolk lipid profiles, carotene, and lutein plus zeaxanthin in egg yolks was studied in hens aged from 23 to 42 weeks (30 hens per treatment. We determined the fatty acid profiles in BMA and in the egg yolk of hens fed different levels of BMA prepared according to different methods. In addition, plasma and yolk lipid profiles, yolk total carotene, and lutein plus zeaxanthin were determined at week 42 of age. Plasma and yolk cholesterol were significantly lower in groups fed diets containing either 3% or 6% BMA than in the control group, but high-density lipoprotein (HDL significantly decreased as BMA concentration increased. There was a significant similar decline in yolk triglycerides with inclusion of either 3% or 6% BMA in the laying hen diet. Palmitic acid was the main saturated fatty acid (SFA found in BMA and oleic acid (omega-9 and linoleic acid (omega-6 were the main unsaturated fatty acids (UFA, while there was a significant increase in palmitic acid in egg yolk when BMA was included at 6%. There was a significant increase in oleic acid (omega-9 when feed containing 3% BMA was given compared to the control group, but this decreased with a further increase in BMA. Linoleic acid (omega-6 also significantly decreased with inclusion of either 3% or 6% BMA. There was a significant increase in total carotene and lutein plus zeaxanthin in the laying hen eggs as a result of feeding diets containing 3% and 6% BMA.

  14. 产朊假丝酵母尿酸酶纳米脂质体的研制及其理化性质%Preparation and Characterization of Uricase Loaded in Lipid Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    刘娟; 谭群友; 王娜; 熊华蓉; 赵春景; 张景勍

    2011-01-01

    目的 研制产朊假丝酵母尿酸酶纳米脂质体(nanoliposomes containing uricase from candida utilis,UCCNLs)并对其理化性质和体外活性进行评价.方法 采用逆向蒸发法制备UCCNLs,以包封率、最小多分散指数、粒径等为评价指标优化制备工艺.考察体外降尿酸活性.考察4,25℃纳米粒的稳定性.结果 醚水比为3:1,脂醇比为1:1,投药量为2mg时,UCCNLs的平均包封率为64.24%,平均粒径为206.73nm,多分散系数为0.247,Zeta电位为- 37.33 mV.将尿酸从0.595 mmol·L-1降至正常水平UCCNLs所需时间约为游离酶的一半.UCCNLs在4℃时具有良好的稳定性.结论 采用逆向蒸发法可制备UCCNLs,工艺简便,包封率高,稳定性较好,体外降尿酸效果好.%OBJECTIVE To prepare lipid nanoparticles containing uricase from Candida utilis(UCCLNs)and to investigate their properties. METHODS UCCLNs were prepared by reverse-phase evaporation method. The entrapment efficiency, polydispersity index, size, and el al. were set as evaluation indexes for optimizing preparation methods. Uricolytic activity in vitro and the stability of drug loaded lipid nanoparticles were investigated. RESULTS The best formula for UCCLNS was as follows: the volume ratio of dieth yl ether and buffer was 3:1; the molar ratio of phosphatidylcholine and cholesterol 1:1; and the uricase amount 2 mg. The entrapment efficiency was 64. 24% , average particle size was 206.73 nm, and Zeta potential was - 37. 33 mV. Compared with native uricase solution, it took about a half time for decreasing uric acid from 0. 595 mmol · L-1 to normal level when the same dosage of UCCLNs were given. UCCLNs were stable under storage conditions. CONCLUSION UCCLNs can be prepared by reverse-phase evaporation method, with the advantages of simple process, small diameter and polydispersity, high encapsulation ratio, good stability and high uricolytic activity.

  15. 丙基硫氧嘧啶固体脂质纳米粒的制备与质量评价%Preparation and Quality Evaluation of Propylthiouracil Solid Lipid Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    徐雄波; 崔叶妹; 宋红娟; 卜振军; 张青松; 唐靖; 马宁

    2016-01-01

    目的:优化丙基硫氧嘧啶(PTU)固体脂质纳米粒(PTU-SLN)的处方和制备工艺,并对PTU-SLN质量进行评价。方法:采用乳化超声分散法制备PTU-SLN,以粒径和包封率为评价指标,以脂质材料、大豆磷脂、泊洛沙姆188用量以及超声时间为考察因素,通过正交试验对处方及工艺进行优化;同时以粒径、Zeta电位、包封率、稳定性及体外累积释放度为指标评价其质量。结果:最优制备处方和工艺为脂质材料0.6 g、大豆磷脂1.0 g、泊洛沙姆1880.8 g、超声时间10 min。所制得的PTU-SLN外观形态圆整,粒径分布均匀,平均粒径为93.5 nm,平均Zeta电位为-30.8 mV,平均包封率为74.9%;4℃条件下放置15 d粒径和外观无明显变化;体外4 h累积释放度达56.1%,24 h累积释放度达98.4%。结论:成功制得PTU-SLN,且处方工艺合理,可达到使药物缓慢释放的效果。%OBJECTIVE:To optimize the formulation and preparation technology of Propylthiouracil(PTU)solid lipid nanopar-ticles(PTU-SLN)and to evaluate the quality of PLN-SLN. METHODS:PTU-SLN was prepared by emulsion ultrasound dispersing method. The formulation of PTU-SLN was optimized by orthogonal design with the entrapment efficacy and particle size as index, using the amount of lipid material,soybean lecithin and poloxamer 188 and ultrasonic time as factors. The quality of prepared nanoparticles was evaluated with particle size,Zeta potential,entrapment efficiency,stability and in vitro drug release rate as in-dex. RESULTS:The optimal formulation and technology was as follows as lipid material 0.6 g,soybean lecithin 1.0 g,poloxamer 188 0.8 g,ultrasonic time 10 min. The obtained PTU-SLN was round and smooth in appearance and distributed evenly in particle size with average particle size of 93.5 nm,Zeta potential of -30.8 mV and average entrapment efficiency of 74.9%. Prepared nanoparticles had no significant change after

  16. Preparation and Characterization of Vincristine Sulfate-loaded Solid Lipid Nanoparticles%硫酸长春新碱固体脂质纳米粒的制备及其性质考察

    Institute of Scientific and Technical Information of China (English)

    夏爱晓; 宋倩倩; 孙渊; 周鹏; 杜有功; 李范珠

    2013-01-01

    OBJECTIVE To prepare vincristine sulfate-solid lipid nanoparticles(VCR-SLN) with single stearic acid glyceride as its lipid matrix and investigate its characterization. METHODS Multiple emulsion-solvent diffusion technique was adopted to prepare VCR-SLN and the orthogonal design was applied to optimize its formula and technology. Its morphology, particle size, ζ potential, drug entrapment efficiency, drug loading capacity and in vitro release of the VCR-SLN were investigated. RESULTS VCR-SLN were spherelike and smooth, the mean particles size was (144.83±2.71)nm, ζ potential was (-24.77±0.513)mV, entrapment efficiency was (40.54±0.45)%, drug loading capacity was (1.14±0.074)%. The release profile of vincristine sulfate in vitro fitted Weibull equation. CONCLUSION VCR-SLN can be prepared very well by multiple emulsion-solvent diffusion technique.%目的 以单硬脂酸甘油酯为载体材料,采用复乳溶剂挥发法制备硫酸长春新碱固体脂质纳米粒(VCR-SLN),并考察其理化性质.方法 采用复乳溶剂挥发法制备VCR-SLN,以正交设计优化处方及制备工艺,并考察其形态、粒径、Zeta电位、包封率、载药量和体外释放.结果 VCR-SLN为类球形实体粒子,平均粒径为(144.83±2.71)nm,Zeta电位为(-24.77±0.513)mV,包封率为(40.54±0.45)%,载药量为(1.14±0.074)%.药物体外释放曲线符合Weibull方程.结论 复乳溶剂挥发法适用于制备硫酸长春新碱固体脂质纳米粒.

  17. 姜黄素脂质立方液晶纳米粒的制备及理化性质研究%Preparation and Physiochemical Properties of Curcumin-loaded Lipid Cubic Liquid Crystalline Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    苏旬; 贺秀丽; 刘秀菊; 郭京艳; 翟光喜

    2012-01-01

    目的:制备姜黄素脂质立方液晶纳米粒,并对其主要理化性质进行评价.方法:采用热处理高压匀质法进行制备,以载药量和包封率为指标,采用均匀设计法对处方和工艺进行优化,并考察其理化性质.结果:制得的液晶纳米粒在电镜下呈类球形,平均粒径176.1 nm,zeta电位-25.19 mV,平均载药量(1.5±0.2)%,包封率(95±1.8)%,36 h体外释放60.0%,释放方程为In(1-Q)=-0.0251t-0.0075.结论:姜黄素脂质立方液晶纳米粒具有较高的包封率和良好的缓释作用.%Objective: To prepare curcumin-loaded lipid cubic liquid crystalline nanoparticles and evaluate its physiochemical properties. Methods:The nanoparticles were prepared using hot and high-pressure homogenization. The prescription and preparation process were optimized by uniform design with drug loading and entrapment efficiency as indexes. Results: The nanoparticles were spherical under transmission electron microscope (TEM) with average particle size of 176. 1 nm, zeta potential of -25.19 mV, average drug loading of (1. 5 ±0. 2) % and entrapment efficiency of (95 ±1.8)%. The release equation; In( 1 - Q) = -0.0251t-0.0075. The cumulative release percentage was 60% at 36 h in vitro. Conclusion:The obtained curcumin-loaded lipid cubic liquid crystalline nanoparticles shows high entrapment efficiency and good sustain release property.

  18. Electronic polymers in lipid membranes.

    Science.gov (United States)

    Johansson, Patrik K; Jullesson, David; Elfwing, Anders; Liin, Sara I; Musumeci, Chiara; Zeglio, Erica; Elinder, Fredrik; Solin, Niclas; Inganäs, Olle

    2015-06-10

    Electrical interfaces between biological cells and man-made electrical devices exist in many forms, but it remains a challenge to bridge the different mechanical and chemical environments of electronic conductors (metals, semiconductors) and biosystems. Here we demonstrate soft electrical interfaces, by integrating the metallic polymer PEDOT-S into lipid membranes. By preparing complexes between alkyl-ammonium salts and PEDOT-S we were able to integrate PEDOT-S into both liposomes and in lipid bilayers on solid surfaces. This is a step towards efficient electronic conduction within lipid membranes. We also demonstrate that the PEDOT-S@alkyl-ammonium:lipid hybrid structures created in this work affect ion channels in the membrane of Xenopus oocytes, which shows the possibility to access and control cell membrane structures with conductive polyelectrolytes.

  19. Biodegradable Poly(D,L-Lactide/Lipid Blend Microparticles Prepared by Oil-in-Water Emulsion Method for Controlled Release Drug Delivery

    Directory of Open Access Journals (Sweden)

    Yaowalak Srisuwan

    2014-03-01

    Full Text Available The effects of blend ratio and drug loading content of poly(D,L-lactide (PDLL/stearic acid blends on microparticle characteristics and drug release behaviors were evaluated. The blend microparticles were prepared by an oil-in-water emulsion solvent evaporation method for drug delivery of a poorly water-soluble model drug, indomethacin. The microparticles were characterized using a combination of scanning electron microscopy (SEM, light scattering particle size analysis, differential scanning calorimetry (DSC and UV-vis spectrophotometry. The blend microparticles with a PDLL/stearic acid blend ratio in the range 100/0-95/5 (w/w exhibited a spherical shape with a smooth surface. Blend microparticles with a similar size (167-177 µm and drug loading efficiency (60-67% were obtained. The drug loading content did not affect the characteristics of the blend microparticles. An in vitro drug release test demonstrated that the level of drug release decreased as the stearic acid blend ratio increased and the drug loading content decreased. The overall results indicated that it was possible to use PDLL/stearic acid blend microparticles as a controlled release drug delivery system.

  20. Preparation of isoandrographolide solid lipid nanoparticles and their in vitro release%异穿心莲内酯固体脂质纳米粒的制备及体外释放研究

    Institute of Scientific and Technical Information of China (English)

    张生杰; 焦文温; 张瑜; 华素; 韩光

    2012-01-01

    Objective To optimize the formulation of isoandrographolide solid lipid nanoparticles (IA-SLN) by central composite design-response surface. Methods IA-SLN were prepared by film-ultrasound dispersing method with entrapment efficiency (EE), diameter, and Zeta potential as evaluation parameters. Effects of carrier ratio, dosage, the concentration of polysorbate on preparation technology were investigated. The results were equations fitted and the optimal conditions were predicted by response surface method. The in vitro release mechanism of IA-SLN was investigated by dialysis method. Results The results showed that EE, mean diameter, and Zeta potential were the best fitted by the second-order polynomial equation, and the multiple correlation coefficients were 0.985 6, 0.913 6, and 0.933 4. Under the optimal condition, the EE, mean diameter, and Zeta potential were 96.62%, 162.4 nm, and -31.6 mV. IA-SLN in vitro release fitted with non-Fick's diffusion mechanisms, therefore the drug diffusion and lipid skeleton dissolution had a synergistic effect. Conclusion The central composite design-response surface method is useful for the optimization of IA-SLN preparation. The established model has good prediction.%目的 采用星点设计-效应面法优化异穿心莲内酯固体脂质纳米粒(IA-SLN)处方工艺,并考察其体外释放特性.方法 采用薄膜-超声分散法制备IA-SLN,以包封率、粒径、Zeta电位为评价指标,考察载体比例、投药量、聚山梨酯80质量分数3因素对制备工艺的影响,并对结果进行方程拟合,用效应面法预测最佳工艺条件;采片用透析法研究IA-SLN体外释放机制.结果 包封率、平均粒径、Zeta电位都以二项式拟合最优,复相关系数R2分别为0.985 6、0.913 6、0.933 4,根据优化方案制备的IA-SLN包封率96.62%、平均粒径162.4 nm、Zeta电位-31.6 mV.IA-SLN体外释放符合non-Fick's扩散机制,药物扩散和脂质骨架溶蚀具有协同作用.结论

  1. The interaction between purple membrane and membrane lipid

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Bacteriorhodopsin in purple membrane was reconstituted into different lipid vesicles. The effect of three different lipids on the structure and function of bacteriorhodopsin in lipid vesicles was studied by the observation on freeze-fracture eletron microscopy, the rotational diffusion of bacteriorhodopsin in lipid vesicles, the measurement of absorption spectrum, and the absorbance change with time. For these prepared samples, the results showed that DMPC was the stable lipid environment of bacteriorhodopsin; egg-pc causeed the loss of retinal chromophore of bacteriorhodopsin and it was not reversible change, cholesterol could stabilize the bacteriorhodopsin in lipid environment,but it caused the aggregation of bacteriorhodopsin.

  2. Binary lipids-based nanostructured lipid carriers for improved oral bioavailability of silymarin.

    Science.gov (United States)

    Shangguan, Mingzhu; Lu, Yi; Qi, Jianping; Han, Jin; Tian, Zhiqiang; Xie, Yunchang; Hu, Fuqiang; Yuan, Hailong; Wu, Wei

    2014-02-01

    The main purpose of this study was to prepare binary lipids-based nanostructured lipid carriers to improve the oral bioavailability of silymarin, a poorly water-soluble liver protectant. Silymarin-loaded nanostructured lipid carriers were prepared by the method of high-pressure homogenization with glycerol distearates (Precirol ATO-5) and oleic acid as the solid and liquid lipids, respectively, and lecithin (Lipoid E 100) and Tween-80 as the emulsifiers. The silymarin-nanostructured lipid carrier prepared under optimum conditions was spherical in shape with mean particle size of ∼78.87 nm, entrapment efficiency of 87.55%, loading capacity of 8.32%, and zeta potential of -65.3 mV, respectively. In vitro release of silymarin-nanostructured lipid carriers was very limited even after 12 h, while in vitro lipolysis showed fast digestion of nanostructured lipid carriers within 1 h. Relative oral bioavailability of silymarin-nanostructured lipid carriers in Beagle dogs was 2.54- and 3.10-fold that of marketed Legalon® and silymarin solid dispersion pellets, respectively. It was concluded that nanostructured lipid carriers were potential drug delivery systems to improve the bioavailability of silymarin. Other than improved dissolution, alternative mechanisms such as facilitated absorption as well as lymphatic transport may contribute to bioavailability enhancement.

  3. Study on Preparation Technique of Ferrous Gluconate-Loaded Solid Lipid Nanoparticles%葡萄糖酸亚铁固体脂质纳米粒的制备工艺研究

    Institute of Scientific and Technical Information of China (English)

    王琳琳; 童群义

    2016-01-01

    Objective] The aim was to explore preparation method of ferrous gluconate-loaded solid lipid nanoparticles. [ Method] The fer-rous gluconate solid lipid nanoparticles ( SLN) was prepared by W/O/W double emulsion techniques. The influences of volume ratio of outer/inner phase, aqueous/oil phase of internal phase and concentration of lecithin applied as the surfactant on the entrapment efficiency of SLN were investigated. [Result] The maximal entrapment efficiency, 52. 48%, was obtained under the circumstances of 0. 2 as the aqueous/oil phase of internal phase, 5∶1 as the volume ratio of outer/ inner phase, and 5% as concentration of lecithin. The addition of sodium alginate with weight ratio of 1∶2 to ferrous gluconate posed a positively impact on the entrapment efficiency, which was 59. 03% and affected the size, Zeta potential and polydispersion index as well. The in vitro release profile showed that SLN could keep integrity in simulated gastric fluid and went through a burst release in simulated intestinal fluid. [ Conclusion] SLN could protect the drug from disintegration and release in the active site and be a new method to produce inorganic iron salts supplementation.%[目的]探索葡萄糖酸亚铁固体脂质纳米粒的制备方法。[方法]采用两步W/O/W乳化方式制备葡萄糖酸亚铁固体脂质纳米粒(SLN)。以包埋率为指标,研究内外相、油水相体积比,卵磷脂浓度对SLN包埋率的影响。[结果]试验确定当内相中水相与油相的体积比为0.2,外水相与内相乳状液的体积比为5∶1,卵磷脂浓度为5%时,SLN的包埋率取得最大值,为52.48%。在内水相引入海藻酸钠(1∶2,W/W)的结果表明,SLN的包埋率增大,为59.03%,粒径、Zeta电位和多分散系数发生变化。体外释放试验表明,SLN能起到保护葡萄糖酸亚铁经受胃酸环境的作用,并在模拟肠液中表现为突释的释放效果。[结论]固体脂质纳米粒对葡萄糖酸亚铁有较好的保护及释

  4. 乳香提取物固体纳米脂质微粒的制备与性能研究%Preparation and performance of solid lipid nanoparticles from Boswellia carterii Birdw extract

    Institute of Scientific and Technical Information of China (English)

    闫广义; 李玢洁; 白林凤; 许菁; 王雪梅

    2015-01-01

    Solid lipid nanoparticles from Boswellia carterii Birdw extract (BCBE -SLN )were prepared via high shear ultrasonic emulsification. Suitable conditions for the preparation were obtained via experiments investigating the changes of shear rate,emulsifying temperature and composition of the ingredient mixture. The particle size,Zeta potential and the morphological characteristics of the BCBE-SLN product were characterized, and the centrifugal stability,storage stability,dilution stability were examined. The percutaneous absorption in vitro test was conducted. Results showed that the average particle size of BCBE-SLN achieves 70.6 nm,PDI is 0.388 ,and Zeta potential is -20.0 mV under the condition as:emulsion temperature is 60 ℃;mass fractions of emulsifiers A-25 and BC -20 are both 0.5%;and those of BCBE and lipid material are both 1.0%;the shear rate is 13 000 r/min for 3 min. The skin permeability of the BCBE-SLN product is good;moreover,the centrifugal,storage and dilution stability of the BCBE-SLN product are also good.%采用高剪切超声乳化法制备乳香提取物固体纳米脂质微粒(BCBE-SLN),通过改变剪切速率、乳化温度和配方组成,得出适宜的制备条件;对所得产品的粒径、Zeta电位及形貌进行了表征;研究了其离心、储存及稀释稳定性;并对其进行体外经皮试验。结果表明:在乳化温度为60℃,乳化剂鲸蜡醇聚醚-20(BC-20)和硬脂醇聚氧乙烯醚-25(A-25)的质量分数均为0.5%,脂质原料和乳香提取物的质量分数均为1.0%,剪切速率为13000 r/min,剪切时间为3 min时,制备的BCBE-SLN的平均粒径为70.6 nm,多分散指数(PDI)为0.388,Zeta电位为-20.0 mV,产品有很好的皮肤渗透性,并具备良好的离心、储存及稀释稳定性。

  5. 响应面法优化高压均质制备DHA固体脂质纳米粒%Preparation of DHA solid lipid nanoparticles by high pressure homogenization using response surface methodology

    Institute of Scientific and Technical Information of China (English)

    胡本涛; 王玉堂; 张振; 黄宇; 刘宁

    2013-01-01

    The easily oxidized docosahexaenoic acid (DHA) was protected by solid lipid nanoparticles ( SLN) . Glyceryl monostearate was used as wall material and DHA algal oil was used as core material to prepare DHA - SLN by high pressure homogenization. The technological parameters were optimized by response surface methodology on the basis of single factor experiment with DHA - SLN embedding rate as response value. The optimal technological parameters were as follows: ratio of core material to wall material 1: 65, homogenization pressure 80 MPa, mass fraction of emulsifier 2. 14% (based on aqueous phase), homogenization times 8. Under these conditions, the embedding rate of DHA - SLN was 74. 45%.%采用固体脂质纳米粒保护容易氧化的二十二碳六烯酸(DHA).以单硬脂酸甘油酯为壁材,DHA藻油为芯材,采用高压均质制备DHA固体脂质纳米粒(DHA-SLN).以DHA-SLN的包封率为指标,通过单因素实验和响应面法优化工艺参数,得出高压均质法制备DHA-SLN的最佳工艺条件是:芯壁比1∶65,均质压力80 MPa,乳化剂质量分数2.14%(占水相),均质8次.在此条件下,实验验证的DHA-SLN的包封率为74.45%.

  6. Lipid signaling in plants

    NARCIS (Netherlands)

    Munnik, T.

    2010-01-01

    This book highlights the current status of plant lipid signaling. Written by leading researchers in the field, the chapters include detailed information on the measurement, regulation and function of phospholipases, lipid kinases, lipid phosphatases, inositolpolyphosphates, polyphosphoinositides, ph

  7. Lipid Metabolism Disorders

    Science.gov (United States)

    ... metabolic disorder, something goes wrong with this process. Lipid metabolism disorders, such as Gaucher disease and Tay-Sachs disease, involve lipids. Lipids are fats or fat-like substances. They ...

  8. Plant lipid signaling protocols

    NARCIS (Netherlands)

    Munnik, T.; Heilmann, I.

    2013-01-01

    Eukaryotic cells are surrounded by membranes consisting of various lipids, including sterols, sphingolipids, glycolipids, and phospholipids. Besides structural functions, membranes also contain lipids with regulatory and signaling roles. Such lipids include polyphosphoinositides, the low-abundant

  9. Effect of different lipids and surfactants on formulation of solid lipid nanoparticles incorporating tamoxifen citrate

    Directory of Open Access Journals (Sweden)

    S U Upadhyay

    2012-01-01

    Full Text Available Tamoxifen Citrate (TC is an estrogen receptor antagonist and drug of choice for hormone sensitive breast cancer. Solid Lipid Nanoparticles loaded with TC were prepared by High Shear Homogenization followed by Ultrasonication. The aim of the present work is to study the effect of four different Solid Lipids and three Surfactants on Formulation and Stability of SLN. They were characterized for Particle size, Polydispersity Index and Zeta Potential by Zetasizer Nano. SLN prepared by Solid Lipid Compritol 888 (Glyceryldibehenate and Tween 80 (1% showed desired Particle Size of 206.9 nm, PDI of 0.046 and Zeta Potential of 9.32 mV.

  10. 高压乳匀法制备中药固体脂质纳米粒%Preparation of solid lipid nanoparticles loaded with traditional Chinese medicine by high-pressure homogenization

    Institute of Scientific and Technical Information of China (English)

    厉英超; 董蕾; 贾皑; 苌新明; 薛挥

    2006-01-01

    目的采用高压乳匀法将中药有效成分包载于固体脂质纳米粒(SLN),并研究制备的纳米粒的主要性质.方法选择水飞蓟宾(SIL)和汉防己甲素(TET)为模型药物,采用高压乳匀法将其分别包载于SLN.在电镜下观察其形态,以粒度分析仪和Zeta电位分析仪测定其粒径和Zeta电位,用葡聚糖凝胶柱层析法和HPLC测定其包封率和载药量,还观察了SLN的稳定性.结果高压乳匀法制备的SIL-SLN呈球状,形态规则,平均粒径为(157±8)nm,Zeta电位为(-35.36±2.68)mV,包封率为95.64%,载药量为4.63%;TET-SLN呈片状存在,不规则,粒径较小,平均粒径为(47±3)nm,Zeta电位为(-32.99±2.54)mV,包封率为97.82%,载药量为4.76%.SIL-SLN和TET-SLN有较高稳定性.结论高压乳匀法适于制备包载中药的SLN.%Objective To investigate the preparation of solid lipid nanoparticles (SLN) loaded with traditional Chinese medicines by high-pressure homogenization, and study the physicochemical characteristics of the particles produced by this method. Methods The model traditional Chinese medicines, silibinin (SIL) and tetrandrine (TET), were incorporated into SLN separately by high-pressure homogenization. Transmission electron microscope was employed to study the shape of the particles. Particle characterization system and zeta potential analyzer were used to study the diameter and zeta potential of SLN in the suspension. The entrapment efficiency and drug loading were determined with the sephadex gel chromatography and high-performance liquid chromatography. The stability of SLN was also studied. Results The SIL-SLNs prepared by high-pressure homogenization were spherical and regular. The mean diameter and zeta potential of SIL-SLN in distilled water were 157±8 nm and -35.36±2.68 mV, respectively. The entrapment efficiency was 95.64%, and the drug loading was 4.63%.The TET-SLN was platelet-shaped, irregular and smaller. The mean diameter and zeta potential of TET-SLN were 47

  11. Biologic Activity of Porphyromonas endodontalis complex lipids

    Science.gov (United States)

    Mirucki, Christopher S.; Abedi, Mehran; Jiang, Jin; Zhu, Qiang; Wang, Yu-Hsiung; Safavi, Kamran E.; Clark, Robert B.; Nichols, Frank C.

    2014-01-01

    Introduction Periapical infections secondary to pulpal necrosis are associated with bacterial contamination of the pulp. Porphyromonas endodontalis, a Gram-negative organism, is considered to be a pulpal pathogen. P. gingivalis is phylogenetically related to P. endodontalis and synthesizes several classes of novel complex lipids that possess biological activity, including the capacity to promote osteoclastogenesis and osteoclast activation. The purpose of this study was to extract and characterize constituent lipids of P. endodontalis, and evaluate their capacity to promote pro-inflammatory secretory responses in the macrophage cell line, RAW 264.7, as well as their capacity to promote osteoclastogenesis and inhibit osteoblast activity. Methods Constituent lipids of both organisms were fractionated by HPLC and were structurally characterized using electrospray-mass spectrometry (ESI-MS) or ESI-MS/MS. The virulence potential of P. endodontalis lipids was then compared with known biologically active lipids isolated from P. gingivalis. Results P. endodontalis total lipids were shown to promote TNF-α secretion from RAW 264.7 cells and the serine lipid fraction appeared to account for the majority of this effect. P. endodontalis lipid preparations also increased osteoclast formation from RAW 264.7 cells but osteoblast differentiation in culture was inhibited and appeared to be dependent on TLR2 expression. Conclusions These effects underscore the importance of P. endodontalis lipids in promoting inflammatory and bone cell activation processes that could lead to periapical pathology. PMID:25146013

  12. Preparation and preliminary characterization of lyophilized astragaloside Ⅳ- loaded nanostructured lipid carriers%黄芪甲苷纳米结构脂质载体冻干粉的制备及其初步质量评价

    Institute of Scientific and Technical Information of China (English)

    陈佳; 龚涛

    2011-01-01

    目的 制备黄芪甲苷纳米结构脂质载体(AST-NLC),初步研究其冻干工艺,并考察其理化性质.方法 采用薄膜-超声分散法制备AST-NLC;选用不同冻干保护剂制备AST-NLC冻干粉末,以外观、色泽、再分散性、粒径和PDI为综合指标,优选保护剂的种类和浓度,拟定冻干工艺;考察AST-NLC的形态和冻干前后的粒径分布、Zeta电位、包封率及载药量.结果 以10%的蔗糖作为冻干保护剂、-40℃超低温冰箱中预冻4h后,迅速放入冷冻干燥机中冷冻干燥24h,所得冻干粉末的外观、色泽、再分散性均较好;AST-NLC在透射电镜下呈球形;冻干前(后)的平均粒径为104.3±1.25 nm(144.1±17.08nn),PDI为0.118±0.033(0.132±0.055),Zeta电位为-7.00±0.35 mV(-11.2±0.9 mV),包封率为94.37%±0.39%(96.60%±0.45%),载药量为2.80%±0.02%(2.60%±0.05%).结论 所用AST-NLC的制备工艺简便,制得的AST-NLC包封率较高;采用优化后的冻干工艺可得到令人满意的AST-NLC冻干粉末.%OBJECTIVE To prepare and characterize the lyophilized Astragaloside IV -loaded nanostructured lipid carriers (AST -NLC). METHODS AST - NLC was prepared by film - ultrasound dispersion technique. The lyophilized AST - NLC were prepared using different supporting agent. The type and concentration of the supporting agents were optimized by the shape,color,redispersion, size and PDI of the lyophilized AST - NLC. The characteristics of AST - NLC, including shape, size, PDI, Zeta potential, entrapment efficiency( EE% ) and drug loading ( DL% ) , before and after freeze - drying were investigated. RESULTS Satisfied lyophilized AST - NLC could be prepared using 10% sucrose as the supporting agent. The freeze - drying process was as follow; pre - cooled at 40℃ for 4 h,freeze -drying for 24 h. AST - NLC presented a spherical shape under transmission elecctron microscopy(TEM). The characteristics before freeze - drying were as follows: average diameter

  13. Preparation and Rat Intestinal Absorption of Baicalin Solid Lipid Nanoparticles%黄芩苷固体脂质纳米粒的制备及大鼠在体肠吸收研究

    Institute of Scientific and Technical Information of China (English)

    李金明; 林东海; 李延团

    2011-01-01

    选用硬脂酸、单硬脂酸甘油酯混合脂质作为载体,以卵磷脂作为乳化剂制备黄芩苷固体脂质纳米粒(BC-SLN),并考察其大鼠在体肠吸收特性.采用热匀质法(hot homogenization technique,HHT)制备BC-SLN,采用循环灌注技术评价黄芩苷固体脂质纳米粒和黄芩苷溶液大鼠在体肠吸收特性.制得的BC-SLN平均粒径为(150.8±47.2)nm,zeta电位为(-39.85±0.86) mV,载药量为(4.86±0.37)%,包封率为(88.52±0.32)%,大鼠在体肠吸收实验表明,BC-SLN与黄芩苷溶液相比,吸收速率常数Ka和每小时吸收百分率p均呈增加趋势,有显著性差异(P<0.05),黄芩苷固体脂质纳米粒能够促进黄芩苷大鼠肠吸收.%Baicalin solid lipid nanoparticles ( BC-SLN) are prepared with a mixture of stearic acid and monos-tearin by hot homogenization technique. The mean diameter of BC-SLN is ( 150. 8 ±47. 2) nm. The zeta potential of BC-SLN is ( - 39. 85 ±0. 86) mV. The drug loading and entrapment efficiency are (4. 86 ± 0. 37)% and (88.52 ±0. 32)%,respectively. The absorption parameters of BC-SLN and baicalin solution in rat intestines are characterized by using recirculating perfusion technique. The Ka and p of BC-SLN in rat intestines are remarkably higher than those of the baicalin solution ( P <0. 05 ). The absorption of BC-SLN in rat intestines is improved significantly compared with the reference baicalin solution.

  14. Preparation and in vitro releasing of sirolimus-nanostructured lipid carriers dispension%西罗莫司纳米结构脂质载体分散液的制备及其体外释放度考察

    Institute of Scientific and Technical Information of China (English)

    吴昊; 宋洪涛

    2012-01-01

    Objective To optimize the preparation and study in vitro releasing of SRL-NLC dispersion. Methods Central composite design-response surface methodology was used to optimize dispersion formulation,then in vitro releasing in 0.4% SDS(sodi-um lauryl sulfate) solution was explored by normal phase dialysis bag method. Results The optimal dispersion had PS (particle size) : 82.54nm,PI(polydisperity index) : 0. 207, Zeta potential: - 18. 0 mv, DL ( drug-loading) : 1.829%, and EE ( entrapment efficiency) : 91.3%; SRL-NLC dispersion had a characterization of 60. 1% accumulated releasing in 0.4% SDS solution. Conclusion The optimal formulation had good feasibility and reproducibility, in vitro releasing curve showed SRL-NLC dispersion had a characterization of 60. 1% accumulated releasing in 0.4% SDS solution.%目的 优化西罗莫司纳米结构脂质载体(sirolimus nanostructured lipid carriers,SRL-NLC)分散液的处方,并考察其体外释放度.方法 采用星点设计-效应面法(central composite design-response surface methodology,CCD-RSM)优化SRL-NLC分散液的处方,并以粒径、分布系数、载药量和包封率作为评价指标,采用正相透析袋法考察SRL-NLC分散液在0.4%SDS(十二烷基硫酸钠)溶液中的释放度.结果 经优化的SRL-NLC分散液平均粒径82.54 nm、分布系数0.207,Zeta电位-18.0mv、载药量1.829%和包封率91.3%,SRL-NLC分散液在0.4% SDS溶液中能持续释放120 h,累积释放量为60.1%.结论 经优化的处方可行性和重现性均较好,SRL-NLC分散液在0.4% SDS溶液中累积释放度为60.1%.

  15. 超临界辅助喷雾法用于固体脂质纳米粒的制备%Supercritical Assisted Atomization for Preparation of Solid Lipid Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    叶邦阜; 袁弘; 杜永忠; 胡富强

    2011-01-01

    OBJECTIVE To prepare the solid lipid nanoparticles(SLN) via supercritical assisted atomization(SAA) and investigate the effect of formulation and process on physicochemical characteristics of nanoparticles (NPs). METHODS With self-made SAA particle-producing equipment, stearic acid(SA) based SLN was produced, and the effect of SA concentration, flow ratio of supercritical CO2 and material solution, pore size of nozzle, on particle size of SLN were investigated to discover the appropriate process conditions. SLN loading insulin, a hydrophilic macromolecule drug, was produced and their physicochemical characteristics was observed, such as size, zeta-potential, entrapment efficiency(EE) and drug-loading ratio(DL). RESULTS Particle size of NPs was depended on material concentration, flow ratio of supercritical CO2 and material solution, pore size of nozzle. SLN with mean size <300 nm were obtained through formulation and process adjustment during preparation . Insulin-loaded SLN with mean size of about 300 nm, EE 72.2% and DL 3.44% was obtained, which released drug slowly during 12 h in vitro. Poloxamer-modified formulation made SLN with reduced size and distribution range, meanwhile the drug EE was decreased and burst-release was significant. CONCLUSION SAA is successfully applied to produce SLN and hydrophilic-drug-loaded SLN with modified releasing profile.%目的 采用超临界辅助喷雾制粒法制备固体脂质纳米粒,并考察工艺与处方因素对纳米粒理化性质的影响.方法 采用自制超临界喷雾制粒设备,制备硬脂酸脂质纳米粒,考察硬脂酸浓度、超临界流体CO_2与载体溶液流量比、喷嘴孔径等对固体脂质纳米粒粒径的影响,筛选合适的处方工艺参数;以亲水性大分子药物胰岛素为模型药物,制备载药固体质纳米粒,评价纳米粒的粒径、电位、包封率、释放度等理化性质.结果 制备得到的纳米粒粒径与载体浓度、超临界流体CO_2与载体

  16. 丹参酮ⅡA固体脂质纳米粒的制备及体外释药%Preparation of tanshinone Ⅱ A solid lipid nanoparticle and evaluation of its oral absorption

    Institute of Scientific and Technical Information of China (English)

    张继东; 万江陵

    2012-01-01

    目的:制备丹参酮ⅡA(TSA)口服固体脂质纳米粒(TSA-SLN),根据相关理化性质预测其口服吸收效果.方法:采用成膜-高压均质法制备TSA-SLN,测定纳米粒的粒径、多分散指数(PDI)、Zeta电位,并考察其热力学行为,高效液相色谱(HPLC)法测试其载药量和包封率,结合体外释放试验和Caco-2细胞单层膜转运试验初步评价了TSA-SLN的口服吸收效果.结果:TSA-SLN水分散粒径(83.6±15.4) nm,PDI为0.203±0.019,Zeta电位(-32.6±1.7)mV,载药量(0.92±0.05)%,包封率(84±7)%;X射线衍射(XRD)和差式热量扫描(DSC)测试结果表明TSA在SLN中以无定型态存在,与市售丹参酮胶囊粉末相比,TSA-SLN的体外累积释放度提高将近20%,Caco-2细胞单层膜的通透率提高4~5倍.结论:TSA-SLN体外释放度高,Caco-2细胞单层膜通透性强,有望提高TSA的口服吸收.%OBJECTIVE To prepare tanshinone DA loaded solid lipid nanoparticle (TSA-SLN), and to predict its oral absorption based on physic-chemical properties. METHODS Membranization-high pressure homogeny method was adopted during the preparation of TSA-SLN, its size, PDI and Zeta potential were tested, and its thermodynamic behavior was investigated. The drug-loaded rate and entrapment rate of TSA-SLN were also estimated by HPLC, and the oral absorption behavior was e-valuated depending on the in vitro release rate and the Caco-2 cell monolayer membrane transportation behavior of TSA. RESULTS TSA-SLN dispersed in water had average size of (83 ± 15)nm, PDI of (0. 203 + 0. 019)and Zeta potential of( - 32. 6 ± 1. 7)mV. Its drug-loaded rate was (0. 92 ± 0. 05)% with the entrapment rate of (84 + 7)%. The fact that in SLN particles TSA existing as amorphous was proved by the results of XRD and DSC respectively. The in vitro release rate of TSA-SLN was 20% higher than that of capsule powder, and the permeability of TSA through Caco-2 cells monolayer membrane had been improved by 4-5 times. CONCLUSION TSA

  17. Preparation of Stable Solid Lipid Nanoparticles (SLNs) Suspension with Combined Surfactants%表面活性剂复配制备稳定的固体脂质纳米粒混悬液

    Institute of Scientific and Technical Information of China (English)

    侯冬枝; 谢长生; 平其能

    2005-01-01

    目的:表面活性剂在固体脂质纳米粒的制备过程中扮演着重要角色,为规避药物对体系的影响,本文选用4种表面活性剂制备了空白而具有良好物理稳定性的固体脂质纳米粒混悬液.方法:用激光散射粒度仪和Zeta电位分析仪(LD)检测平均粒径、颗粒分布范围和Zeta电位,另外还进行了DSC热分析和颗粒形态的TEM观察.结果:离子型表面活性剂脱氧胆酸钠可以提高纳米粒的Zeta电位从而提高系统物理稳定性,但乳化率低;非离子乳化剂Pluronic F-68可以起到空间稳定的作用从而避免胶体系统中颗粒的聚结.结论:4种表面活性剂的复配[两种非离子乳化剂(Pluronic F-68和Tween 80),离子型表面活性剂(脱氧胆酸钠)以及卵磷脂]可以制备稳定6个月而不分层的纳米混悬液.%AIM:Surfactants and their blend play important roles in the preparation of solid lipid nanoparticles (SLNs).In this study,four types of surfactant were employed to investigate the influence of the surfactants on properties of SLNs in the absence of model drugs thereby avoiding the interaction between the surfactant and the drug.METHODS:The physicochemical properties of the colloidal systems,such as mean particle size,distribution range and Zeta potential,were investigated by laser diffractometry and the DSC analysis was performed as well.RESULTS:It was found that ionic surfactants,such as sodium deoxycholate, increased the Zeta potential of nanoparticles leading to improve the physical stability of the system.But it showed obviously relative low emulsification efficiency in the preparation.Non-ionic emulsifier,especially Pluronic F-68, offered additional steric stabilization effect avoiding aggregation of the fine particles in the colloidal system.CONCLUSION:The formulation in the study for the first time combined four types of additives including ionic surfactant (sodium deoxycholate),non-ionic emulsifier (Pluronic F-68 and Tween-80),and

  18. Multiscale molecular modeling of tertiary supported lipid bilayers

    Science.gov (United States)

    Ranz, Holden T.; Faller, Roland

    2015-08-01

    Ternary lipid bilayer systems assembled from mixtures of dipalmitoylphosphatidylcholine (DPPC), dioleoylphosphatidylcholine (DOPC), and cholesterol have been studied using coarse-grained molecular dynamics at biologically relevant temperatures (280 K to 310 K), which are between the chain melting temperatures of the pure lipid component. Free lipid bilayers were simulated using the MARTINI model (Stage I) and a variant with water-water interactions reduced to 76% (Stage II). The latter was subsequently used for preparing supported lipid bilayer simulations (Stage III). Clustering of like lipids was observed, but the simulation timescale did not yield larger phaseseparated domains.

  19. Interactions and Translational Dynamics of Phosphatidylinositol Bisphosphate (PIP2) Lipids in Asymmetric Lipid Bilayers.

    Science.gov (United States)

    Shi, Xiaojun; Kohram, Maryam; Zhuang, Xiaodong; Smith, Adam W

    2016-02-23

    Phosphatidylinositol phosphate (PIP) lipids are critical to many cell signaling pathways, in part by acting as molecular beacons that recruit peripheral membrane proteins to specific locations within the plasma membrane. Understanding the biophysics of PIP-protein interactions is critical to developing a chemically detailed model of cell communication. Resolving such interactions is challenging, even in model membrane systems, because of the difficulty in preparing PIP-containing membranes with high fluidity and integrity. Here we report on a simple, vesicle-based protocol for preparing asymmetric supported lipid bilayers in which fluorescent PIP lipid analogues are found only on the top leaflet of the supported membrane facing the bulk solution. With this asymmetric distribution of lipids between the leaflets, the fluorescent signal from the PIP lipid analogue reports directly on interactions between the peripheral molecules and the top leaflet of the membrane. Asymmetric PIP-containing bilayers are an ideal platform to investigate the interaction of PIP with peripheral membrane proteins using fluorescence-based imaging approaches. We demonstrate their usefulness here with a combined fluorescence correlation spectroscopy and single particle tracking study of the interaction between PIP2 lipids and a polycationic polymer, quaternized polyvinylpyridine (QPVP). With this approach we are able to quantify the microscopic features of the mobility coupling between PIP2 lipids and polybasic QPVP. With single particle tracking we observe individual PIP2 lipids switch from Brownian to intermittent motion as they become transiently trapped by QPVP.

  20. Lipid membranes on nanostructured silicon.

    Energy Technology Data Exchange (ETDEWEB)

    Slade, Andrea Lynn; Lopez, Gabriel P. (University of New Mexico, Albuquerque, NM); Ista, Linnea K. (University of New Mexico, Albuquerque, NM); O' Brien, Michael J. (University of New Mexico, Albuquerque, NM); Sasaki, Darryl Yoshio; Bisong, Paul (University of New Mexico, Albuquerque, NM); Zeineldin, Reema R. (University of New Mexico, Albuquerque, NM); Last, Julie A.; Brueck, Stephen R. J. (University of New Mexico, Albuquerque, NM)

    2004-12-01

    A unique composite nanoscale architecture that combines the self-organization and molecular dynamics of lipid membranes with a corrugated nanotextured silicon wafer was prepared and characterized with fluorescence microscopy and scanning probe microscopy. The goal of this project was to understand how such structures can be assembled for supported membrane research and how the interfacial interactions between the solid substrate and the soft, self-assembled material create unique physical and mechanical behavior through the confinement of phases in the membrane. The nanometer scale structure of the silicon wafer was produced through interference lithography followed by anisotropic wet etching. For the present study, a line pattern with 100 nm line widths, 200 nm depth and a pitch of 360 nm pitch was fabricated. Lipid membranes were successfully adsorbed on the structured silicon surface via membrane fusion techniques. The surface topology of the bilayer-Si structure was imaged using in situ tapping mode atomic force microscopy (AFM). The membrane was observed to drape over the silicon structure producing an undulated topology with amplitude of 40 nm that matched the 360 nm pitch of the silicon structure. Fluorescence recovery after photobleaching (FRAP) experiments found that on the microscale those same structures exhibit anisotropic lipid mobility that was coincident with the silicon substructure. The results showed that while the lipid membrane maintains much of its self-assembled structure in the composite architecture, the silicon substructure indeed influences the dynamics of the molecular motion within the membrane.

  1. 布洛芬固体脂质纳米粒的制备及家兔体内药动学研究%Preparation of Ibuprofen Solid Lipid Nanoparticles and Its Pharmacokinetics in Rabbit

    Institute of Scientific and Technical Information of China (English)

    车成凯; 宋真玉; 梁荣才; 孙考祥; 王爱萍

    2014-01-01

    采用乳化分散-超声法制备布洛芬固体脂质纳米粒(IB - SLN),对其粒径、zeta 电位、包封率、载药量、体外释放等进行体外评价,并考察 IB - SLN 经皮给药后兔体内药动学特征.结果显示,研究制备的 IB - SLN 的平均粒径为(100±20)nm,zeta 电位为-43.9 mV,包封率为92.6%,载药量为3.33%.兔体内药动学研究显示,IB - SLN 可有效促进布洛芬的经皮吸收,布洛芬固体脂质纳米粒凝胶剂经皮给药后的 AUC 和 Cmax分别为640.86 ng·h / mL 和65.94 ng / mL,分别是布洛芬凝胶剂的12.6倍和4.5倍.研究结果提示,固体脂质纳米粒作为布洛芬经皮给药载体可有效促进药物的透皮吸收,并可使药物缓慢平稳释放,其应用前景广泛.%Ibuprofen solid lipid nanoparticles(IB-SLN)is prepared by using the method of emulsification disper-sion-ultrasonication. The particle size,zeta potential,encapsulation efficiency,drug loading and release behaviors of IB-SLN are evaluated in vitro,the pharmacokinetic characteristics in rabbits are investigated after percutaneous administration. The results are as followthe particle size is 100 ± 20 nm,the zeta potential is - 43. 9 mV,the drug loading of IB-SLN is 3. 33% ,and the encapsulation efficiency is 92. 6% . The pharmacokinetic study in rab-bits after percutaneous administration demonstrates that IB-SLN can improve the transdermal absorption of ibuprofen effectively. The AUC and Cmax of IB-SLN transdermal gels are 640. 86 ng·h·mL - 1 and 65. 94 ng·mL - 1 ,which are 12. 6 and 4. 5 folds,respectively,compared with the cases of ibuprofen transdermal gels. The SLN can effec-tively enhance the transdermal penetration and bring a slow and balanced release of IB. Therefore,SLN could be a potential delivery system for TDDS.

  2. Doxorubicin Lipid Complex Injection

    Science.gov (United States)

    Doxorubicin lipid complex is used to treat ovarian cancer that has not improved or that has worsened after treatment with other medications. Doxorubicin lipid complex is also used to treat Kaposi's ...

  3. Irinotecan Lipid Complex Injection

    Science.gov (United States)

    Irinotecan lipid complex is used in combination with other medications to treat pancreatic cancer that has spread to other ... worsened after treatment with other chemotherapy medications. Irinotecan lipid complex is in a class of antineoplastic medications ...

  4. Daunorubicin Lipid Complex Injection

    Science.gov (United States)

    Daunorubicin lipid complex is used to treat advanced Kaposi's sarcoma (a type of cancer that causes abnormal tissue to ... body) related to acquired immunodeficiency syndrome (AIDS). Daunorubicin lipid complex is in a class of medications called ...

  5. Vincristine Lipid Complex Injection

    Science.gov (United States)

    Vincristine lipid complex is used to treat a certain type of acute lymphoblastic leukemia (ALL; a type of cancer ... least two different treatments with other medications. Vincristine lipid complex is in a class of medications called ...

  6. Parenteral Nutrition and Lipids.

    Science.gov (United States)

    Raman, Maitreyi; Almutairdi, Abdulelah; Mulesa, Leanne; Alberda, Cathy; Beattie, Colleen; Gramlich, Leah

    2017-04-14

    Lipids have multiple physiological roles that are biologically vital. Soybean oil lipid emulsions have been the mainstay of parenteral nutrition lipid formulations for decades in North America. Utilizing intravenous lipid emulsions in parenteral nutrition has minimized the dependence on dextrose as a major source of nonprotein calories and prevents the clinical consequences of essential fatty acid deficiency. Emerging literature has indicated that there are benefits to utilizing alternative lipids such as olive/soy-based formulations, and combination lipids such as soy/MCT/olive/fish oil, compared with soybean based lipids, as they have less inflammatory properties, are immune modulating, have higher antioxidant content, decrease risk of cholestasis, and improve clinical outcomes in certain subgroups of patients. The objective of this article is to review the history of IVLE, their composition, the different generations of widely available IVLE, the variables to consider when selecting lipids, and the complications of IVLE and how to minimize them.

  7. Clinical Research of Tongfenqing Powder Preparation for Infusion on Blood Lipid and Hemorheology for Gouty Arthritis%痛风清冲剂对痛风性关节炎患者血脂与血液流变学影响的临床研究

    Institute of Scientific and Technical Information of China (English)

    曾荣南; 吴启富; 接红宇; 孙德华; 王繁盛; 戚晶敏

    2012-01-01

    Objective To observe the impacts of tongfengqing powder preparation for infusion on blood lipid and hemorheology for the patients with gouty arthritis and explore the mechanism of it in the treatment of gouty arthritis. Methods 75 cases of gouty arthritis were selected and randomized into two groups. In a treatment group( 39 cases ), tongfengqing powder preparation for infusion was provided. In a control group ( 36 cases ), allopurinol tablets were prescribed. Either group was treated for one session( 4 weeks ). The blood lipid, blood uric acid, erythrocyte sedimentation rate( ESR),C -reactive protein( CRP )and hemorheology were detected and compared before and after treatment in two groups. Results After treatment, the levels of blood lipid, blood uric acid, ESR, CRP and hemorheology were all reduced significantly as compared with those before treatment! P < 0. 01 ). The statistical significant differences presented in comparison with the control group( P < 0. 01 ). Conclusion Tongfengqing powder preparation for infusion treats effectively gouty arthritis,which is probably related to the obvious improvements in blood lipid,blood uric acid,ESR,CRP and hemorheology.%目的 观察痛风清冲剂对痛风性关节炎患者血脂与血液流变学的影响,探讨其治疗痛风性关节炎的作用机制.方法 选取诊断为痛风性关节炎患者75例,随机分为两组.治疗组39例服用痛风清冲剂治疗,对照组36例服用别嘌醇片,两组均治疗1个疗程(4周);分别对两组患者治疗前后的血脂、血尿酸、血沉、CRP及血液流变学进行检测并进行比较.结果 治疗组治疗后血脂、血尿酸、血沉、C反应蛋白(CRP)及血液流变学指标较治疗前均显著降低(P<0.01);与对照组治疗后比较差异有统计学意义(P<0.01).结论 通风清冲剂能有效治疗痛风性关节炎,可能与其能明显改善患者血脂、血尿酸、血沉、CRP及血液流变学多项指标有关.

  8. Lipid exchange by ultracentrifugation

    DEFF Research Database (Denmark)

    Drachmann, Nikolaj Düring; Olesen, Claus

    2014-01-01

    Lipids play an important role in maintaining P-type ATPase structure and function, and often they are crucial for ATPase activity. When the P-type ATPases are in the membrane, they are surrounded by a mix of different lipids species with varying aliphatic chain lengths and saturation......, and the complex interplay between the lipids and the P-type ATPases are still not well understood. We here describe a robust method to exchange the majority of the lipids surrounding the ATPase after solubilisation and/or purification with a target lipid of interest. The method is based on an ultracentrifugation...... step, where the protein sample is spun through a dense buffer containing large excess of the target lipid, which results in an approximately 80-85 % lipid exchange. The method is a very gently technique that maintains protein folding during the process, hence allowing further characterization...

  9. Nutrients and neurodevelopment: lipids.

    Science.gov (United States)

    González, Horacio F; Visentin, Silvana

    2016-10-01

    Nutrients, lipids in particular, make up the central nervous system structure and play major functional roles: they stimulate development, migration, and nerve cell differentiation. They are part of gray matter, white matter, nerve nuclei, and synaptogenesis. Breast milk contains lipids which are crucial for infant brain development. The lipid profile of breast milk was used as a guideline for the development of breast milk substitutes. However, to date, no substitute has matched it. Complementary feeding should include docosahexaenoic acid, arachidonic acid, other polyunsaturated fatty acids, saturated fatty acids, and complex lipids found in milk fat. The lipid composition of breast milk depends on maternal intake and nutritional status during pregnancy and breast-feeding. It has a great impact on development. Our goal is to review scientific literature regarding the role of lipids on infant brain development and the importance of breast milk lipid composition, maternal diet, and complementary feeding.

  10. Lipid Structure in Triolein Lipid Droplets

    DEFF Research Database (Denmark)

    Chaban, Vitaly V; Khandelia, Himanshu

    2014-01-01

    Lipid droplets (LDs) are primary repositories of esterified fatty acids and sterols in animal cells. These organelles originate on the lumenal or cytoplasmic side of endoplasmic reticulum (ER) membrane and are released to the cytosol. In contrast to other intracellular organelles, LDs are composed...... of a mass of hydrophobic lipid esters coved by phospholipid monolayer. The small size and unique architecture of LDs makes it complicated to study LD structure by modern experimental methods. We discuss coarse-grained molecular dynamics (MD) simulations of LD formation in systems containing 1-palmitoyl-2...... to coarse-grained simulations, the presence of PE lipids at the interface has a little impact on distribution of components and on the overall LD structure. (4) The thickness of the lipid monolayer at the surface of the droplet is similar to the thickness of one leaflet of a bilayer. Computer simulations...

  11. Reconstitution of the Leucine Transport System of Lactococcus lactis into Liposomes Composed of Membrane-Spanning Lipids from Sulfolobus acidocaldarius

    NARCIS (Netherlands)

    in t Veld, Geertruida; Elferink, Maria; Driessen, Arnold J.M.; Konings, Wilhelmus

    1992-01-01

    The effect of bipolar tetraether lipids, extracted from the thermophilic archaebacterium Sulfolobus acidocaldarius, on the branched-chain amino acid transport system of the mesophilic bacterium Lactococcus lactis was investigated. Liposomes were prepared from mixtures of monolayer lipids and the

  12. Studying lipid-protein interactions with electron paramagnetic resonance spectroscopy of spin-labeled lipids.

    Science.gov (United States)

    Páli, Tibor; Kóta, Zoltán

    2013-01-01

    Spin label electron paramagnetic resonance (EPR) of lipid-protein interactions reveals crucial features of the structure and assembly of integral membrane proteins. Spin label EPR spectroscopy is the technique of choice to characterize the protein-solvating lipid shell in its highly dynamic nature, because the EPR spectra of lipids that are spin labeled close to the terminal methyl end of their acyl chains display two spectral components, those corresponding to lipids directly contacting the protein and those corresponding to lipids in the bulk fluid bilayer regions of the membrane. In this chapter, typical spin label EPR procedures are presented that allow determination of the stoichiometry of interaction of spin-labeled lipids with the intra-membranous region of membrane proteins or polypeptides, as well as the association constant of the spin-labeled lipid with respect to the host lipid. The lipids giving rise to the so-called immobile spectral component in the EPR spectrum of such samples are identified as the motionally restricted first-shell lipids solvating membrane proteins in biomembranes. Stoichiometry and selectivity are directly related to the structure of the intra-membranous sections of membrane-associated proteins or polypeptides and can be used to study the state of assembly of such proteins in the membrane. Since these characteristics of lipid-protein interactions are discussed in detail in the literature [see Marsh (Eur Biophys J 39:513-525, 2010) for a most recent review], here we focus more on how to spin label model and biomembranes and how to measure and analyze the two-component EPR spectra of spin-labeled lipids in phospholipid bilayers that contain proteins or polypeptides. After a description of how to prepare spin-labeled model and native biological membranes, we present the reader with computational procedures for determining the molar fraction of motionally restricted lipids when both, one, or none of the pure isolated-mobile or

  13. Polyene-lipids: a new tool to image lipids

    DEFF Research Database (Denmark)

    Kuerschner, Lars; Ejsing, Christer S.; Ekroos, Kim

    2005-01-01

    conjugated double bonds as a new type of lipid tag. Polyene-lipids exhibit a unique structural similarity to natural lipids, which results in minimal effects on the lipid properties. Analyzing membrane phase partitioning, an important biophysical and biological property of lipids, we demonstrated...... the superiority of polyene-lipids to both NBD- and BODIPY-tagged lipids. Cells readily take up various polyene-lipid precursors and generate the expected end products with no apparent disturbance by the tag. Applying two-photon excitation microscopy, we imaged the distribution of polyene-lipids in living...

  14. Anesthetics interacting with lipid rafts.

    Science.gov (United States)

    Bandeiras, Cátia; Serro, Ana Paula; Luzyanin, Konstantin; Fernandes, Anabela; Saramago, Benilde

    2013-01-23

    The exact mechanism by which anesthetics induce cell membrane-mediated modifications is still an open question. Although the fluidization effect of the anesthetic molecules on the cellular membrane is widely recognized, it is not known if anesthetics show any preference for specific membrane domains, namely the lipid rafts. The importance of these membrane micro-domains derives from the fact that they have been associated with cell signaling pathways, as well as with specific drug interactions. The objective of this work is to contribute for the elucidation of this question through the comparison of the anesthetic interactions with membranes of various lipid compositions. Liposomes prepared with an equimolar mixture of POPC, sphingomyelin and cholesterol, were chosen as models for lipid rafts. The interactions of these liposomes with two local anesthetics, tetracaine and lidocaine, and one general anesthetic, propofol, were studied. The effect of cholesterol was investigated by comparing anesthetic interactions with POPC/SM liposomes and POPC/SM/CHOL liposomes. The following experimental techniques were used: quartz crystal microbalance with dissipation, differential scanning calorimetry and phosphorus nuclear magnetic resonance. Although the liposomes investigated by the different techniques are not in the same conditions, it is possible to assemble the information obtained from all experimental techniques employed to reach a general conclusion. Tetracaine interacts more with raftlike domains, lidocaine induces stronger modifications on POPC/SM liposomes and the results for propofol are not fully conclusive but it seems to be the least prone to lipid interactions. The results were compared with those obtained with DMPC-containing liposomes, reported in a previous work.

  15. Lipid Microarray Biosensor for Biotoxin Detection.

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Anup K.; Throckmorton, Daniel J.; Moran-Mirabal, Jose C.; Edel, Joshua B.; Meyer, Grant D.; Craighead, Harold G.

    2006-05-01

    We present the use of micron-sized lipid domains, patterned onto planar substrates and within microfluidic channels, to assay the binding of bacterial toxins via total internal reflection fluorescence microscopy (TIRFM). The lipid domains were patterned using a polymer lift-off technique and consisted of ganglioside-populated DSPC:cholesterol supported lipid bilayers (SLBs). Lipid patterns were formed on the substrates by vesicle fusion followed by polymer lift-off, which revealed micron-sized SLBs containing either ganglioside GT1b or GM1. The ganglioside-populated SLB arrays were then exposed to either Cholera toxin subunit B (CTB) or Tetanus toxin fragment C (TTC). Binding was assayed on planar substrates by TIRFM down to 1 nM concentration for CTB and 100 nM for TTC. Apparent binding constants extracted from three different models applied to the binding curves suggest that binding of a protein to a lipid-based receptor is strongly affected by the lipid composition of the SLB and by the substrate on which the bilayer is formed. Patterning of SLBs inside microfluidic channels also allowed the preparation of lipid domains with different compositions on a single device. Arrays within microfluidic channels were used to achieve segregation and selective binding from a binary mixture of the toxin fragments in one device. The binding and segregation within the microfluidic channels was assayed with epifluorescence as proof of concept. We propose that the method used for patterning the lipid microarrays on planar substrates and within microfluidic channels can be easily adapted to proteins or nucleic acids and can be used for biosensor applications and cell stimulation assays under different flow conditions. KEYWORDS. Microarray, ganglioside, polymer lift-off, cholera toxin, tetanus toxin, TIRFM, binding constant.4

  16. Development and evaluation of lipid nanoparticles for camptothecin de-livery: a comparison of solid lipid nanoparticles, nanostructured lipid car-riers, and lipid emulsion

    Institute of Scientific and Technical Information of China (English)

    Zih-rou HUANG; Shu-chiou HUA; Yueh-lung YANG; Jia-you FANG

    2008-01-01

    Aim:Camptothecin is an anticancer drug that acta against a broad spectrum of tumors. The clinical application of camptothecin is limited by its insolubility, instability, and toxicity problems. The aim of this study was to develop and characterize lipid nanoparticles with different lipid cores which can circumvent these problems. Methods: Lipid nanoparticles made of Precirol (solid lipid nanoparticles; SLN-P), Compritol (SLN-C), Precirol+squalene (nanostructured lipid carriers; NLC), and squalene (a lipid emulsion; LE) as the lipid core ma-terial were prepared. These systems were assessed and compared by evaluat-ing the mean diameter, surface charge, molecular environment, camptothecin release, and cell viability against a melanoma. The safety and storage stability of these systems were also preliminarily examined. Results: The particle size ranged from 190 to 310 nm, with the NLC and LE showing the smallest and largest sizes, respectively. The in vitro drug release occurred in a sustained manner in decreasing order as follows: LE>NLC>SLN-P>SLN-C. It was found that varying the type of inner phase had profound effects on cell viability. The SLN-P generally showed higher cytotoxicity than the free control. The treat-ment of melanomas with the camptothecin-loaded SLN-C and NLC yielded cytotoxicity comparable to that of the free form. The percentage of erythrocyte hemolysis by all nanoparticles was ≤5%, suggesting a good tolerance to lipid nanoparticles. Conclusion: The results collectively suggest that the SLN-P may have the potential to serve as a delivery system for parenteral camptothecin ad-ministration because of the sustained drug release, strong cytotoxicity, limited hemolysis, and good storage stability.

  17. Incorporation of large guest molecules into liposomes via chemical reactions in lipid membranes.

    Science.gov (United States)

    Tsuchiya, Yuki; Sugikawa, Kouta; Ueda, Masafumi; Ikeda, Atsushi

    2017-02-22

    The incorporation of hydrophobic guest molecules into lipid membranes by the exchange of the guest molecule from a cyclodextrin (CDx) complex to a liposome is limited to guest molecules that can be included in CDxs. To solve this problem, large guest molecules were incorporated into liposomes by chemical reactions of guest molecules in lipid membranes. Stable lipid-membrane-incorporated fullerene derivatives with large substituent(s) were prepared by Diels-Alder reactions in lipid membranes.

  18. 地西泮固体脂质纳米粒的制备及大鼠经鼻腔给药的药动学研究%Preparation of Diazepam Solid Lipid Nanoparticles and Its Pharmacokinetics after Intranasal Administration in Rats

    Institute of Scientific and Technical Information of China (English)

    马莉; 魏玉辉; 段好刚; 武琴园; 张建强; 武新安

    2011-01-01

    目的 制备地西泮固体脂质纳米粒,评价其制剂学性质,并探讨其经鼻腔给药后的药动学过程.方法 用高温乳化-低温固化法制备地西泮固体脂质纳米粒,考察了其包封率、体外释药、粒径分布、Zeta电位和形态;大鼠经鼻腔给予固体脂质纳米粒或静脉给予地西泮注射液后经股动脉插管采集血样,采用HPLC测定血药浓度,以DAS1.0软件估算药动学参数.结果 制备的地西泮固体脂质纳米粒形态为类球形,平均粒径为(104.4±0.56)nm;Zeta电位为(-18.50±0.98)mV;包封率为(98.8±3)%.经鼻腔给药后,地西泮固体脂质纳米粒的tmax为11 min,ρmax为(0.33±0.01)μg·mL-1,绝对生物利用度为67.01%.结论 鼻腔给予地西泮固体脂质纳米粒后吸收迅速,绝对生物利用度较高,有望成为治疗癫痫持续状态的新型制剂.%OBJECTIVE To prepare diazepam solid lipid nanoparticles, evaluate the pharmacy characters and study the pharmacokinetics after intranasal administration. METHODS Diazepam solid lipid nanoparticles were prepared by high temperature emulsification-low temperature solidification method. The entrapment efficiency, particle size distrubtion, Zeta potential and morphology were measured. After administrating solid lipid nanoparticles in intranasal routes or diazepam parenteral solution via intravenous, the blood samples were collected from the femoral artery. Drug concentration in plasma were analyzed by HPLC method. The concentration-time curves were obtained, and pharmacokinetic parameters were obtained by DAS 1.0. RESULTS The morphology of diazepam solid lipid nanoparticles obtained were appoximately spherical. The average particle size was ( 104. 4 ± 0. 56 ) nm. The Zeta potential was ( - 18. 50 ± 0. 98 ) mV. Encapsulating efficiency was (98. 8 ± 3 )%. After intranasal aministration of diazepam solid lipid nanoparticles, tmax was 11 min, pmax was (0. 33 ±0. 01 ) μg · mL-1 , and the absolute bioavailability was 67

  19. Lipid bilayers and interfaces

    NARCIS (Netherlands)

    Kik, R.A.

    2007-01-01

    In biological systems lipid bilayers are subject to many different interactions with other entities. These can range from proteins that are attached to the hydrophilic region of the bilayer or transmembrane proteins that interact with the hydrophobic region of the lipid bilayer. Interaction between

  20. The protein and lipid composition of arterial elastin and its relationship to lipid accumulation in the atherosclerotic plaque.

    Science.gov (United States)

    Kramsch, D M; Franzblau, C; Hollander, W

    1971-08-01

    Elastin preparations from intimal layers and the media of normal and atherosclerotic human aortae were analyzed for protein and lipid content. In atherosclerotic aortae, elastin from plaques was compared with elastin from adjacent normal appearing areas of the same aorta. Arterial elastin purified by alkaline extraction appeared to be a protein-lipid complex containing free and ester cholesterol, phospholipids, and triglycerides. The lipid component of normal arterial elastin was small (1-2%). With increasing severity of atherosclerosis, there was a progressive accumulation of lipid in intimal elastin from plaques, reaching a mean lipid content of 37% in severe plaques. The increase in the lipid content of plaque elastic preparations was mainly due to large increases in cholesterol, over 80% of which was cholesteryl ester. This deposition of cholesterol in plaque elastin accounted for 20-34% of the total cholesterol content of the plaque. The increased lipid deposition in plaque elastin was associated with alterations in the amino acid composition of plaque elastin. In elastin from plaque intima, the following polar amino acids were increased significantly: aspartic acid, threonine, serine, glutamic acid, lysine, histidine, and arginine; whereas, cross-linking amino acids: desmosine, isodesmosine, and lysinonorleucine were decreased significantly. The amino acid and lipid composition of elastin from normal appearing aortic areas was comparable to that of normal arterial elastin except for intimal elastin directly adjacent to and medial elastin directly below the most severe plaques.The data indicate that the focal lipid deposition in early atherosclerotic plaques is due to a large extent to lipid accumulations in altered elastin protein of localized intimal areas. Continued lipid deposition in altered elastin appears to contribute substantially to the progressive lipid accumulation in the plaque. The study suggests that elastin of intimal elastic membranes may play

  1. Lipids and lipid binding proteins: a perfect match.

    Science.gov (United States)

    Glatz, Jan F C

    2015-02-01

    Lipids serve a great variety of functions, ranging from structural components of biological membranes to signaling molecules affecting various cellular functions. Several of these functions are related to the unique physico-chemical properties shared by all lipid species, i.e., their hydrophobicity. The latter, however, is accompanied by a poor solubility in an aqueous environment and thus a severe limitation in the transport of lipids in aqueous compartments such as blood plasma and the cellular soluble cytoplasm. Specific proteins which can reversibly and non-covalently associate with lipids, designated as lipid binding proteins or lipid chaperones, greatly enhance the aqueous solubility of lipids and facilitate their transport between tissues and within tissue cells. Importantly, transport of lipids across biological membranes also is facilitated by specific (membrane-associated) lipid binding proteins. Together, these lipid binding proteins determine the bio-availability of their ligands, and thereby markedly influence the subsequent processing, utilization, or signaling effect of lipids. The bio-availability of specific lipid species thus is governed by the presence of specific lipid binding proteins, the affinity of these proteins for distinct lipid species, and the presence of competing ligands (including pharmaceutical compounds). Recent studies suggest that post-translational modifications of lipid binding proteins may have great impact on lipid-protein interactions. As a result, several levels of regulation exist that together determine the bio-availability of lipid species. This short review discusses the significance of lipid binding proteins and their potential application as targets for therapeutic intervention.

  2. The choice of homogenisation equipment affects lipid oxidation in emulsions

    DEFF Research Database (Denmark)

    Horn, Anna Frisenfeldt; Nielsen, Nina Skall; Jensen, Louise Helene Søgaard

    2012-01-01

    in emulsions has been shown to be affected by the emulsification conditions. The objective of this study was to investigate the influence of homogenisation equipment (microfluidizer vs. two-stage valve homogeniser) on lipid oxidation in 10% fish oil-in-water emulsions prepared with two different milk proteins....... Emulsions were prepared at pH 7 with similar droplet sizes. Results showed that the oxidative stability of emulsions prepared with sodium caseinate was not influenced by the type of homogeniser used. In contrast, the type of homogenisation equipment significantly influenced lipid oxidation when whey protein...

  3. Big, Fat World of Lipids

    Science.gov (United States)

    ... Science Home Page The Big, Fat World of Lipids By Emily Carlson Posted August 9, 2012 Cholesterol ... ways to diagnose and treat lipid-related conditions. Lipid Encyclopedia Just as genomics and proteomics spurred advances ...

  4. Atomic force microscopy of model lipid membranes.

    Science.gov (United States)

    Morandat, Sandrine; Azouzi, Slim; Beauvais, Estelle; Mastouri, Amira; El Kirat, Karim

    2013-02-01

    Supported lipid bilayers (SLBs) are biomimetic model systems that are now widely used to address the biophysical and biochemical properties of biological membranes. Two main methods are usually employed to form SLBs: the transfer of two successive monolayers by Langmuir-Blodgett or Langmuir-Schaefer techniques, and the fusion of preformed lipid vesicles. The transfer of lipid films on flat solid substrates offers the possibility to apply a wide range of surface analytical techniques that are very sensitive. Among them, atomic force microscopy (AFM) has opened new opportunities for determining the nanoscale organization of SLBs under physiological conditions. In this review, we first focus on the different protocols generally employed to prepare SLBs. Then, we describe AFM studies on the nanoscale lateral organization and mechanical properties of SLBs. Lastly, we survey recent developments in the AFM monitoring of bilayer alteration, remodeling, or digestion, by incubation with exogenous agents such as drugs, proteins, peptides, and nanoparticles.

  5. Avanti lipid tools: connecting lipids, technology, and cell biology.

    Science.gov (United States)

    Sims, Kacee H; Tytler, Ewan M; Tipton, John; Hill, Kasey L; Burgess, Stephen W; Shaw, Walter A

    2014-08-01

    Lipid research is challenging owing to the complexity and diversity of the lipidome. Here we review a set of experimental tools developed for the seasoned lipid researcher, as well as, those who are new to the field of lipid research. Novel tools for probing protein-lipid interactions, applications for lipid binding antibodies, enhanced systems for the cellular delivery of lipids, improved visualization of lipid membranes using gold-labeled lipids, and advances in mass spectrometric analysis techniques will be discussed. Because lipid mediators are known to participate in a host of signal transduction and trafficking pathways within the cell, a comprehensive lipid toolbox that aids the science of lipidomics research is essential to better understand the molecular mechanisms of interactions between cellular components. This article is part of a Special Issue entitled Tools to study lipid functions.

  6. Regulation of lipid metabolism

    Institute of Scientific and Technical Information of China (English)

    Peng LI

    2011-01-01

    @@ Lipids including cholesterol, phospholipids, fatty acids and triacylglycerols are important cellular constituents involved in membrane structure, energy homeostasis and many biological processes such as signal transduction, organelle development and cell differentiation.Recently, the area of lipid metabolism has drawn a great deal of attention due to its emerging role in the development of metabolic disorders such as obesity, diabetes, atherosclerosis and liver steatosis.We decided to organize a special issue of Frontiers in Biology focusing on our current understanding of lipid metabolism.

  7. Lake Superior lipids

    Science.gov (United States)

    Fish chemistry data (d13C, d15N, C:N, lipid content) published in Rapid Commun. Mass Spectrom. 2015, 29, 2069??2077 DOI: 10.1002/rcm.7367This dataset is associated with the following publication:Hoffman , J., M. Sierszen , and A. Cotter. Fish tissue lipid-C:N relationships for correcting ä13C values and estimating lipid content in aquatic food web studies. Rapid Communications in Mass Spectrometry. Wiley InterScience, Silver Spring, MD, USA, 29(21): 2069–2077, (2015).

  8. Preparation and characterization of podophyllotoxin-loaded nanostructured lipid carriers%鬼臼毒素纳米脂质载体的制备及质量考察

    Institute of Scientific and Technical Information of China (English)

    江中洪; 曾抗; 李国锋; 谷东风; 任非; 史毓杰

    2008-01-01

    目的:纳米脂质载体是近年来继固体脂质纳米粒发展起来的第2代亚微粒载药系统,具有较高的载药量和物理稳定性.探讨鬼臼毒素-脂质纳米粒(podophyllotoxin-loaded nanostructured lipid carrier,PPT-NLC)的制备方法及理化性质.方法:实验于2006-08/2007-10在南方医科大学药学部实验室完成.选择固体脂质硬脂酸、单硬脂酸甘油脂和液态脂质油酸,采用改良的乳化蒸发-低温固化法制备PPT-NLC,用同法制备不含油酸的PPT-固体脂质纳米粒(Solid lipid nanoparticles,SLN)纳米粒混悬液.用透射电镜、Zeta电位仪、高效液相色谱法、pH计考察PPT-NLC理化性质,并比较SLN与NLC的包封率和稳定性.结果:透射电镜下PPT-NLC外形呈圆形或椭圆形,平均粒径为(88.2±8.4)nm,多分散指数为0.190±0.085,Zeta电位为(-33.2±3.1)mV,包封率为86.6%.PPT-SLN分别为(75.3±16.2)nm,0.300±0.072,(-25.2±3.4)mV,包封率为76.5%.结论:PPT-NLC制备工艺简单,分布均匀,稳定性较SLN好,包封率高.

  9. Perspectives on marine zooplankton lipids

    DEFF Research Database (Denmark)

    Kattner, G.; Hagen, W.; Lee, R.F.

    2007-01-01

    We developed new perspectives to identify important questions and to propose approaches for future research on marine food web lipids. They were related to (i) structure and function of lipids, (ii) lipid changes during critical life phases, (iii) trophic marker lipids, and (iv) potential impact...... of climate change. The first addresses the role of lipids in membranes, storage lipids, and buoyancy with the following key question: How are the properties of membranes and deposits affected by the various types of lipids? The second deals with the importance of various types of lipids during reproduction......, development, and resting phases and addresses the role of the different storage lipids during growth and dormancy. The third relates to trophic marker lipids, which are an important tool to follow lipid and energy transfer through the food web. The central question is how can fatty acids be used to identify...

  10. Lipid-based antifungal agents: current status.

    Science.gov (United States)

    Arikan, S; Rex, J H

    2001-03-01

    Immunocompromised patients are well known to be predisposed to developing invasive fungal infections. These infections are usually difficult to diagnose and more importantly, the resulting mortality rate is high. The limited number of antifungal agents available and their high rate of toxicity are the major factors complicating the issue. However, the development of lipid-based formulations of existing antifungal agents has opened a new era in antifungal therapy. The best examples are the lipid-based amphotericin B preparations, amphotericin B lipid complex (ABLC; Abelcet), amphotericin B colloidal dispersion (ABCD; Amphotec or Amphocil), and liposomal amphotericin B (AmBisome). These formulations have shown that antifungal activity is maintained while toxicity is reduced. This progress is followed by the incorporation of nystatin into liposomes. Liposomal nystatin formulation is under development and studies of it have provided encouraging data. Finally, lipid-based formulations of hamycin, miconazole, and ketoconazole have been developed but remain experimental. Advances in technology of liposomes and other lipid formulations have provided promising new tools for management of fungal infections.

  11. Natural lipids in nanostructured lipid carriers and its cytotoxicity

    Science.gov (United States)

    Lima, Paula A.; Rampazo, Caroline A. D.; Costa, Amanda F.; Rodrigues, Tiago; Watashi, Carolina M.; Durán, Nelson

    2017-06-01

    Nanostructured lipid carriers (NLCs) are active carrier systems which modulate the sustained release of actives and protect unstable compounds against degradation. NLCs can also protect skin from sun light, due to its particulates nature, which gives them intrinsic scattering properties. In this work, we present the preparation of NLCs using natural lipids and its cytotoxicity profile. It was used a vegetal butter with melting point (m.p.) ~32-40°C, an animal wax (m.p. 35-40°C) and a vegetal oil (boiling point ~120-150°C). NLCs were prepared by hot high pressure homogenization method and particles were characterized by average size (Zave), polydispersity index (PDI) and zeta potential (PZ) (Fig.1). The thermal behavior of the NLCs was studied using Differential Scanning Calorimetry (DSC). All the formulations were followed up for 60 days in order to evaluate their stability. NLCs exhibited a Zave around 150-200 nm, PDI less than 0.2 and PZ varying from -25 to -40 mV. The m.p. for the lyophilized NLCs was about 40-56°C. Cytotoxicity of the formulations were evaluated for human keratinocytes (HaCaT) and melanocytes (Melan-A) in the exponential growth phase. Cell viability was used as indicator of cytotoxicity and determined after 4 days of culture by MTT assay. It was found that the NLC formulations were not toxic against HaCaT and Melan-A cells. Results showed that the NLCs produced are potential carriers for nanocosmetics and sunscreen products.

  12. Preparation and optimization of dexamethasone acetate solid lipid nanoparticles by orthogonal design%醋酸地塞米松固体脂质纳米粒的制备与处方优化

    Institute of Scientific and Technical Information of China (English)

    杜洋; 黄华; 胡荣

    2009-01-01

    目的:制备醋酸地塞米松(dexamethasone acetate,DA)固体脂质纳米粒(solid lipid nanoparticles,SLN)并优化其处方组成.方法:采用乳化蒸发法制备醋酸地塞米松固体脂质纳米粒(DA-SLN).以包封率、载药量及粒径为考察指标,运用正交试验设计优化处方.结果:DA-SLN的最优处方组成为A2 B2 C2 D2,即药脂比1∶10,泊洛沙姆质量分数为2.0%,乳化温度为70℃,乳剂与分散相体积比为1∶6.优化处方的各指标值依次为粒径(180.8±3.3)nm,载药量(3.21±0.01)%,包封率(78.7±0.5)%.结论:乳化蒸发法适于制备DA-SLN,经优选后得到的处方合理、可行,可用于DA新型局部给药制剂的研究.

  13. Preparation of low calorie structured lipids catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene(TBD)-functionalized mesoporous SBA-15 silica in a heterogeneous manner.

    Science.gov (United States)

    Xie, Wenlei; Qi, Cong

    2014-04-16

    1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD, a strong bicyclic guanidine base) functionalized SBA-15 material has been found to be an efficient solid catalyst for the interesterification between tributyrin and methyl stearate in a solvent-free system for the production of low-calorie structured lipid (LCSL). The solid base catalyst was characterized by using small-angle X-ray scattering, Fourier transform infrared spectra, thermo gravimetric analysis, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption, and elemental analysis techniques. The obtained LCSL was analyzed by reverse-phase high-performance liquid chromatography for triacylglycerol composition. The influence of various reaction parameters, such as the substrate ratio, reaction temperature, and reaction time, on the interesterification reaction was investigated systematically. More than 90% LCSL was obtained at 80 °C within 1 h when the methyl stearate/tributyrin molar ratio of 2:1 was employed. The obtained solid catalyst could be recovered easily and reused for several recycles with a negligible loss of activity. By using the solid base catalyst, an eco-friendly more benign process for the interesterification reaction in a heterogeneous manner was developed.

  14. 443 Review Lipids

    African Journals Online (AJOL)

    Marinda

    2009-07-20

    Jul 20, 2009 ... Keywords: lipid emulsion therapy; local anaesthetic toxicity; local anaesthetic cardiotoxicity; .... of particular importance in generating sufficient ATP from fats because ..... Propofol is poorly water soluble and is dissolved in the.

  15. Metabolism. Part III: Lipids.

    Science.gov (United States)

    Bodner, George M.

    1986-01-01

    Describes the metabolic processes of complex lipids, including saponification, activation and transport, and the beta-oxidation spiral. Discusses fatty acid degradation in regard to biochemical energy and ketone bodies. (TW)

  16. Lipid-modifying therapy

    African Journals Online (AJOL)

    2009-03-20

    Mar 20, 2009 ... risk reduction for most patients, while patients with severe ... He runs the Diabetic, Endocrine and Lipid clinics at R K Khan Hospital. Treatment .... retinopathy requiring laser therapy). ... Despite knowledge of the risk factors for.

  17. Dynamic Transbilayer Lipid Asymmetry

    OpenAIRE

    van Meer, Gerrit

    2011-01-01

    Flippases move lipids from the outer leaflet of the membrane to the inner leaflet; floppases export them in the opposite direction. This creates an asymmetry critical for membrane function and facilitates vesicle budding.

  18. Solid Lipid Nanoparticles of Guggul Lipid as Drug Carrier for Transdermal Drug Delivery

    Directory of Open Access Journals (Sweden)

    Praveen Kumar Gaur

    2013-01-01

    Full Text Available Diclofenac sodium loaded solid lipid nanoparticles (SLNs were formulated using guggul lipid as major lipid component and analyzed for physical parameters, permeation profile, and anti-inflammatory activity. The SLNs were prepared using melt-emulsion sonication/low temperature-solidification method and characterized for physical parameters, in vitro drug release, and accelerated stability studies, and formulated into gel. Respective gels were compared with a commercial emulgel (CEG and plain carbopol gel containing drug (CG for ex vivo and in vivo drug permeation and anti-inflammatory activity. The SLNs were stable with optimum physical parameters. GMS nanoparticle 1 (GMN-1 and stearic acid nanoparticle 1 (SAN-1 gave the highest in vitro drug release. Guggul lipid nanoparticle gel 3 (GLNG-3 showed 104.68 times higher drug content than CEG in receptor fluid. The enhancement ratio of GLNG-3 was 39.43 with respect to CG. GLNG-3 showed almost 8.12 times higher Cmax than CEG at 4 hours. The AUC value of GLNG-3 was 15.28 times higher than the AUC of CEG. GLNG-3 showed edema inhibition up to 69.47% in the first hour. Physicochemical properties of major lipid component govern the properties of SLN. SLN made up of guggul lipid showed good physical properties with acceptable stability. Furthermore, it showed a controlled drug release profile along with a promising permeation profile.

  19. Polymerized planar suspended lipid bilayers for single ion channel recordings: comparison of several dienoyl lipids.

    Science.gov (United States)

    Heitz, Benjamin A; Xu, Juhua; Jones, Ian W; Keogh, John P; Comi, Troy J; Hall, Henry K; Aspinwall, Craig A; Saavedra, S Scott

    2011-03-01

    The stabilization of suspended planar lipid membranes, or black lipid membranes (BLMs), through polymerization of mono- and bis-functionalized dienoyl lipids was investigated. Electrical properties, including capacitance, conductance, and dielectric breakdown voltage, were determined for BLMs composed of mono-DenPC, bis-DenPC, mono-SorbPC, and bis-SorbPC both prior to and following photopolymerization, with diphytanoyl phosphocholine (DPhPC) serving as a control. Poly(lipid) BLMs exhibited significantly longer lifetimes and increased the stability of air-water transfers. BLM stability followed the order bis-DenPC > mono-DenPC ≈ mono-SorbPC > bis-SorbPC. The conductance of bis-SorbPC BLMs was significantly higher than that of the other lipids, which is attributed to a high density of hydrophilic pores, resulting in relatively unstable membranes. The use of poly(lipid) BLMs as matrices for supporting the activity of an ion channel protein (IC) was explored using α-hemolysin (α-HL), a model IC. Characteristic i-V plots of α-HL were maintained following photopolymerization of bis-DenPC, mono-DenPC, and mono-SorbPC, demonstrating the utility of these materials for preparing more durable BLMs for single-channel recordings of reconstituted ICs.

  20. Lipids of mitochondria.

    Science.gov (United States)

    Horvath, Susanne E; Daum, Günther

    2013-10-01

    A unique organelle for studying membrane biochemistry is the mitochondrion whose functionality depends on a coordinated supply of proteins and lipids. Mitochondria are capable of synthesizing several lipids autonomously such as phosphatidylglycerol, cardiolipin and in part phosphatidylethanolamine, phosphatidic acid and CDP-diacylglycerol. Other mitochondrial membrane lipids such as phosphatidylcholine, phosphatidylserine, phosphatidylinositol, sterols and sphingolipids have to be imported. The mitochondrial lipid composition, the biosynthesis and the import of mitochondrial lipids as well as the regulation of these processes will be main issues of this review article. Furthermore, interactions of lipids and mitochondrial proteins which are highly important for various mitochondrial processes will be discussed. Malfunction or loss of enzymes involved in mitochondrial phospholipid biosynthesis lead to dysfunction of cell respiration, affect the assembly and stability of the mitochondrial protein import machinery and cause abnormal mitochondrial morphology or even lethality. Molecular aspects of these processes as well as diseases related to defects in the formation of mitochondrial membranes will be described. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Preparation of PEGylated solid lipid nanoparticles of furanodiene and the macrophage uptake in vitro%PEG化呋喃二烯固体脂质纳米粒的制备及体外巨噬细胞摄取研究

    Institute of Scientific and Technical Information of China (English)

    谢鑫鑫; 王俊腾; 秦利芳; 林东海

    2012-01-01

    Objective; To prepare and investigate the characteristics and cell uptake properties of furano-diene solid lipid nanoparticles surface-modified with poly ( ethylene glycol) ( PEG-FDE-SLN ). Methods-. PEG-FDE-SLN was prepared by emulsification-evaporation technique. Its characteristics, including mean size, polydis-persity index, Zeta potential, entrapment efficiency and drug loading, were evaluated. The preparation conditions were optimized by means of monofactorial design. Mouse peritoneal macrophage (MPM) was used to evaluate the uptake of PEG-FDE-SLN by cells in vitro. Results; The optimized preparation conditions were obtained as follows; 100 mg glylergl monostearate was solid lipid, 40 mg medium chain triglycerides was liquid lipid, 13 mg lecithin was emulsifier, and polyethylene glycol stearate was 150 mg. The mean size of PEG-FDE-SLN was (272.9 ±2.4) nm, polydispersity index was (0. 193 ±0. 022) , Zeta potential was ( - 19. 82 ± 0. 52 ) mV , and entrapment efficiency was (90.0 ±1.0)%. With adding the polyethylene glycol stearate and increasing the molecular weight of PEG, the uptake of FDE-SLN by MPM decreased gradually. Conclusion; PEG-FDE-SLN can improve the escape effect of MPM. The PEG chain length has effect on the uptake of FDE-SLN by MPM , namely the longer of PEG chain length, the less uptake by MPM.%目的:研究PEG化呋喃二烯固体脂质纳米粒(PEG-FDE-SLN)的制备方法,并考察其理化性质及细胞摄取性能.方法:实验采用乳化蒸发-低温固化法制备PEG-FDE-SLN,以粒径、Zeta电位、多分散系数、包封率为评价指标,通过单因素考察选择制备PEG-FDE-SLN的最佳处方.以小鼠腹腔巨噬细胞(MPM)为模型做体外细胞摄取实验.结果:制备PEG-FDE-SLN的最佳处方为固态脂质单硬脂酸甘油酯100 mg,液态脂质中碳链三酰甘油40 mg,乳化剂蛋黄卵磷脂13 mg,聚乙二醇硬脂酸酯150 mg,制备的样品粒径为(272.9±2.4) nm,多分散系数为(0.193±0.022),Zeta

  2. Omental Lipid-Coated Mesh

    Science.gov (United States)

    2011-06-16

    civilian medicine. REFERENCES: 1. Takada T, Kamei Y, Iwata T, et al. Effect of Omental Lipid Fraction on Enhancement of Skin Flap Survival. Annals of...Characterization of Feline Omentum Lipids. Lipids, 1987; 22:229-235. 7. Nottebaert M, Lane J, Juhn A, et al. Omental Angiogenic Lipid Fraction and

  3. Perspectives on marine zooplankton lipids

    DEFF Research Database (Denmark)

    Kattner, G.; Hagen, W.; Lee, R.F.

    2007-01-01

    We developed new perspectives to identify important questions and to propose approaches for future research on marine food web lipids. They were related to (i) structure and function of lipids, (ii) lipid changes during critical life phases, (iii) trophic marker lipids, and (iv) potential impact ...

  4. Microemulsion extrusion technique: a new method to produce lipid nanoparticles

    Science.gov (United States)

    de Jesus, Marcelo Bispo; Radaic, Allan; Zuhorn, Inge S.; de Paula, Eneida

    2013-10-01

    Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been intensively investigated for different applications, including their use as drug and gene delivery systems. Different techniques have been employed to produce lipid nanoparticles, of which high pressure homogenization is the standard technique that is adopted nowadays. Although this method has a high efficiency, does not require the use of organic solvents, and allows large-scale production, some limitations impede its application at laboratory scale: the equipment is expensive, there is a need of huge amounts of surfactants and co-surfactants during the preparation, and the operating conditions are energy intensive. Here, we present the microemulsion extrusion technique as an alternative method to prepare lipid nanoparticles. The parameters to produce lipid nanoparticles using microemulsion extrusion were established, and the lipid particles produced (SLN, NLC, and liposomes) were characterized with regard to size (from 130 to 190 nm), zeta potential, and drug (mitoxantrone) and gene (pDNA) delivery properties. In addition, the particles' in vitro co-delivery capacity (to carry mitoxantrone plus pDNA encoding the phosphatase and tensin homologue, PTEN) was tested in normal (BALB 3T3 fibroblast) and cancer (PC3 prostate and MCF-7 breast) cell lines. The results show that the microemulsion extrusion technique is fast, inexpensive, reproducible, free of organic solvents, and suitable for small volume preparations of lipid nanoparticles. Its application is particularly interesting when using rare and/or costly drugs or ingredients (e.g., cationic lipids for gene delivery or labeled lipids for nanoparticle tracking/diagnosis).

  5. Microemulsion extrusion technique: a new method to produce lipid nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Marcelo Bispo de, E-mail: dejesusmb@gmail.com; Radaic, Allan [University of Campinas-UNICAMP, Department of Biochemistry, Institute of Biology (Brazil); Zuhorn, Inge S. [University of Groningen, Department of Membrane Cell Biology, University Medical Center (Netherlands); Paula, Eneida de [University of Campinas-UNICAMP, Department of Biochemistry, Institute of Biology (Brazil)

    2013-10-15

    Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have been intensively investigated for different applications, including their use as drug and gene delivery systems. Different techniques have been employed to produce lipid nanoparticles, of which high pressure homogenization is the standard technique that is adopted nowadays. Although this method has a high efficiency, does not require the use of organic solvents, and allows large-scale production, some limitations impede its application at laboratory scale: the equipment is expensive, there is a need of huge amounts of surfactants and co-surfactants during the preparation, and the operating conditions are energy intensive. Here, we present the microemulsion extrusion technique as an alternative method to prepare lipid nanoparticles. The parameters to produce lipid nanoparticles using microemulsion extrusion were established, and the lipid particles produced (SLN, NLC, and liposomes) were characterized with regard to size (from 130 to 190 nm), zeta potential, and drug (mitoxantrone) and gene (pDNA) delivery properties. In addition, the particles' in vitro co-delivery capacity (to carry mitoxantrone plus pDNA encoding the phosphatase and tensin homologue, PTEN) was tested in normal (BALB 3T3 fibroblast) and cancer (PC3 prostate and MCF-7 breast) cell lines. The results show that the microemulsion extrusion technique is fast, inexpensive, reproducible, free of organic solvents, and suitable for small volume preparations of lipid nanoparticles. Its application is particularly interesting when using rare and/or costly drugs or ingredients (e.g., cationic lipids for gene delivery or labeled lipids for nanoparticle tracking/diagnosis)

  6. RaftProt: mammalian lipid raft proteome database.

    Science.gov (United States)

    Shah, Anup; Chen, David; Boda, Akash R; Foster, Leonard J; Davis, Melissa J; Hill, Michelle M

    2015-01-01

    RaftProt (http://lipid-raft-database.di.uq.edu.au/) is a database of mammalian lipid raft-associated proteins as reported in high-throughput mass spectrometry studies. Lipid rafts are specialized membrane microdomains enriched in cholesterol and sphingolipids thought to act as dynamic signalling and sorting platforms. Given their fundamental roles in cellular regulation, there is a plethora of information on the size, composition and regulation of these membrane microdomains, including a large number of proteomics studies. To facilitate the mining and analysis of published lipid raft proteomics studies, we have developed a searchable database RaftProt. In addition to browsing the studies, performing basic queries by protein and gene names, searching experiments by cell, tissue and organisms; we have implemented several advanced features to facilitate data mining. To address the issue of potential bias due to biochemical preparation procedures used, we have captured the lipid raft preparation methods and implemented advanced search option for methodology and sample treatment conditions, such as cholesterol depletion. Furthermore, we have identified a list of high confidence proteins, and enabled searching only from this list of likely bona fide lipid raft proteins. Given the apparent biological importance of lipid raft and their associated proteins, this database would constitute a key resource for the scientific community.

  7. Comprehensive analysis of lipid composition in crude palm oil using multiple lipidomic approaches.

    Science.gov (United States)

    Cheong, Wei Fun; Wenk, Markus R; Shui, Guanghou

    2014-05-20

    Palm oil is currently the leading edible oil consumed worldwide. Triacylglycerol (TAG) and diacylglycerol (DAG) are the dominant lipid classes in palm oil. Other lipid classes present in crude palm oil, such as phospholipids and galactolipids, are very low in abundance. These low-abundance lipids constitute key intermediates in lipid biosynthesis. In this study, we applied multiple lipidomic approaches, including high-sensitivity and high-specificity multiple reaction monitoring, to comprehensively quantify individual lipid species in crude palm oil. We also established a new liquid chromatography-coupled mass spectrometry method that allows direct quantification of low-abundance galactolipids in palm oil without the need for sample pretreatment. As crude palm oil contains large amounts of neutral lipids, our direct-detection method circumvents many of the challenges encountered with conventional lipid quantification methods. This approach allows direct measurement of lipids with no hassle during sample preparation and is more accurate and precise compared with other methods.

  8. Interaction of antimicrobial peptides with lipid membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hanulova, Maria

    2008-12-15

    This study aims to investigate the difference in the interaction of antimicrobial peptides with two classes of zwitterionic peptides, phosphatidylethanolamines (PE) and phosphatidylcholines (PC). Further experiments were performed on model membranes prepared from specific bacterial lipids, lipopolysaccharides (LPS) isolated from Salmonella minnesota. The structure of the lipid-peptide aqueous dispersions was studied by small-and wide-angle X-ray diffraction during heating and cooling from 5 to 85 C. The lipids and peptides were mixed at lipid-to-peptide ratios 10-10000 (POPE and POPC) or 2-50 (LPS). All experiments were performed at synchrotron soft condensed matter beamline A2 in Hasylab at Desy in Hamburg, Germany. The phases were identified and the lattice parameters were calculated. Alamethicin and melittin interact in similar ways with the lipids. Pure POPC forms only lamellar phases. POPE forms lamellar phases at low temperatures that upon heating transform into a highly curved inverse hexagonal phase. Insertion of the peptide induced inverse bicontinuous cubic phases which are an ideal compromise between the curvature stress and the packing frustration. Melittin usually induced a mixture of two cubic phases, Im3m and Pn3m, with a ratio of lattice parameters close to 1.279, related to the underlying minimal surfaces. They formed during the lamellar to hexagonal phase transition and persisted during cooling till the onset of the gel phase. The phases formed at different lipid-to-peptide ratios had very similar lattice parameters. Epitaxial relationships existed between coexisting cubic phases and hexagonal or lamellar phases due to confinement of all phases to an onion vesicle, a vesicle with several layers consisting of different lipid phases. Alamethicin induced the same cubic phases, although their formation and lattice parameters were dependent on the peptide concentration. The cubic phases formed during heating from the lamellar phase and their onset

  9. The Impact of Variables on Particle Size of Solid Lipid Nanoparticles and Nanostructured Lipid Carriers; A Comparative Literature Review

    Science.gov (United States)

    Azhar Shekoufeh Bahari, Leila; Hamishehkar, Hamed

    2016-01-01

    During the past decade, pharmaceutical science has seen rapid growth in interest for nanoscale materials. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are popular research topics recently introduced as nano-scale drug carriers; they have shown numerous merits in drug delivery. Size is the most important index in a nanocarrier affecting its drug delivery efficiency. The influence of preparation conditions and type of lipidic components on the size of SLN and NLC in comparable states seems to be interesting for researchers who investigate these types of carriers. This review highlights the results of SLN and NLC particle size and size distribution comparisons. PMID:27478775

  10. Supercritical fluid precipitation of ketoprofen in novel structured lipid carriers for enhanced mucosal delivery--a comparison with solid lipid particles.

    Science.gov (United States)

    Gonçalves, V S S; Matias, A A; Rodríguez-Rojo, S; Nogueira, I D; Duarte, C M M

    2015-11-10

    Structured lipid carriers based on mixture of solid lipids with liquid lipids are the second generation of solid lipid particles, offering the advantage of improved drug loading capacity and higher storage stability. In this study, structured lipid carriers were successfully prepared for the first time by precipitation from gas saturated solutions. Glyceryl monooleate (GMO), a liquid glycerolipid, was selected in this work to be incorporated into three solid glycerolipids with hydrophilic-lipophilic balance (HLB) ranging from 1 to 13, namely Gelucire 43/01™, Geleol™ and Gelucire 50/13™. In general, microparticles with a irregular porous morphology and a wide particle size distribution were obtained. The HLB of the individual glycerolipids might be a relevant parameter to take into account during the processing of solid:liquid lipid blends. As expected, the addition of a liquid lipid into a solid lipid matrix led to increased stability of the lipid carriers, with no significant modifications in their melting enthalpy after 6 months of storage. Additionally, Gelucire 43/01™:GMO particles were produced with different mass ratios and loaded with ketoprofen. The drug loading capacity of the structured lipid carriers increased as the GMO content in the particles increased, achieving a maximum encapsulation efficiency of 97% for the 3:1 mass ratio. Moreover, structured lipid carriers presented an immediate release of ketoprofen from its matrix with higher permeation through a mucous-membrane model, while solid lipid particles present a controlled release of the drug with less permeation capacity.

  11. Formulation and in vitro characterization of domperidone loaded solid lipid nanoparticles and nanostructured lipid carriers

    Directory of Open Access Journals (Sweden)

    RP Thatipamula

    2011-03-01

    Full Text Available Background and the purpose of the study: Domperidone (DOM is a dopamine- receptor (D2 antagonist, widely used in the treatment of motion-sickness. The pharmacokinetic parameters of DOM make it a suitable candidate for development of Solid Lipid Nanoparticle (SLN and Nanostructured Lipide Carrier (NLC. The purpose of the present investigation was to prepare and evaluate DOM loaded solid lipid nanoparticles (DOM-SLN and DOM loaded nanostructured lipid carriers (DOM-NLC. Methods: DOM loaded SLN and NLC were prepared by hot homogenization followed by ultrasonication technique, using trimyristin as solid lipid, cetyl recinoleate as liquid lipid and a mixture of soy phosphatidylcholine (99% and tween 80 as surfactant. SLN and NLC were characterized for particle size, polydispersity index (PDI, zeta potential and entrapment efficiency. The effects of composition of lipid materials and surfactant mixture on the particle size, PDI, zeta potential, drug entrapment efficiency, and in vitro drug release behavior were investigated. DSC analysis was performed to characterize the state of drug and lipid modification. Shape and surface morphology were determined by transmission electron microscopy (TEM. SLN and NLC formulations were subjected to stability study over a period of 40 days. Results: The mean particle size, PDI, zeta potential and entrapment efficiency of optimized SLN (SLN1 and NLC were found to be 30.45 nm, 0.156, 12.40 mV, 87.84 % and 32.23 nm, 0.160, 10.47 mV, 90.49 % respectively. DSC studies revealed that DOM was in an amorphous state and triglycerides were in the β prime form in SLN and NLC. Shape and surface morphology was determined by TEM revealed fairly spherical shape of nanoparticles. In vitro release studies demonstrated that both the SLN and NLC formulations possessed a controlled release over a period of 24 hrs. SLN and NLC formulations were subjected to stability over a period of 40 days. There was no significant (P < 0.05 change

  12. Heart, lipids and hormones

    Directory of Open Access Journals (Sweden)

    Peter Wolf

    2017-05-01

    Full Text Available Cardiovascular disease is the leading cause of death in general population. Besides well-known risk factors such as hypertension, impaired glucose tolerance and dyslipidemia, growing evidence suggests that hormonal changes in various endocrine diseases also impact the cardiac morphology and function. Recent studies highlight the importance of ectopic intracellular myocardial and pericardial lipid deposition, since even slight changes of these fat depots are associated with alterations in cardiac performance. In this review, we overview the effects of hormones, including insulin, thyroid hormones, growth hormone and cortisol, on heart function, focusing on their impact on myocardial lipid metabolism, cardiac substrate utilization and ectopic lipid deposition, in order to highlight the important role of even subtle hormonal changes for heart function in various endocrine and metabolic diseases.

  13. LIPID PEROXIDATION IN PREECLAMPSIA

    Directory of Open Access Journals (Sweden)

    T.Sharmila Krishna

    2015-03-01

    Full Text Available Hypertension in pregnancy is a leading cause of both maternal and fetal mortality and morbidity. Preeclampsia is characterised by hypertension and proteinuria. Lipid peroxidation is an important factor in the pathophysiology of Preeclampsia. The present study was undertaken to determine Serum Malondialdehyde (MDA levels , a product of lipid peroxidation , in clinically diagnosed Preeclamptic women(n=30 and the values were compared with that of Normotensive pregnant women (n=30 aged between 18-30yrs. All of them were in their third trimester and were primigravida. Serum MDA was estimated by TBARS (thiobarbituric acid reactive substances method. We observed that Serum MDA levels were significantly increased in Preeclamptic women (p <0.000 as compared to that of Normotensive pregnant women . Increased levels of lipid peroxiation product - MDA may contribute to the pathophysiology of Preeclampsia.

  14. Designing lipids for selective partitioning into liquid ordered membrane domains.

    Science.gov (United States)

    Momin, Noor; Lee, Stacey; Gadok, Avinash K; Busch, David J; Bachand, George D; Hayden, Carl C; Stachowiak, Jeanne C; Sasaki, Darryl Y

    2015-04-28

    Self-organization of lipid molecules into specific membrane phases is key to the development of hierarchical molecular assemblies that mimic cellular structures. While the packing interaction of the lipid tails should provide the major driving force to direct lipid partitioning to ordered or disordered membrane domains, numerous examples show that the headgroup and spacer play important but undefined roles. We report here the development of several new biotinylated lipids that examine the role of spacer chemistry and structure on membrane phase partitioning. The new lipids were prepared with varying lengths of low molecular weight polyethylene glycol (EGn) spacers to examine how spacer hydrophilicity and length influence their partitioning behavior following binding with FITC-labeled streptavidin in liquid ordered (Lo) and liquid disordered (Ld) phase coexisting membranes. Partitioning coefficients (Kp Lo/Ld) of the biotinylated lipids were determined using fluorescence measurements in studies with giant unilamellar vesicles (GUVs). Compared against DPPE-biotin, DPPE-cap-biotin, and DSPE-PEG2000-biotin lipids, the new dipalmityl-EGn-biotin lipids exhibited markedly enhanced partitioning into liquid ordered domains, achieving Kp of up to 7.3 with a decaethylene glycol spacer (DP-EG10-biotin). We further demonstrated biological relevance of the lipids with selective partitioning to lipid raft-like domains observed in giant plasma membrane vesicles (GPMVs) derived from mammalian cells. Our results found that the spacer group not only plays a pivotal role for designing lipids with phase selectivity but may also influence the structural order of the domain assemblies.

  15. Porphyromonas gingivalis Lipids Inhibit Osteoblastic Differentiation and Function▿

    Science.gov (United States)

    Wang, Yu-Hsiung; Jiang, Jin; Zhu, Qiang; AlAnezi, Amer Z.; Clark, Robert B.; Jiang, Xi; Rowe, David W.; Nichols, Frank C.

    2010-01-01

    Porphyromonas gingivalis produces unusual sphingolipids that are known to promote inflammatory reactions in gingival fibroblasts and Toll-like receptor 2 (TLR2)-dependent secretion of interleukin-6 from dendritic cells. The aim of the present study was to examine whether P. gingivalis lipids inhibit osteoblastic function. Total lipids from P. gingivalis and two fractions, phosphoglycerol dihydroceramides and phosphoethanolamine dihydroceramides, were prepared free of lipid A. Primary calvarial osteoblast cultures derived from 5- to 7-day-old CD-1 mice were used to examine the effects of P. gingivalis lipids on mineralized nodule formation, cell viability, apoptosis, cell proliferation, and gene expression. P. gingivalis lipids inhibited osteoblast differentiation and fluorescence expression of pOBCol2.3GFP in a concentration-dependent manner. However, P. gingivalis lipids did not significantly alter osteoblast proliferation, viability, or apoptosis. When administered during specific intervals of osteoblast growth, P. gingivalis total lipids demonstrated inhibitory effects on osteoblast differentiation only after the proliferation stage of culture. Reverse transcription-PCR confirmed the downregulation of osteoblast marker genes, including Runx2, ALP, OC, BSP, OPG, and DMP-1, with concurrent upregulation of RANKL, tumor necrosis factor alpha, and MMP-3 genes. P. gingivalis total lipids and lipid fractions inhibited calvarial osteoblast gene expression and function in vivo, as determined by the loss of expression of another osteoblast differentiation reporter, pOBCol3.6GFPcyan, and reduced uptake of Alizarin complexone stain. Finally, lipid inhibition of mineral nodule formation in vitro was dependent on TLR2 expression. Our results indicate that inhibition of osteoblast function and gene expression by P. gingivalis lipids represents a novel mechanism for altering alveolar bone homeostasis at periodontal disease sites. PMID:20584977

  16. Bioorthogonal chemical reporters for analyzing protein lipidation and lipid trafficking.

    Science.gov (United States)

    Hang, Howard C; Wilson, John P; Charron, Guillaume

    2011-09-20

    Protein lipidation and lipid trafficking control many key biological functions in all kingdoms of life. The discovery of diverse lipid species and their covalent attachment to many proteins has revealed a complex and regulated network of membranes and lipidated proteins that are central to fundamental aspects of physiology and human disease. Given the complexity of lipid trafficking and the protein targeting mechanisms involved with membrane lipids, precise and sensitive methods are needed to monitor and identify these hydrophobic molecules in bacteria, yeast, and higher eukaryotes. Although many analytical methods have been developed for characterizing membrane lipids and covalently modified proteins, traditional reagents and approaches have limited sensitivity, do not faithfully report on the lipids of interest, or are not readily accessible. The invention of bioorthogonal ligation reactions, such as the Staudinger ligation and azide-alkyne cycloadditions, has provided new tools to address these limitations, and their use has begun to yield fresh insight into the biology of protein lipidation and lipid trafficking. In this Account, we discuss how these new bioorthogonal ligation reactions and lipid chemical reporters afford new opportunities for exploring the biology of lipid-modified proteins and lipid trafficking. Lipid chemical reporters from our laboratory and several other research groups have enabled improved detection and large-scale proteomic analysis of fatty-acylated and prenylated proteins. For example, fatty acid and isoprenoid chemical reporters in conjunction with bioorthogonal ligation methods have circumvented the limited sensitivity and hazards of radioactive analogues, allowing rapid and robust fluorescent detection of lipidated proteins in all organisms tested. These chemical tools have revealed alterations in protein lipidation in different cellular states and are beginning to provide unique insights in mechanisms of regulation. Notably, the

  17. Lipids-based nanostructured lipid carriers (NLCs) for improved oral bioavailability of sirolimus.

    Science.gov (United States)

    Yu, Qin; Hu, Xiongwei; Ma, Yuhua; Xie, Yunchang; Lu, Yi; Qi, Jianping; Xiang, Li; Li, Fengqian; Wu, Wei

    2016-05-01

    The main purpose of this study was to improve the oral bioavailability of sirolimus (SRL), a poorly water-soluble immunosuppressant, by encapsulating into lipids-based nanostructured lipid carriers (NLCs). SRL-loaded NLCs (SRL-NLCs) were prepared by a high-pressure homogenization method with glycerol distearates (PRECIROL ATO-5) as the solid lipid, oleic acid as the liquid lipids, and Tween 80 as the emulsifier. The SRL-NLCs prepared under optimum conditions was spherical in shape with a mean particle size of about 108.3 nm and an entrapment efficiency of 99.81%. In vitro release of SRL-NLCs was very slow, about 2.15% at 12 h, while in vitro lipolysis test showed fast digestion of the NLCs within 1 h. Relative oral bioavailability of SRL-NLCs in Beagle dogs was 1.81-folds that of the commercial nanocrystalline sirolimus tablets Rapamune®. In conclusion, the NLCs show potential to improve the oral bioavailability of SRL.

  18. How proteins move lipids and lipids move proteins

    NARCIS (Netherlands)

    Sprong, H.|info:eu-repo/dai/nl/222364815; van der Sluijs, P.; van Meer, G.|info:eu-repo/dai/nl/068570368

    2001-01-01

    Cells determine the bilayer characteristics of different membranes by tightly controlling their lipid composition. Local changes in the physical properties of bilayers, in turn, allow membrane deformation, and facilitate vesicle budding and fusion. Moreover, specific lipids at specific locations

  19. Design of lipid microparticle dispersions based on the physicochemical properties of the lipid and aqueous phase.

    Science.gov (United States)

    Lauterbach, Andreas; Müller-Goymann, Christel C

    2015-10-15

    Lipid microparticle (LMP) dispersions may be utilized as novel pharmaceutical dosage forms for different administration routes. The particle size and particle size distribution of the LMPs can be classified to the most crucial specifications for therapeutical and research applications. The size parameters can be adjusted via the physicochemical properties of the inner lipid and the outer aqueous phase. In the present study, ten different solid lipids with incorporated lecithin and four concentrations of the surfactant poloxamer 407 (P407) were utilized for LMP dispersion preparation. Physicochemical properties of the bulk and dispersed lipid matrices as well as features of the P407 solutions were determined. Correlations between the mean particle size (mean) of the LMPs and the span as parameter for the particle size distribution as responses were identified by plotting against the measured physicochemical parameters. Most significant linear correlations were found between the mean and the micellization onset temperature (Tmicell) in the parent solution and the dynamic viscosity of the emulsifier solution at 25 °C and between the span and the Tmicell in the LMP dispersion. Consequently, P407 micelles as a reservoir for surfactant monomers and the overall viscosity as a separator between newly-formed lipid droplets are fundamental stabilizing parameters. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Preparation and Quality Control of Quetiapine Fumarate Solid Lipid Nanoparticles in situ Nasal Gel%富马酸喹硫平鼻用固体脂质纳米粒原位凝胶的制备及质量控制

    Institute of Scientific and Technical Information of China (English)

    李见春; 张文静; 朱娜; 张红敏; 王秀; 张劲

    2015-01-01

    OBJECTIVE:To prepare and evaluate the quality of Quetiapine fumarate solid lipid nanoparticles(QF-SLN)in situ nasal gel. METHODS:With the oil phase of dissoned glycerin monostearate,emulsifier of sorbitan oleate,and co-emulsifier of n-butyl alcohol,the proportion of emulsifier and co-emulsifier (Km) was screened by ternary phase diagrams. QF-SLN was pre-pared through the micro-emulsion technology,the gelling temperature was set as index,the mass fraction of poloxamerln 407 (P407)and P188 of in situ gel formulation was optimized by the central composite design-response surface methodology. in situ for-mation of QF-SLN was examined by transmission electron microscope,the particle size and potential distribution were determined by Malvern laser granularity equipment,and the encapsulation efficiency and stability were determined by the ultrafiltration centri-fuge tube and HPLC. RESULTS:The formulation of solid lipid nanoparticlesl was biggest at Km=1∶9. The optimized formulation was with 21% P407,5.6% P188 and 73.4% water. The prepared QF-SLN in situ nasal gel was uniform sphere,with an average particle size of (136.3 ± 6.4) nm and encapsulation efficiency of (97.60 ± 0.48)%. There were no obvious changes in the particle size and entrapment efficiency at 4℃within one month. CONCLUSIONS:The QF-SLN in situ nasal gel is successfully prepared.%目的:制备富马酸喹硫平鼻用固体脂质纳米粒(QF-SLN)原位凝胶,并进行质量控制。方法:以加热融化的单硬脂酸甘油酯为油相,油酸山梨坦为乳化剂,正丁醇为助乳化剂,通过三元相图筛选乳化剂与助乳化剂比例(Km),采用微乳法制备QF-SLN。以胶凝温度为指标,采用星点设计-效应面法优化原位凝胶处方中泊洛沙姆407(P407)、P188的质量分数。透射电镜观察所制原位凝胶的颗粒形态,马尔文粒度电位仪测定粒径大小和电位分布,超滤离心配合反相高效液相色谱法测定包封率

  1. Lipid-protein interactions in plasma membranes of fiber cells isolated from the human eye lens.

    Science.gov (United States)

    Raguz, Marija; Mainali, Laxman; O'Brien, William J; Subczynski, Witold K

    2014-03-01

    The protein content in human lens membranes is extremely high, increases with age, and is higher in the nucleus as compared with the cortex, which should strongly affect the organization and properties of the lipid bilayer portion of intact membranes. To assess these effects, the intact cortical and nuclear fiber cell plasma membranes isolated from human lenses from 41- to 60-year-old donors were studied using electron paramagnetic resonance spin-labeling methods. Results were compared with those obtained for lens lipid membranes prepared from total lipid extracts from human eyes of the same age group [Mainali, L., Raguz, M., O'Brien, W. J., and Subczynski, W. K. (2013) Biochim. Biophys. Acta]. Differences were considered to be mainly due to the effect of membrane proteins. The lipid-bilayer portions of intact membranes were significantly less fluid than lipid bilayers of lens lipid membranes, prepared without proteins. The intact membranes were found to contain three distinct lipid environments termed the bulk lipid domain, boundary lipid domain, and trapped lipid domain. However, the cholesterol bilayer domain, which was detected in cortical and nuclear lens lipid membranes, was not detected in intact membranes. The relative amounts of bulk and trapped lipids were evaluated. The amount of lipids in domains uniquely formed due to the presence of membrane proteins was greater in nuclear membranes than in cortical membranes. Thus, it is evident that the rigidity of nuclear membranes is greater than that of cortical membranes. Also the permeability coefficients for oxygen measured in domains of nuclear membranes were significantly lower than appropriate coefficients measured in cortical membranes. Relationships between the organization of lipids into lipid domains in fiber cells plasma membranes and the organization of membrane proteins are discussed.

  2. 去唾液酸糖蛋白受体介导的肝靶向纳米脂质超声造影剂的制备及体外实验%Preparation of asialoglycoprotein receptor-mediated hepatic targeting nano- lipid ultrasound contrast agent and its ultrasound imaging in vitro

    Institute of Scientific and Technical Information of China (English)

    余进洪; 王志刚; 郑元义; 项莹霞; 李奥; 李巧

    2011-01-01

    Objective To prepare the liver targeting nano-liquid perfluorocarbon ultrasound contrast agent and observe its general characteristics;to observe the targeting combined effects of the human liver cells L02 and the targeted ultrasound contrast agent ;to evaluate the gathering imaging effects of the targeted ultrasound contrast agent. Methods Amine method was used to prepared asialoglycoprotein Gal specific ligand polylysine (Gal-PLL), rotary evaporator and sonicated liquid fluorocarbon were used to prepare nano lipid ultrasound contrast agent. Human liver cell L02 were cultured, the combined effects were observed according to the reacting time of the cells and the targeted nano-lipid ultrasound contrast agent. The nanolipid ultrasound contrast agent and the degassed_ water_ were loaded into cysts and their ultrasound imaging effects were observed by ultrasound diagnostic apparatus Philips iU22. Results The particle size of the liquid fluorocarbon nano-targeted lipid ultrasound contrast agent was extremely small, uniform, cylindrical and spherical. The cysts in vitro showed that the side of the targeted liquid perfluorocarbon nano-lipid ultrasound contrast agent showed high echo. Conclusions The targeted liquid perfluorocarbon nano-lipid ultrasound contrast agent can be effectively targeted to the human liver cells L02 due to carrying home-made Gal-PLL. The targeted ultrasound contrast agents can be imaging by ultrasound and be confirmed in vitro.The size of the contrast agent was small, therefore, it can be considered an ideal ultrasonic molecular probe and achieve the ultrasound molecular imaging in cell level.%目的 以肝细胞膜特异性受体去唾液酸糖蛋白受体为靶向受体,利用共价结合的原理,制备出肝靶向性液态氟碳纳米超声造影剂,观察该造影剂的一般特性、与人肝细胞L02的靶向结合及体外聚集显像效果.方法 利用还原胺法制备去唾液酸糖蛋白特异性配体半乳糖化多聚赖氨酸(Gal

  3. Lipid Therapy for Intoxications

    NARCIS (Netherlands)

    Robben, Joris Henricus; Dijkman, Marieke Annet

    2017-01-01

    This review discusses the use of intravenous lipid emulsion (ILE) in the treatment of intoxications with lipophilic agents in veterinary medicine. Despite growing scientific evidence that ILE has merit in the treatment of certain poisonings, there is still uncertainty on the optimal composition of t

  4. Lipids in cheese

    Science.gov (United States)

    Lipids are present in cheese at levels above 20 percent and are analyzed by several techniques. Scanning electron microscopy and confocal laser scanning microscopy are used to examine the microstructure, gas chromatography is employed to look at fatty acid composition, and differential scanning cal...

  5. Lipid Therapy for Intoxications

    NARCIS (Netherlands)

    Robben, Joris Henricus; Dijkman, Marieke Annet

    2017-01-01

    This review discusses the use of intravenous lipid emulsion (ILE) in the treatment of intoxications with lipophilic agents in veterinary medicine. Despite growing scientific evidence that ILE has merit in the treatment of certain poisonings, there is still uncertainty on the optimal composition of t

  6. 星点设计-效应面法优化姜黄素正负离子纳米结构脂质载体处方%Optimization of preparation of curcumin-catanionic nanoparticles lipid carriers by central composite design-response surface methodology

    Institute of Scientific and Technical Information of China (English)

    刘碧林; 石明芯; 朱照静; 晏声蕾; 张景勍

    2016-01-01

    目的 采用星点设计-效应面法(CCD-RSM)筛选姜黄素(Cur)正负离子纳米结构脂质载体(Cur-CNLC)最佳处方.方法 采用薄膜分散-超声乳化法制备Cur-CNLC,分别以固体脂质质量(X1)、液体脂质质量(X2)、卵磷脂质量(X3)和混合表面活性剂用量(X4)为考察对象,以包封率(Y1)和脂质载药量(Y2)为考察指标,根据CCD原理和多元线性回归及二项式拟合建立指标与因素之间的数学关系,经RSM预测最优处方.结果 按最优处方制备的Cur-CNLC包封率为(94.38±2.67)%,与预测值的偏差为1.23%;脂质载药量为(6.93±0.39)%,与预测值的偏差为2.62%;平均粒径为(235.9±9.6)nm,多分散指数(PDI)为0.272±0.017,Zeta电位为(-28.40±0.35)mV.结论 采用CCD-RSM优化的Cur-CNLC,包封率高,稳定性好,方法可靠.%Objective To optimize the formulation of curcumin-catanionic nanoparticles lipid carriers (Cur-CNLC) by central composite design-response surface methodology (CCD-RSM).Methods Cur-CNLC were prepared by film dispersion-ultrasonic emulsifying method.A four factor,five-level central composite design was employed,with the solid lipid quality (X1),liquid lipid quality (X2),lecithin quality (X3),and mixed surfactant concentration (X4) as the independent variables.The dependent variables were the entrapment efficiency (Y1) and drug loading (Y2).The data were simulated using multi-linear equation and second-order polynomial equation,the possibly optimal formulation was predicted by response surface method.Results The entrapment efficiency,drug loading,average particle size,polydispersity,and Zeta potential of the Cur-CNLCs prepared under the optimized conditions were (94.38 ± 2.67)%,(6.93 ± 0.39)%,(235.9 ± 9.6) nm,0.272 ± 0.017,and (-28.40 ± 0.35) mV,respectively.The bias between the measured values and the predicted ones is less than 5%.Conclusion The CCD-RSM is effective and suitable for optimizing the formulation of Cur-CNLC.

  7. Amphotericin B Lipid Complex Injection

    Science.gov (United States)

    Amphotericin B lipid complex injection is used to treat serious, possibly life-threatening fungal infections in people who did not respond ... to tolerate conventional amphotericin B therapy. Amphotericin B lipid complex injection is in a class of medications ...

  8. Lipid nanoparticles as vehicles for topical psoralen delivery: solid lipid nanoparticles (SLN) versus nanostructured lipid carriers (NLC).

    Science.gov (United States)

    Fang, Jia-You; Fang, Chia-Lang; Liu, Chi-Hsien; Su, Yu-Han

    2008-10-01

    Solid lipid nanoparticles (SLN) were developed by using Precirol ATO 5 as the solid core of the particles for topical psoralen delivery. Nanostructured lipid carriers (NLC) consisting of Precirol and squalene, a liquid lipid, were also prepared for comparison. SLN and NLC showed respective mean particle sizes of approximately 300 and 200nm, respectively. Viscosity, polarity, and differential scanning calorimetry (DSC) studies were performed to characterize the physicochemical properties of the SLN and NLC. The viscosity of all nanoparticulate systems exhibited Newtonian behavior except the NLC with Tween 80 and soybean phospholipids as the emulsifiers (NLC-Tw). According to the DSC thermograms, the melting peak of Precirol shifted from 58 to 55 degrees C after incorporating squalene into the solid lipid cores (of NLC), which suggests defects in the crystalline lattice of the lipid cores and smaller particle sizes. Three psoralen derivatives for psoriasis treatments were loaded in SLN and NLC to examine their ability to permeate skin. The permeability of psoralens increased in the order of 8-methoxypsoralen (8-MOP)>5-methoxypsoralen (5-MOP)>4,5,8-trimethylpsoralen (TMP). Enhanced permeation and controlled release of psoralen delivery were both achieved using the NLC. The in vitro permeation results showed that NLC-Tw increased the 8-MOP flux 2.8 times over that of a conventional emulsion. Hyperproliferative or psoriasis-like skin produced by repeated strippings in the dorsal skin of nude mouse was also used as a permeation barrier. The results showed that the entrapment of 8-MOP in nanoparticulate systems could minimize the permeation differentiation between normal and hyperproliferative skin compared to the free drug in an aqueous control.

  9. Optimization of 5-fluorouracil solid-lipid nanoparticles: a preliminary study to treat colon cancer

    OpenAIRE

    Alaa Eldeen B. Yassin, Md. Khalid Anwer, Hammam A. Mowafy, Ibrahim M. El-Bagory, Mohsen A. Bayomi, Ibrahim A. Alsarra

    2010-01-01

    Solid lipid nanoparticle (SLNs) formulae were utilized for the release of 5-fluorouracil (5-FU) inside the colonic medium for local treatment of colon cancer. SLNs were prepared by double emulsion-solvent evaporation technique (w/o/w) using triglyceride esters, Dynasan™ 114 or Dynasan™ 118 along with soyalecithin as the lipid parts. Different formulation parameters; including type of Dynasan, soyalicithin:Dynasan ratio, drug:total lipid ratio, and polyvinyl alcohol (PVA) concentra...

  10. Optimization of 5-flurouracil solid-lipid nanoparticles: a preliminary study to treat colon cancer

    OpenAIRE

    Yassin, Alaa Eldeen B; Anwer, Md. Khalid; Mowafy, Hammam A.; El-Bagory, Ibrahim M.; Bayomi, Mohsen A.; Ibrahim A. Alsarra

    2010-01-01

    Solid lipid nanoparticle (SLNs) formulae were utilized for the release of 5-flurouracil (5-FU) inside the colonic medium for local treatment of colon cancer. SLNs were prepared by double emulsion-solvent evaporation technique (w/o/w) using triglyceride esters, Dynasan™ 114 or Dynasan™ 118 along with soyalecithin as the lipid parts. Different formulation parameters; including type of Dynasan, soyalicithin:Dynasan ratio, drug:total lipid ratio, and polyvinyl alcohol (PVA) concentration were stu...

  11. Lipid nanotube or nanowire sensor

    Science.gov (United States)

    Noy, Aleksandr; Bakajin, Olgica; Letant, Sonia; Stadermann, Michael; Artyukhin, Alexander B.

    2009-06-09

    A sensor apparatus comprising a nanotube or nanowire, a lipid bilayer around the nanotube or nanowire, and a sensing element connected to the lipid bilayer. Also a biosensor apparatus comprising a gate electrode; a source electrode; a drain electrode; a nanotube or nanowire operatively connected to the gate electrode, the source electrode, and the drain electrode; a lipid bilayer around the nanotube or nanowire, and a sensing element connected to the lipid bilayer.

  12. Lanolin-derived lipid mixtures mimic closely the lipid composition and organization of vernix caseosa lipids.

    Science.gov (United States)

    Rissmann, Robert; Oudshoorn, Marion H M; Kocks, Elise; Hennink, Wim E; Ponec, Maria; Bouwstra, Joke A

    2008-10-01

    The aim of the present study was to use semi-synthetic lipid mixtures to mimic the complex lipid composition, organization and thermotropic behaviour of vernix caseosa (VC) lipids. As VC shows multiple protecting and barrier supporting properties before and after birth, it is suggested that a VC substitute could be an innovative barrier cream for barrier deficient skin. Lanolin was selected as the source of the branched chain sterol esters and wax esters--the main lipid classes of VC. Different lipid fractions were isolated from lanolin and subsequently mixed with squalene, triglycerides, cholesterol, ceramides and fatty acids to generate semi-synthetic lipid mixtures that mimic the lipid composition of VC, as established by high-performance thin-layer chromatography. Differential scanning calorimetry and Fourier transform infrared spectroscopy investigations revealed that triglycerides play an important role in the (lateral) lipid organization and thermotropic behaviour of the synthetic lipid mixtures. Excellent resemblance of VC lipids was obtained when adding unsaturated triglycerides. Moreover, these lipid mixtures showed similar long range ordering as VC. The optimal lipid mixture was evaluated on tape-stripped hairless mouse skin in vivo. The rate of barrier recovery was increased and comparable to VC lipid treatment.

  13. Lipid characterization of human saliva.

    Science.gov (United States)

    Defagó, Maria Daniela; Valentich, Mirta Ana; Actis, Adriana Beatriz

    2011-12-01

    Salivary lipids have been scarcely studied, and the reported results present disparities. This literature review is presented based on the importance of saliva as a diagnostic and/or prognostic medium for various diseases, its lipid content, and on its potential use for the analysis of nutritional markers that contribute to the study of diseases related to lipid consumption and metabolism.

  14. Solid lipid nanoparticles suspension versus commercial solutions for dermal delivery of minoxidil.

    Science.gov (United States)

    Padois, Karine; Cantiéni, Céline; Bertholle, Valérie; Bardel, Claire; Pirot, Fabrice; Falson, Françoise

    2011-09-15

    Solid lipid nanoparticles have been reported as possible carrier for skin drug delivery. Solid lipid nanoparticles are produced from biocompatible and biodegradable lipids. Solid lipid nanoparticles made of semi-synthetic triglycerides stabilized with a mixture of polysorbate and sorbitan oleate were loaded with 5% of minoxidil. The prepared systems were characterized for particle size, pH and drug content. Ex vivo skin penetration studies were performed using Franz-type glass diffusion cells and pig ear skin. Ex vivo skin corrosion studies were realized with a method derived from the Corrositex(®) test. Solid lipid nanoparticles suspensions were compared to commercial solutions in terms of skin penetration and skin corrosion. Solid lipid nanoparticles suspensions have been shown as efficient as commercial solutions for skin penetration; and were non-corrosive while commercial solutions presented a corrosive potential. Solid lipid nanoparticles suspensions would constitute a promising formulation for hair loss treatment. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. New research on development of solid lipid nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To review the latest research development of the solid lipid nanoparticles (SLN) according to the recent relevant literatures. Each preparations of the SLN have advantages and disadvantages. Among the total preparations of the SLN, the high pressure homogenization (HPH) and the microemulsion technique are to praise highly. The drug incorporation and release profiles could be modified as adjustment of production parameters. The SLN is an excellent drug delivery system and has broad prospects in the pharmaceutical field.

  16. Lipid domains in bicelles containing unsaturated lipids and cholesterol.

    Science.gov (United States)

    Cho, Hyo Soon; Dominick, Johnna L; Spence, Megan M

    2010-07-22

    We have created a stable bicelle system capable of forming micrometer-scale lipid domains that orient in a magnetic field, suitable for structural biology determination in solid-state NMR. The bicelles consisted of a mixture of cholesterol, saturated lipid (DMPC), and unsaturated lipid (POPC), a mixture commonly used to create domains in model membranes, along with a short chain lipid (DHPC) that allows formation of the bicelle phase. While maintaining a constant molar ratio of long to short chain lipids, q = ([POPC]+[DMPC])/[DHPC] = 3, we varied the concentrations of the unsaturated lipid, POPC, and cholesterol to observe the effects of the components on bicelle stability. Using (31)P solid-state NMR, we observed that unsaturated lipids (POPC) greatly destabilized the alignment of the membranes in the magnetic field, while cholesterol stabilized their alignment. By combining cholesterol and unsaturated lipids in the bicelles, we created membranes aligning uniformly in the magnetic field, despite very high concentrations of unsaturated lipids. These bicelles, with high concentrations of both cholesterol and unsaturated lipid, showed similar phase behavior to bicelles commonly used in structural biology, but aligned over a wider temperature range (291-314 K). Domains were observed by measuring time-dependent diffusion constants reflecting restricted diffusion of the lipids within micrometer-scale regions of the bicelles. Micron-scale domains have never been observed in POPC/DMPC/cholesterol vesicles, implying that bilayers in bicelles show different phase behavior than their counterparts in vesicles, and that bilayers in bicelles favor domain formation.

  17. Stability of lipid excipients in solid lipid nanoparticles.

    Science.gov (United States)

    Radomska-Soukharev, Anna

    2007-07-10

    The paper is devoted to the investigation of chemical stability of lipids used as excipients in the production of Solid Lipid Nanoparticles (SLN). Different lipids and amounts of surfactants were considered. Most of the formulations were produced using identical binary surfactant mixtures and concentrations to analyze the effect of the chemical nature of the lipids on their stability in SLN. In some formulations, surfactants were exchanged or their concentration was increased to assess the contribution of surfactants on stability of lipids particles. Solid Lipid Nanoparticles were characterized by photon correlation spectroscopy, laser diffractometry, zeta potential determination and differential scanning calorimetry. Potential effects of lipid crystallinity and modifications were assessed. A gas chromatography (GC) analysis in combination with a method for lipid extraction from aqueous SLN dispersions was used to investigate the chemical stability of the lipid excipients forming the particle matrix. All formulations were produced by the hot homogenization technique. The production process of SLN itself did not affect the chemical stability of lipid excipient forming the particle matrix. The formulations where lipids consisted of trigylicerides showed a negligible decomposition of the structure during incubation at 25 degrees C. Dynasan 118 showed the highest chemical stability (loss<4%) within two years.

  18. An oral delivery system for indomethicin engineered from cationic lipid emulsions and silica nanoparticles

    DEFF Research Database (Denmark)

    Simovic, Spomenka; Hui, He; Song, Yunmei;

    2010-01-01

    We report on a porous silica-lipid hybrid microcapsule (SLH) oral delivery system for indomethacin fabricated from Pickering emulsion templates, where the drug forms an electrostatic complex with cationic lipid present in the oil phase. Dry SLH microcapsules prepared either by spray drying...

  19. Cation permeability of liposomes as a function of the chemical composition of the lipid bilayers

    NARCIS (Netherlands)

    Scarpa, A.; Gier, J. de

    1971-01-01

    1. 1.|Comparable liposome preparations were obtained from lipids differing in degree of unsaturation and cholesterol content. 2. 2.|An exchange between alkali ions and protons through the bilayers was induced by replacing the alkali ions on the one side of the outer lipid membrane by impermeable

  20. Cationic lipids delay the transfer of plasmid DNA to lysosomes.

    Science.gov (United States)

    Wattiaux, R; Jadot, M; Laurent, N; Dubois, F; Wattiaux-De Coninck, S

    1996-10-14

    Plasmid 35S DNA, naked or associated with different cationic lipid preparations was injected to rats. Subcellular distribution of radioactivity in the liver one hour after injection, was established by centrifugation methods. Results show that at that time, 35S DNA has reached lysosomes. On the contrary, when 35S DNA was complexed with lipids, radioactivity remains located in organelles whose distribution after differential and isopycnic centrifugation, is clearly distinct from that of arylsulfatase, lysosome marker enzyme. Injection of Triton WR 1339, a specific density perturbant of lysosomes, four days before 35S DNA injection causes a density decrease of radioactivity bearing structures, apparent one hour after naked 35S DNA injection but visible only after more than five hours, when 35S DNA associated with a cationic lipid is injected. These observations show that cationic lipids delay the transfer to lysosomes, of plasmid DNA taken up by the liver.

  1. Polyglutamine expansion in huntingtin increases its insertion into lipid bilayers.

    Science.gov (United States)

    Kegel, Kimberly B; Schewkunow, Vitali; Sapp, Ellen; Masso, Nicholas; Wanker, Erich E; DiFiglia, Marian; Goldmann, Wolfgang H

    2009-09-25

    An expanded polyglutamine (Q) tract (>37Q) in huntingtin (htt) causes Huntington disease. Htt associates with membranes and polyglutamine expansion in htt may alter membrane function in Huntington disease through a mechanism that is not known. Here we used differential scanning calorimetry to examine the effects of polyQ expansion in htt on its insertion into lipid bilayers. We prepared synthetic lipid vesicles composed of phosphatidylcholine and phosphatidylethanolamine and tested interactions of htt amino acids 1-89 with 20Q, 32Q or 53Q with the vesicles. GST-htt1-89 with 53Q inserted into synthetic lipid vesicles significantly more than GST-htt1-89 with 20Q or 32Q. We speculate that by inserting more into cell membranes, mutant huntingtin could increase disorder within the lipid bilayer and thereby disturb cellular membrane function.

  2. Preparation of Oridonin long-circulating solid lipid nanoparticle and its inhibitory effect on SGC-7901 cells%冬凌草甲素长循环固体脂质纳米粒的制备及对人胃癌SGC-7901细胞的抑制作用

    Institute of Scientific and Technical Information of China (English)

    陈莹; 李岩; 蔡爽

    2013-01-01

    目的 制备冬凌草甲素长循环固体脂质纳米粒(ORI-LSLN),并考察其理化性质和对人胃癌SGC-7901细胞的抑制作用.方法 采用熔融均质法制备ORI-LSLN,并对其形态、粒径分布、电位、包封率和载药量等性质进行考察.以冬凌草甲素溶液(ORI)、冬凌草甲素固体脂质纳米粒(ORI-SLN)为对照,进行ORI-LSLN体外释放试验.采用MTT法测定ORI-LSLN对人胃癌SGC-7901细胞的抑制作用.结果 制备的ORI-LSLN呈类球形,平均粒径112 nm,Zeta电位为-31.6 mV,包封率为90.4%,载药量为5.1%.体外释放结果表明,ORI-SLN和ORI-LSLN在释放初期并无显著区别,后期ORI-SLN释放较快,24 h基本释放完全,而ORI-SLN则需要36 h才完全释放,表现了更好的缓释效果.ORI-LSLN对人胃癌SGC-7901细胞具有较强的毒性作用.结论 熔融均质法制备的ORI-LSLN包封率高、载药量大,工艺易于工业化,与ORI-SLN相比,ORI-LSLN更具有较好的抗癌药物缓释制剂潜力.%Objective To prepare Oridonin-loaded long-circulating solid lipid nanoparticles (ORI-LSLN),and investigate its physic-chemical properties and the anticancer effect on human stomach SGC-7901 cells in vitro.Methods ORI-LSLN was prepared by melt emulsification and high-pressure homogenization method.The properties of ORI-LSLN such as morphology,particle size,Zeta potential,entrapment efficiency,drug loading were evaluated.ORI solution and Oridonin-loaded solid lipid nanoparticles (ORI-SLN) were taken as controls to carry out release test in vitro.MTT method was used to detect the inbibitional effect of ORI-LSLN on SGC-7901 cells.Results ORI-LSLN was spherical under transmission electron microscopy (TEM),the mean particle size,Zeta potential,entrapment efficiency and drug loading were 112 nm,-31.6 mV,90.4% and 5.1%,respectively.The release results showed that both ORI-LSLN and ORI-SLN had burst release in the initial period.ORI-LSLN nearly full release at 36 h and exhibiting a better

  3. Probing lipid mobility of raft-exhibiting model membranes by fluorescence correlation spectroscopy

    NARCIS (Netherlands)

    Kahya, N; Scherfeld, D; Bacia, K; Poolman, B; Schwille, P

    2003-01-01

    Confocal fluorescence microscopy and fluorescence correlation spectroscopy (FCS) have been employed to investigate the lipid spatial and dynamic organization in giant unilamellar vesicles (GUVs) prepared from ternary mixtures of dioleoyl-phosphatidylcholine/sphingomyelin/ cholesterol. For a certain

  4. Biosensor for dopamine based on stabilized lipid films with incorporated resorcin[4]arene receptor.

    Science.gov (United States)

    Nikolelis, Dimitrios P; Theoharis, George

    2003-04-01

    This work reports a technique for the stabilization after storage in air of a lipid film with incorporated resorcin[4]arene receptor based biosensor for dopamine. Microporous filters composed of glass fibers (nominal pore sizes, 0.7 and 1.0 microm) were used as supports for the formation and stabilization of these devices and the lipid film is formed on the filter by polymerization prior its use. Methacrylic acid was the functional monomer, ethylene glycol dimethacrylate was the crosslinker and 2,2'-azobis-(2-methylpropionitrile) was the initiator. The stability of the lipid films by incorporation of a receptor for the preparation of stabilized lipid film biosensor is studied throughout this work. The response towards dopamine of the present stabilized for repetitive uses lipid membrane biosensor composed of dipalmitoyl phosphatidylcholine and dipalmitoyl phosphatidic acid was compared with planar freely suspended bilayer lipid membranes (BLMs). The stabilized lipid membranes provided similar artificial ion gating events as BLMs in the form of transient signals and can function for repetitive uses after storage in air. However, the response of the stabilized lipid films was slower than that of the freely suspended BLMs. This will allow the practical use of the techniques for chemical sensing based on lipid films and commercialization of these devices, because it is now possible to prepare stabilized lipid film based biosensors and store them in the air.

  5. Dysregulated lipid metabolism in cancer

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Alteration of lipid metabolism has been increasingly recognized as a hallmark of cancer cells. The changes of expression and activity of lipid metabolizing enzymes are directly regulated by the activity of oncogenic signals. The dependence of tumor cells on the dysregulated lipid metabolism suggests that proteins involved in this process are excellent chemotherapeutic targets for cancer treatment. There are currently several drugs under development or in clinical trials that are based on specifically targeting the altered lipid metabolic pathways in cancer cells. Further understanding of dysregulated lipid metabolism and its associated signaling pathways will help us to better design efficient cancer therapeutic strategy.

  6. Lipids and immune function.

    Science.gov (United States)

    Vitale, J J; Broitman, S A

    1981-09-01

    There is in vitro and in vivo evidence to suggest that dietary lipids play a role in modulating immune function. A review of the current literature on the interrelationships among dietary lipids, blood cholesterol levels, immunosuppression, and tumorigenesis makes for a very strong argument that (a) immunosuppression may be causally related to lymphoproliferative disorders, as well as to tumorigenesis and (b) diets high in polyunsaturated fat, relative to diets high in saturated fat, are more immunosuppressive and are better promotors of tumorigenesis. The effects of dietary fat on immune function seem to be mediated though its component parts, the unsaturated fatty acids, specially linoleic, linolenic, and arachidonic. It is not clear how these components affect immune function. Several studies suggest that one effect is mediated by altering the lipid component of the cell membrane and thus its fluidity; the more fluid the membrane, the less responsive it is. Thus, fluidity of both immune cells and those to be destroyed or protected may be affected. The effects of saturated as well as unsaturated fatty acids may be mediated by modulating serum lipoprotein levels, prostaglandin metabolism, and cholesterol concentrations and metabolism.

  7. Tear Film Lipids

    Science.gov (United States)

    Butovich, Igor A.

    2013-01-01

    Human meibomian gland secretions (MGS, or meibum) are formed from a complex mixture of lipids of different classes such as wax esters, cholesteryl esters, (O-acyl)-ω-hydroxy fatty acids (OAHFA) and their esters, acylglycerols, diacylated diols, free fatty acids, cholesterol, and a smaller amount of other polar and nonpolar lipids, whose chemical nature and the very presence in MGS have been a matter of intense debates. The purpose of this review is to discuss recent results that were obtained using different experimental techniques, estimate limitations of their usability, and discuss their biochemical, biophysical, and physiological implications. To create a lipid map of MGS and tears, the results obtained in the author’s laboratory were integrated with available information on chemical composition of MGS and tears. The most informative approaches that are available today to researchers, such as HPLC-MS, GC-MS, and proton NMR, are discussed in details. A map of the meibomian lipidome (as it is seen in reverse phase liquid chromatography/mass spectrometry experiments) is presented. Directions of future efforts in the area are outlined. PMID:23769846

  8. Nanostructured Lipid Carriers Loaded with Baicalin: An Efficient Carrier for Enhanced Antidiabetic Effects

    OpenAIRE

    Feng Shi; Zheng Wei; Yingying Zhao; Ximing Xu

    2016-01-01

    Context: Recent studies have demonstrated that baicalin has antihyperglycemic effects by inhibiting lipid peroxidation. Baicalin is low hydrophilic and poorly absorbed after oral administration. Thus, a suitable formulation is highly desired to overcome the disadvantages of baicalin. Objective: The objective of this work was to prepare baicalin-loaded nanostructured lipid carriers (B-NLCs) for enhanced antidiabetic effects. Materials and Methods: B-NLCs were prepared by high-pressure homogeni...

  9. CIDE proteins and lipid metabolism.

    Science.gov (United States)

    Xu, Li; Zhou, Linkang; Li, Peng

    2012-05-01

    Lipid homeostasis is maintained through the coordination of lipid metabolism in various tissues, including adipose tissue and the liver. The disruption of lipid homeostasis often results in the development of metabolic disorders such as obesity, diabetes mellitus, liver steatosis, and cardiovascular diseases. Cell death-inducing DNA fragmentation factor 45-like effector family proteins, including Cidea, Cideb, and Fsp27 (Cidec), are emerging as important regulators of various lipid metabolic pathways and play pivotal roles in the development of metabolic disorders. This review summarizes the latest cell death-inducing DNA fragmentation factor 45-like effector protein discoveries related to the control of lipid metabolism, with emphasis on the role of these proteins in lipid droplet growth in adipocytes and in the regulation of very low-density lipoprotein lipidation and maturation in hepatocytes.

  10. Effect of sterilization on the physical stability of brimonidine-loaded solid lipid nanoparticles and nanostructured lipid carriers.

    Science.gov (United States)

    El-Salamouni, Noha S; Farid, Ragwa M; El-Kamel, Amal H; El-Gamal, Safaa S

    2015-12-30

    Nanoparticulate delivery systems have recently been under consideration for topical ophthalmic drug delivery. Brimonidine base-loaded solid lipid nanoparticles and nanostructured lipid carrier formulations were prepared using glyceryl monostearate as solid lipid and were evaluated for their physical stability following sterilization by autoclaving at 121°C for 15min. The objective of this work was to evaluate the effect of autoclaving on the physical appearance, particle size, polydispersity index, zeta potential, entrapment efficiency and particle morphology of the prepared formulations, compared to non-autoclaved ones. Results showed that, autoclaving at 121°C for 15min allowed the production of physically stable formulations in nanometric range, below 500nm suitable for ophthalmic application. Moreover, the autoclaved samples appeared to be superior to non-autoclaved ones, due to their increased zeta potential values, indicating a better physical stability. As well as, increased amount of brimonidine base entrapped in the tested formulations.

  11. Effect of compound preparation of common yam rhizome and balsampear fruit on blood glucose and lipid in rats with type 2 diabetes mellitus%山药苦瓜复方制剂降低2型糖尿病大鼠血糖和血脂的实

    Institute of Scientific and Technical Information of China (English)

    张志平; 邹丽宜; 吴铁; 尤婷婷; 吴怡

    2006-01-01

    BACKGROUND: Chinese herbs of common yam rhizome, balsampear fruit and bagasse fiber have good effects on decreasing blood glucose and lipid, but its mechanism is unclear.OBJECTIVE: To observe the effect of compound preparation of common yam rhizome and balsampear fruit on blood glucose, lipid, blood insulin and anti-infection of rats with type 2 diabetes mellitus (DM).DESIGN: Randomized controlled animal study.SETTING: Technological Developing Center, Pharmacological Department, Experimental Animal Center, and Central Laboratory of Guangdong Medical College.MATERIALS: A total of 80 female SD rats with 4 months old and of SPF grade were selected in this study. Flumamine (Jilin Dongbeiya Pharmaceutical Co., Ltd., batch number: 040126); total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and triacylglycerol (TG) (Beijing Zhongsheng Biotechnological Co. Ltd.); Surestep Life scan blood glucose meter and test paper (Johnson Company, USA); insulin radio-immunity kit (Shanghai Navy Medical Institute); UV-3010 ultraviolet spectrophotometer (Japan Shimadzu); compound preparation of common yam rhizome and balsampear fruit (Technological Developing Center of Guangdong Medical College, batch number: 040321); suspension was extracted from common yam rhizome, balsampear fruit and dietary fiber of bagasse through water with 1 kg/L raw materials.METHODS: Animal breeding and samples collecting were carried out in the Experimental Animal Center and Technological Developing Central Laboratory of Guangdong Medical College from June 2004 to December 2005; meanwhile, detection of marker was carried out in the Pharmacological Department and Central Laboratory of Guangdong Medical College. ①Twenty rats were randomly selected as normal control group and perfused with 5 mL/kg saline every day. Other 60 rats were perfused with 5 mL/kg fat emulsion once a day for 4 weeks, and then, rats were fasted for 12hours and peritoneally injected with 2 g/L streptozotocin (30 mg

  12. Ketone-body utilization and lipid synthesis by developing rat brain—a comparison between in vivo and in vitro experiments

    NARCIS (Netherlands)

    Klein, W.; Lopes-Cardozo, M.

    1984-01-01

    The distribution of ketone bodies between oxidation and lipid synthesis was analysed in homogenates of developing rat brain. The capacity for lipid synthesis of homogenized or minced brain preparations was compared with rates of lipid synthesis in vivo, assessed by incorporation of ³H from

  13. Ketone-body utilization and lipid synthesis by developing rat brain—a comparison between in vivo and in vitro experiments

    NARCIS (Netherlands)

    Klein, W.; Lopes-Cardozo, M.

    1984-01-01

    The distribution of ketone bodies between oxidation and lipid synthesis was analysed in homogenates of developing rat brain. The capacity for lipid synthesis of homogenized or minced brain preparations was compared with rates of lipid synthesis in vivo, assessed by incorporation of ³H from ³H20 into

  14. Lipid nanocarriers: influence of lipids on product development and pharmacokinetics.

    Science.gov (United States)

    Pathak, Kamla; Keshri, Lav; Shah, Mayank

    2011-01-01

    Lipid nanocarriers are on the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery. Owing to their size-dependent properties, lipid nanoparticles offer the possibility for development of new therapeutics and an alternative system to other colloidal counterparts for drug administration. An important point to be considered in the selection of a lipid for the carrier system is its effect on the properties of the nanocarrier and also its intended use, as different types of lipids differ in their nature. Researchers around the globe have tapped the potential of solid lipid nanoparticles (SLNs) in developing formulation(s) that can be administered by various routes such as oral, ocular, parenteral, topical, and pulmonary. Since the start of this millennium, a new generation of lipid nanoparticles, namely nanostructured lipid carriers (NLCs), lipid drug conjugates (LDCs), and pharmacosomes, has evolved that have the potential to overcome the limitations of SLNs. The current review article presents broad considerations on the influence of various types of lipids on the diverse characteristics of nanocarriers, encompassing their physicochemical, formulation, pharmacokinetic, and cytotoxic aspects.

  15. Deposition of Thin Lipid Films Prepared by Electrospraying

    NARCIS (Netherlands)

    Khan, M.K.I.; Mujawar, L.H.; Schutyser, M.A.I.; Schroën, C.G.P.H.; Boom, R.M.

    2013-01-01

    An efficient way to apply coatings on complex surfaces is electrospraying. We report on coating of porous model surfaces with well-defined properties using a multiple nozzle electrospraying system to spray sunflower oil and butter-based coating materials. Selected model surfaces were nickel membrane

  16. Lipides polaires marins

    OpenAIRE

    Fanni Jacques; Linder Michel; Parmentier Michel

    2004-01-01

    Les lipides polaires marins, notamment les phospholipides (PL), retiennent depuis quelques années l’attention des chercheurs et des industriels en raison de leur composition, particulièrement riche en acides gras polyinsaturés à longue chaîne (AGPI-LC). Ils combinent ainsi les propriétés reconnues des AGPI-LC à l’intérêt métabolique et structural des phospholipides. Les sources sont nombreuses et d’accès très diversifié. Le défi industriel provient de leurs caractéristiques amphiphiles et aro...

  17. Chlorosome lipids from Chlorobium tepidum

    DEFF Research Database (Denmark)

    Sørensen, Peder Grove; Cox, Raymond Pickett; Miller, Mette

    2008-01-01

    We have extracted polar lipids and waxes from isolated chlorosomes from the green sulfur bacterium Chlorobium tepidum and determined the fatty acid composition of each lipid class. Polar lipids amounted to 4.8 mol per 100 mol bacteriochlorophyll in the chlorosomes, while non-polar lipids (waxes......) were present at a ratio of 5.9 mol per 100 mol bacteriochlorophyll. Glycolipids constitute 60 % of the polar lipids while phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, and an aminoglycosphingolipid make up respectively 15, 3, 8 and 12 %. A novel glycolipid was identified...... as a rhamnose derivative of monogalactosyldiacylglycerol, while the other major glycolipid was monogalactosyldiacylglycerol. Tetradecanoic acid was the major fatty acid in the aminoglycosphingolipid, while the other polar lipids contained predominantly hexandecanoic acid. The chlorosome waxes are esters...

  18. Texture of lipid bilayer domains

    DEFF Research Database (Denmark)

    Jensen, Uffe Bernchou; Brewer, Jonathan R.; Midtiby, Henrik Skov

    2009-01-01

    chains. By imaging the intensity variations as a function of the polarization angle, we map the lateral variations of the lipid tilt within domains. Results reveal that gel domains are composed of subdomains with different lipid tilt directions. We have applied a Fourier decomposition method......We investigate the texture of gel (g) domains in binary lipid membranes composed of the phospholipids DPPC and DOPC. Lateral organization of lipid bilayer membranes is a topic of fundamental and biological importance. Whereas questions related to size and composition of fluid membrane domain...... are well studied, the possibility of texture in gel domains has so far not been examined. When using polarized light for two-photon excitation of the fluorescent lipid probe Laurdan, the emission intensity is highly sensitive to the angle between the polarization and the tilt orientation of lipid acyl...

  19. Multivariate design for the evaluation of lipid and surfactant composition effect for optimisation of lipid nanoparticles.

    Science.gov (United States)

    Martins, Susana; Tho, Ingunn; Souto, Eliana; Ferreira, Domingos; Brandl, Martin

    2012-04-11

    Physicochemical properties of lipid nanoparticles (LN), such as size, size distribution and surface charge, have a major influence both, on in vitro stability and delivery of the incorporated drug in vivo. With the purpose of understanding how these properties are influenced by variations of LN composition (e.g. lipid and surfactant type and concentration) 2(2) factorial designs with centre point were applied for several types of lipids and surfactants in the present study. Tested factors and levels were the type and concentration of lipid (cetyl palmitate, Dynasan 114 and Witepsol E85) at the concentrations of 5%, 10% and 15%, in combination with type and concentration of surfactant (polysorbate 20, 40, 60 and 80 and poloxamer 188 and 407) at concentrations of 0.8%, 1.2% and 2.0%. Responses measured within the design space were the mean size and polydispersity index (photon correlation spectroscopy), content of microparticles (optical single particle sizing), macroscopic appearance, pH and zeta potential on the day of production, 1 and 2 years after production. Multivariate evaluation and modelling were performed starting with a principal component analysis (PCA) and followed by partial least square regression analysis (PLS) to assess both qualitative and quantitative influence of the investigated factors in the LN. Our study showed that both, lipid and surfactant concentration and the type of surfactant are crucial parameters for the particle size of the LN prepared by high pressure homogenisation (HPH). For LN stability during 2 years both, lipid and surfactant types and concentrations were identified as the most relevant parameters. Among the surfactants most suitable for producing LN with small sizes were the polysorbates and the lipid yielding best storage stability was cetyl palmitate. Furthermore, the models allowed the prediction of the mean size of LN that could be achieved with a certain lipid/surfactant combination and concentration. The obtained

  20. DEVELOPMENT OF NOVEL LIPID BASED DRUG DELIVERY SYSTEM FOR RALOXIFENE HYDROCHLORIDE

    Directory of Open Access Journals (Sweden)

    Vijaykumar Nekkanti

    2012-09-01

    Full Text Available Lipid-based delivery systems are becoming increasingly popular as carriers of drugs due to their ability to overcome barriers to oral absorption. The objective of the present study was to prepare novel lipid-based formulation of a sparingly soluble drug, Raloxifene hydrochloride (RLX to increase its saturation solubility and dissolution velocity for enhancing bioavailability while reducing systemic variability. Lipid-based formulations were prepared using melt solubilization technique. The liquid formulations were converted into a solid intermediate by adsorbing onto an inert carrier and blended with excipients for encapsulation. The solid state properties, surface morphology and in-vitro release characteristics of the lipid formulations were investigated and compared with commercial formulation. The characterization of lipid formulations using Differential scanning calorimetry (DSC, X-ray powder diffraction (XRPD and Scanning electron microscopy (SEM indicated that the drug is completely enveloped in the lipid core. The dissolution characteristics of lipid based formulation filled in hard gelatin capsules showed faster rate of drug dissolution as compared to commercial tablet formulation (Fiona®. The in-vitro release studies in fed state simulated intestinal fluid (FeSSIF and fasted state simulated intestinal fluid (FaSSIF media indicated that, the variability in fed and fasted conditions was significantly reduced with lipid based formulation. The results from this study suggest the potential use of lipid based formulation a means of improving solubility, dissolution and concomitantly the bioavailability of a sparingly soluble drug like RLX.

  1. Lipids and membrane lateral organization

    Directory of Open Access Journals (Sweden)

    Sandro eSonnino

    2010-11-01

    Full Text Available Shortly after the elucidation of the very basic structure and properties of cellular membranes, it became evident that cellular membranes are highly organized structures with multiple and multi-dimensional levels of order. Very early observations suggested that the lipid components of biological membranes might be active players in the creations of these levels of order. In the late 80’s, several different and diverse experimental pieces of evidence coalesced together giving rise to the lipid raft hypothesis. Lipid rafts became enormously (and, in the opinion of these authors, sometimes acritically popular, surprisingly not just within the lipidologist community (who is supposed to be naturally sensitive to the fascination of lipid rafts. Today, a PubMed search using the key word lipid rafts returned a list of 3767 papers, including 690 reviews (as a term of comparison, searching over the same time span for a very hot lipid-related key word, ceramide returned 6187 hits with 799 reviews, and a tremendous number of different cellular functions have been described as lipid raft-dependent. However, a clear consensus definition of lipid raft has been proposed only in recent times, and the basic properties, the ruling forces, and even the existence of lipid rafts in living cells have been recently matter of intense debate. The scenario that is gradually emerging from the controversies elicited by the lipid raft hypothesis emphasize multiple roles for membrane lipids in determining membrane order, that encompasses their tendency to phase separation but are clearly not limited to this. In this review, we would like to re-focus the attention of the readers on the importance of lipids in organizing the fine structure of cellular membranes.

  2. Absorption Of Dietary Lipid Components

    OpenAIRE

    Abdulkadir Hurşit

    2015-01-01

    Although the digestion and absorption of lipids that are necessary for the survival of living organisms are well known in general terms, nevertheless how different lipids to be digested, how it is distributed into the bloodstream, and how to be used by the cells, are unknown issues by most non specialist people. In recent years, knowledge of lipid digestion and absorption has expanded considerably. More insight has been gained in the mechanism of action of H + pump as a transport system in fa...

  3. Drug release mechanisms of compressed lipid implants.

    Science.gov (United States)

    Kreye, F; Siepmann, F; Siepmann, J

    2011-02-14

    The aim of this study was to elucidate the mass transport mechanisms controlling drug release from compressed lipid implants. The latter steadily gain in importance as parenteral controlled release dosage forms, especially for acid-labile drugs. A variety of lipid powders were blended with theophylline and propranolol hydrochloride as sparingly and freely water-soluble model drugs. Cylindrical implants were prepared by direct compression and thoroughly characterized before and after exposure to phosphate buffer pH 7.4. Based on the experimental results, an appropriate mathematical theory was identified in order to quantitatively describe the resulting drug release patterns. Importantly, broad release spectra and release periods ranging from 1 d to several weeks could easily be achieved by varying the type of lipid, irrespective of the type of drug. Interestingly, diffusion with constant diffusivities was found to be the dominant mass transport mechanism, if the amount of water within the implant was sufficient to dissolve all of the drug. In these cases an analytical solution of Fick's second law could successfully describe the experimentally measured theophylline and propranolol hydrochloride release profiles, even if varying formulation and processing parameters, e.g. the type of lipid, initial drug loading, drug particles size as well as compression force and time. However, based on the available data it was not possible to distinguish between drug diffusion control and water diffusion control. The obtained new knowledge can nevertheless significantly help facilitating the optimization of this type of advanced drug delivery systems, in particular if long release periods are targeted, which require time consuming experimental trials.

  4. Solution preparation

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, M.G.

    1982-01-01

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results.

  5. In vitro digestion of curcuminoid-loaded lipid nanoparticles

    Science.gov (United States)

    Noack, Andreas; Oidtmann, Johannes; Kutza, Johannes; Mäder, Karsten

    2012-09-01

    Curcuminoid-loaded lipid nanoparticles were produced by melt homogenization. The used lipid matrices were medium chain triglycerides, trimyristin (TM), and tristearin. The mean particle size of the preparations was between 130 and 180 nm. The incorporated curcuminoids revealed a good stability over a period of 12 months. The curcuminoid-loaded lipid nanoparticles were intended for the oral delivery of curcuminoids. Therefore, the fate of the triglyceride matrix in simulated gastric and simulated intestinal media under the influence of pepsin and pancreatin, respectively, was assessed. The degradation of the triglycerides was monitored by the pH-stat method and with high performance thin layer chromatography in connection with spectrodensitometry to quantify the different lipid fractions. The TM nanoparticles were not degraded in simulated gastric fluid (SGF), but the decomposition of the triglyceride matrix was rapid in the intestinal media. The digestion process was faster in the simulated fed state medium compared to the simulated fasted state medium. Additionally, the stability of the incorporated drug was tested in the respective physiological media. The curcuminoids showed an overall good stability in the different test media. The release of the curcuminoids from the lipid nanoparticles was determined by fluorescence imaging techniques. A slow release of the drug was found in phosphate buffer. In contrast, a more distinct release of the curcuminoids was verifiable in SGF and in simulated intestinal fluids. Overall, it was considered that the transfer of the drug into the outer media was mainly triggered by the lipid degradation and not by drug release.

  6. Formulation, stability and degradation kinetics of intravenous cinnarizine lipid emulsion.

    Science.gov (United States)

    Shi, Shuai; Chen, Hao; Cui, Yue; Tang, Xing

    2009-05-21

    Cinnarizine was loaded in the lipid emulsion to develop an intravenous formulation with good physical and chemical stability. High-pressure homogenization was used to prepare the lipid emulsion. The factors influencing the stability of cinnarizine lipid emulsion, such as different drug loading methods, pH, temperature, sterilization methods and sterilization time were monitored by high-performance liquid chromatograph. The degradation of cinnarizine in aqueous solution and lipid emulsion both followed apparent first-order kinetics. A possible degradation mechanism was postulated by the bell-shaped pH-rate profile of cinnarizine. Localization of the drug in the interfacial lecithin layer significantly improved the chemical stability of cinnarizine and its stabilizing mechanism was thoroughly discussed and proved. The activation energy of cinnarizine in lipid emulsion was calculated to be 51.27 kJ/mol which was similar to that in aqueous solution. This indicates that the stabilizing effect of the drug carrier on cinnarizine was not an alteration of the degradation reaction. In addition, shelf-life of cinnarizine in lipid emulsion was estimated to be 1471.6 days at 4 degrees C, which is much longer compared with 19.8 days in aqueous solution. The final products were stable enough to resist a 121 degrees C rotating steam sterilization for 15 min.

  7. Lipid-coated gold nanocomposites for enhanced cancer therapy.

    Science.gov (United States)

    Kang, Ji Hee; Ko, Young Tag

    2015-01-01

    The aim of the work reported here was to develop lipid-coated multifunctional nanocomposites composed of drugs and nanoparticles for use in cancer therapy. We incorporated thermosensitive phospholipids onto the surface of anisotropic gold nanoparticles (AuNPs) to further enhance drug delivery, with possible additional applications for in vivo imaging and photothermal cancer therapy. Lipid-coated nanohybrids loaded with the drug docetaxel (DTX) were prepared by a thin-film formation, hydration, and sonication method. Nanoparticles and their composites were characterized using particle-size analysis, zeta potential measurements, transmission electron microscopy, UV-visible spectroscopy, and reverse-phase high-performance liquid chromatography, demonstrating successful loading of DTX into the lipid bilayer on the surface of the gold nanoparticles. Initial in vitro studies using breast-cancer (MCF-7) and melanoma (B16F10) cell lines demonstrated that the drug-containing nanocomposites at equivalent drug concentrations caused significant cytotoxicity compared to free DTX. Differential flow cytometry analysis confirmed the improved cellular uptake of lipid-coated nanocomposites. Our preliminary results show that DTX-loaded anionic lipid-coated gold nanorod (AL_AuNR_DTX) and cationic lipid-coated gold nanoparticle (CL_AuNP_DTX) possess effective tumor cell-suppression abilities and can therefore be considered promising chemotherapeutic agents. Further evaluation of the therapeutic efficacy of these hybrid nanoparticles combined with external near-infrared photothermal treatment is warranted to assess their synergistic anticancer actions and potential bioimaging applications.

  8. In vitro digestion of curcuminoid-loaded lipid nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Noack, Andreas; Oidtmann, Johannes; Kutza, Johannes; Maeder, Karsten, E-mail: maeder@pharmazie.uni-halle.de [Martin Luther University Halle-Wittenberg, Department of Pharmaceutical Technology and Biopharmaceutics, Institute of Pharmacy (Germany)

    2012-09-15

    Curcuminoid-loaded lipid nanoparticles were produced by melt homogenization. The used lipid matrices were medium chain triglycerides, trimyristin (TM), and tristearin. The mean particle size of the preparations was between 130 and 180 nm. The incorporated curcuminoids revealed a good stability over a period of 12 months. The curcuminoid-loaded lipid nanoparticles were intended for the oral delivery of curcuminoids. Therefore, the fate of the triglyceride matrix in simulated gastric and simulated intestinal media under the influence of pepsin and pancreatin, respectively, was assessed. The degradation of the triglycerides was monitored by the pH-stat method and with high performance thin layer chromatography in connection with spectrodensitometry to quantify the different lipid fractions. The TM nanoparticles were not degraded in simulated gastric fluid (SGF), but the decomposition of the triglyceride matrix was rapid in the intestinal media. The digestion process was faster in the simulated fed state medium compared to the simulated fasted state medium. Additionally, the stability of the incorporated drug was tested in the respective physiological media. The curcuminoids showed an overall good stability in the different test media. The release of the curcuminoids from the lipid nanoparticles was determined by fluorescence imaging techniques. A slow release of the drug was found in phosphate buffer. In contrast, a more distinct release of the curcuminoids was verifiable in SGF and in simulated intestinal fluids. Overall, it was considered that the transfer of the drug into the outer media was mainly triggered by the lipid degradation and not by drug release.

  9. Curcuminoids-loaded lipid nanoparticles: novel approach towards malaria treatment.

    Science.gov (United States)

    Nayak, Aditya P; Tiyaboonchai, Waree; Patankar, Swati; Madhusudhan, Basavaraj; Souto, Eliana B

    2010-11-01

    In the present work, curcuminoids-loaded lipid nanoparticles for parenteral administration were successfully prepared by a nanoemulsion technique employing high-speed homogenizer and ultrasonic probe. For the production of nanoparticles, trimyristin, tristerin and glyceryl monostearate were selected as solid lipids and medium chain triglyceride (MCT) as liquid lipid. Scanning electron microscopy (SEM) revealed the spherical nature of the particles with sizes ranging between 120 and 250 nm measured by photon correlation spectroscopy (PCS). The zeta potential of the particles ranged between -28 and -45 mV depending on the nature of the lipid matrix produced, which also influenced the entrapment efficiency (EE) and drug loading capacity (LC) found to be in the range of 80-94% and 1.62-3.27%, respectively. The LC increased reciprocally on increasing the amount of MCT as confirmed by differential scanning calorimetry (DSC). DSC analyses revealed that increasing imperfections within the lipid matrix allowed for increasing encapsulation parameters. Nanoparticles were further sterilized by filtration process which was found to be superior over autoclaving in preventing thermal degradation of thermo-sensitive curcuminoids. The in vivo pharmacodynamic activity revealed 2-fold increase in antimalarial activity of curcuminoids entrapped in lipid nanoparticles when compared to free curcuminoids at the tested dosage level. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  10. Lipid hydroperoxides in plants.

    Science.gov (United States)

    Griffiths, G; Leverentz, M; Silkowski, H; Gill, N; Sánchez-Serrano, J J

    2000-12-01

    Hydroperoxides are the primary oxygenated products of polyunsaturated fatty acids and were determined spectrophotometrically based on their reaction with an excess of Fe2+ at low pH in the presence of the dye Xylenol Orange. Triphenylphosphine-mediated hydroxide formation was used to authenticate the signal generated by the hydroperoxides. The method readily detected lipid peroxidation in a range of plant tissues including Phaseolus hypocotyls (26 +/- 5 nmol.g of fresh weight(-1); mean +/- S.D.), Alstroemeria floral tissues (sepals, 66+/-13 nmol.g of fresh weight(-1); petals, 49+/-6 nmol.g of fresh weight(-1)), potato leaves (334+/-75 nmol.g of fresh weight(-1)), broccoli florets (568+/-68 nmol.g of fresh weight(-1)) and Chlamydomonas cells (602+/-40 nmol.g of wet weight(-1)). Relative to the total fatty acid content of the tissues, the percentage hydroperoxide content was within the range of 0.6-1.7% for all tissue types (photosynthetic and non-photosynthetic) and represents the basal oxidation level of membrane fatty acids in plant cells. Leaves of transgenic potato with the fatty acid hydroperoxide lyase enzyme expressed in the antisense orientation were elevated by 38%, indicating a role for this enzyme in the maintenance of cellular levels of lipid hydroperoxides.

  11. FORMULATION AND CHARACTERIZATION OF SOLID LIPID NANOPARTICLES FOR TRANSDERMAL DELIVERY OF TESTOSTERONE

    Directory of Open Access Journals (Sweden)

    L. K. Omray

    2014-07-01

    Full Text Available Present study deals with the formulation and characterization of testosterone bearing solid lipid nanoparticles for transdermal drug delivery. Solid lipid nanoparticles of testosterone were prepared by ether injection method. Solid lipid nanoparticles were prepared by testosterone, glyceryl mono stearate, brij 35, propylene glycol and double distilled water. Four different formulations i.e. F1 to F4 were prepared in different quantity of brij 35. All the solid lipid nanoparticles formulations were characterized on the basis of electron microscopy, particle size by zeta sizer, polydispersity index, encapsulation efficiency, viscosity and in vitro drug release study. Average size and polydispersity index of developed formulation F3 found to have 298 nm and 0.328 respectively, determined by zeta sizer. Encapsulation efficiency of formulation F3 was found to have 54.16%. Viscosity of formulation was also enough to handle for transdermal application. All the formulations followed zero order release profile.

  12. Synthesis and biophysical characterization of chlorambucil anticancer ether lipid prodrugs.

    Science.gov (United States)

    Pedersen, Palle J; Christensen, Mikkel S; Ruysschaert, Tristan; Linderoth, Lars; Andresen, Thomas L; Melander, Fredrik; Mouritsen, Ole G; Madsen, Robert; Clausen, Mads H

    2009-05-28

    The synthesis and biophysical characterization of four prodrug ether phospholipid conjugates are described. The lipids are prepared from the anticancer drug chlorambucil and have C16 and C18 ether chains with phosphatidylcholine or phosphatidylglycerol headgroups. All four prodrugs have the ability to form unilamellar liposomes (86-125 nm) and are hydrolyzed by phospholipase A(2), resulting in chlorambucil release. Liposomal formulations of prodrug lipids displayed cytotoxicity toward HT-29, MT-3, and ES-2 cancer cell lines in the presence of phospholipase A(2), with IC(50) values in the 8-36 microM range.

  13. Synthesis and Biophysical Characterization of Chlorambucil Anticancer Ether Lipid Prodrugs

    DEFF Research Database (Denmark)

    Pedersen, Palle Jacob; Christensen, Mikkel Stochkendahl; Ruysschaert, Tristan

    2009-01-01

    The synthesis and biophysical characterization of four prodrug ether phospholipid conjugates are described. The lipids are prepared from the anticancer drug chlorambucil and have C16 and C18 ether chains with phosphatidylcholine or phosphatidylglycerol headgroups. All four prodrugs have the ability...... to form unilamellar liposomes (86-125 nm) and are hydrolyzed by phospholipase A2, resulting in chlorambucil release. Liposomal formulations of prodrug lipids displayed cytotoxicity toward HT-29, MT-3, and ES-2 cancer cell lines in the presence of phospholipase A2, with IC50 values in the 8-36 μM range....

  14. Structural characterization of suppressor lipids by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Rovillos, Mary Joy; Pauling, Josch Konstantin; Hannibal-Bach, Hans Kristian

    2016-01-01

    RATIONALE: Suppressor lipids were originally identified in 1993 and reported to encompass six lipid classes that enable Saccharomyces cerevisiae to live without sphingolipids. Structural characterization, using non-mass spectrometric approaches, revealed that these suppressor lipids are very long...... chain fatty acid (VLCFA)-containing glycerophospholipids with polar head groups that are typically incorporated into sphingolipids. Here we report, for the first time, the structural characterization of the yeast suppressor lipids using high-resolution mass spectrometry. METHODS: Suppressor lipids were...... isolated by preparative chromatography and subjected to structural characterization using hybrid quadrupole time-of-flight and ion trap-orbitrap mass spectrometry. RESULTS: Our investigation recapitulates the overall structural features of the suppressor lipids and provides an in-depth characterization...

  15. Update of the LIPID MAPS comprehensive classification system for lipids

    NARCIS (Netherlands)

    Fahy, E.; Subramaniam, S.; Murphy, R.C.; Nishijima, M.; Raetz, C.R.H.; Shimizu, T.; Spener, F.; van Meer, G.; Wakelam, M.J.O.; Dennis, E.A.

    2009-01-01

    In 2005, the International Lipid Classification and Nomenclature Committee under the sponsorship of the LIPID MAPS Consortium developed and established a “Comprehensive Classification System for Lipids” based on well-defined chemical and biochemical principles and using an ontology that is extensibl

  16. Study of antioxidant enzymes, lipid peroxidation, lipid profile and ...

    African Journals Online (AJOL)

    McRoy

    Background: The oxidative stress and inflammation are cooperative events involved in atherosclerosis ... reactive protein (hs-CRP) and lipid status parameters in the patients with coronary artery .... Data were analyzed with t-test and expressed as mean ± SD. ... biomolecules including; lipids, proteins and DNA. Antioxidative ...

  17. Update of the LIPID MAPS comprehensive classification system for lipids

    NARCIS (Netherlands)

    Fahy, E.; Subramaniam, S.; Murphy, R.C.; Nishijima, M.; Raetz, C.R.H.; Shimizu, T.; Spener, F.; van Meer, G.|info:eu-repo/dai/nl/068570368; Wakelam, M.J.O.; Dennis, E.A.

    2009-01-01

    In 2005, the International Lipid Classification and Nomenclature Committee under the sponsorship of the LIPID MAPS Consortium developed and established a “Comprehensive Classification System for Lipids” based on well-defined chemical and biochemical principles and using an ontology that is

  18. Solid lipid nanoparticles for parenteral drug delivery

    NARCIS (Netherlands)

    Wissing, S.A.; Kayser, Oliver; Muller, R.H.

    2004-01-01

    This review describes the use of nanoparticles based on solid lipids for the parenteral application of drugs. Firstly, different types of nanoparticles based on solid lipids such as "solid lipid nanoparticles" (SLN), "nanostructured lipid carriers" (NLC) and "lipid drug conjugate" (LDC) nanoparticle

  19. Solid lipid nanoparticles for parenteral drug delivery

    NARCIS (Netherlands)

    Wissing, S.A.; Kayser, Oliver; Muller, R.H.

    2004-01-01

    This review describes the use of nanoparticles based on solid lipids for the parenteral application of drugs. Firstly, different types of nanoparticles based on solid lipids such as "solid lipid nanoparticles" (SLN), "nanostructured lipid carriers" (NLC) and "lipid drug conjugate" (LDC)

  20. Proteomic Profiling of Detergent Resistant Membranes (Lipid Rafts) of Prostasomes.

    Science.gov (United States)

    Dubois, Louise; Ronquist, Karl K Göran; Ek, Bo; Ronquist, Gunnar; Larsson, Anders

    2015-11-01

    Prostasomes are exosomes derived from prostate epithelial cells through exocytosis by multivesicular bodies. Prostasomes have a bilayered membrane and readily interact with sperm. The membrane lipid composition is unusual with a high contribution of sphingomyelin at the expense of phosphatidylcholine and saturated and monounsaturated fatty acids are dominant. Lipid rafts are liquid-ordered domains that are more tightly packed than the surrounding nonraft phase of the bilayer. Lipid rafts are proposed to be highly dynamic, submicroscopic assemblies that float freely within the liquid disordered membrane bilayer and some proteins preferentially partition into the ordered raft domains. We asked the question whether lipid rafts do exist in prostasomes and, if so, which proteins might be associated with them. Prostasomes of density range 1.13-1.19g/ml were subjected to density gradient ultracentrifugation in sucrose fabricated by phosphate buffered saline (PBS) containing 1% Triton X-100 with capacity for banding at 1.10 g/ml, i.e. the classical density of lipid rafts. Prepared prostasomal lipid rafts (by gradient ultracentrifugation) were analyzed by mass spectrometry. The clearly visible band on top of 1.10g/ml sucrose in the Triton X-100 containing gradient was subjected to liquid chromatography-tandem MS and more than 370 lipid raft associated proteins were identified. Several of them were involved in intraluminal vesicle formation, e.g. tetraspanins, ESCRTs, and Ras-related proteins. This is the first comprehensive liquid chromatography-tandem MS profiling of proteins in lipid rafts derived from exosomes. Data are available via ProteomeXchange with identifier PXD002163.

  1. Molecular Dynamics of Lipid Bilayers

    Science.gov (United States)

    1989-08-09

    The aim of this work is to study, by molecular dynamics simulations, the properties of lipid bilayers. We have applied the vectorizable, order-N...fast angle-dependent force/potential algorithms to treat angle bending and torsion. Keywords: Molecular dynamics , Lipid bilayers.

  2. Fasting and nonfasting lipid levels

    DEFF Research Database (Denmark)

    Langsted, Anne; Freiberg, Jacob J; Nordestgaard, Børge G

    2008-01-01

    Lipid profiles are usually measured after fasting. We tested the hypotheses that these levels change only minimally in response to normal food intake and that nonfasting levels predict cardiovascular events.......Lipid profiles are usually measured after fasting. We tested the hypotheses that these levels change only minimally in response to normal food intake and that nonfasting levels predict cardiovascular events....

  3. Fasting and nonfasting lipid levels

    DEFF Research Database (Denmark)

    Langsted, Anne; Freiberg, Jacob J; Nordestgaard, Børge G

    2008-01-01

    Lipid profiles are usually measured after fasting. We tested the hypotheses that these levels change only minimally in response to normal food intake and that nonfasting levels predict cardiovascular events.......Lipid profiles are usually measured after fasting. We tested the hypotheses that these levels change only minimally in response to normal food intake and that nonfasting levels predict cardiovascular events....

  4. Lipid droplets, lipophagy, and beyond.

    Science.gov (United States)

    Wang, Chao-Wen

    2016-08-01

    Lipids are essential components for life. Their various structural and physical properties influence diverse cellular processes and, thereby, human health. Lipids are not genetically encoded but are synthesized and modified by complex metabolic pathways, supplying energy, membranes, signaling molecules, and hormones to affect growth, physiology, and response to environmental insults. Lipid homeostasis is crucial, such that excess fatty acids (FAs) can be harmful to cells. To prevent such lipotoxicity, cells convert excess FAs into neutral lipids for storage in organelles called lipid droplets (LDs). These organelles do not simply manage lipid storage and metabolism but also are involved in protein quality management, pathogenesis, immune responses, and, potentially, neurodegeneration. In recent years, a major trend in LD biology has centered around the physiology of lipid mobilization via lipophagy of fat stored within LDs. This review summarizes key findings in LD biology and lipophagy, offering novel insights into this rapidly growing field. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.

  5. Roles of Lipids in Photosynthesis.

    Science.gov (United States)

    Kobayashi, Koichi; Endo, Kaichiro; Wada, Hajime

    2016-01-01

    Thylakoid membranes in cyanobacterial cells and chloroplasts of algae and higher plants are the sites of oxygenic photosynthesis. The lipid composition of the thylakoid membrane is unique and highly conserved among oxygenic photosynthetic organisms. Major lipids in thylakoid membranes are glycolipids, monogalactosyldiacylglycerol, digalactosyldiacylglycerol and sulfoquinovosyldiacylglycerol, and the phospholipid, phosphatidylglycerol. The identification of almost all genes involved in the biosynthesis of each lipid class over the past decade has allowed the generation and isolation of mutants of various photosynthetic organisms incapable of synthesizing specific lipids. Numerous studies using such mutants have revealed that these lipids play important roles not only in the formation of the lipid bilayers of thylakoid membranes but also in the folding and assembly of the protein subunits in photosynthetic complexes. In addition to the studies with the mutants, recent X-ray crystallography studies of photosynthetic complexes in thylakoid membranes have also provided critical information on the association of lipids with photosynthetic complexes and their activities. In this chapter, we summarize our current understanding about the structural and functional involvement of thylakoid lipids in oxygenic photosynthesis.

  6. The Flexibility of Ectopic Lipids

    Directory of Open Access Journals (Sweden)

    Hannah Loher

    2016-09-01

    Full Text Available In addition to the subcutaneous and the visceral fat tissue, lipids can also be stored in non-adipose tissue such as in hepatocytes (intrahepatocellular lipids; IHCL, skeletal (intramyocellular lipids; IMCL or cardiac muscle cells (intracardiomyocellular lipids; ICCL. Ectopic lipids are flexible fuel stores that can be depleted by physical exercise and repleted by diet. They are related to obesity and insulin resistance. Quantification of IMCL was initially performed invasively, using muscle biopsies with biochemical and/or histological analysis. 1H-magnetic resonance spectroscopy (1H-MRS is now a validated method that allows for not only quantifying IMCL non-invasively and repeatedly, but also assessing IHCL and ICCL. This review summarizes the current available knowledge on the flexibility of ectopic lipids. The available evidence suggests a complex interplay between quantitative and qualitative diet, fat availability (fat mass, insulin action, and physical exercise, all important factors that influence the flexibility of ectopic lipids. Furthermore, the time frame of the intervention on these parameters (short-term vs. long-term appears to be critical. Consequently, standardization of physical activity and diet are critical when assessing ectopic lipids in predefined clinical situations.

  7. Neuroimaging of Lipid Storage Disorders

    Science.gov (United States)

    Rieger, Deborah; Auerbach, Sarah; Robinson, Paul; Gropman, Andrea

    2013-01-01

    Lipid storage diseases, also known as the lipidoses, are a group of inherited metabolic disorders in which there is lipid accumulation in various cell types, including the central nervous system, because of the deficiency of a variety of enzymes. Over time, excessive storage can cause permanent cellular and tissue damage. The brain is particularly…

  8. The Flexibility of Ectopic Lipids.

    Science.gov (United States)

    Loher, Hannah; Kreis, Roland; Boesch, Chris; Christ, Emanuel

    2016-09-14

    In addition to the subcutaneous and the visceral fat tissue, lipids can also be stored in non-adipose tissue such as in hepatocytes (intrahepatocellular lipids; IHCL), skeletal (intramyocellular lipids; IMCL) or cardiac muscle cells (intracardiomyocellular lipids; ICCL). Ectopic lipids are flexible fuel stores that can be depleted by physical exercise and repleted by diet. They are related to obesity and insulin resistance. Quantification of IMCL was initially performed invasively, using muscle biopsies with biochemical and/or histological analysis. ¹H-magnetic resonance spectroscopy (¹H-MRS) is now a validated method that allows for not only quantifying IMCL non-invasively and repeatedly, but also assessing IHCL and ICCL. This review summarizes the current available knowledge on the flexibility of ectopic lipids. The available evidence suggests a complex interplay between quantitative and qualitative diet, fat availability (fat mass), insulin action, and physical exercise, all important factors that influence the flexibility of ectopic lipids. Furthermore, the time frame of the intervention on these parameters (short-term vs. long-term) appears to be critical. Consequently, standardization of physical activity and diet are critical when assessing ectopic lipids in predefined clinical situations.

  9. Lipides polaires marins

    Directory of Open Access Journals (Sweden)

    Fanni Jacques

    2004-03-01

    Full Text Available Les lipides polaires marins, notamment les phospholipides (PL, retiennent depuis quelques années l’attention des chercheurs et des industriels en raison de leur composition, particulièrement riche en acides gras polyinsaturés à longue chaîne (AGPI-LC. Ils combinent ainsi les propriétés reconnues des AGPI-LC à l’intérêt métabolique et structural des phospholipides. Les sources sont nombreuses et d’accès très diversifié. Le défi industriel provient de leurs caractéristiques amphiphiles et aromatiques particulièrement marquées qui rend leur extraction très difficile.

  10. Preparation and in vitro-in vivo Evaluation of Long-circulating Solid Lipid Nanoparticles Loaded with Praziquantel%吡喹酮长循环固体脂质纳米粒的制备及体内外质量评价

    Institute of Scientific and Technical Information of China (English)

    邹永华; 丁劲松; 郑志难; 张龙贵; 马宁

    2012-01-01

    采用乳化-超声分散法制备了吡喹酮固体脂质纳米粒(1-SLN),并以二硬脂酰磷脂酰乙醇胺-聚乙二醇2000为材料同法制备了长循环固体脂质纳米粒(1-LCN).考察了1-SLN和1-LCN粒径、包封率、固有水化层厚度和体外24 h累积释放率,结果分别为(95.57±1.27)和(77.79±1.01)nm、(72.7±2.7)%和(68.2±3.5)%、(1.56±0.32)和(7.03±0.39) nm,以及(77.7±3.5)%和(87.4±4.2)%.两者的体外巨噬细胞吞噬率分别为(10.21±2.85)%、(1.62+0.41)%.经家兔耳缘静脉注射后,1 -LCN较1-SLN和1溶液的半衰期和AUC显著增加,提示其具有长循环效果.%Praziquantel solid lipid nanoparticles (1-SLN) and its long-circulating solid lipid nanoparticles (1-LCN) with distearoyl phosphoethanolamine-polyethylene glycol 2000 (DSPE-PEG 2000) as the material were prepared by emulsification-ultrasonic dispersion method. The particle size, encapsulation efficiency, fixed aqueous layer thickness and cumulative release rate at 24 h of 1-SLN and 1-LCN were (95.57±1.27) and (77.79±1.01)nm, (72.7± 2.7) % and (68.2±3.5) %, (1.56±0.32) and (7.03±0.39)nm, (77.7±3.5) % and (87.4±4.2) %, respectively. The in vitro phagocytize rate of 1-SLN and 1-LCN by peritoneal macrophages were (10.21±2.85) % and (1.62±0.41) %, respectively. The pharmacokinetic behavior in rabbits of 1 solution, 1-SLN and 1-LCN after ear intravenous administration were investigated. The results showed that the half-life and AUC of 1-LCN group were significantly increased compared with the solution and SLN groups. It indicated that the nanoparticles modified with DSPE-PEG 2000 had a long-circulation property.

  11. Lipid functionalized biopolymers: A review.

    Science.gov (United States)

    Qurat-Ul-Ain; Zia, Khalid Mahmood; Zia, Fatima; Ali, Muhammad; Rehman, Saima; Zuber, Mohammad

    2016-12-01

    Lipids are the main source of energy and widely used for various applications. In this review, the modification of lipids by using them in combination with other biomaterials like natural and synthetic polymers is elaborated. These new blends have characteristic features of both polymers and are characterized by different techniques (NMR, DSC, TGA, IR and Raman spectroscopy etc.) to understand their structure, properties and functional behavior. Lipids are hydrophobic, have anti-oxidant and anti-bacterial properties and thus impart hydrophobicity and flexibility to the polymers. While the polymers, on the other hand, make the lipids tougher. Properties of few polymers such as starch, polyethylene protein and chitosan that have brittleness, low combustion rate and hydrophobicity, are improved by incorporation of lipids ultimately increased their flexibility, combustion rate and hydrophobicity respectively. This review article is also focused on emerging fields for the applications of these composite materials. The most notable application of composite materials are in the field of paint industry.

  12. Lipids changes in liver cancer

    Institute of Scientific and Technical Information of China (English)

    JIANG Jing-ting; XU Ning; ZHANG Xiao-ying; WU Chang-ping

    2007-01-01

    Liver is one of the most important organs in energy metabolism.Most plasma apolipoproteins and endogenous lipids and lipoproteins are synthesized in the liver.It depends on the integrity of liver cellular function,which ensures homeostasis of lipid and lipoprotein metabolism.When liver cancer occurs,these processes are impaired and the plasma lipid and lipoprotein patterns may be changed.Liver cancer is the fifth common malignant tumor worldwide,and is closely related to the infections of hepatitis B virus (HBV) and hepatitis C virus (HCV).HBV and HCV infections are quite common in China and other Southeast Asian countries.In addition,liver cancer is often followed by a procession of chronic hepatitis or cirrhosis,so that hepatic function is damaged obviously on these bases,which may significantly influence lipid and lipoprotein metabolism in vivo.In this review we summarize the clinical significance of lipid and lipoprotein metabolism under liver cancer.

  13. Lipid traffic: the ABC of transbilayer movement

    NARCIS (Netherlands)

    Raggers, R.J.; Pomorski, T.; Holthuis, J.C.M.; Kälin, N.; van Meer, G.

    2000-01-01

    Membrane lipids do not spontaneously exchange between the two leaflets of lipid bilayers because the polar headgroups cannot cross the hydrophobic membrane interior. Cellular membranes, notably eukaryotic plasma membranes, are equipped with special proteins that actively translocate lipids from one

  14. Aspirin Increases the Solubility of Cholesterol in Lipid Membranes

    Science.gov (United States)

    Alsop, Richard; Barrett, Matthew; Zheng, Sonbo; Dies, Hannah; Rheinstadter, Maikel

    2014-03-01

    Aspirin (ASA) is often prescribed for patients with high levels of cholesterol for the secondary prevention of myocardial events, a regimen known as the Low-Dose Aspirin Therapy. We have recently shown that Aspirin partitions in lipid bilayers. However, a direct interplay between ASA and cholesterol has not been investigated. Cholesterol is known to insert itself into the membrane in a dispersed state at moderate concentrations (under ~37.5%) and decrease fluidity of membranes. We prepared model lipid membranes containing varying amounts of both ASA and cholesterol molecules. The structure of the bilayers as a function of ASA and cholesterol concentration was determined using high-resolution X-ray diffraction. At cholesterol levels of more than 40mol%, immiscible cholesterol plaques formed. Adding ASA to the membranes was found to dissolve the cholesterol plaques, leading to a fluid lipid bilayer structure. We present first direct evidence for an interaction between ASA and cholesterol on the level of the cell membrane.

  15. Difluoromethane preparation

    NARCIS (Netherlands)

    Wiersma, A.; Sandt, E.J.A.; Van Bekkum, H.; Makkee, M.; Moulijn, J.A.

    1996-01-01

    Abstract of NL 9401574 (A) The invention relates to a method for preparing difluoromethane, wherein dichlorodifluoromethane or monochlorodifluoromethane is brought into contact with hydrogen in the presence of palladium on activated carbon, wherein the loading of the palladium on the activated c

  16. Lipid composition of integral purple membrane by 1H and 31P NMR.

    Science.gov (United States)

    Renner, Christian; Kessler, Brigitte; Oesterhelt, Dieter

    2005-08-01

    In the purple membrane (PM) of halobacteria, lipids stabilize the trimeric arrangement of bacteriorhodopsin (BR) molecules and mediate the packing of the trimers in a regular crystalline arrangement. To date, the identification and quantification of these lipids has been based either on lipid extraction procedures or structural models. By directly solubilizing PMs from Halobacterium salinarum in aqueous detergent solutions (SDS or Triton X-100), we avoided any separation or modification steps that might modify the lipid composition or even the lipid molecules themselves. Our analysis of integral PM preparations should resolve partially conflicting literature data on the lipid composition of the PM. Using 31P and 1H NMR of detergent-solubilized but otherwise untreated samples, we found two glycolipids and 6.4 +/- 0.1 phospholipids per BR molecule, 4.4 +/- 0.1 of the latter being the phosphatidylglycerophosphate methyl ester. The only glycolipid detected was S-TGD-1. For an additional glycolipid, glycocardiolipin, that was recently identified in lipid extracts, we show that it was produced mainly during the lipid extraction procedure but also was partially dependent on the preparation of the PM suspensions.

  17. Anionic lipid binding to the foreign protein MGS provides a tight coupling between phospholipid synthesis and protein overexpression in Escherichia coli.

    Science.gov (United States)

    Ariöz, Candan; Ye, Weihua; Bakali, Amin; Ge, Changrong; Liebau, Jobst; Götzke, Hansjörg; Barth, Andreas; Wieslander, Ake; Mäler, Lena

    2013-08-20

    Certain membrane proteins involved in lipid synthesis can induce formation of new intracellular membranes in Escherichia coli, i.e., intracellular vesicles. Among those, the foreign monotopic glycosyltransferase MGS from Acholeplasma laidlawii triggers such massive lipid synthesis when overexpressed. To examine the mechanism behind the increased lipid synthesis, we investigated the lipid binding properties of MGS in vivo together with the correlation between lipid synthesis and MGS overexpression levels. A good correlation between produced lipid quantities and overexpressed MGS protein was observed when standard LB medium was supplemented with four different lipid precursors that have significant roles in the lipid biosynthesis pathway. Interestingly, this correlation was highest concerning anionic lipid production and at the same time dependent on the selective binding of anionic lipid molecules by MGS. A selective interaction with anionic lipids was also observed in vitro by (31)P NMR binding studies using bicelles prepared with E. coli lipids. The results clearly demonstrate that the discriminative withdrawal of anionic lipids, especially phosphatidylglycerol, from the membrane through MGS binding triggers an in vivo signal for cells to create a "feed-forward" stimulation of lipid synthesis in E. coli. By this mechanism, cells can produce more membrane surface in order to accommodate excessively produced MGS molecules, which results in an interdependent cycle of lipid and MGS protein synthesis.

  18. SOLID LIPID NANOPARTICLES AND NANO LIPID CARRIERS: AS NOVEL SOLID LIPID BASED DRUG CARRIER

    Directory of Open Access Journals (Sweden)

    Girish B. Singhal

    2011-02-01

    Full Text Available Interest in lipid based drug delivery has developed over the past decade fuelled by a better understanding of the multiple roles lipids may play in enhancing oral bioavailability. Moreover, the emergence of novel excipients with acceptable regulatory and safety profiles coupled with advances in formulation technologies have greatly improved the potential for successful lipid based formulations. Solid lipid nanoparticles (SLN introduced in 1991 represent an alternative carrier system to traditional colloidal carriers, such as emulsions, liposomes and polymeric micro- and nanoparticles. SLN combine advantages of the traditional systems but avoid some of their major disadvantages. This paper reviews the present state of the art regarding production techniques for SLN/ nanostructured lipid carrier (NLC, drug incorporation method and types, stability. The potential of SLN/NLC to be exploited for the different administration routes is also highlighted.

  19. Formulation and characterization of solid lipid nanoparticles, nanostructured lipid carriers and nanoemulsion of lornoxicam for transdermal delivery

    Directory of Open Access Journals (Sweden)

    Gönüllü Ümit

    2015-03-01

    Full Text Available Solid lipid nanoparticles (SLN, nanostructured lipid carriers (NLC and nanoemulsion (NE of lornoxicam (LRX were prepared for the treatment of painful and inflammatory conditions of the skin. Compritol® 888 ATO, Lanette® O and oleic acid were used as solid and liquid lipids. SLN, NLC and NE were found physically stable at various temperatures for 6 months. Case I diffusional drug release was detected as the dominant mechanism indicating Fickian drug diffusion from nanoparticles and nanoemulsion. The highest rate of drug penetration through rat skin was obtained with NE followed by NLC, SLN and a gel formulation. Nanoformulations significantly increased drug penetration through rat skin compared to the gel (p < 0.05. Thus, SLN, NLC and NE of LRX can be suggested for relieving painful and inflammatory conditions of the skin

  20. Formulation and characterization of solid lipid nanoparticles, nanostructured lipid carriers and nanoemulsion of lornoxicam for transdermal delivery.

    Science.gov (United States)

    Gönüllü, Ümit; Üner, Melike; Yener, Gülgün; Karaman, Ecem Fatma; Aydoğmuş, Zeynep

    2015-03-01

    Solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) and nanoemulsion (NE) of lornoxicam (LRX) were prepared for the treatment of painful and inflammatory conditions of the skin. Compritol® 888 ATO, Lanette® O and oleic acid were used as solid and liquid lipids. SLN, NLC and NE were found physically stable at various temperatures for 6 months. Case I diffusional drug release was detected as the dominant mechanism indicating Fickian drug diffusion from nanoparticles and nanoemulsion. The highest rate of drug penetration through rat skin was obtained with NE followed by NLC, SLN and a gel formulation. Nanoformulations significantly increased drug penetration through rat skin compared to the gel (pSLN, NLC and NE of LRX can be suggested for relieving painful and inflammatory conditions of the skin.

  1. Nanostructured lipid carrier versus solid lipid nanoparticles of simvastatin: comparative analysis of characteristics, pharmacokinetics and tissue uptake.

    Science.gov (United States)

    Tiwari, Radheshyam; Pathak, Kamla

    2011-08-30

    Nanostructured lipid carrier (NLC) system of simvastatin was investigated for improvement in release, pharmacokinetics and biodistribution over its solid lipid nanoparticles (SLN). The NLC formulations prepared by solvent injection technique were optimized by 2(3) full factorial design. Optimized NLC was deduced on the basis of dependent variables that were analyzed using Design expert 8.0.2 software (Stat Ease, Inc., USA). Pareto charts and response surface plots were utilized to study the effect of variables on the response parameters. The optimized NLC was a suspension of nanosized homogeneous particles with significantly higher entrapment efficiency (>90%) and lower recrystallization properties (pdrug absorbed. This investigation demonstrated the superiority of NLC over SLN for improved oral delivery and it was deduced that the liquid lipid, oleic acid was the principal formulation factor responsible for the improvement in characteristics, pharmacokinetics and biodistribution of NLCs. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Lipid composition of human meibum

    Directory of Open Access Journals (Sweden)

    R. Schnetler

    2013-12-01

    Full Text Available The structure and function of meibomian gland lipids in the tear film are highly complex. Evidence shows that the precorneal tear film consists of discrete layers: the inner mucin layer, the middle aqueous layer and the outer lipid layer. In this review we focus on the outer, biphasic lipid layer of the tear film which consists of a ‘thick’ outer, non-polar layer  and a ‘thin’ inner, polar layer. We discuss the main composition of the polar and non-polar lipids within meibum (wax esters, cholesteryl esters, mono-, di- and tri-acylglycerols, ceramides, phospholipids  et cetera. We address the composition of meibomian lipids in subjects suffering from various ocular diseases in comparison with the composition in healthy individuals. Further analysis is needed to determine whether a correlation exists between the etiology of various ocular diseases and the fluctuation on the lipids as well as to establish whether or not tear lipid analysis can be used as a diagnostic tool.

  3. Reconstitution of the Leucine Transport System of Lactococcus lactis into Liposomes Composed of Membrane-Spanning Lipids from Sulfolobus acidocaldarius

    NARCIS (Netherlands)

    in t Veld, Geertruida; Elferink, Maria; Driessen, Arnold J.M.; Konings, Wilhelmus

    1992-01-01

    The effect of bipolar tetraether lipids, extracted from the thermophilic archaebacterium Sulfolobus acidocaldarius, on the branched-chain amino acid transport system of the mesophilic bacterium Lactococcus lactis was investigated. Liposomes were prepared from mixtures of monolayer lipids and the bil

  4. Engineering of budesonide-loaded lipid-polymer hybrid nanoparticles using a quality-by-design approach

    DEFF Research Database (Denmark)

    Leng, Donglei; Thanki, Kaushik; Fattal, Elias

    2017-01-01

    with small interfering RNA (siRNA) for COPD management. Lipid-modified PLGA nanoparticles (LPNs) based on biodegradable poly(DL-lactic-co-glycolic acid) (PLGA) and the cationic lipid dioleyltrimethylammonium propane (DOTAP) were prepared using a double emulsion solvent evaporation method. A quality...

  5. 辅酶Q1O纳米结构脂质载体的制备及皮肤靶向性评价%Study on the preparation and epidermal targeting of Q1O-loaded nanostructured lipid carriers

    Institute of Scientific and Technical Information of China (English)

    姜霞; 陈思渊; 刘卫

    2012-01-01

    OBJECTIVE To prepare coenzyme Q10 loaded nanostructured lipid carriers (Q10-NLC) and to investigate their stability, in vitro drug release profile and epidermal targeting effect METHODS Q10-NLC was prepared by high pressure mi-crofluidics technique. Formulations were optimized with response surface desiga Q10-NLC was characterized by PCS, TEM, DSC and PXRD. The skin penetration of Q10-NLC was evaluated with Franz diffusion cell In vitro release profile, long-term stability and light stability were also evaluated. RESULTS The optimized formulation was obtained by response surface design. The size of optimized Q10-NLC was 151.7 nm, PD10. 144, Zeta potential -44. 1 mV, drug loading 2. 51 %. Encapsulation efficiency 100%. After exposure to day light for 24 h, the amount of Q10 in Q10-NLC decreased only 5. 59%, while in Q10 emulsion decreased 24. 61 % and QlO-ethanol solution 49. 74%. In vitro release study, Q10-NLC showed prolonged release profile. In vitro skin permeation study indicated that the accumulative uptake of Q10 in epidermal of Q10-NLC was 10.11 times over QlO emulsion. CONCLUSION Q10-NLC exhibited a significant epidermal targeting effect and good long-term stability and light stability, which was proved to be a promising carrier for topical delivery of Q10.%目的:研制辅酶Q10纳米结构脂质载体(Q10-NLC),并对其皮肤靶向性进行评价.方法:采用高压微射流技术制备Q10-NLC,运用响应面设计优化处方,并对其理化性能、稳定性及体外释放行为进行表征;采用Franze扩散池法评价Q10-NLC体外透皮性能.结果:通过响应面设计得到Q10-NLC优化处方,按照优化处方制备的Q10-NLC粒径为151.7 nm,多分散指数(PDI)0.144,Zeta电位-44.1 mV,载药量2.51%,包封率100%;24 h光照后,Q10-NLC中Q10含量下降5.59%,显著低于乳剂和乙醇溶液中Q10的光解量;体外药物释放表明,Q10-NLC具有明显的缓释行为;体外透皮吸收实验结果显示,Q10-NLC的

  6. Study on the Preparation and in Vitro Properties of Glycyrrhetinic Acid Long-circulating Solid Lipid Nanoparticles%甘草次酸长循环固体脂质纳米粒的制备与体外性能研究

    Institute of Scientific and Technical Information of China (English)

    王炯; 周小菊; 胡先明

    2012-01-01

    OBJECTIVE: To prepare Glycyrrhetinic acid long-circulating solid lipid nanoparticles (GA-LSLN) and to investigate its properties in vitro. METHODS: GA-LSLN was prepared by emulsion-solvent evaporation-high pressure homogenization method. The size, Zeta potential, encapsulation efficiency and drug loading of GA-SLN were measured. The in vitro drug release of GA-LSLN was studied. SK-Hep-1 and MV 4-11 were treated with DEXA, GA and GA-LSLN. The cytotoxicity of GA-LSLN were evaluated by MTT method. RESULTS: The size, Zeta potential, encapsulation efficiency and drug loading of GA-LSLN were 103.1 nm, -36.2 mv, 94.6% and 11.3% , respectively. The release profile fitted well to the first-order rate process. The IC? Of DEXA, GA and free GA-LSLN to SK-Hep-1 were (199 ± 10) ,(32 ± 7), (141 ±5) umol-L~'. The Icso of them to MV 4-11 were (25 ± 3), (20 ± 5), (63 + 4) umol-L1. CONCLUSION: The GA-LSLN has sound particle size, high encapsulation efficiency and drug loading amount, and show sustained-release effect. GA and GA-LSLN show good cytotoxicity to SK-Hep-1 and MV 4-11.%目的:制备甘草次酸长循环固体脂质纳米粒(GA-LSLN),并对其体外性能进行考察.方法:采用乳化溶剂挥发-高压匀质法制备GA-LSLN,测定其粒径、Zeta电位、包封率和载药量,并对其体外释药进行研究;同时以地塞米松(DEXA)、游离甘草次酸(GA)和GA-LSLN作用于肝癌细胞SK-Hep-1和急性髓细胞白血病细胞MV 4-11,采用MTT法考察细胞毒性.结果:GA-LSLN的平均粒径为130.1nm,Zeta电位为-36.2 mV,包封率为94.6%,载药量为11.3%,其体外释放规律符合一级速率过程.DEXA、GA和GA-LSLN对SK-Hep-1细胞的半数抑制浓度(IC50)分别为(199±10)、(32±7)、(141±5)μmol· L-1,对MV 4-11的IC50分别为(25±3)、(20±5)、(63±4) μmol· L-1.结论:制备的GA-LSLN粒径、包封率和载药量均较理想,药物能达到缓释的作用,GA和GA-LSLN对肝癌细胞和白血病细胞均有较强的细胞毒性.

  7. The role of ceramide chain length distribution on the barrier properties of the skin lipid membranes.

    Science.gov (United States)

    Mojumdar, E H; Kariman, Z; van Kerckhove, L; Gooris, G S; Bouwstra, J A

    2014-10-01

    The skin barrier function is provided by the stratum corneum (SC). The lipids in the SC are composed of three lipid classes: ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs) which form two crystalline lamellar structures. In the present study, we investigate the effect of CER chain length distribution on the barrier properties of model lipid membranes mimicking the lipid composition and organization of SC. The membranes were prepared with either isolated pig CERs (PCERs) or synthetic CERs. While PCERs have a wide chain length distribution, the synthetic CERs are quite uniform in chain length. The barrier properties were examined by means of permeation studies using hydrocortisone as a model drug. Our studies revealed a reduced barrier in lipid membranes prepared with PCERs compared to synthetic CERs. Additional studies revealed that a wider chain length distribution of PCERs results in an enhanced hexagonal packing and increased conformational disordering of the lipid tails compared to synthetic CERs, while the lamellar phases did not change. This demonstrates that the chain length distribution affects the lipid barrier by reducing the lipid ordering and density within the lipid lamellae. In subsequent studies, the effect of increased levels of FFAs or CERs with a long acyl chain in the PCERs membranes was also studied. These changes in lipid composition enhanced the level of orthorhombic packing, reduced the conformational disordering and increased the barrier of the lipid membranes. In conclusion, the CER chain length distribution is an important key factor for maintaining a proper barrier. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Lipid peroxidation and water penetration in lipid bilayers

    DEFF Research Database (Denmark)

    Conte, Elena; Megli, Francesco Maria; Khandelia, Himanshu

    2012-01-01

    Lipid peroxidation plays a key role in the alteration of cell membrane's properties. Here we used as model systems multilamellar vesicles (MLVs) made of the first two products in the oxidative cascade of linoleoyl lecithin, namely 1-palmitoyl-2-(13-hydroperoxy-9,11-octadecanedienoyl)-lecithin (Hp......PLPC) and 1-palmitoyl-2-(13-hydroxy-9,11-octadecanedienoyl)-lecithin (OHPLPC), exhibiting a hydroperoxide or a hydroxy group at position 13, respectively. The two oxidized lipids were used either pure or in a 1:1 molar ratio mixture with untreated 1-palmitoyl-2-linoleoyl-lecithin (PLPC). The model membranes...... were doped with spin-labeled lipids to study bilayer alterations by electron paramagnetic resonance (EPR) spectroscopy. Two different spin-labeled lipids were used, bearing the doxyl ring at position (n) 5 or 16: γ-palmitoyl-β-(n-doxylstearoyl)-lecithin (n-DSPPC) and n-doxylstearic acid (n-DSA). Small...

  9. Dietary lipids and cancer.

    Science.gov (United States)

    Granados, S; Quiles, J L; Gil, A; Ramírez-Tortosa, M C

    2006-05-01

    Cancer is one of the main causes of death in Western countries. Among the factors that contribute to the appearance of this disease, diet has a fundamental role, and specifically fats are the main component related to the increase in the incidence of cancerous diseases, particularly breast, colon-rectal, and prostate cancer. From dietary lipids, much attention has been given to the beneficial effects of fish oil, rich in polyunsaturated fatty acids n-3 serie, as well as of olive oil, rich in monounsaturated fatty acids--primarily oleic acid. On the contrary, a negative effect has been reported for polyunsaturated fatty acids n-6 serie and for saturated fatty acids. Nutrition constitutes an important aspect of the life of cancer patients. Currently, nutritional formulas are being designed with supplements of polyunsaturated n-3 fatty acids and other components such as arginine, RNA, lysine, etc., with the aim of ameliorating the effects of this pathology. The results demonstrate the lower morbility and therefore improved quality of life, a decline in mortality, and a reduction in related costs.

  10. Hybrid lipid-based nanostructures

    Science.gov (United States)

    Dayani, Yasaman

    Biological membranes serve several important roles, such as structural support of cells and organelles, regulation of ionic and molecular transport, barriers to non-mediated transport, contact between cells within tissues, and accommodation of membrane proteins. Membrane proteins and other vital biomolecules incorporated into the membrane need a lipid membrane to function. Due to importance of lipid bilayers and their vital function in governing many processes in the cell, the development of various models as artificial lipid membranes that can mimic cell membranes has become a subject of great interest. Using different models of artificial lipid membranes, such as liposomes, planar lipid bilayers and supported or tethered lipid bilayers, we are able to study many biophysical processes in biological membranes. The ability of different molecules to interact with and change the structure of lipid membranes can be also investigated in artificial lipid membranes. An important application of lipid bilayer-containing interfaces is characterization of novel membrane proteins for high throughput drug screening studies to investigate receptor-drug interactions and develop biosensor systems. Membrane proteins need a lipid bilayer environment to preserve their stability and functionality. Fabrication of materials that can interact with biomolecules like proteins necessitates the use of lipid bilayers as a mimic of cell membranes. The objective of this research is to develop novel hybrid lipid-based nanostructures mimicking biological membranes. Toward this aim, two hybrid biocompatible structures are introduced: lipid bilayer-coated multi-walled carbon nanotubes (MWCNTs) and hydrogel-anchored liposomes with double-stranded DNA anchors. These structures have potential applications in biosensing, drug targeting, drug delivery, and biophysical studies of cell membranes. In the first developed nanostructure, lipid molecules are covalently attached to the surfaces of MWCNTs, and

  11. Controlled release implants based on cast lipid blends.

    Science.gov (United States)

    Kreye, F; Siepmann, F; Zimmer, A; Willart, J F; Descamps, M; Siepmann, J

    2011-05-18

    The aim of this study was to use lipid:lipid blends as matrix formers in controlled release implants. The systems were prepared by melting and casting and thoroughly characterized before and after exposure to the release medium. Based on the experimental results, a mechanistic realistic mathematical model was used to get further insight into the underlying drug release mechanisms. Importantly, broad spectra of drug release patterns could be obtained by simply varying the lipid:lipid blend ratio in implants based on Precirol ATO 5 (glyceryl palmitostearate):Dynasan 120 (hardened soybean oil) mixtures loaded with propranolol hydrochloride. Release periods ranging from a few days up to several months could be provided. Interestingly, the drug release rate monotonically decreased with increasing Dynasan 120 content, except for implants containing about 20-25% Precirol, which exhibited surprisingly high release rates. This could be attributed to the incomplete miscibility of the two lipids at these blend ratios: DSC thermograms showed phase separation in these systems. This is likely to cause differences in the implants' microstructure, which determines the mobility of water and dissolved drug as well as the mechanical stability of the systems. Purely diffusion controlled drug release was only observed at Precirol ATO 5 contents around 5-10%. In all other cases, limited drug solubility effects or matrix former erosion are also expected to play a major role. Thus, lipid:lipid blends are very interesting matrix formers in controlled release implants. However, care must be taken with respect to the mutual miscibility of the compounds: in case of phase separation, surprisingly high drug release rates might be observed.

  12. Differential Effect of Plant Lipids on Membrane Organization

    Science.gov (United States)

    Grosjean, Kevin; Mongrand, Sébastien; Beney, Laurent; Simon-Plas, Françoise; Gerbeau-Pissot, Patricia

    2015-01-01

    The high diversity of the plant lipid mixture raises the question of their respective involvement in the definition of membrane organization. This is particularly the case for plant plasma membrane, which is enriched in specific lipids, such as free and conjugated forms of phytosterols and typical phytosphingolipids, such as glycosylinositolphosphoceramides. This question was here addressed extensively by characterizing the order level of membrane from vesicles prepared using various plant lipid mixtures and labeled with an environment-sensitive probe. Fluorescence spectroscopy experiments showed that among major phytosterols, campesterol exhibits a stronger ability than β-sitosterol and stigmasterol to order model membranes. Multispectral confocal microscopy, allowing spatial analysis of membrane organization, demonstrated accordingly the strong ability of campesterol to promote ordered domain formation and to organize their spatial distribution at the membrane surface. Conjugated sterol forms, alone and in synergy with free sterols, exhibit a striking ability to order membrane. Plant sphingolipids, particularly glycosylinositolphosphoceramides, enhanced the sterol-induced ordering effect, emphasizing the formation and increasing the size of sterol-dependent ordered domains. Altogether, our results support a differential involvement of free and conjugated phytosterols in the formation of ordered domains and suggest that the diversity of plant lipids, allowing various local combinations of lipid species, could be a major contributor to membrane organization in particular through the formation of sphingolipid-sterol interacting domains. PMID:25575593

  13. Anisotropic metal growth on phospholipid nanodiscs via lipid bilayer expansion

    Science.gov (United States)

    Oertel, Jana; Keller, Adrian; Prinz, Julia; Schreiber, Benjamin; Hübner, René; Kerbusch, Jochen; Bald, Ilko; Fahmy, Karim

    2016-05-01

    Self-assembling biomolecules provide attractive templates for the preparation of metallic nanostructures. However, the intuitive transfer of the “outer shape” of the assembled macromolecules to the final metallic particle depends on the intermolecular forces among the biomolecules which compete with interactions between template molecules and the metal during metallization. The shape of the bio-template may thus be more dynamic than generally assumed. Here, we have studied the metallization of phospholipid nanodiscs which are discoidal particles of ~10 nm diameter containing a lipid bilayer ~5 nm thick. Using negatively charged lipids, electrostatic adsorption of amine-coated Au nanoparticles was achieved and followed by electroless gold deposition. Whereas Au nanoparticle adsorption preserves the shape of the bio-template, metallization proceeds via invasion of Au into the hydrophobic core of the nanodisc. Thereby, the lipidic phase induces a lateral growth that increases the diameter but not the original thickness of the template. Infrared spectroscopy reveals lipid expansion and suggests the existence of internal gaps in the metallized nanodiscs, which is confirmed by surface-enhanced Raman scattering from the encapsulated lipids. Interference of metallic growth with non-covalent interactions can thus become itself a shape-determining factor in the metallization of particularly soft and structurally anisotropic biomaterials.

  14. Oral insulin delivery by means of solid lipid nanoparticles

    OpenAIRE

    Sarmento, Bruno; Martins, Susana; Ferreira, Domingos; Eliana B. Souto

    2007-01-01

    The aim of this work was to produce and characterize cetyl palmitate-based solid lipid nanoparticles (SLN) containing insulin, and to evaluate the potential of these colloidal carriers for oral administration. SLN were prepared by a modified solvent emulsification-evaporation method based on a w/o/w double emulsion. The particle size, zeta potential and association efficiency of unloaded and insulin-loaded SLN were determined and were found to be around 350 nm, negatively charged and the insu...

  15. Effect of intensive laser irradiation on lipid peroxidation in retina

    Energy Technology Data Exchange (ETDEWEB)

    Lyakhnovich, G.V.; Guseynov, T.M.; Zheltov, G.I.; Glazkov, V.N.; Naumovich, A.S.; Koney, S.V.; Volotovskiy, I.D.

    1986-01-01

    A study was made of the effect of intensive laser irradiation on the kinetics of lipid peroxidation in the retina in in vivo and in vitro conditions and also considered the possible influence on these processes of vitamin E and selenium, which have endogenous antioxidants and play an active part in the regulation of the oxidizing processes in membranes was considered. Tests in vitro were conducted on preparations of bovine eyes; in vivo studies were conducted on Chinchilla rabbits.

  16. [Effect of polyethylene glycol-lipid derivatives on the stability of grafted liposomes].

    Science.gov (United States)

    Xu, Yang; Shi, Li; Deng, Yi-hui

    2011-10-01

    It is reported that polyethylene glycol-lipid (PEG-lipid) derivatives increase liposomes stability, prolong the blood circulation of liposomes, enhance their tumor-targeting efficiency, and improve drug efficacy. Therefore, it is of great importance to investigate the influence of modified PEG-lipid derivatives on the physical, chemical, and biological characteristics of liposomes for the promotion of dealing with the existed problems, such as the accelerated blood clearance (ABC) phenomenon when repeated intravous injection at a certain time-interval, and developing novel targeted pharmaceutical preparations. In this review, the effects of modified PEG-lipid derivatives were summarized in many aspects. It indicats that the chemical bonds (amide, ether, ester, and disulfide) between PEG and lipid, as well as the species of lipids, such as the commonly used phosphatidylethanolamine, cholesterol, and diacylglycerol have substantial effects on the grafted liposomes stability in vitro and in vivo. Besides, the properties of lipids (the fatty acid chain length and saturation) and the groups (methoxy, carboxylic and amino) at the distal ends of the PEG chains were also considered to be important factors. In the end, the influence of the average molecular weight of PEG and the molar ratio of PEG-lipid derivatives in the total lipid were further focused.

  17. Tea Dietary Fiber Improves Serum and Hepatic Lipid Profiles in Mice Fed a High Cholesterol Diet.

    Science.gov (United States)

    Guo, Wenxin; Shu, Yang; Yang, Xiaoping

    2016-06-01

    Tea dietary fiber (TDF) was prepared from tea residues and modified to get cellulose-modified TDF (CTDF) by cellulase or micronized TDF (MTDF) by ultrafine grinding. The in vitro lipid-binding capacities of the three fibers and their effects on serum and hepatic lipid profiles in mice fed a high cholesterol diet were evaluated. The results showed that the three fibers had excellent lipid-binding capacities, and the cholesterol- and sodium cholate-binding capacities of CTDF and MTDF were significantly higher than those of TDF. Animal studies showed that, compared to model control, the three fibers significantly decreased mice average daily gain, gain: feed, and liver index, reduced total cholesterol (TC), triglyceride, and low density lipoprotein-cholesterol of serum and liver, increased serum and hepatic high density lipoprotein-cholesterol to TC ratio, and promoted the excretion of fecal lipids, and they also significantly increased the activities of superoxide dismutase and glutathione peroxidase of serum and liver, and decreased lipid peroxidation; moreover, the effects of CTDF and MTDF were better than that of TDF. It was concluded that the three fibers could improve serum and hepatic lipid profiles in mice fed a high cholesterol diet and the mechanism of action might be due to the promotion of fecal excretion of lipids through their lipid-binding ability and the inhibition of lipid peroxidation. These findings suggest that tea dietary fiber has the potential to be used as a functional ingredient to control cardiovascular disease.

  18. Analysis of Lipid Experiments (ALEX)

    DEFF Research Database (Denmark)

    Husen, Peter; Tarasov, Kirill; Katafiasz, Maciej

    2013-01-01

    Global lipidomics analysis across large sample sizes produces high-content datasets that require dedicated software tools supporting lipid identification and quantification, efficient data management and lipidome visualization. Here we present a novel software-based platform for streamlined data ...

  19. SOLID LIPID NANOPARTICLES: A REVIEW

    Directory of Open Access Journals (Sweden)

    Mudavath Hanumanaik*, Sandeep Kumar Patel and K. Ramya Sree

    2013-03-01

    Full Text Available ABSTRACT: Solid lipid nanoparticles (SLN are at the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery and research. Due to their unique size dependent properties, lipid nanoparticles offer possibility to develop new therapeutics. The ability to incorporate drugs into nanocarriers offers a new prototype in drug delivery that could use for drug targeting. Hence solid lipid nanoparticles hold great promise for reaching the goal of controlled and site specific drug delivery and hence attracted wide attention of researchers. This review presents a broad treatment of solid lipid nanoparticles discussing their aims, production procedures, advantages, limitations and their possible remedies. Appropriate analytical techniques for the characterization of SLN like Photon Correlation Spectroscopy (PCS, Scanning Electron Microscopy (SEM, and Differential Scanning Calorimetry are highlighted. Aspects of SLN route of administration and the in vivo fate of the carriers are also discussed.

  20. Lipid dynamics at dendritic spines.

    Science.gov (United States)

    Dotti, Carlos Gerardo; Esteban, Jose Antonio; Ledesma, María Dolores

    2014-01-01

    Dynamic changes in the structure and composition of the membrane protrusions forming dendritic spines underlie memory and learning processes. In recent years a great effort has been made to characterize in detail the protein machinery that controls spine plasticity. However, we know much less about the involvement of lipids, despite being major membrane components and structure determinants. Moreover, protein complexes that regulate spine plasticity depend on specific interactions with membrane lipids for proper function and accurate intracellular signaling. In this review we gather information available on the lipid composition at dendritic spine membranes and on its dynamics. We pay particular attention to the influence that spine lipid dynamism has on glutamate receptors, which are key regulators of synaptic plasticity.

  1. Influence of Surfactant and Lipid Type on the Physicochemical Properties and Biocompatibility of Solid Lipid Nanoparticles

    Directory of Open Access Journals (Sweden)

    Carine Dal Pizzol

    2014-08-01

    Full Text Available Nine types of solid lipid nanoparticle (SLN formulations were produced using tripalmitin (TPM, glyceryl monostearate (GM or stearic acid (SA, stabilized with lecithin S75 and polysorbate 80. Formulations were prepared presenting PI values within 0.25 to 0.30, and the physicochemical properties, stability upon storage and biocompatibility were evaluated. The average particle size ranged from 116 to 306 nm, with a negative surface charge around −11 mV. SLN presented good stability up to 60 days. The SLN manufactured using SA could not be measured by DLS due to the reflective feature of this formulation. However, TEM images revealed that SA nanoparticles presented square/rod shapes with an approximate size of 100 nm. Regarding biocompatibility aspects, SA nanoparticles showed toxicity in fibroblasts, causing cell death, and produced high hemolytic rates, indicating toxicity to red blood cells. This finding might be related to lipid type, as well as, the shape of the nanoparticles. No morphological alterations and hemolytic effects were observed in cells incubated with SLN containing TPM and GM. The SLN containing TPM and GM showed long-term stability, suggesting good shelf-life. The results indicate high toxicity of SLN prepared with SA, and strongly suggest that the components of the formulation should be analyzed in combination rather than separately to avoid misinterpretation of the results.

  2. Influence of surfactant and lipid type on the physicochemical properties and biocompatibility of solid lipid nanoparticles.

    Science.gov (United States)

    Pizzol, Carine Dal; Filippin-Monteiro, Fabíola Branco; Restrepo, Jelver Alexander Sierra; Pittella, Frederico; Silva, Adny Henrique; Alves de Souza, Paula; Machado de Campos, Angela; Creczynski-Pasa, Tânia Beatriz

    2014-08-20

    Nine types of solid lipid nanoparticle (SLN) formulations were produced using tripalmitin (TPM), glyceryl monostearate (GM) or stearic acid (SA), stabilized with lecithin S75 and polysorbate 80. Formulations were prepared presenting PI values within 0.25 to 0.30, and the physicochemical properties, stability upon storage and biocompatibility were evaluated. The average particle size ranged from 116 to 306 nm, with a negative surface charge around -11 mV. SLN presented good stability up to 60 days. The SLN manufactured using SA could not be measured by DLS due to the reflective feature of this formulation. However, TEM images revealed that SA nanoparticles presented square/rod shapes with an approximate size of 100 nm. Regarding biocompatibility aspects, SA nanoparticles showed toxicity in fibroblasts, causing cell death, and produced high hemolytic rates, indicating toxicity to red blood cells. This finding might be related to lipid type, as well as, the shape of the nanoparticles. No morphological alterations and hemolytic effects were observed in cells incubated with SLN containing TPM and GM. The SLN containing TPM and GM showed long-term stability, suggesting good shelf-life. The results indicate high toxicity of SLN prepared with SA, and strongly suggest that the components of the formulation should be analyzed in combination rather than separately to avoid misinterpretation of the results.

  3. Mealworms: Alternate Source of Lipids

    OpenAIRE

    2014-01-01

    The aim of present study was to determine the physicochemical properties of the oil obtained from Tenebrio molitor larvae (mealworms) and explore its potential as edible oil. Five batches of Tenebrio molitor larvae were investigated for their lipid content and physiochemical properties. Three batches were reared in lab (3 different productions) and two were purchased from a local supplier. The lipids were extracted using a cold extraction technique employing 2:1 ratio chloroform/methanol as s...

  4. How Prepared is Prepared Enough?

    Science.gov (United States)

    Porter-Levy; Macleod; Rickert

    1996-10-01

    A 17-year-old female was in the final stage in treatment of right unilateral cleft lip and palate. She had undergone a number of previous surgeries. Hearing and speech were good on evaluation, and her social and family situation were deemed excellent. After preparatory orthodontics she underwent a Lefort I maxillary advancement. Surgery was successful and she was admitted into postoperative recovery. However, the lack of adequate preoperative preparation caused traumatic reaction from the patient and her parents: anxiety over appearance, crying, refusal of oral fluids and oral care, refusal of analgesia, and refusal to mobilize. The patience and persistence of hospital staff slowly overcame all adversities and the patient moved on to full and successful recovery, but this case prompted changes in preoperative procedures and involvement of patients and their families in postoperative meal selection, planing, and preparation.

  5. Lipid metabolism in experimental animals

    Directory of Open Access Journals (Sweden)

    Sánchez-Muñiz, Francisco J.

    1998-08-01

    Full Text Available Publications are scarce in the way in chich metabolic processes are affected by the ingestion of heated fats used to prepare food. Similarly studies measuring metabolic effects of the consumption on fried food are poorly known. The purpose of this presentation is to summarize information on frying fats and frying foods upon lipid metabolism in experimental animals. Food consumption is equivalent or even higher when oils or the fat content of frying foods are poorly alterated decreasing their acceptability when their alteration degree increase. After 4hr. experiment the digestibility and absorption coefficients of a single dosis of thermooxidized oils were significantly decreased in rats, however the digestive utilization of frying thermooxidized oils included in diets showed very little change in comparison with unused oils by feeding trials on rats. Feeding rats different frying fats induced a slight hypercholesterolemic effect being the magnitude of this effect related to the linoleic decrease in diet produced by frying. However HDL, the main rat-cholesterol carrier, also increased, thus the serum cholesterol/HDL-cholesterol ratio did not change. Results suggest that rats fed frying fats adapt their lipoprotein metabolism increasing the number of HDL particles. Deep fat frying deeply changed the fatty acid composition of foods, being possible to increase their n-9 or n-6 fatty acid and to decrease the saturated fatty acid contents by frying. When olive oil-and sunflower oil-fried sardines were used as the only protein and fat sources of rats-diets in order to prevent the dietary hypercholesterolemia it was provided that both fried-sardine diets showed a powerful check effect on the cholesterol raising effect induced by dietary cholesterol. The negative effect of feeding rats cholesterol plus bovine bile to induce hypercholesterolemia on some cell-damage markers such as lactate dehydrogenase, transaminases, alkaline phosphatase, was

  6. NMR spectroscopy for evaluation of lipid oxidation

    Science.gov (United States)

    During storage and use of edible oils and other lipid-containing foods, reactions between lipids and oxygen occur, resulting in lipid oxidation and the subsequent development of off-flavors and odors. Accurate and timely assessment of lipid oxidation is critical for effective quality control of food...

  7. Lipid nanotube formation using space-regulated electric field above interdigitated electrodes.

    Science.gov (United States)

    Bi, Hongmei; Fu, Dingguo; Wang, Lei; Han, Xiaojun

    2014-04-22

    Lipid nanotubes have great potential in biology and nanotechnology. Here we demonstrate a method to form lipid nanotubes using space-regulated AC electric fields above coplanar interdigitated electrodes. The AC electric field distribution can be regulated by solution height above the electrodes. The ratio of field component in x axis (Ex) to field component in z axis (Ez) increases dramatically at solution height below 50 μm; therefore, at lower solution height, the force from Ex predominantly drives lipids to form lipid nanotubes along with the electric field direction. The forces exerted on the lipid nanotube during its formation were analyzed in detail, and an equation was obtained to describe the relationship among nanotube length and field frequency, amplitude, and time. We believe that the presented approach opens a way to design and prepare nanoscale materials with unique structural and functional properties using space-regulated electric fields.

  8. Effect of Solid Lipid Nanoparticle-Encapsulated Antimicrobial Peptide on Keratinocyte Migration and Wound Healing

    Science.gov (United States)

    2013-05-03

    suspension with100-µL trypan blue (1:1) (Sigma-Aldrich, St. Louis, MO). 10 µL of cell and trypan blue solution was analyzed by Countess TM...of morphine and solid lipid nanoparticle. Journal of Biotechnology 2010 148: 24-30. 24. Marsh PD. Dental Plaque: biological significance of a...nanoparticles (SLN) and nanostructured lipid carriers (NLC) in cosmetic and dermatological preparations. Adv Drug Deliv. 2002 Rev 54 supplement 1: S131-55

  9. Phase structure of liposome in lipid mixtures.

    Science.gov (United States)

    Zhang, Tianxi; Li, Yuzhuo; Mueller, Anja

    2011-11-01

    Gas microbubbles present in ultrasound imaging contrast agents are stabilized by lipid aggregates that typically contain a mixture of lipids. In this study, the phase structure of the lipid mixtures that contained two or three lipids was investigated using three different methods: dynamic light scattering, (1)H NMR, and microfluidity measurements with fluorescence probes. Three lipids that are commonly present in imaging agents (DPPC, DPPE-PEG, and DPPA) were used. Two types of systems, two-lipid model systems and simulated imaging systems were investigated. The results show that liposomes were the dominant aggregates in all the samples studied. The polar PEG side chains from the PEGylated lipid lead to the formation of micelles and micellar aggregates in small sizes. In the ternary lipid systems, almost all the lipids were present in bilayers with micelles absent and free lipids at very low concentration. These results suggest that liposomes, not micelles, contribute to the stabilization of microbubbles in an ultrasound imaging contrast agent.

  10. Lipid nanoparticle interactions and assemblies

    Science.gov (United States)

    Preiss, Matthew Ryan

    Novel liposome-nanoparticle assemblies (LNAs) provide a biologically inspired route for designing multifunctional bionanotheranostics. LNAs combine the benefits of lipids and liposomes to encapsulate, transport, and protect hydrophilic and hydrophobic therapeutics with functional nanoparticles. Functional nanoparticles endow LNAs with additional capabilities, including the ability to target diseases, triggered drug release, controlled therapeutic output, and diagnostic capabilities to produce a drug delivery system that can effectively and efficiently deliver therapeutics while reducing side effects. Not only could LNAs make existing drugs better, they could also provide an avenue to allow once promising non-approved drugs (rejected due to harmful side effects, inadequate pharmacokinetics, and poor efficacy) to be safely used through targeted and controlled delivery directly to the diseased site. LNAs have the potential to be stimuli responsive, delivering drugs on command by external (ultrasound, RF heating, etc.) or internal (pH, blood sugar, heart rate, etc.) stimuli. Individually, lipids and nanoparticles have been clinically approved for therapy, such as Doxil (a liposomal doxorubicin for cancer treatment), and diagnosis, such as Feridex (an iron oxide nanoparticle an MRI contrast enhancement agent for liver tumors). In order to engineer these multifunctional LNAs for theranostic applications, the interactions between nanoparticles and lipids must be better understood. This research sought to explore the formation, design, structures, characteristics, and functions of LNAs. To achieve this goal, different types of LNAs were formed, specifically magnetoliposomes, bilayer decorated LNAs (DLNAs), and lipid-coated magnetic nanoparticles (LMNPs). A fluorescent probe was embedded in the lipid bilayer of magnetoliposomes allowing the local temperature and membrane fluidity to be observed. When subjected to an electromagnetic field that heated the encapsulated iron

  11. Solid lipid nanoparticles and nanostructured lipid carriers--innovative generations of solid lipid carriers.

    Science.gov (United States)

    Shidhaye, S S; Vaidya, Reshma; Sutar, Sagar; Patwardhan, Arati; Kadam, V J

    2008-10-01

    The first generation of solid lipid carrier systems in nanometer range, Solid Lipid Nanoparticles (SLN), was introduced as an alternative to liposomes. SLN are aqueous colloidal dispersions, the matrix of which comprises of solid biodegradable lipids. SLN are manufactured by techniques like high pressure homogenization, solvent diffusion method etc. They exhibit major advantages such as modulated release, improved bioavailability, protection of chemically labile molecules like retinol, peptides from degradation, cost effective excipients, improved drug incorporation and wide application spectrum. However there are certain limitations associated with SLN, like limited drug loading capacity and drug expulsion during storage, which can be minimized by the next generation of solid lipids, Nanostructured lipid carriers (NLC). NLC are lipid particles with a controlled nanostructure that improves drug loading and firmly incorporates the drug during storage. Owing to their properties and advantages, SLN and NLC may find extensive application in topical drug delivery, oral and parenteral administration of cosmetic and pharmaceutical actives. Cosmeceuticals is emerging as the biggest application target of these carriers. Carrier systems like SLN and NLC were developed with a perspective to meet industrial needs like scale up, qualification and validation, simple technology, low cost etc. This paper reviews present status of SLN and NLC as carrier systems with special emphasis on their application in Cosmeceuticals; it also gives an overview about various manufacturing techniques of SLN and NLC.

  12. Mass Spectrometry Methodology in Lipid Analysis

    OpenAIRE

    Lin Li; Juanjuan Han; Zhenpeng Wang; Jian'an Liu; Jinchao Wei; Shaoxiang Xiong; Zhenwen Zhao

    2014-01-01

    Lipidomics is an emerging field, where the structures, functions and dynamic changes of lipids in cells, tissues or body fluids are investigated. Due to the vital roles of lipids in human physiological and pathological processes, lipidomics is attracting more and more attentions. However, because of the diversity and complexity of lipids, lipid analysis is still full of challenges. The recent development of methods for lipid extraction and analysis and the combination with bioinformatics tech...

  13. [Lipids, depression and suicide].

    Science.gov (United States)

    Colin, A; Reggers, J; Castronovo, V; Ansseau, M

    2003-01-01

    Polyunsatured fatty acids are made out of a hydrocarbonated chain of variable length with several double bonds. The position of the first double bond (omega) differentiates polyunsatured omega 3 fatty acids (for example: alpha-linolenic acid or alpha-LNA) and polyunsatured omega 6 fatty acids (for example: linoleic acid or LA). These two classes of fatty acids are said to be essential because they cannot be synthetised by the organism and have to be taken from alimentation. The omega 3 are present in linseed oil, nuts, soya beans, wheat and cold water fish whereas omega 6 are present in maize, sunflower and sesame oil. Fatty acids are part of phospholipids and, consequently, of all biological membranes. The membrane fluidity, of crucial importance for its functioning, depends on its lipidic components. Phospholipids composed of chains of polyunsatured fatty acids increase the membrane fluidity because, by bending some chains, double bonds prevent them from compacting themselves perfectly. Membrane fluidity is also determined by the phospholipids/free cholesterol ratio, as cholesterol increases membrane viscosity. A diet based on a high proportion of essential polyunsatured fatty acids (fluid) would allow a higher incorporation of cholesterol (rigid) in the membranes to balance their fluidity, which would contribute to lower blood cholesterol levels. Brain membranes have a very high content in essential polyunsatured fatty acids for which they depend on alimentation. Any dietary lack of essential polyunsatured fatty acids has consequences on cerebral development, modifying the activity of enzymes of the cerebral membranes and decreasing efficiency in learning tasks. The prevalence of depression seems to increase continuously since the beginning of the century. Though different factors most probably contribute to this evolution, it has been suggested that it could be related to an evolution of alimentary patterns in the Western world, in which polyunsatured omega 3

  14. Lipid formulation as a drug carrier for drug delivery.

    Science.gov (United States)

    Tomii, Yoshifumi

    2002-01-01

    In recent years, a Drug Delivery System (DDS), a preparative approach attracts the attention in the development of new drugs. DDS focuses on the regulation of the in vivo dynamics, such as absorption, distribution, metabolism, and elimination, thereby improving the effectiveness and the safety of the drugs by an applicable use of drug preparation technologies. A conventional intravenous dosage form of Amphotericin B (AmB), Fungizone, is the most effective clinically available for treating fungal infections. However, the clinical efficacy of AmB is limited by its adverse effects. Several lipid formulations, such as Liposomal AmB (L-AmB), AmB lipid complex (ABLC), and AmB colloidal dispersion (ABCD), with reduced side effects have been developed. These formulations are reported to have excellent safety and efficacy. However, comparable efficacy can be achieved only when they are administered at high doses than AmB. One of the problems of using these formulations is that they are easily taken up by the reticuloendothelial system (RES). An artificial lipoprotein-like particles, a novel drug carrier Lipid Nano-Sphere (LNS), which is 25 - 50 nm in size and is composed of phospholipids and simple lipid. LNS show a higher plasma concentration of drugs and lower uptake by RES-tissue different forms other lipid base drug carriers. In vitro and in vivo, LNS incorporating AmB, NS-718, shows reduced toxicity, while maintaining activity against fungi. LNS have a unique characteristic as an effective carrier of AmB for treatment of fungal infection.

  15. Control of lignin solubility and particle formation modulates its antioxidant efficiency in lipid medium

    DEFF Research Database (Denmark)

    Barsberg, Søren Talbro; Thygesen, Lisbeth Garbrecht; Sanadi, Anand Ramesh

    2014-01-01

    Lignin is an abundant plant polymer usually regarded as waste material. In the present work, antioxidant properties of lignin preparations with differing lipid solubility were studied using biodiesel as a convenient lipid test substrate. In place of formerly used assays, we used attenuated total...... reflectance (ATR) FT-IR spectroscopy to follow in situ biodiesel autoxidation on a heated ATR crystal as a function of time. The study demonstrates that a complex balance between intrinsic (chemical) efficiency, solubility, and particle formation controls the antioxidant efficiency of differently prepared...... lignin fractions. It was found that solubility and particle formation of lignin preparations strongly modulate its antioxidant efficiency and that these properties might depend on the presence of lipid components within the original lignin source....

  16. Hybrid Lipid as Biological Surfactants

    Science.gov (United States)

    Brewster, Robert; Pincus, Phil; Safran, Sam

    2009-03-01

    Systems capable of forming finite-sized, equilibrium domains are of biological interest in the context of membrane rafts where it has been observed that certain cellular functions are mediated by small (nanometric to tens of nanometers) domains with specific lipid composition that differs from the average composition of the membrane. These small domains are composed mainly of lipids with completely saturated hydrocarbon tails that show good orientational order in the membrane. The surrounding phase consists mostly of lipids with at least one unsaturated bond in the hydrocarbon tails which forces a ``kink'' in the chain and inhibits ordering. In vitro, this phase separation can be replicated; however, the finite domains coarsen into macroscopic domains with time. We have extended a model for the interactions of lipids in the membrane, akin to that developed in the group of Schick (Elliott et al., PRL 2006 and Garbes Putzel and Schick, Biophys. J. 2008), which depends entirely on the local ordering of hydrocarbon tails. We generalize this model to an additional species and identify a biologically relevant component, a lipid with one fully saturated hydrocarbon chain and one chain with at least one unsaturated bond, that may serve as a line-active component, capable of reducing the line tension between domains to zero, thus stabilizing finite sized domains in equilibrium.

  17. Immunological Regulation by Bioactive Lipids.

    Science.gov (United States)

    Taketomi, Yoshitaka; Murakami, Makoto

    2017-01-01

     Mast cells originate from hematopoietic stem cells and undergo terminal maturation in the extravascular tissues, in which they are ultimately resident. Mast maturation, phenotype, and function are dictated by the local microenvironment, which has a significant influence on the ability of mast cells to recognize and respond to stimuli. Activation of mast cells can lead to the release of three distinct classes of mediators, including preformed mediators stored in secretory granules, newly transcribed cytokines and chemokines, and de novo-synthesized bioactive lipid mediators. It is currently recognized that bioactive lipids such as arachidonic acid metabolites (prostaglandins and leukotrienes) released from mast cells modulate innate and adaptive immune responses both directly and indirectly through communication with other microenvironmental immune cells or stroma cells. Moreover, mast cells express a variety of lipid receptors and, if activated by bioactive lipids such as arachidonic acid, ω3 fatty acids, lysophospholipids, and their metabolites, can alter the release and production of other mediators including histamine, cytokines, and chemokines, and thereby alter homeostatic or pathophysiological responses. This review focuses on newly identified functional aspects of bioactive lipids with regard to their immune regulation and functional outcomes in both homeostasis and allergic disease.

  18. Non-lamellar lipid liquid crystalline structures at interfaces.

    Science.gov (United States)

    Chang, Debby P; Barauskas, Justas; Dabkowska, Aleksandra P; Wadsäter, Maria; Tiberg, Fredrik; Nylander, Tommy

    2015-08-01

    The self-assembly of lipids leads to the formation of a rich variety of nano-structures, not only restricted to lipid bilayers, but also encompassing non-lamellar liquid crystalline structures, such as cubic, hexagonal, and sponge phases. These non-lamellar phases have been increasingly recognized as important for living systems, both in terms of providing compartmentalization and as regulators of biological activity. Consequently, they are of great interest for their potential as delivery systems in pharmaceutical, food and cosmetic applications. The compartmentalizing nature of these phases features mono- or bicontinuous networks of both hydrophilic and hydrophobic domains. To utilize these non-lamellar liquid crystalline structures in biomedical devices for analyses and drug delivery, it is crucial to understand how they interact with and respond to different types of interfaces. Such non-lamellar interfacial layers can be used to entrap functional biomolecules that respond to lipid curvature as well as the confinement. It is also important to understand the structural changes of deposited lipid in relation to the corresponding bulk dispersions. They can be controlled by changing the lipid composition or by introducing components that can alter the curvature or by deposition on nano-structured surface, e.g. vertical nano-wire arrays. Progress in the area of liquid crystalline lipid based nanoparticles opens up new possibilities for the preparation of well-defined surface films with well-defined nano-structures. This review will focus on recent progress in the formation of non-lamellar dispersions and their interfacial properties at the solid/liquid and biologically relevant interfaces.

  19. Direct observation of lipid domains in free standing bilayers: from simple to complex lipid mixtures

    DEFF Research Database (Denmark)

    Bagatolli, Luis A

    2003-01-01

    The direct observation of temperature-dependent lipid phase equilibria, using two-photon excitation fluorescence microscopy on giant unilamellar vesicles (GUVs) composed of different lipid mixtures, provides novel information about the physical characteristics of lipid domain coexistence. Physica...

  20. Lipids, lipid droplets and lipoproteins in their cellular context; an ultrastructural approach

    NARCIS (Netherlands)

    Mesman, R.J.

    2013-01-01

    Lipids are essential for cellular life, functioning either organized as bilayer membranes to compartmentalize cellular processes, as signaling molecules or as metabolic energy storage. Our current knowledge on lipid organization and cellular lipid homeostasis is mainly based on biochemical data.

  1. Evaluation of Physarum polycephalum plasmodial growth and lipid production using rice bran as a carbon source.

    Science.gov (United States)

    Tran, Hanh; Stephenson, Steven; Pollock, Erik

    2015-08-01

    The myxomycete Physarum polycephalum appears to have remarkable potential as a lipid source for biodiesel production. The present study evaluated the use of rice bran as a carbon source and determined the medium components for optimum growth and lipid production for this organism. Optimization of medium components by response surface methodology showed that rice bran and yeast extract had significant influences on lipid and biomass production. The optimum medium consisted of 37.5 g/L rice bran, 0.79 g/L yeast extract and 12.5 g/L agar, and this yielded 7.5 g/L dry biomass and 0.9 g/L lipid after 5 days. The biomass and lipid production profiles revealed that these parameters increased over time and reached their maximum values (10.5 and 1.26 g/L, respectively) after 7 days. Physarum polycephalum growth decreased on the spent medium but using the latter increased total biomass and lipid concentrations to 14.3 and 1.72 g/L, respectively. An effective method for inoculum preparation was developed for biomass and lipid production by P. polycephalum on a low-cost medium using rice bran as the main carbon source. These results also demonstrated the feasibility of scaling up and reusing the medium for additional biomass and lipid production.

  2. Carbamate-linked cationic lipids with different hydrocarbon chains for gene delivery.

    Science.gov (United States)

    Shi, Jia; Yu, Shijun; Zhu, Jie; Zhi, Defu; Zhao, Yinan; Cui, Shaohui; Zhang, Shubiao

    2016-05-01

    A series of carbamate-linked cationic lipids containing saturated or unsaturated hydrocarbon chains and quaternary ammonium head were designed and synthesized. After recrystallization, carbamate-linked cationic lipids with high purity (over 95%) were obtained. The structures of these lipids were proved by IR spectrum, HR-ESI-MS, HPLC, (1)H NMR and (13)C NMR. The liposomes were prepared by using these cationic lipids and neutral lipid DOPE. Particle size and zeta-potential were studied to show that they were suitable for gene transfection. The DNA-bonding ability of C12:0, C14:0 and C18:1 cationic liposomes was much better than others. The results of transfection showed that hydrophobic chains of these lipids have great effects on their transfection activity. The lipids bearing C12:0, C14:0 saturated chains or C18:1 unsaturated chain showed relatively higher transfection efficiency and lower cytotoxicity. So these cationic lipids could be used as non-viral gene carriers for further studies. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. In vitro characterization and in vivo evaluation of nanostructured lipid curcumin carriers for intragastric administration.

    Science.gov (United States)

    Fang, Min; Jin, Yilin; Bao, Wei; Gao, Hui; Xu, Mengjin; Wang, Di; Wang, Xia; Yao, Ping; Liu, Liegang

    2012-01-01

    Curcumin has a variety of pharmacological effects. However, poor water solubility and low oral bioavailability limit its clinical utility. A delivery system for nanostructured lipid carriers has been reported to be a promising approach to enhancing the oral absorption of curcumin. The aim of the present study was to investigate the pharmacokinetics, tissue distribution, and relative bioavailability of curcumin in rats after a single intragastric dose of a nanostructured lipid curcumin carrier formulation. Nanostructured lipid curcumin carriers were prepared using the ethanol dripping method and characterized in terms of the particle size, polydispersity index, zeta potential, differential scanning calorimetry, drug-loading capacity, encapsulation efficiency, and in vitro release. The pharmacokinetics and tissue distribution of nanostructured lipid curcumin carriers and curcumin suspension were compared after intragastric administration. Nanostructured lipid curcumin carriers showed a significantly higher peak plasma concentration (564.94 ± 14.98 ng/mL versus 279.43 ± 7.21 ng/mL, P nanostructured lipid curcumin carrier formulation, tissue concentrations of curcumin also increased, especially in the brain. The nanostructured lipid curcumin carrier formulation improved the ability of curcumin to cross the blood-brain barrier, with an 11.93-fold increase in the area under the curve achieved in the brain when compared with curcumin suspension. The nanostructured lipid carrier formulation significantly improved the oral bioavailability of curcumin and represents a promising method for its oral delivery.

  4. Formulation and evaluation of chitosan solid lipid nanoparticles of carbamazepine

    Directory of Open Access Journals (Sweden)

    Nair Rahul

    2012-06-01

    Full Text Available Abstract The present work aims at preparing aqueous suspension of Solid lipid Nanoparticles containing Chitosan (CT which is a biopolymer that exhibits a number of interesting properties which include controlled drug delivery. Carbamezapine (CBZ is a lipophilic drug which shows it antiepileptic activity by inactivating sodium channels. The solid lipid Nanoparticles (SLN of Chitosan-CBZ were prepared by using solvent injection method using ethanol as organic solvent. The prepared SLN formulations exhibited high encapsulation efficiency, high physical stability. The drug incorporated SLNs have demonstrated that the controlled release patterns of the drug for prolonged period. The prepared SLNs were characterized for surface morphology by SEM analysis, entrapment efficiency, zeta potential, FTIR, DSC and In-vitro diffusion studies. The hydrodynamic mean diameter and zeta potential were 168.7 ±1.8 nm and −28.9 ±2.0 mV for SLN-chitosan-CBZ respectively. Therefore chitosan-SLN can be good candidates to encapsulate CBZ and to increase its therapeutic efficacy in the treatment of Epilepsy.

  5. Mass Spectrometry Methodology in Lipid Analysis

    Directory of Open Access Journals (Sweden)

    Lin Li

    2014-06-01

    Full Text Available Lipidomics is an emerging field, where the structures, functions and dynamic changes of lipids in cells, tissues or body fluids are investigated. Due to the vital roles of lipids in human physiological and pathological processes, lipidomics is attracting more and more attentions. However, because of the diversity and complexity of lipids, lipid analysis is still full of challenges. The recent development of methods for lipid extraction and analysis and the combination with bioinformatics technology greatly push forward the study of lipidomics. Among them, mass spectrometry (MS is the most important technology for lipid analysis. In this review, the methodology based on MS for lipid analysis was introduced. It is believed that along with the rapid development of MS and its further applications to lipid analysis, more functional lipids will be identified as biomarkers and therapeutic targets and for the study of the mechanisms of disease.

  6. Dynamics, Surface Electrostatics and Phase Properties of Nanoscale Curved Lipid Bilayers

    Science.gov (United States)

    Koolivand, Amir

    phase of the bilayer was higher in smaller vesicles likely due to a larger number of defects in smaller vesicles allowing more water soluble molecules partitioning into lipid bilayers. However, the rotational correlation time for TEMPO slows down in smaller vesicles indicating an increase in the lipid packing. Pulsed EPR techniques, HYSCORE and ESEEM spectroscopy, were used to detect local water concentration and distinguish the hydrogen bonded water to the nitroxide from the bulk one. HYSCORE was then employed to investigate the effect of bilayer curvature on the water penetration into lipid bilayer and it was found that the higher curved lipids allow more water to penetrate into lipid bilayer as a result of more defects in the highly curved lipid vesicles. Nanopore-confined lipid bilayers formed inside ordered nanochannels of anodic aluminum oxide (AAO) have found many practical applications, serving as thermodynamically stable biophysical models of cellular membranes of concave curvature and allowing for stabilization of membrane proteins in functional conformations. It was found that surface potential of POPG lipids inside the AAO pores are higher than that of vesicles---the effect that is attributed to highly ordered and packed lipids inside the AAO nanopores. At pH=7.0 the AAO zeta potential was found to be -29+/-0.64 mV. Cytochrome C and poly glutamic acid as positively and negatively charged macromolecules in physiological pH (7.4) were used to prepare multilayer protein nanotubes and cytochrome c interaction with AAO was studied by CD and UV-Vis spectroscopy. Lipid nanotube arrays containing a transmembrane WALP peptide were also formed and these macroscopically aligned lipid nanotubes were studied by CD spectroscopy. The lipid phase transition of DMPC and binding of melittin, an antibacterial peptide model, were observed from a frequency change for the QCM quartz-AAO-Lipid as a promising "biosensor".

  7. Identification of Lipid Binding Modulators Using the Protein-Lipid Overlay Assay.

    Science.gov (United States)

    Tang, Tuo-Xian; Xiong, Wen; Finkielstein, Carla V; Capelluto, Daniel G S

    2017-01-01

    The protein-lipid overlay assay is an inexpensive, easy-to-implement, and high-throughput methodology that employs nitrocellulose membranes to immobilize lipids in order to rapid screen and identify protein-lipid interactions. In this chapter, we show how this methodology can identify potential modulators of protein-lipid interactions by screening water-soluble lipid competitors or even the introduction of pH changes during the binding assay to identify pH-dependent lipid binding events.

  8. Blood lipids and prostate cancer

    DEFF Research Database (Denmark)

    Bull, Caroline J; Bonilla, Carolina; Holly, Jeff M P

    2016-01-01

    Genetic risk scores were used as unconfounded instruments for specific lipid traits (Mendelian randomization) to assess whether circulating lipids causally influence prostate cancer risk. Data from 22,249 prostate cancer cases and 22,133 controls from 22 studies within the international PRACTICAL...... into logistic regression models to estimate the presence (and direction) of any causal effect of each lipid trait on prostate cancer risk. There was weak evidence for an association between the LDL genetic score and cancer grade: the odds ratio (OR) per genetically instrumented standard deviation (SD) in LDL......, comparing high- (≥7 Gleason score) versus low-grade (cancers was 1.50 (95% CI: 0.92, 2.46; P = 0.11). A genetically instrumented SD increase in TGs was weakly associated with stage: the OR for advanced versus localized cancer per unit increase in genetic risk score was 1.68 (95% CI: 0...

  9. Fuel from microalgae lipid products

    Energy Technology Data Exchange (ETDEWEB)

    Hill, A.M.; Feinberg, D.A.

    1984-04-01

    The large-scale production of microalgae is a promising method of producing a renewable feedstock for a wide variety of fuel products currently refined from crude petroleum. These microalgae-derived products include lipid extraction products (triglycerides, fatty acids, and hydrocarbons) and catalytic conversion products (paraffins and olefins). Microalgal biomass productivity and lipid composition of current experimental systems are estimated at 66.0 metric tons per hectare year and 30% lipid content. Similar yields in a large-scale facility indicate that production costs are approximately six times higher than the average domestic price for crude, well-head petroleum. Based on achievable targets for productivity and production costs, the potential for microalgae as a fuel feedstock is presented in context with selected process refining routes and is compared with conventional and alternative feedstocks (e.g., oilseeds) with which microalgae must compete. 24 references, 9 figures, 4 tables.

  10. Yeast lipid metabolism at a glance.

    Science.gov (United States)

    Klug, Lisa; Daum, Günther

    2014-05-01

    During the last decades, lipids have gained much attention due to their involvement in health and disease. Lipids are required for the formation of membranes and contribute to many different processes such as cell signaling, energy supply, and cell death. Various organelles such as the endoplasmic reticulum, mitochondria, peroxisomes, and lipid droplets are involved in lipid metabolism. The yeast Saccharomyces cerevisiae has become a reliable model organism to study biochemistry, molecular biology, and cell biology of lipids. The availability of mutants bearing defects in lipid metabolic pathways and the ease of manipulation by culture conditions facilitated these investigations. Here, we summarize the current knowledge about lipid metabolism in yeast. We grouped this large topic into three sections dealing with (1) fatty acids; (2) membrane lipids; and (3) storage lipids. Fatty acids serve as building blocks for the synthesis of membrane lipids (phospholipids, sphingolipids) and storage lipids (triacylglycerols, steryl esters). Phospholipids, sterols, and sphingolipids are essential components of cellular membranes. Recent investigations addressing lipid synthesis, degradation, and storage as well as regulatory aspects are presented. The role of enzymes governing important steps of the different lipid metabolic pathways is described. Finally, the link between lipid metabolic and dynamic processes is discussed.

  11. 叶酸靶向载紫杉醇磷脂-聚合物杂化纳米粒的制备及其体外细胞评价%Preparation and in vitro evaluation of folate-targeted lipid-polymer hybrid nanoparticles loaded with paclitaxel

    Institute of Scientific and Technical Information of China (English)

    陈卓; 王海; 肖宝; 胡春艳; 务圣洁; 樊帆; 秦玉; 朱敦皖; 张琳华

    2016-01-01

    Objective To prepare folate-targeted lipid-polymner hybrid nanoparticles loaded with paclitaxel (PTX-FLPNPs),evaluate its in vitro cellular uptake and cytotoxicity.Methods PTX-FLPNPs composed of PCL-PEG-PCL,DSPE-mPEG2000 and Folate-PEG(2000)-DSPE were prepared by thin-film hydration method,and characterized in terms of morphology,particle size and size distribution,drug loading and encapsulation efficiency.The uptake efficiency of FLPNPs in breast carcinoma cells EMT-6 was evaluated by confocal laser scanning microscopy.The cytotoxicity of PTX-FLPNPs against EMT-6 cells was determined by MTS assay.Results PTX-FLPNPs showed spherical core-shell morphology with narrow size distribution.The PTX-FLPNPs with 30% drugloading content were found as spherical shape with average particle diameter of (279.9±8.7) nm,polydispersity index of (0.173±0.021),Zeta potential of (-17.5±1.1) mV,drug loading of (27.36±.0.91)% and encapsulation efficiency of(91.16± 1.12)%.The internalization efficiency of FLPNPs was obviously higher that of LPNPs in EMT-6 cells which overexpress folate receptor (P<0.05).The cytotoxic effect of PTX-loaded FLPNPs was lower than that of PTX injection,but higher than that of PTX-loaded LPNPs (without folate conjugation).Conclusions The PTX-FLPNPs exhibits high drug-loading content and drug encapsulating efficiency,uniform size with narrow size distribution,high internalization efficiency in EMT6 cells by active targeting-mediated endocytosis.The PTX-FLPNPs would be a promising nanosized drug formulation for tumor-targeted therapy.%目的 制备具有叶酸靶向性的载紫杉醇磷脂-聚合物杂化纳米粒(PTX-FLPNPs),并研究其对乳腺癌细胞EMT-6的细胞毒性及体外细胞吞噬.方法 以聚己内酯-聚乙二醇-聚己内酯(PCL-PEG-PCL)、二硬脂酰基磷脂酰乙醇胺-甲氧基聚乙二醇(DSPE-mPEG2000)和叶酸偶联的磷脂(Folate-PEG(2000)-DSPE)为药物载体,通过薄膜水化法自组装

  12. Charge-reversal Lipids, Peptide-based Lipids, and Nucleoside-based Lipids for Gene Delivery

    Science.gov (United States)

    LaManna, Caroline M.; Lusic, Hrvoje; Camplo, Michel; McIntosh, Thomas J.; Barthélémy, Philippe; Grinstaff, Mark W.

    2013-01-01

    Conspectus Twenty years after gene therapy was introduced in the clinic, advances in the technique continue to garner headlines as successes pique the interest of clinicians, researchers, and the public. Gene therapy’s appeal stems from its potential to revolutionize modern medical therapeutics by offering solutions to a myriad of diseases by tailoring the treatment to a specific individual’s genetic code. Both viral and non-viral vectors have been used in the clinic, but the low transfection efficiencies when utilizing non-viral vectors have lead to an increased focus on engineering new gene delivery vectors. To address the challenges facing non-viral or synthetic vectors, specifically lipid-based carriers, we have focused on three main themes throughout our research: 1) that releasing the nucleic acid from the carrier will increase gene transfection; 2) that utilizing biologically inspired designs, such as DNA binding proteins, to create lipids with peptide-based headgroups will improve delivery; and 3) that mimicking the natural binding patterns observed within DNA, by using lipids having a nucleoside headgroup, will give unique supramolecular assembles with high transfection efficiency. The results presented in this Account demonstrate that cellular uptake and transfection efficacy can be improved by engineering the chemical components of the lipid vectors to enhance nucleic acid binding and release kinetics. Specifically, our research has shown that the incorporation of a charge-reversal moiety to initiate change of the lipid from positive to negative net charge during the transfection process improves transfection. In addition, by varying the composition of the spacer (rigid, flexible, short, long, and aromatic) between the cationic headgroup and the hydrophobic chains, lipids can be tailored to interact with different nucleic acids (DNA, RNA, siRNA) and accordingly affect delivery, uptake outcomes, and transfection efficiency. Introduction of a peptide

  13. Distribution of neutral lipids in the lipid droplet core

    DEFF Research Database (Denmark)

    Chaban, Vitaly V; Khandelia, Himanshu

    2014-01-01

    Cholesteryl esters (CEs) are a form of cholesterol (CHOL) storage in the living cells, as opposed to free CHOL. CEs are major constituents of low density lipoprotein particles. Therefore, CEs are implicated in provoking atherosclerosis. Arranged into cytoplasmic lipid droplets (LDs), CEs are stored...

  14. Cholesterol lipids and cholesterol-containing lipid rafts in bacteria.

    Science.gov (United States)

    Huang, Zhen; London, Erwin

    2016-09-01

    Sterols are important components of eukaryotic membranes, but rare in bacteria. Some bacteria obtain sterols from their host or environment. In some cases, these sterols form membrane domains analogous the lipid rafts proposed to exist in eukaryotic membranes. This review describes the properties and roles of sterols in Borrelia and Helicobacter.

  15. Solid lipid extrusion of sustained release dosage forms.

    Science.gov (United States)

    Reitz, Claudia; Kleinebudde, Peter

    2007-09-01

    The applicability of the solid lipid extrusion process as preparations method for sustained release dosage forms was investigated in this study. Two lipids with similar melting ranges but of different composition, glyceryl palmitostearate (Precirol ATO 5) and glyceryl trimyristate (Dynasan 114), and mixtures of each lipid with 50% or 75% theophylline were extruded at temperatures below their melting ranges. Extrudates were analyzed using differential scanning calorimetry, scanning electron microscopy, porosity measurements and in vitro drug dissolution studies. The possibility of processing lipids by softening instead of complete melting and without subsequent formation of low-melting, metastable polymorphs could be demonstrated. Extrudates based on formulations of glyceryl palmitostearate/theophylline (50:50) and glyceryl trimyristate/theophylline (50:50) showed sustained release properties. An influence of extrusion conditions on the matrix structure was shown for extrudates based on a mixture of glyceryl trimyristate and theophylline (50:50). Glyceryl trimyristate tended to solidify in porous structures after melting. Exceeding a material temperature of 50.5 degrees C led to porous extrudate matrices with a faster drug release. The production of novel, non porous sustained release matrices was possible at a material temperature of 49.5 degrees C. Extrudates based on glyceryl trimyristate/theophylline (50:50) only slight changes in melting enthalpy and stable drug release profiles.

  16. Nanoparticle-lipid bilayer interactions studied with lipid bilayer arrays

    Science.gov (United States)

    Lu, Bin; Smith, Tyler; Schmidt, Jacob J.

    2015-04-01

    The widespread environmental presence and commercial use of nanoparticles have raised significant health concerns as a result of many in vitro and in vivo assays indicating toxicity of a wide range of nanoparticle species. Many of these assays have identified the ability of nanoparticles to damage cell membranes. These interactions can be studied in detail using artificial lipid bilayers, which can provide insight into the nature of the particle-membrane interaction through variation of membrane and solution properties not possible with cell-based assays. However, the scope of these studies can be limited because of the low throughput characteristic of lipid bilayer platforms. We have recently described an easy to use, parallel lipid bilayer platform which we have used to electrically investigate the activity of 60 nm diameter amine and carboxyl modified polystyrene nanoparticles (NH2-NP and COOH-NP) with over 1000 lipid bilayers while varying lipid composition, bilayer charge, ionic strength, pH, voltage, serum, particle concentration, and particle charge. Our results confirm recent studies finding activity of NH2-NP but not COOH-NP. Detailed analysis shows that NH2-NP formed pores 0.3-2.3 nm in radius, dependent on bilayer and solution composition. These interactions appear to be electrostatic, as they are regulated by NH2-NP surface charge, solution ionic strength, and bilayer charge. The ability to rapidly measure a large number of nanoparticle and membrane parameters indicates strong potential of this bilayer array platform for additional nanoparticle bilayer studies.The widespread environmental presence and commercial use of nanoparticles have raised significant health concerns as a result of many in vitro and in vivo assays indicating toxicity of a wide range of nanoparticle species. Many of these assays have identified the ability of nanoparticles to damage cell membranes. These interactions can be studied in detail using artificial lipid bilayers, which

  17. Highly antioxidant carotene-lipid nanocarriers: synthesis and antibacterial activity

    Science.gov (United States)

    Lacatusu, Ioana; Badea, Nicoleta; Ovidiu, Oprea; Bojin, Dionezie; Meghea, Aurelia

    2012-06-01

    The objective of this study was to explore the potential of two natural oils (squalene—Sq and grape seed oil—GSO) to prepare biocompatible antioxidant nanostructured lipid carriers—NLCs as a safety and protective formulation for sensitive β-carotene. For this purpose different oil-in-water nanoemulsions stabilized by a combination of alkylpolyoxy ethylene sorbitans, lecithin and a block copolymer, were prepared using a melt high-shear homogenization process. The physico-chemical characteristics of the carotene-loaded NLCs were firstly investigated in detail. The smaller lipid nanoparticles have been obtained by using Tween 20 as main non-ionic surfactant, with average diameters of about 85 nm for GSO and 89 nm for Sq, with a polydispersity index Escherichia coli bacteria. The antibacterial analysis shown that loaded-NLCs develop an effective inhibition zone against bacteria growth and it was dependent in a higher extent on the liquid lipid and carotene concentrations than on their particle size.

  18. Nanostructured Lipid Carriers Loaded with Baicalin: An Efficient Carrier for Enhanced Antidiabetic Effects.

    Science.gov (United States)

    Shi, Feng; Wei, Zheng; Zhao, Yingying; Xu, Ximing

    2016-01-01

    Recent studies have demonstrated that baicalin has antihyperglycemic effects by inhibiting lipid peroxidation. Baicalin is low hydrophilic and poorly absorbed after oral administration. Thus, a suitable formulation is highly desired to overcome the disadvantages of baicalin. The objective of this work was to prepare baicalin-loaded nanostructured lipid carriers (B-NLCs) for enhanced antidiabetic effects. B-NLCs were prepared by high-pressure homogenization method using Precirol as the solid lipid and Miglyol as the liquid lipid. The properties of the NLCs, such as particle size, zeta potential (ZP), and drug encapsulation efficiency (EE), were investigated. The morphology of NLCs was observed by transmission electron microscopy. In addition, drug release and antidiabetic activity were also studied. The results revealed that B-NLCs particles were uniformly in the nanosize range and of spherical morphology with a mean size of 92 ± 3.1 nm, a ZP of -31.35 ± 3.08 mV, and an EE of 85.29 ± 3.42%. Baicalin was released from NLCs in a sustained manner. In addition, B-NLCs showed a significantly higher antidiabetic efficacy compared with baicalin. B-NLCs described in this study are well-suited for the delivery of baicalin. Currently, herbal medicines have attracted increasing attention as a complementary approach for type 2 diabetesBaicalin has antihyperglycemic effects by inhibiting lipid peroxidationA suitable formulation is highly desired to overcome the disadvantages (poor solubility and low bioavailability) of baicalinNanostructured lipid carriers could enhance the antidiabetic effects of baicalin. Abbreviations used: B-NLCs: Baicalin-Loaded Nanostructured Lipid Carriers, B-SUS: Baicalin Water Suspension, EE: Encapsulation Efficiency, FBG: Fasting Blood Glucose, HbAlc: Glycosylated Hemoglobin, HPLC: High-performance Liquid Chromatography; NLCs: Nanostructured Lipid Carriers, PI: Polydispersity Index, SD: Sprague-Dawley, SLNs: Solid lipid nanoparticles, STZ

  19. Characterization of lipid model membranes designed for studying impact of ceramide species on drug diffusion and penetration.

    Science.gov (United States)

    Ochalek, M; Heissler, S; Wohlrab, J; Neubert, R H H

    2012-05-01

    The stratum corneum (SC) intercellular lipid matrix plays a crucial role in the skin barrier function. In the present study, lipid model membranes mimicking its phase behavior were prepared and characterized using different analytical techniques (i.a. SAXD, HPTLC, ESEM, confocal Raman imaging, ATR-FTIR spectroscopy) in order to obtain well-standardized model membranes for diffusion and penetration studies. The lipid model membranes should be used in the future for studying the impact of each ceramide species on the diffusion and penetration of drugs. The SAXD study confirmed that the lipids within artificial lipid systems are arranged similarly to the lipids in the human SC. The polarization microscopic and ESEM images showed the homogenous deposition of lipids on the polycarbonate filter. Both the HPTLC and confocal Raman imaging studies proved the homogenous distribution of individual lipid classes within the lipid model membranes. First in vitro diffusion experiments (performed using an ATR-FTIR diffusion cell) of the hydrophilic compound, urea, revealed that the lipid model membrane represents even stronger diffusion barrier than the human SC. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Lipid particle size effect on water vapor permeability and mechanical properties of whey protein/beeswax emulsion films.

    Science.gov (United States)

    Pérez-Gago, M B; Krochta, J M

    2001-02-01

    Lipid particle size effects on water vapor permeability (WVP) and mechanical properties of whey protein isolate (WPI)/beeswax (BW) emulsion films were investigated. Emulsion films containing 20 and 60% BW (dry basis) and mean lipid particle sizes ranging from 0.5 to 2.0 microm were prepared. BW particle size effects on WVP and mechanical properties were observed only in films containing 60% BW. WVP of these films decreased as lipid particle size decreased. As drying temperature increased, film WVPs decreased significantly. Meanwhile, tensile strength and elongation increased as BW particle size decreased. However, for 20% BW emulsion films, properties were not affected by lipid particle size. Results suggest that increased protein-lipid interactions at the BW particle interfaces, as particle size decreased and resulting interfacial area increased, result in stronger films with lower WVPs. Observing this effect depends on a large lipid content within the protein matrix. At low lipid content, the effect of interactions at the protein-lipid interfaces is not observed, due to the presence of large protein-matrix regions of the film without lipid, which are not influenced by protein-lipid interactions.

  1. You Sank My Lipid Rafts!

    Science.gov (United States)

    Campbell, Tessa N.

    2009-01-01

    The plasma membrane is the membrane that serves as a boundary between the interior of a cell and its extracellular environment. Lipid rafts are microdomains within a cellular membrane that possess decreased fluidity due to the presence of cholesterol, glycolipids, and phospholipids containing longer fatty acids. These domains are involved in many…

  2. Lipids of the Golgi membrane

    NARCIS (Netherlands)

    van Meer, G.

    1998-01-01

    The thin membrane of the endoplasmic reticulum matures into the thick plasma membrane in the Golgi apparatus. Along the way, the concentrations of cholesterol and sphingolipids increase. Here, Gerrit van Meer discusses how this phenomenon may reflect an intricate lipid-protein sorting machinery. Syn

  3. Spin-label studies on the anchoring and lipid-protein interactions of avidin with N-biotinylphosphatidylethanolamines in lipid bilayer membranes.

    Science.gov (United States)

    Swamy, M J; Marsh, D

    1997-06-17

    The specific binding of hen egg white avidin to phosphatidylcholine lipid membranes containing spin-labeled N-biotinylphosphatidylethanolamines (biotin-PESLs) was investigated by using ESR spectroscopy. Spin-labeled biotin-PEs were prepared with the nitroxide group at position C-5, C-8, C-10, C-12, or C-14 of the sn-2 chain and were incorporated at 1 mol % in lipid bilayer membranes of dimyristoylphosphatidylcholine. Binding of avidin produced a strong and selective restriction of the biotin-PE lipid mobility at all positions of chain labeling, as shown by the ESR spectra recorded in the fluid lipid phase. The spectral components of the fraction of the biotin-PESLs that were not complexed by avidin indicated that the mobility of the bulk membrane lipids was unperturbed by binding avidin, as demonstrated by difference spectroscopy. Comparison of the positional profiles and temperature dependences of the outer hyperfine splittings from the biotin-PESLs suggests that the C-12 and C-14 positions of the avidin-bound biotin-PEs are in register with the C-5 and C-7/C-6 positions, respectively, of the chains of the bulk membrane lipids. This indicates that the biotin-PEs are partially withdrawn from the membrane, with a vertical displacement of ca. 7-8 A, on complexation with avidin. In addition, the specific lipid-protein interaction with avidin results in a selective reduction in the rates of lipid chain motion, as shown by the increased ESR line widths. These data define the way in which avidin is anchored to lipid membranes containing biotin-PEs.

  4. The Membrane and Lipids as Integral Participants in Signal Transduction: Lipid Signal Transduction for the Non-Lipid Biochemist

    Science.gov (United States)

    Eyster, Kathleen M.

    2007-01-01

    Reviews of signal transduction have often focused on the cascades of protein kinases and protein phosphatases and their cytoplasmic substrates that become activated in response to extracellular signals. Lipids, lipid kinases, and lipid phosphatases have not received the same amount of attention as proteins in studies of signal transduction.…

  5. Exogenous ether lipids predominantly target mitochondria.

    Directory of Open Access Journals (Sweden)

    Lars Kuerschner

    Full Text Available Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking.

  6. Substrate-supported lipid nanotube arrays.

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A. I.; Poluektov, O. G.; Chemistry; North Carolina State

    2003-07-16

    This Communication describes the self-assembly of phospholipids into lipid nanotubes inside nanoporous anodic aluminum oxide substrate. Orientations of the lipid molecules in such lipid nanoscale structures were verified by high-resolution spin labeling EPR at 95 GHz. The static order parameter of lipids in such nanotube arrays was determined from low-temperature EPR spectra and was found to be exceptionally high, S{sub static} {approx} 0.9. We propose that substrate-supported lipid nanotube arrays have potential for building robust biochips and biosensors in which rigid nanoporous substrates protect the bilayer surface from contamination. The total bilayer surface in the lipid nanotube arrays is much greater than that in the planar substrate-supported membranes. The lipid nanotube arrays seem to be suitable for developing patterned lipid deposition and could be potentially used for patterning of membrane-associated molecules.

  7. Hydrostatic Pressure Promotes Domain Formation in Model Lipid Raft Membranes.

    Science.gov (United States)

    Worcester, David L; Weinrich, Michael

    2015-11-01

    Neutron diffraction measurements demonstrate that hydrostatic pressure promotes liquid-ordered (Lo) domain formation in lipid membranes prepared as both oriented multilayers and unilamellar vesicles made of a canonical ternary lipid mixture for which demixing transitions have been extensively studied. The results demonstrate an unusually large dependence of the mixing transition on hydrostatic pressure. Additionally, data at 28 °C show that the magnitude of increase in Lo caused by 10 MPa pressure is much the same as the decrease in Lo produced by twice minimum alveolar concentrations (MAC) of general anesthetics such as halothane, nitrous oxide, and xenon. Therefore, the results may provide a plausible explanation for the reversal of general anesthesia by hydrostatic pressure.

  8. Physicochemical characterization techniques for solid lipid nanoparticles: principles and limitations.

    Science.gov (United States)

    Kathe, Niranjan; Henriksen, Brian; Chauhan, Harsh

    2014-12-01

    Solid lipid nanoparticles (SLNs) are gaining importance due to numerous advantages they offer as a drug delivery system. SLN incorporate poorly soluble drugs, proteins, biologicals, etc. SLN are prepared by techniques like high-pressure homogenization, sonication and employs a wide range of lipids and surfactants. Physicochemical characterization techniques include particle size analysis, zeta potential and determination of crystallinity/polymorphism. Furthermore, drug loading and drug entrapment efficiency are common parameters used to test the efficiency of SLN. Most importantly, the functionality assay of SLN is essential to predict the activity and performance in vivo. The review presented discusses the importance of SLN in drug delivery with emphasis on principles and limitations associated with their physicochemical characterization.

  9. Supported lipid bilayers as templates to design manganese oxide nanoparticles

    Indian Academy of Sciences (India)

    J Maheshkumar; B Sreedhar; B U Nair; A Dhathathreyan

    2012-09-01

    This work reports on the preparation of nanoclusters of manganese oxide using biotemplating techniques. Supported lipid bilayers (SLBs) on quartz using cationic lipid [Dioctadecyldimethylammonium bromide (DOMA)] and mixed systems with neutral phospholipids dipalmitoyl phosphatidylcholine (DPPC) and dioleoyl phosphatidylcholine (DOPC) have been used as templates to synthesize these nanoparticles in a waterbased medium at room temperature. The Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM) show manganese oxide nanostructures that are composed of crystals or small clusters in the size range of 20-50 nm in diameter. Small angle XRD showed that template removal through calcining process results in nanostructures of the manganese oxide in sizes from 30 to 50 nm. Using these organized assemblies it is possible to control the nano and mesoscopic morphologies of particles and both rod-like and spherical particles can be synthesized.

  10. Adsorption of protein-coated lipid droplets to mixed biopolymer hydrogel surfaces: role of biopolymer diffusion.

    Science.gov (United States)

    Vargas, Maria; Weiss, Jochen; McClements, D Julian

    2007-12-18

    The adsorption of charged particles to hydrogel surfaces is important in a number of natural and industrial processes. In this study, the adsorption of cationic lipid droplets to the surfaces of anionic hydrogels was examined. An oil-in-water emulsion containing cationic beta-lactoglobulin-coated lipid droplets was prepared (d32=0.24 microm, zeta=+74 mV, pH 3.0). An anionic hydrogel containing 0.1 wt % beet pectin and 1.5 wt % agar (pH 3.0) was prepared. Emulsions containing different lipid droplet concentrations (0.3-5 wt %) were brought into contact with the hydrogel surfaces for different times (0-24 h). The adsorption of lipid droplets to the hydrogel surfaces could not be explained by a typical adsorption isotherm. We found that the electrical charge on the nonadsorbed lipid droplets became less positive or even became negative in the presence of the hydrogel and that extensive droplet aggregation occurred, which was attributed to the ability of pectin molecules to diffuse through the hydrogels and interact with the lipid droplets. These results may have important consequences for understanding certain industrial and biological processes, as well as for the design of controlled or triggered release systems.

  11. Cefuroxime axetil loaded solid lipid nanoparticles for enhanced activity against S. aureus biofilm.

    Science.gov (United States)

    Singh, Bhupender; Vuddanda, Parameswara Rao; M R, Vijayakumar; Kumar, Vinod; Saxena, Preeti S; Singh, Sanjay

    2014-09-01

    The present research work is focused on the development of solid lipid nanoparticles of cefuroxime axetil (CA-SLN) for its enhanced inhibitory activity against Staphylococcus aureus produced biofilm. CA-SLN was prepared by solvent emulsification/evaporation method using single lipid (stearic acid (SA)) and binary lipids (SA and tristearin (TS)). Process variables such as volume of dispersion medium, concentration of surfactant, homogenization speed and time were optimized. The prepared SLN were characterized for encapsulation efficiency, drug polymer interaction studies (DSC and FT-IR), shape and surface morphology (SEM and AFM), in vitro drug release, stability studies and in vitro anti biofilm activity against S. aureus biofilm. Among the process variables, increased volume of dispersion medium, homogenization speed and time led to increase in particle size whereas increase in surfactant concentration decreased the particle size. SLN prepared using binary lipids exhibited higher entrapment efficiency than the single lipid. DSC and FT-IR studies showed no incompatible interaction between drug and excipients. CA-SLN showed two folds higher anti-biofilm activity in vitro than pristine CA against S. aureus biofilm.

  12. Optimizing Cationic and Neutral Lipids for Efficient Gene Delivery at High Serum Content

    Science.gov (United States)

    Majzoub, Ramsey N.; Hwu, Yeu-kuang; Liang, Keng S.; Leal, Cecília; Safinya, Cyrus R.

    2014-01-01

    Background Cationic liposome (CL)-DNA complexes are promising gene delivery vectors with potential applications in gene therapy. A key challenge in creating CL-DNA complexes for applications is that their transfection efficiency (TE) is adversely affected by serum. In particular, little is known about the effects of high serum contents on TE even though this may provide design guidelines for applications in vivo. Methods We prepared CL-DNA complexes in which we varied the neutral lipid (DOPC, glycerol-monooleate (GMO), cholesterol), the headgroup charge and chemical structure of the cationic lipid, and the ratio of neutral to cationic lipid; we then measured the TE of these complexes as a function of serum content and assessed their cytotoxicity. We tested selected formulations in two human cancer cell lines (M21/melanoma and PC-3/prostate cancer). Results In the absence of serum, all CL-DNA complexes of custom-synthesized multivalent lipids show high TE. Certain combinations of multivalent lipids and neutral lipids, such as MVL5(5+)/GMO-DNA complexes or complexes based on the dendritic-headgroup lipid TMVLG3(8+) exhibited high TE both in the absence and presence of serum. Although their TE still dropped to a small extent in the presence of serum, it reached or surpassed that of benchmark commercial transfection reagents, in particular at high serum content. Conclusions Two-component vectors (one multivalent cationic lipid and one neutral lipid) can rival or surpass benchmark reagents at low and high serum contents (up to 50%, v/v). We suggest guidelines for optimizing the serum resistance of CL-DNA complexes based on a given cationic lipid. PMID:24753287

  13. Nanostructured lipid carriers versus microemulsions for delivery of the poorly water-soluble drug luteolin.

    Science.gov (United States)

    Liu, Ying; Wang, Lan; Zhao, Yiqing; He, Man; Zhang, Xin; Niu, Mengmeng; Feng, Nianping

    2014-12-10

    Nanostructured lipid carriers and microemulsions effectively deliver poorly water-soluble drugs. However, few studies have investigated their ability and difference in improving drug bioavailability, especially the factors contributed to the difference. Thus, this study was aimed at investigating their efficiency in bioavailability enhancement based on studying two key processes that occur in NLC and ME during traverse along the intestinal tract: the solubilization process and the intestinal permeability process. The nanostructured lipid carriers and microemulsions had the same composition except that the former were prepared with solid lipids and the latter with liquid lipids; both were evaluated for particle size and zeta potential. Transmission electron microscopy, differential scanning calorimetry, and X-ray diffraction were performed to characterize their properties. Furthermore, in vitro drug release, in situ intestinal absorption, and in vitro lipolysis were studied. The bioavailability of luteolin delivered using nanostructured lipid carriers in rats was compared with that delivered using microemulsions and suspensions. The in vitro analysis revealed different release mechanisms for luteolin in nanostructured lipid carriers and microemulsions, although the in situ intestinal absorption was similar. The in vitro lipolysis data indicated that digestion speed and extent were higher for microemulsions than for nanostructured lipid carriers, and that more of the former partitioned to the aqueous phase. The in vivo bioavailability analysis in rats indicated that the oral absorption and bioavailability of luteolin delivered using nanostructured lipid carriers and microemulsions were higher than those of luteolin suspensions. Nanostructured lipid carriers and microemulsions improved luteolin's oral bioavailability in rats. The rapid lipid digestion and much more drug solubilized available for absorption in microemulsions may contribute to better absorption and

  14. Spontaneous Formation of Lipid Nanotubes and Lipid Nanofibers from Giant Charged Dendrimer Lipids

    Science.gov (United States)

    Zidovska, Alexandra; Ewert, Kai K.; Safinya, Cyrus R.; Quispe, Joel; Carragher, Bridgett; Potter, Clinton S.

    2007-03-01

    Liposomes have attracted much scientific interest due to their applications in model cells studies and in drug encapsulation. We report on the discovery of new vesicle phases formed in mixtures of MVLBG2, DOPC and water. MVLBG2 is a newly synthesized highly charged (16+) lipid (K. Ewert et al., JACS, 2006) with giant dendrimer headgroup thus leading to a high spontaneous curvature of the molecule. In combination with zero-curvature DOPC, MVLBG2 exhibits a rich phase diagram showing novel vesicle morphologies such as bones, lipid nanotubes and nanofibers as revealed by differential contrast microscopy (DIC) and cryo-TEM. At the micron scale DIC reveals a new phase consisting of bone-like vesicles. This novel morphology persists down to the nanometer scale as shown by cryo-TEM. The nanotubes are of diameter 10-50 nm, length > 1μm and consist of a single lipid bilayer. A surprising new morphology arises resulting from a spontaneous topological transition from tubes to lipid nanorods. Funded by DOE DE-FG-02-06ER46314, NIH GM-59288, NSF DMR-0503347.

  15. Myoglobin-induced lipid oxidation : A review

    DEFF Research Database (Denmark)

    Baron, Caroline; Andersen, H.J.

    2002-01-01

    An overview of myoglobin-initiated lipid oxidation in simple model systems, muscle, and muscle-based foods is presented. The potential role of myoglobin spin and redox states in initiating lipid oxidation is reviewed. Proposed mechanisms for myoglobin- initiated lipid oxidation in muscle tissue (p...

  16. How Do Lipids Localize in Lewy Bodies?

    NARCIS (Netherlands)

    Chaudhary, Himanshu; Subramaniam, Vinod; Claessens, Mireille

    2014-01-01

    Lewy bodies are the pathological hallmark of Parkinson's disease (PD). While fibrillar α-synuclein (αS) is the main protein component of Lewy bodies, these structures also contain lipids. To elucidate the presence of lipids in Lewy bodies, we investigated the interaction of lipids with monomeric and

  17. Structural investigations on lipid nanoparticles containing high amounts of lecithin.

    Science.gov (United States)

    Schubert, Martin Alexander; Harms, Meike; Müller-Goymann, Christel Charlotte

    2006-02-01

    Solid lipid nanoparticles (SLN), an alternative colloidal drug delivery system to polymer nanoparticles, emulsions and liposomes, possess inherent low incorporation rates resulting from the crystalline structure of the solid lipid. To increase the drug loading capacity of SLN, matrix modification by incorporation of the amphiphilic lipid lecithin within the lipid matrices has been proposed as a promising alternative. The objective of this work is to investigate the effects of the lecithin on the microstructure of matrix modified SLN. In addition, these systems were checked for the existence of aggregates like mixed micelles, liposomes, etc., which could possibly be formed by lecithin leakage into the aqueous phase during the preparation process. For this purpose, laser diffraction, photon correlation spectroscopy (PCS), small angle X-ray scattering (SAXS), nuclear magnetic resonance (NMR) and transmission electron microscopy (TEM) were performed to investigate the structure, mobility, and molecular environment of the compounds. Lecithin incorporation within the lipid matrices resulted in a concentration dependent decrease in particle size up to a critical concentration of 30%. Lecithin incorporation up to 50% was investigated but caused no further particle size decrease. TEM revealed anisometrical and crystalline platelets of ellipsoidal to disc-like shape. Furthermore, SAXS and TEM showed no signs of lecithin and nonionic emulsifier derived aggregates in the aqueous phase. This points in agreement with NMR measurements to a strong attachment of both substances to the SLN surfaces. The proposed structure of the particles after melt emulsification consists of two different layers: a crystalline triglyceride-rich core is covered in dependence of the lecithin content either by a monomolecular or multimolecular lecithin/Solutol HS15 (SOL) layer.

  18. Variables affecting lipid oxidation in dried microencapsulated oils

    Directory of Open Access Journals (Sweden)

    Márquez-Ruiz, Gloria

    2003-09-01

    Full Text Available Dried microencapsulated oils are powdery foods or ingredients, prepared by drying natural or formulated emulsions, wherein the oil globules are dispersed in a matrix of saccharides and/or proteins. The study of lipid oxidation in microencapsulated oils is a very difficult task since, in addition to the numerous variables normally involved in lipid oxidation, mainly unsaturation degree, oxygen, light, temperature, prooxidants and antioxidants, other factors exert an important influence in these heterophasic lipid systems. In this paper, the present state of the art on lipid oxidation in dried microencapsulated oils is reviewed, focused on the variables specifically involved in oxidation of these lipid systems. Such variables include those pertaining to the preparation process (type and concentration of the matrix components and drying procedure and those related to the physicochemical properties of microencapsulated oils (particle size, oil globule size, lipid distribution, water activity, pH and interactions between matrix components.Los aceites microencapsulados son alimentos o ingredientes en polvo preparados mediante secado de emulsiones naturales o formuladas, donde los glóbulos de aceite se encuentran dispersos en una matriz de hidratos de carbono y/o proteínas. El estudio de la oxidación lipídica en aceites microencapsulados es muy difícil ya que, además de las numerosas variables implicadas normalmente en la oxidación lipídica, principalmente el grado de insaturación, oxígeno, luz, temperatura, prooxidantes y antioxidantes, en estos sistemas lipídicos heterofásicos existen otros factores que ejercen una importante influencia. En este trabajo, se revisa la situación actual del conocimiento sobre oxidación lipídica en aceites microencapsulados en relación con las variables que intervienen específicamente en la oxidación de estos sistemas lipídicos. Concretamente, dichas variables incluyen las implicadas en el proceso de

  19. Novel formulation of a methotrexate derivative with a lipid nanoemulsion

    Science.gov (United States)

    Moura, Juliana A; Valduga, Claudete J; Tavares, Elaine R; Kretzer, Iara F; Maria, Durvanei A; Maranhão, Raul C

    2011-01-01

    Background Lipid nanoemulsions that bind to low-density lipoprotein receptors can concentrate chemotherapeutic agents in tissues with low-density lipoprotein receptor overexpression and decrease the toxicity of the treatment. The aim of this study was to develop a new formulation using a lipophilic derivative of methotrexate, ie, didodecyl methotrexate (ddMTX), associated with a lipid nanoemulsion (ddMTX-LDE). Methods ddMTX was synthesized by an esterification reaction between methotrexate and dodecyl bromide. The lipid nanoemulsion was prepared by four hours of ultrasonication of a mixture of phosphatidylcholine, triolein, and cholesteryloleate. Association of ddMTX with the lipid nanoemulsion was performed by additional cosonication of ddMTX with the previously prepared lipid nanoemulsion. Formulation stability was evaluated, and cell uptake, cytotoxicity, and acute animal toxicity studies were performed. Results The yield of ddMTX incorporation was 98% and the particle size of LDE-ddMTX was 60 nm. After 48 hours of incubation with plasma, approximately 28% ddMTX was released from the lipid nanoemulsion. The formulation remained stable for at least 45 days at 4°C. Cytotoxicity of LDE-ddMTX against K562 and HL60 neoplastic cells was higher than for methotrexate (50% inhibitory concentration [IC50] 1.6 versus 18.2 mM and 0.2 versus 26 mM, respectively), and cellular uptake of LDE-ddMTX was 90-fold higher than that of methotrexate in K562 cells and 75-fold in HL60 cells. Toxicity of LDE-ddMTX, administered at escalating doses, was higher than for methotrexate (LD50 115 mg/kg versus 470 mg/kg; maximum tolerated dose 47 mg/kg versus 94 mg/kg) in mice. However, the hematological toxicity of LDE-ddMTX was lower than for methotrexate. Conclusion LDE-ddMTX was stable, and uptake of the formulation by neoplastic cells was remarkably greater than of methotrexate, which resulted in markedly greater cytotoxicity. LDE-ddMTX is thus a promising formulation to be tested in

  20. Wheat leaf lipids during heat stress: II. Lipids experiencing coordinated metabolism are detected by analysis of lipid co-occurrence.

    Science.gov (United States)

    Narayanan, Sruthi; Prasad, P V Vara; Welti, Ruth

    2016-03-01

    Identifying lipids that experience coordinated metabolism during heat stress would provide information regarding lipid dynamics under stress conditions and assist in developing heat-tolerant wheat varieties. We hypothesized that co-occurring lipids, which are up-regulated or down-regulated together through time during heat stress, represent groups that can be explained by coordinated metabolism. Wheat plants (Triticum aestivum L.) were subjected to 12 days of high day and/or night temperature stress, followed by a 4-day recovery period. Leaves were sampled at four time points, and 165 lipids were measured by electrospray ionization-tandem mass spectrometry. Correlation analysis of lipid levels in 160 leaf samples from each of two wheat genotypes revealed 13 groups of lipids. Lipids within each group co-occurred through the high day and night temperature stress treatments. The lipid groups can be broadly classified as groups containing extraplastidic phospholipids, plastidic glycerolipids, oxidized glycerolipids, triacylglycerols, acylated sterol glycosides and sterol glycosides. Current knowledge of lipid metabolism suggests that the lipids in each group co-occur because they are regulated by the same enzyme(s). The results suggest that increases in activities of desaturating, oxidizing, glycosylating and acylating enzymes lead to simultaneous changes in levels of multiple lipid species during high day and night temperature stress in wheat.

  1. Lipids, membrane proteins and natural membranes studied by neutron scattering and diffraction: A review

    Science.gov (United States)

    Zaccai, Giuseppe

    1986-02-01

    Diffraction first observed from myelin 50 years ago was correctly attributed to a fluid crystal of lipids, because similar patterns were observed from extracted lipid preparations. Following on more recent X-ray work which characterized a variety of lipid-water structures, neutron diffraction experiments have provided detailed descriptions of the molecular conformations in lipid bilayers. For a long time, however, the molecular structure of membrane proteins remained elusive and the development of detergents for the extraction of active membrane proteins, and the discovery of naturally crystalline purple membrane were important breakthroughs in this field. Structural parameters of membrane proteins solubilised in detergent have been measured by neutron scattering with contrast variation techniques. Purple membrane has been studied extensively by neutron diffraction. It is an excellent illustration of the use of deuterium labeling by different approaches to address specific questions of molecular structure. These studies are reviewed with a special emphasis on aspects which are applicable to membranes in general.

  2. The fusion of lipid droplets is involved in fat loss during cooking of duck "foie gras".

    Science.gov (United States)

    Théron, L; Astruc, T; Bouillier-Oudot, M; Molette, C; Vénien, A; Peyrin, F; Vitezica, Z G; Fernandez, X

    2011-12-01

    Fat loss during cooking of duck "foie gras" is the main quality issue in processing plants. To better understand this phenomenon, a histological and ultrastructural study was conducted. The aim was to characterize changes in lipid droplets of duck "foie gras" related to fat loss during cooking. Ten fatty livers were sampled before and after cooking and prepared for optical and transmission electron microscopy. In raw livers, the lipid droplets were nearly spherical while after cooking, they were larger and lost their spherical shape. We also observed a decrease in the number of droplets after cooking, probably due to droplet fusion caused by the heat treatment. Before cooking, there were fewer lipid droplets and a higher osmium tetroxyde staining intensity in the fatty liver, which later gave a lower technological yield. Fat loss during cooking was higher when there was more fusion of lipid droplets before cooking.

  3. Nanostructured lipid carriers (NLC) on the basis of Siberian pine (Pinus sibirica) seed oil.

    Science.gov (United States)

    Averina, E S; Seewald, G; Müller, R H; Radnaeva, L D; Popov, D V

    2010-01-01

    Nanostructured lipid carriers (NLC) are new drug systems composed of physiological lipid materials. The possibility of including different types of lipids into the NLC structure revealed the wide prospects for using biologically active natural oils for the development of the cutaneous preparations. In this study the formulation parameters of NLC on the basis of Siberian pine seed oil were evaluated including concentration of lipids, types of surfactants and storage conditions (4 degrees C, 20 degrees C, 40 degrees C). Size distribution and storage stability of formulations produced by hot high pressure homogenisation were investigated by laser diffractometry and photon correlation spectroscopy. The NLC were characterised by their melting behaviour using differential scanning calorimetry. The obtained data indicated the high physical stability of the developed NLC formulations.

  4. Further characterization of theobroma oil-beeswax admixtures as lipid matrices for improved drug delivery systems.

    Science.gov (United States)

    Attama, A A; Schicke, B C; Müller-Goymann, C C

    2006-11-01

    There is an increasing interest in lipid based drug delivery systems due to factors such as better characterization of lipidic excipients and formulation versatility and the choice of different drug delivery systems. It is important to know the thermal characteristics, crystal habit, texture, and appearance of a new lipid matrix when determining its suitability for use in certain pharmaceutical application. It is line with this that this research was embarked upon to characterize mixtures of beeswax and theobroma oil with a view to applying their admixtures in drug delivery systems such as solid lipid nanoparticles and nanostructured lipid carriers. Admixtures of theobroma oil and beeswax were prepared to contain 25% w/w, 50% w/w, and 75% w/w of theobroma oil. The admixtures were analyzed by differential scanning calorimetry (DSC), small angle X-ray diffraction (SAXD), wide angle X-ray diffraction (WAXD), and isothermal heat conduction microcalorimetry (IMC). The melting behavior and microstructures of the lipid admixtures were monitored by polarized light microscopy (PLM). Transmission electron microscopy (TEM) was used to study the internal structures of the lipid bases. DSC traces indicated that the higher melting peaks were roughly constant for the different admixtures, but lower melting peaks significantly increased (p beeswax in all the lipid matrix admixtures at all stages of the study. PLM micrographs revealed differences with regard to the thermal and optical behaviors depending on the composition of the matrix. The lipid matrix consisting of 75% w/w of theobroma oil showed a spherulite texture after 4 weeks of isothermal storage. Crystallization exotherms of lipid matrices containing 50% w/w and 25% w/w of theobroma oil showed change in modification after 30 min with the latter having a greater time-dependent crystallization. Generally, low non-integral Avrami exponents and growth rate constants were obtained for all the lipid matrices, with the admixture

  5. Lipid drug conjugate nanoparticle as a novel lipid nanocarrier for the oral delivery of decitabine: ex vivo gut permeation studies

    Science.gov (United States)

    Neupane, Yub Raj; Sabir, M. D.; Ahmad, Nafees; Ali, Mushir; Kohli, Kanchan

    2013-10-01

    The purpose of this study was to develop lipid drug conjugate (LDC) nanoparticles of decitabine (DCB) using stearic acid as a lipid to increase the permeability of the drug along with its protection from chemical degradation. The LDC was prepared by salt formation of DCB with stearic acid and followed by cold homogenization technique to produce the LDC nanoparticles. The role of key independent variables influencing on dependent variables were determined by using a Box-Behnken design. The optimized batch revealed spherical morphology under TEM analysis with particle size of 202.6 ± 1.65 nm and 0.334 ± 0.987 PDI. The zeta potential and %EE were found to be -33.6 ± 0.845 mV and 68.89% ± 0.59 respectively. Lyophilized powder showed the crystalline structure under DSC analysis. In vitro release studies showed the initial burst release followed by a sustained release up to 24 h in PBS pH 7.4 and the data were further studied using release kinetic models which revealed the first-order model as a best-fitting model. Ex vivo gut permeation studies proved that the formulation containing lipid and surfactants has a higher permeability than the plain drug solution with nearly fourfold increase in the apparent permeability coefficients. Finally, LDC nanoparticles prepared by using stearic acid as a lipid and surfactants as Tween 80, Poloxamer 188, and Labrasol in equal ratio possess high potential for the oral delivery of hydrophilic drugs.

  6. Minoxidil-loaded nanostructured lipid carriers (NLC): characterization and rheological behaviour of topical formulations.

    Science.gov (United States)

    Silva, A C; Santos, D; Ferreira, D C; Souto, E B

    2009-03-01

    Lipid nanoparticles are used as biocompatible carriers for several types of drugs intended for pharmaceutical, cosmetic, and biochemical purposes. The wide range of lipids and surfactants available for the production of such particles turns these carriers highly suitable for distinct applications (topical, dermal and transdermal, parenteral, pulmonary, and oral administration). This work describes the development of a special type of lipid particles, namely nanostructured lipid carriers (NLC), for minoxidil as an alternative to conventional topical alcoholic solutions. NLC were composed of stearic acid and oleic acid, being the matrix stabilized with poloxamer 188 in aqueous dispersion. To develop a suitable topical formulation, lipid dispersions were further mixed with freshly prepared Carbopol or perfluorocarbon based hydrogels. Minoxidil-loaded NLC were approximately 250 nm in size before the entrapment within the gel network and remained below 500 nm after mixing with both types of hydrogels. The occurrence of minoxidil crystallization in the aqueous phase of lipid dispersions was discarded under analysis by light microscopy and by scanning electron microscopy. Differential scanning calorimetry was used to assess the recrystallization index (i.e. measure of the percentage of lipid matrix that is crystallized) of the particles, which was shown to be 62% for minoxidil-free dispersions and 68% for minoxidil-loaded NLC dispersions. Rheological analysis of hydrogels containing NLC dispersions showed typical pseudoplastic behaviour which makes them suitable for topical purposes.

  7. Recent advances in lipid nanoparticle formulations with solid matrix for oral drug delivery.

    Science.gov (United States)

    Das, Surajit; Chaudhury, Anumita

    2011-03-01

    Lipid nanoparticles based on solid matrix have emerged as potential drug carriers to improve gastrointestinal (GI) absorption and oral bioavailability of several drugs, especially lipophilic compounds. These formulations may also be used for sustained drug release. Solid lipid nanoparticle (SLN) and the newer generation lipid nanoparticle, nanostructured lipid carrier (NLC), have been studied for their capability as oral drug carriers. Biodegradable, biocompatible, and physiological lipids are generally used to prepare these nanoparticles. Hence, toxicity problems related with the polymeric nanoparticles can be minimized. Furthermore, stability of the formulations might increase than other liquid nano-carriers due to the solid matrix of these lipid nanoparticles. These nanoparticles can be produced by different formulation techniques. Scaling up of the production process from lab scale to industrial scale can be easily achieved. Reasonably high drug encapsulation efficiency of the nanoparticles was documented. Oral absorption and bioavailability of several drugs were improved after oral administration of the drug-loaded SLNs or NLCs. In this review, pros and cons, different formulation and characterization techniques, drug incorporation models, GI absorption and oral bioavailability enhancement mechanisms, stability and storage condition of the formulations, and recent advances in oral delivery of the lipid nanoparticles based on solid matrix will be discussed. © 2010 American Association of Pharmaceutical Scientists

  8. Effect of emulsifier on oxidation properties of fish oil-based structured lipid emulsions.

    Science.gov (United States)

    Fomuso, Lydia B; Corredig, Milena; Akoh, Casimir C

    2002-05-08

    The effects of the emulsifiers lecithin, Tween 20, whey protein isolate, mono-/diacylglycerols, and sucrose fatty acid ester on oxidation stability of a model oil-in-water emulsion prepared with enzymatically synthesized menhaden oil-caprylic acid structured lipid were evaluated. Oxidation was monitored by measuring lipid hydroperoxides, thiobarbituric acid reactive substances, and the ratio of combined docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents to palmitic acid in the emulsion. After high-pressure homogenization, all emulsions, except those prepared with lecithin, had similar droplet size distributions. All structured lipid emulsions, except for the lecithin-stabilized emulsions, were stable to creaming over the 48-day period studied. Emulsifier type and concentration affected oxidation rate, with 0.25% emulsifier concentration generally having a higher oxidation rate than 1% emulsifier concentration. Overall, oxidation did not progress significantly enough in 48 days of storage to affect DHA and EPA levels in the emulsion.

  9. Lipids and Fatty Acids in Algae: Extraction, Fractionation into Lipid Classes, and Analysis by Gas Chromatography Coupled with Flame Ionization Detector (GC-FID).

    Science.gov (United States)

    Guihéneuf, Freddy; Schmid, Matthias; Stengel, Dagmar B

    2015-01-01

    Despite the number of biochemical studies exploring algal lipids and fatty acid biosynthesis pathways and profiles, analytical methods used by phycologists for this purpose are often diverse and incompletely described. Potential confusion and potential variability of the results between studies can therefore occur due to change of protocols for lipid extraction and fractionation, as well as fatty acid methyl esters (FAME) preparation before gas chromatography (GC) analyses. Here, we describe a step-by-step procedure for the profiling of neutral and polar lipids using techniques such as solid-liquid extraction (SLE), thin-layer chromatography (TLC), and gas chromatography coupled with flame ionization detector (GC-FID). As an example, in this protocol chapter, analyses of neutral and polar lipids from the marine microalga Pavlova lutheri (an EPA/DHA-rich haptophyte) will be outlined to describe the distribution of fatty acid residues within its major lipid classes. This method has been proven to be a reliable technique to assess changes in lipid and fatty acid profiles in several other microalgal species and seaweeds.

  10. Natural lipid nanoparticles containing nimesulide: synthesis, characterization and in vivo antiedematogenic and antinociceptive activities.

    Science.gov (United States)

    Raffin, Renata P; Lima, Amanda; Lorenzoni, Ricardo; Antonow, Michelli B; Turra, Cláudia; Alves, Marta P; Fagan, Solange B

    2012-04-01

    Lipid nanoparticles are drug delivery systems able to increase bioavailability of poorly soluble drugs. They can be prepared with different lipid materials, especially natural lipids. Shea butter is a natural lipid obtained from the Butyrospermum parkii seed and rich in oleic and stearic acids. Nimesulide is a COX 2 selective anti-inflammatory that is poorly soluble in water. The purpose of this study was to develop and characterize shea butter lipid nanoparticles using a new technique and evaluate the in vivo activity of these nanoparticles. Lipid nanoparticles were prepared by melting shea butter and mixing with an aqueous phase using a high shear mixer. The nanoparticles presented pH of 6.9 +/- 0.1, mean particle size of 90 nm and a narrow polydispersity (0.21). Zeta potential was around -20 mV and the encapsulation efficiency was 97.5%. Drug release was evaluated using dialysis bags and presented monoexponential profile with t50% of 4.80 h (free drug t50% was only 2.86 h). Antinociceptive activity was performed by the acetic acid model. Both nimesulide and nimesulide-loaded nanoparticles presented significant activity compared to the control. The in vivo anti-inflammatory activity was evaluated by paw edema and was statistically different for the nanoparticles containing nimesulide compared to free nimesulide, blank nanoparticles and saline. In conclusion, the use of shea butter as encapsulating lipid was very successful and allowed nanoparticles to be prepared with a very simple technique. The nanoparticles presented significant pharmacological effects that were not seen for free drug administration.

  11. Aerosol preparation of intact lipoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Benner, W. Henry (Danville, CA); Krauss, Ronald M (Berkeley, CA); Blanche, Patricia J (Berkeley, CA)

    2012-01-17

    A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

  12. Mineralization of annexin-5-containing lipid-calcium-phosphate complexes: modulation by varying lipid composition and incubation with cartilage collagens.

    Science.gov (United States)

    Genge, Brian R; Wu, Licia N Y; Wuthier, Roy E

    2008-04-11

    Matrix vesicles (MVs) in the growth plate bind to cartilage collagens and initiate mineralization of the extracellular matrix. Native MVs have been shown to contain a nucleational core responsible for mineral formation that is comprised of Mg(2+)-containing amorphous calcium phosphate and lipid-calcium-phosphate complexes (CPLXs) and the lipid-dependent Ca(2+)-binding proteins, especially annexin-5 (Anx-5), which greatly enhances mineral formation. Incorporation of non-Ca(2+)-binding MV lipids impedes mineral formation by phosphatidylserine (PS)-CPLX. In this study, nucleators based on amorphous calcium phosphate (with or without Anx-5) were prepared with PS alone, PS + phosphatidylethanolamine (PE), or PS + PE and other MV lipids. These were incubated in synthetic cartilage lymph containing no collagen or containing type II or type X collagen. Dilution of PS with PE and other MV lipids progressively retarded nucleation. Incorporation of Anx-5 restored nucleational activity to the PS:PE CPLX; thus PS and Anx-5 proved to be critical for nucleation of mineral. Without Anx-5, induction of mineral formation was slow unless high levels of Ca(2+) were used. The presence of type II collagen in synthetic cartilage lymph improved both the rate and amount of mineral formation but did not enhance nucleation. This stimulatory effect required the presence of the nonhelical telopeptides. Although type X collagen slowed induction, it also increased the rate and amount of mineral formation. Both type II and X collagens markedly increased mineral formation by the MV-like CPLX, requiring Anx-5 to do so. Thus, Anx-5 enhances nucleation by the CPLXs and couples this to propagation of mineral formation by the cartilage collagens.

  13. Polydopamine-Supported Lipid Bilayers

    Directory of Open Access Journals (Sweden)

    Souryvanh Nirasay

    2012-12-01

    Full Text Available We report the formation of lipid membranes supported by a soft polymeric cushion of polydopamine. First, 20 nm thick polydopamine films were formed on mica substrates. Atomic force microscopy imaging indicated that these films were also soft with a surface roughness of 2 nm under hydrated conditions. A zwitterionic phospholipid bilayer was then deposited on the polydopamine cushion by fusion of dimyristoylphosphatidylcholine (DMPC and dioleoylphosphatidylcholine (DOPC vesicles. Polydopamine films preserved the lateral mobility of the phospholipids as shown by fluorescence microscopy recovery after photobleaching (FRAP experiments. Diffusion coefficients of ~5.9 and 7.2 µm2 s−1 were respectively determined for DMPC and DOPC at room temperature, values which are characteristic of lipids in a free standing bilayer system.

  14. Polydopamine-Supported Lipid Bilayers

    Science.gov (United States)

    Nirasay, Souryvanh; Badia, Antonella; Leclair, Grégoire; Claverie, Jerome P.; Marcotte, Isabelle

    2012-01-01

    We report the formation of lipid membranes supported by a soft polymeric cushion of polydopamine. First, 20 nm thick polydopamine films were formed on mica substrates. Atomic force microscopy imaging indicated that these films were also soft with a surface roughness of 2 nm under hydrated conditions. A zwitterionic phospholipid bilayer was then deposited on the polydopamine cushion by fusion of dimyristoylphosphatidylcholine (DMPC) and dioleoylphosphatidylcholine (DOPC) vesicles. Polydopamine films preserved the lateral mobility of the phospholipids as shown by fluorescence microscopy recovery after photobleaching (FRAP) experiments. Diffusion coefficients of ~5.9 and 7.2 µm2 s−1 were respectively determined for DMPC and DOPC at room temperature, values which are characteristic of lipids in a free standing bilayer system.

  15. Observation of inhomogeneity in the lipid composition of individual nanoscale liposomes

    DEFF Research Database (Denmark)

    Larsen, Jannik; Hatzakis, Nikos; Stamou, Dimitrios

    2011-01-01

    Liposomes, or vesicles, have been studied extensively both as models of biological membranes and as drug delivery vehicles. Typically it is assumed that all liposomes within the same preparation are identical. Here by employing pairs of fluorescently labeled lipids we demonstrated an up to 10-fold...

  16. Effects of ovariectomy and resistance training on lipid content in skeletal muscle, liver, and heart; fat depots; and lipid profile

    National Research Council Canada - National Science Library

    Baldissera, Vilmar; de Andrade Perez, Sérgio Eduardo; Prestes, Jonato; Domingos, Mateus Moraes; Shiguemoto, Gilberto Eiji; Pereira, Guilherme Borges; Bernardes, Celene Fernandes; Duarte, Josiane Oliveira; Leite, Richard Diego

    2009-01-01

    The aim of the present study was to investigate the effects of resistance training on skeletal muscle lipid content, liver lipid content, heart lipid content, fat depots, and lipid profile in ovariectomized rats...

  17. Transfection Studies with Colloidal Systems Containing Highly Purified Bipolar Tetraether Lipids from Sulfolobus acidocaldarius

    Science.gov (United States)

    Pinnapireddy, Shashank Reddy; Baghdan, Elias; Jedelská, Jarmila

    2017-01-01

    Lipid vectors are commonly used to facilitate the transfer of nucleic acids into mammalian cells. In this study, two fractions of tetraether lipids from the archaea Sulfolobus acidocaldarius were extracted and purified using different methods. The purified lipid fractions polar lipid fraction E (PLFE) and hydrolysed glycerol-dialkyl-nonitol tetraether (hGDNT) differ in their structures, charge, size, and miscibility from conventional lipids. Liposomes were prepared by mixing tetraether lipids with cholesterol (CH) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) resulting in stable vectors for gene delivery. Lipoplexes were prepared by complexation of liposomes with a luciferase expressing plasmid (pCMV-luc) at certain nitrogen-to-phosphorus (N/P) ratios and optimised for the transient transfection of ovarian adenocarcinoma cells (SK-OV-3). Complexation efficacy was investigated by gel-red fluorescence assay. Biophysical properties, like size, surface charge, and morphology, were investigated by differential light scattering (DLS), atomic force microscopy (AFM), and scanning electron microscopy (Cryo-SEM), respectively, revealing structural differences between liposomes and lipoplexes. A range of stable transfecting agents containing tetraether lipids were obtained by incorporating 5 mol% of tetraether lipids. Lipoplexes showed a decrease in free gel-red with increasing N/P ratios indicating efficient incorporation of plasmid DNA (pDNA) and remarkable stability. Transfection experiments of the lipoplexes revealed successful and superior transfection of SK-OV-3 cell line compared to the commercially available DOTAP and branched polyethyleneimine (25 kDa bPEI).

  18. Transfection Studies with Colloidal Systems Containing Highly Purified Bipolar Tetraether Lipids from Sulfolobus acidocaldarius.

    Science.gov (United States)

    Engelhardt, Konrad H; Pinnapireddy, Shashank Reddy; Baghdan, Elias; Jedelská, Jarmila; Bakowsky, Udo

    2017-01-01

    Lipid vectors are commonly used to facilitate the transfer of nucleic acids into mammalian cells. In this study, two fractions of tetraether lipids from the archaea Sulfolobus acidocaldarius were extracted and purified using different methods. The purified lipid fractions polar lipid fraction E (PLFE) and hydrolysed glycerol-dialkyl-nonitol tetraether (hGDNT) differ in their structures, charge, size, and miscibility from conventional lipids. Liposomes were prepared by mixing tetraether lipids with cholesterol (CH) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) resulting in stable vectors for gene delivery. Lipoplexes were prepared by complexation of liposomes with a luciferase expressing plasmid (pCMV-luc) at certain nitrogen-to-phosphorus (N/P) ratios and optimised for the transient transfection of ovarian adenocarcinoma cells (SK-OV-3). Complexation efficacy was investigated by gel-red fluorescence assay. Biophysical properties, like size, surface charge, and morphology, were investigated by differential light scattering (DLS), atomic force microscopy (AFM), and scanning electron microscopy (Cryo-SEM), respectively, revealing structural differences between liposomes and lipoplexes. A range of stable transfecting agents containing tetraether lipids were obtained by incorporating 5 mol% of tetraether lipids. Lipoplexes showed a decrease in free gel-red with increasing N/P ratios indicating efficient incorporation of plasmid DNA (pDNA) and remarkable stability. Transfection experiments of the lipoplexes revealed successful and superior transfection of SK-OV-3 cell line compared to the commercially available DOTAP and branched polyethyleneimine (25 kDa bPEI).

  19. Transfection Studies with Colloidal Systems Containing Highly Purified Bipolar Tetraether Lipids from Sulfolobus acidocaldarius

    Directory of Open Access Journals (Sweden)

    Konrad H. Engelhardt

    2017-01-01

    Full Text Available Lipid vectors are commonly used to facilitate the transfer of nucleic acids into mammalian cells. In this study, two fractions of tetraether lipids from the archaea Sulfolobus acidocaldarius were extracted and purified using different methods. The purified lipid fractions polar lipid fraction E (PLFE and hydrolysed glycerol-dialkyl-nonitol tetraether (hGDNT differ in their structures, charge, size, and miscibility from conventional lipids. Liposomes were prepared by mixing tetraether lipids with cholesterol (CH and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP resulting in stable vectors for gene delivery. Lipoplexes were prepared by complexation of liposomes with a luciferase expressing plasmid (pCMV-luc at certain nitrogen-to-phosphorus (N/P ratios and optimised for the transient transfection of ovarian adenocarcinoma cells (SK-OV-3. Complexation efficacy was investigated by gel-red fluorescence assay. Biophysical properties, like size, surface charge, and morphology, were investigated by differential light scattering (DLS, atomic force microscopy (AFM, and scanning electron microscopy (Cryo-SEM, respectively, revealing structural differences between liposomes and lipoplexes. A range of stable transfecting agents containing tetraether lipids were obtained by incorporating 5 mol% of tetraether lipids. Lipoplexes showed a decrease in free gel-red with increasing N/P ratios indicating efficient incorporation of plasmid DNA (pDNA and remarkable stability. Transfection experiments of the lipoplexes revealed successful and superior transfection of SK-OV-3 cell line compared to the commercially available DOTAP and branched polyethyleneimine (25 kDa bPEI.

  20. Exploring the Correlation Between Lipid Packaging in Lipoplexes and Their Transfection Efficacy

    Directory of Open Access Journals (Sweden)

    Afzal R. Mohammed

    2011-11-01

    Full Text Available Whilst there is a large body of evidence looking at the design of cationic liposomes as transfection agents, correlates of formulation to function remain elusive. In this research, we investigate if lipid packaging can give further insights into transfection efficacy. DNA lipoplexes composed of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE or 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE in combination with 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP or 1,2-stearoyl-3-trimethylammonium-propane (DSTAP were prepared by the lipid hydration method. Each of the formulations was prepared by hydration in dH2O or phosphate buffer saline (PBS to investigate the effect of buffer salts on lipoplex physicochemical characteristics and in vitro transfection. In addition, Langmuir monolayer studies were performed to investigate any possible correlation between lipid packaging and liposome attributes. Using PBS, rather than dH2O, to prepare the lipoplexes increased the size of vesicles in most of formulations and resulted in variation in transfection efficacies. However, one combination of lipids (DSPE:DOTAP could not form liposomes in PBS, whilst the DSPE:DSTAP combination could not form liposomes in either aqueous media. Monolayer studies demonstrated saturated lipid combinations offered dramatically closer molecular packing compared to the other combinations which could suggest why this lipid combination could not form vesicles. Of the lipoplexes prepared, those formulated with DSTAP showed higher transfection efficacy, however, the effect of buffer on transfection efficiency was formulation dependent.

  1. Dynamics of multicomponent lipid membranes

    Science.gov (United States)

    Camley, Brian Andrew

    We present theoretical and computational descriptions of the dynamics of multicomponent lipid bilayer membranes. These systems are both model systems for "lipid rafts" in cell membranes and interesting physical examples of quasi-two-dimensional fluids. Our chief tool is a continuum simulation that uses a phase field to track the composition of the membrane, and solves the hydrodynamic equations exactly using the appropriate Green's function (Oseen tensor) for the membrane. We apply this simulation to describe the diffusion of domains in phase-separated membranes, the dynamics of domain flickering, and the process of phase separation in lipid membranes. We then derive an analytical theory to describe domain flickering that is consistent with our simulation results, and use this to analyze experimental measurements of membrane domains. Through this method, we measure the membrane viscosity solely from fluorescence microscopy measurements. We study phase separation in quasi-two-dimensional membranes in depth with both simulations and scaling theory, and classify the different scaling regimes and morphologies, which differ from pure two-dimensional fluids. Our results may explain previous inconsistent measurements of the dynamical scaling exponent for phase separation in membranes. We also extend our theory beyond the simplest model, including the possibility that the membrane will be viscoelastic, as well as considering the inertia of the membrane and the fluid surrounding the membrane.

  2. Stratum corneum barrier lipids in cholesteatoma

    DEFF Research Database (Denmark)

    Svane-Knudsen, V; Halkier-Sørensen, L; Rasmussen, G;

    2000-01-01

    Specimens from primary cholesteatomas were examined under the electron microscope using a lipid-retaining method that is best suited for intracellular lipids and a method that is best for intercellular lipids. In the stratum granulosum of the squamous epithelium, a large number of Odland bodies...... emerged. When the corneocyte reaches the transitional stage to the stratum corneum, the Odland bodies accumulate near the cell membrane and discharge their contents of lipid and enzymes. The lipids are reorganized into multiple long sheets of lamellar structures that embrace the keratinized corneocytes......, as seen in the formation and maintenance of the cutaneous permeability barrier. In this study we draw the attention to the facts that the cholesteatoma epithelium is capable of producing not only cholesterol, but also several lipids, and that the lipid molecules are organized in multilamellar structures...

  3. Stratum Corneum Barrier Lipids in Cholesteatoma

    DEFF Research Database (Denmark)

    Svane-Knudsen, V; Halkier-Sørensen, L; Rasmussen, G

    2000-01-01

    emerged. When the corneocyte reaches the transitional stage to the stratum corneum, the Odland bodies accumulate near the cell membrane and discharge their contents of lipid and enzymes. The lipids are reorganized into multiple long sheets of lamellar structures that embrace the keratinized corneocytes......Specimens from primary cholesteatomas were examined under the electron microscope using a lipid-retaining method that is best suited for intracellular lipids and a method that is best for intercellular lipids. In the stratum granulosum of the squamous epithelium, a large number of Odland bodies......, as seen in the formation and maintenance of the cutaneous permeability barrier. In this study we draw the attention to the facts that the cholesteatoma epithelium is capable of producing not only cholesterol, but also several lipids, and that the lipid molecules are organized in multilamellar structures...

  4. Introduction to fatty acids and lipids.

    Science.gov (United States)

    Burdge, Graham C; Calder, Philip C

    2015-01-01

    The purpose of this article is to describe the structure, function and metabolism of fatty acids and lipids that are of particular importance in the context of parenteral nutrition. Lipids are a heterogeneous group of molecules that share the common property of hydrophobicity. Lipids range in structure from simple short hydrocarbon chains to more complex molecules, including triacylglycerols, phospholipids and sterols and their esters. Lipids within each class may differ structurally. Fatty acids are common components of complex lipids, and these differ according to chain length and the presence, number and position of double bonds in the hydrocarbon chain. Structural variation among complex lipids and among fatty acids gives rise to functional differences that result in different impacts upon metabolism and upon cell and tissue responses. Fatty acids and complex lipids exhibit a variety of structural variations that influence their metabolism and their functional effects.

  5. Lipid metabolism in Drosophila: development and disease

    Institute of Scientific and Technical Information of China (English)

    Zhonghua Liu; Xun Huang

    2013-01-01

    Proteins,nucleic acids,and lipids are three major components of the cell.Despite a few basic metabolic pathways,we know very little about lipids,compared with the explosion of knowledge about proteins and nucleic acids.How many different forms of lipids are there? What are the in vivo functions of individual lipid? How does lipid metabolism contribute to normal development and human health? Many of these questions remain unanswered.For over a century,the fruit fly Drosophila melanogaster has been used as a model organism to study basic biological questions.In recent years,increasing evidences proved that Drosophila models are highly valuable for lipid metabolism and energy homeostasis researches.Some recent progresses of lipid metabolic regulation during Drosophila development and in Drosophila models of human diseases will be discussed in this review.

  6. Solid lipid nanoparticles loading adefovir dipivoxil for antiviral therapy

    OpenAIRE

    Zhang, Xing-Guo; Miao, Jing; Li, Min-wei; Jiang,Sai-Ping; Hu, Fu-Qiang; Du, Yong-Zhong

    2008-01-01

    Herein, solid lipid nanoparticles (SLN) were proposed as a new drug delivery system for adefovir dipivoxil (ADV). The octadecylamine-fluorescein isothiocynate (ODA-FITC) was synthesized and used as a fluorescence maker to be incorporated into SLN to investigate the time-dependent cellular uptake of SLN by HepG2.2.15. The SLN of monostearin with ODA-FITC or ADV were prepared by solvent diffusion method in an aqueous system. About 15 wt% drug entrapment efficiency (EE) and 3 wt% drug loading (D...

  7. Preparing for Surgery

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Preparing for Surgery Home For Patients Search FAQs Preparing for Surgery ... Surgery FAQ080, August 2011 PDF Format Preparing for Surgery Gynecologic Problems What is the difference between outpatient ...

  8. Preparing for Surgery

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Preparing for Surgery Home For Patients Search FAQs Preparing for Surgery ... Surgery FAQ080, August 2011 PDF Format Preparing for Surgery Gynecologic Problems What is the difference between outpatient ...

  9. Lipid-lipid and lipid-drug interactions in biological membranes

    Science.gov (United States)

    Martynowycz, Michael W.

    Interactions between lipids and drug molecules in biological membranes help govern proper biological function in organisms. The mechanisms responsible for hydrophobic drug permeation remain elusive. Many small molecule drugs are hydrophobic. These drugs inhibit proteins in the cellular interior. The rise of antibiotic resistance in bacteria is thought to be caused by mutations in protein structure, changing drug kinetics to favor growth. However, small molecule drugs have been shown to have different mechanisms depending in the structure of the lipid membrane of the target cell. Biological membranes are investigated using Langmuir monolayers at the air-liquid interface. These offer the highest level of control in the mimetic system and allow them to be investigated using complementary techniques. Langmuir isotherms and insertion assays are used to determine the area occupied by each lipid in the membrane and the change in area caused by the introduction of a drug molecule, respectively. Specular X-ray reflectivity is used to determine the electron density of the monolayer, and grazing incidence X-ray diffraction is used to determine the in-plane order of the monolayer. These methods determine the affinity of the drug and the mechanism of action. Studies are presented on hydrophobic drugs with mammalian membrane mimics using warfarin along with modified analogues, called superwarfarins. Data shows that toxicity of these modified drugs are modulated by the membrane cholesterol content in cells; explaining several previously unexplained effects of the drugs. Membrane mimics of bacteria are investigated along with their interactions with a hydrophobic antibiotic, novobiocin. Data suggests that permeation of the drug is mediated by modifications to the membrane lipids, and completely ceases translocation under certain circumstances. Circumventing deficiencies in small, hydrophobic drugs is approached by using biologically mimetic oligomers. Peptoids, mimetic of host

  10. The 'Ethereal' nature of TLR4 agonism and antagonism in the AGP class of lipid A mimetics.

    Science.gov (United States)

    Bazin, Hélène G; Murray, Tim J; Bowen, William S; Mozaffarian, Afsaneh; Fling, Steven P; Bess, Laura S; Livesay, Mark T; Arnold, Jeffrey S; Johnson, Craig L; Ryter, Kendal T; Cluff, Christopher W; Evans, Jay T; Johnson, David A

    2008-10-15

    To overcome the chemical and metabolic instability of the secondary fatty acyl residues in the AGP class of lipid A mimetics, the secondary ether lipid analogs of the potent TLR4 agonist CRX-527 (2) and TLR4 antagonist CRX-526 (3) were synthesized and evaluated along with their ester counterparts for agonist/antagonist activity in both in vitro and in vivo models. Like CRX-527, the secondary ether lipid 4 showed potent agonist activity in both murine and human models. Ether lipid 5, on the other hand, showed potent TLR4 antagonist activity similar to CRX-526 in human cell assays, but did not display any antagonist activity in murine models and, in fact, was weakly agonistic. Glycolipids 2, 4, and 5 were synthesized via a new highly convergent method utilizing a common advanced intermediate strategy. A new method for preparing (R)-3-alkyloxytetradecanoic acids, a key component of ether lipids 4 and 5, is also described.

  11. Oxidation of lipid and protein in horse mackerel (Trachurus trachurus) mince and washed minces during processing and storage

    DEFF Research Database (Denmark)

    Eymard, Sylvie; Baron, Caroline; Jacobsen, Charlotte

    2009-01-01

    on oxidation. Subsequently the different products were stored for up to 96 h at 5 degrees C and samples were taken out regularly for analysis. Lipid oxidation was investigated by measuring primary oxidation products (lipid hydroperoxides) and secondary oxidation products (volatiles). Protein oxidation...... was followed by determination of protein solubility, protein thiol groups and protein carbonyl groups using colorimetric methods as well as western blotting for protein carbonyl groups. Lipid and protein oxidation markers indicated that both lipid and protein oxidation took place during processing......Protein and lipid oxidation was followed during processing and storage of mince and washed minces prepared from horse mackerel (Trachurus trachunts). Briefly horse mackerel mince (MO) was washed with three volumes of water, mimicking the surimi production and different washed products were obtained...

  12. Isolation and analysis of membrane lipids and lipid rafts in common carp (Cyprinus carpio L.).

    Science.gov (United States)

    Brogden, Graham; Propsting, Marcus; Adamek, Mikolaj; Naim, Hassan Y; Steinhagen, Dieter

    2014-03-01

    Cell membranes act as an interface between the interior of the cell and the exterior environment and facilitate a range of essential functions including cell signalling, cell structure, nutrient uptake and protection. It is composed of a lipid bilayer with integrated proteins, and the inner leaflet of the lipid bilayer comprises of liquid ordered (Lo) and liquid disordered (Ld) domains. Lo microdomains, also named as lipid rafts are enriched in cholesterol, sphingomyelin and certain types of proteins, which facilitate cell signalling and nutrient uptake. Lipid rafts have been extensively researched in mammals and the presence of functional lipid rafts was recently demonstrated in goldfish, but there is currently very little knowledge about their composition and function in fish. Therefore a protocol was established for the analysis of lipid rafts and membranous lipids in common carp (Cyprinus carpio L.) tissues. Twelve lipids were identified and analysed in the Ld domain of the membrane with the most predominant lipids found in all tissues being; triglycerides, cholesterol, phosphoethanolamine and phosphatidylcholine. Four lipids were identified in lipid rafts in all tissues analysed, triglycerides (33-62%) always found in the highest concentration followed by cholesterol (24-32%), phosphatidylcholine and sphingomyelin. Isolation of lipid rafts was confirmed by identifying the presence of the lipid raft associated protein flotillin, present at higher concentrations in the detergent resistant fraction. The data provided here build a lipid library of important carp tissues as a baseline for further studies into virus entry, protein trafficking or environmental stress analysis.

  13. Application of Box-Behnken design for optimization of formulation parameters for nanostructured lipid carriers of candesartan cilexetil

    Directory of Open Access Journals (Sweden)

    Hetal P Thakkar

    2014-01-01

    Full Text Available This study deals with development and optimization of nanostructured lipid carriers (NLCs of candesartan cilexetil (CC for improving its oral bioavailability. From solubility and lipid-water partition studies of CC in various lipids, glyceryl monostearate (GMS and glyceryl monocaprylate were selected as solid lipid and liquid lipid, respectively. NLCs were formulated by hot melt-emulsification-ultrasonication method. A three-factor, three-level Box-Behnken design was used to optimize the independent variables, lipid: drug ratio (X1, solid lipid: liquid lipid ratio (X2 and surfactant concentration (X3. Different batches were prepared and evaluated for responses, particle size (Y1, zeta potential (Y2 and % entrapment efficiency (Y3. Response surface plots and perturbation plots were constructed to study the effect of factors on responses. The optimized formulation containing X1 - 22.47:1, X2 - 7.23:1 and X3 - 1.97% was prepared and evaluated. Observed values for Y1, Y2, and Y3 were found to be closer to the predicted values thus validating the optimization method. Differential scanning calorimetry thermograms of pure drug, GMS and lyophilized drug loaded NLCs indicated complete miscibility of drug into lipids. The release of CC from the NLCs conducted in artificial gastric fluid (pH 1.2 was much higher than in phosphate buffer solution (pH 6.8. The formulated NLCs were found to be more stable at refrigerated condition (5°C ± 3°C as compared with room temperature (25°C ± 2°C/60% RH% ± 5% RH. The use of design approach helped to identify critical formulation parameters in CC loaded NLCs preparation.

  14. Phospholipid composition and organization of cytochrome c oxidase preparations as determined by 31P-nuclear magnetic resonance.

    Science.gov (United States)

    Seelig, A; Seelig, J

    1985-05-14

    The molecular organization as well as the composition of the phospholipids in cytochrome c oxidase preparations (bovine heart) were investigated by 31P-nuclear magnetic resonance. In the so-called 'lipid-rich' preparation the lipids were found to form a fluid bilayer around the enzyme since the 31P-NMR spectrum was characteristic of a fast, axially symmetric motion of the phosphate groups with a chemical shift anisotropy of delta sigma = -45 ppm. In contrast, the 'lipid-depleted' cytochrome c oxidase gave rise to a broader spectrum where the motion of the phospholipids was no longer axially symmetric. Nevertheless, the total width of the spectrum was still considerably narrower than observed for immobilized phospholipids in solid crystals. Both enzyme preparations were dissolved in 1% detergent solution and used for high-resolution 31P-NMR spectroscopy. Narrow lines of about 20 Hz linewidth were obtained for both types of enzyme preparations, and well-resolved resonances could be assigned to cardiolipin, phosphatidylethanolamin and phosphatidylcholine. The major differences between lipid-rich and lipid-depleted cytochrome c oxidase were the absolute amount of phospholipid associated with the protein and the relative contribution of the individual lipid classes to the 31P-NMR spectrum. For lipid-rich cytochrome c oxidase about 130 molecules phospholipid were bound per enzyme (approx. 11 cardiolipins, 54 phosphatidylethanolamines and 64 phosphatidylcholines). For lipid-depleted cytochrome c oxidase only 6-18 lipids were bound per enzyme (1 or 2 cardiolipins, 3-8 phosphatidylethanolamines and 2-8 phosphatidylcholines). In contrast to earlier suggestions that cardiolipin is the only remaining lipid in lipid-depleted cytochrome c oxidase, the 31P-NMR studies demonstrate that all three lipids remain associated with the protein.

  15. Solid-Supported Lipid Membranes: Formation, Stability and Applications

    Science.gov (United States)

    Goh, Haw Zan

    insulating and structural properties. Preparation conditions are screened for those that are optimal for stBLM formation. Concentrations of lipid vesicles, hydrophobicity of SAMs, the presence of calcium and high concentrations of salt are identified as the key parameters. We show that stBLMs can be formed with vesicles of different compositions. Vesicle hemifusion opens up a new route in preserving the chemical compositions of stBLMs and facilitating membrane proteins incorporation. In Chapter 6, we visualize the hemifusion pathway of giant unilamellar vesicles (GUVs) with planar hydrophobic surfaces at the single vesicle level with fluorescence video microscopy. When a GUV hemifuses to a surface, its outer leaflet breaks apart and remains connected to the surface presumably through a hemifusion diaphragm. Lipids from the outer leaflet are transferred to the surface as a lipid monolayer that expands radially outward from the hemifusion diaphragm, thereby forming the loosely packed outer hemifusion zone. In Chapter 7, we develop an in vitro assay employing stBLMs and lipid vesicles to examine the functionality of GRASP in membrane tethering. Membrane-bound GRASP on opposing membranes dimerizes and tethers fluorescently-labeled vesicles to stBLMs. The fluorescence intensity of images taken at stBLM surfaces is used to quantify the tethering activity. Both wild type and mutant proteins were studied to shed light on the molecular mechanism of tethering. We show that the GRASP domain is sufficient and necessary for membrane tethering. In addition, the tethering capability of GRASP is impaired when the internal ligands and the binding pockets participating in dimerization are deleted and mutated. Membrane anchors, sizes of vesicles and membrane compositions are explored for their influence on the outcomes of the assay. Furthermore, preliminary analysis from neutron reflectivity measurements shows that both the internal ligands and binding pockets are exposed instead of buried

  16. Synthesis of linear and cyclic peptide-PEG-lipids for stabilization and targeting of cationic liposome-DNA complexes.

    Science.gov (United States)

    Ewert, Kai K; Kotamraju, Venkata Ramana; Majzoub, Ramsey N; Steffes, Victoria M; Wonder, Emily A; Teesalu, Tambet; Ruoslahti, Erkki; Safinya, Cyrus R

    2016-03-15

    Because nucleic acids (NAs) have immense potential value as therapeutics, the development of safe and effective synthetic NA vectors continues to attract much attention. In vivo applications of NA vectors require stabilized, nanometer-scale particles, but the commonly used approaches of steric stabilization with a polymer coat (e.g., PEGylation; PEG=poly(ethylene glycol)) interfere with attachment to cells, uptake, and endosomal escape. Conjugation of peptides to PEG-lipids can improve cell attachment and uptake for cationic liposome-DNA (CL-DNA) complexes. We present several synthetic approaches to peptide-PEG-lipids and discuss their merits and drawbacks. A lipid-PEG-amine building block served as the common key intermediate in all synthetic routes. Assembling the entire peptide-PEG-lipid by manual solid phase peptide synthesis (employing a lipid-PEG-carboxylic acid) allowed gram-scale synthesis but is mostly applicable to linear peptides connected via their N-terminus. Conjugation via thiol-maleimide or strain-promoted (copper-free) azide-alkyne cycloaddition chemistry is highly amenable to on-demand preparation of peptide-PEG-lipids, and the appropriate PEG-lipid precursors are available in a single chemical step from the lipid-PEG-amine building block. Azide-alkyne cycloaddition is especially suitable for disulfide-bridged peptides such as iRGD (cyclic CRGDKGPDC). Added at 10 mol% of a cationic/neutral lipid mixture, the peptide-PEG-lipids stabilize the size of CL-DNA complexes. They also affect cell attachment and uptake of nanoparticles in a peptide-dependent manner, thereby providing a platform for preparing stabilized, affinity-targeted CL-DNA nanoparticles.

  17. Topical Amphotericin B solid lipid nanoparticles: Design and development.

    Science.gov (United States)

    Butani, Dhruv; Yewale, Chetan; Misra, Ambikanandan

    2016-03-01

    The present work is focused on design and development of topical Amphotericin B solid lipid nanoparticles (SLNs) to improve the therapeutic antifungal activity. Amphotericin B loaded SLNs were prepared by novel solvent diffusion method and were characterized for particle size, zeta potential, drug entrapment, surface morphology, in vitro antifungal activity, ex vivo permeation, retention and skin-irritation. Optimized SLNs were spherical with average size of 111.1±2.2nm, zeta potential of -23.98±1.36mV and 93.8±1.8% of drug entrapment. Characterization of Amphotericin B SLNs by differential scanning calorimetry, Fourier transform infrared spectroscopy and Powder X-ray diffraction studies revealed absence of interaction between Amphotericin B and lipid. Amphotericin B is well dispersed in the lipid matrix without any crystallization. The SLNs were lyophilized with and without cryoprotectants to evaluate the stability and it was observed that the particle size of the SLNs significantly increased in SLN formulations lyophilized without cryoprotectant. The optimized SLN 5 formulation exhibited 2 fold higher drug permeation as compared to plain drug dispersion and higher zone of inhibition in Trichophyton rubrum fungal species. Formulation was found to be stable at 2-8°C and 25±2°C for the period of three months. Results of present study indicate that SLNs are suitable carriers for entrapment of poorly water soluble drugs and for enhancement of therapeutic efficacy of antifungal drug.

  18. Modification of oral absorption of oxyresveratrol using lipid based nanoparticles.

    Science.gov (United States)

    Sangsen, Yaowaporn; Wiwattanawongsa, Kamonthip; Likhitwitayawuid, Kittisak; Sritularak, Boonchoo; Wiwattanapatapee, Ruedeekorn

    2015-07-01

    The aim of this study was to develop and assess nanostructured lipid carriers (NLC) compared to solid lipid nanoparticles (SLN) for improving the oral bioavailability of oxyresveratrol (OXY). The OXY formulated as SLN (OXY-SLN) and NLC (OXY-NLC) were prepared by a high shear homogenization technique. The optimized OXY-NLC (NLC3) produced smaller nanoparticle sizes (96±0.9nm) than that of the OXY-SLN (108±0.3nm) with a homogeneous size distribution and a high zeta potential. The spherical NLC had a significantly higher efficiency for OXY entrapment (89±0.1%) and a better stability than the SLN after storage for 12 months at 4±2°C according to parameters such as smaller particles, greater zeta potential and a higher loading capacity (pSLN. The accumulated drug in an amorphous state in the NLC was also confirmed by powder X-ray diffraction (PXRD). The in vitro release profiles of the OXY-NLC showed a more sustained release compared to the SLN and unformulated OXY. The in vivo pharmacokinetic profiles implied enterohepatic recycling of OXY in the Wistar rat. Meanwhile, the oral absorption pattern of OXY was modified by both types of lipid nanoparticles. The SLN and NLC increased the relative bioavailability of OXY to 125% and 177%, respectively, compared with unformulated OXY. These findings indicated that NLC could be used as a potential carrier to improve the oral bioavailability of OXY.

  19. Methods for lipid nanostructure investigation at neutron and synchrotron sources

    Science.gov (United States)

    Kiselev, M. A.

    2011-03-01

    A lipid membrane is a main component of biological membranes. Contemporary bionanotechnologies use phospholipids and ceramides as basic components of drugs and cosmetic preparations. Phospholipids-based nanoparticles are used as drug carriers. Effective development of bionanotechnologies in Russia calls for creation of physical methods to diagnose the particle nanostructure which would be promising for application in pharmacology. Radiation with wavelengths of 1-10 Å is an adequate instrument for detecting the nanostructure of lipid bi- and monolayers. The review deals with methods that apply neutron scattering and synchrotron radiation for studying nanostructures of lipid membranes, phospholipid nanoparticles, and phospholipid monolayers on a water surface by techniques of diffraction, small-angle scattering, and reflectometry. The importance of the mutually complementary application of neutron and synchrotron radiation for solving urgent problems of membrane biophysics, microbiology, dermapharmacology, and bionanotechnologies is demonstrated by particular examples of studies of phospholipid membranes and ceramide-based membranes. The efficiency of development and application of new methods for solving urgent problems of biophysics is shown. The review is written on the basis of results obtained over the period of 1999-2010 at the Joint Institute for Nuclear Research (JINR) Laboratory of Neutron Physics in collaboration with the Pharmaceutical Departments of universities of France (Paris-Sud, Chatenay Malabry) and Germany (Martin Luther University, Halle). The experiments were performed at various European and Russian neutron and synchrotron sources.

  20. Atomic force microscope visualization of lipid bilayer degradation due to action of phospholipase A(2) and Humicola lanuginosa lipase

    DEFF Research Database (Denmark)

    Balashev, Konstantin; DiNardo, N. John; Callisen, Thomas H.;

    2007-01-01

    at the surface of a supported lipid bilayer. In particular, the time course of the degradation of lipid bilayers by Phospholipase A(2) (PLA(2)) and Humicola Lanuginosa Lipase (HLL) has been investigated. Contact mode imaging allows visualization of enzyme activity on the substrate with high lateral resolution....... Lipid bilayers were prepared by the Langmuir-Blodgett technique and transferred to an AFM liquid cell. Following injection of the enzyme into the liquid cell, a sequence of images was acquired at regular time intervals to allow the identification of substrate structure, preferred sites of enzyme...

  1. Effects of PEGylated lipid nanoparticles on the oral absorption of one BCS II drug: a mechanistic investigation.

    Science.gov (United States)

    Zhang, Xingwang; Chen, Guijiang; Zhang, Tianpeng; Ma, Zhiguo; Wu, Baojian

    2014-01-01

    Lipid nanocarriers are becoming a versatile platform for oral delivery of lipophilic drugs. In this article, we aimed to explore the gastrointestinal behaviors of lipid nanoparticles and the effect of PEGylation on oral absorption of fenofibrate (FN), a Biopharmaceutics Classification System (BCS) II model drug. FN-loaded PEGylated lipid nanoparticles (FN-PLNs) were prepared by the solvent-diffusion method and characterized by particle size distribution, morphology, Fourier transform infrared spectroscopy, and drug release. Lipolytic experiments were performed to assess the resistance of lipid nanoparticles against pancreatic lipase. Pharmacokinetics was evaluated in rats after oral administration of FN preparations. The obtained FN-PLNs were 186.7 nm in size with an entrapment efficiency of >95%. Compared to conventional lipid nanoparticles, PLNs exhibited slower drug release in the lipase-containing medium, strikingly reduced mucin binding, and suppressed lipolysis in vitro. Further, oral absorption of FN was significantly enhanced using PLNs with relative bioavailability of 123.9% and 157.0% to conventional lipid nanoparticles and a commercial formulation (Lipanthyl(®)), respectively. It was demonstrated that reduced mucin trapping, suppressed lipolysis, and/or improved mucosal permeability were responsible for increased oral absorption. These results facilitated a better understanding of the in vivo fate of lipid nanoparticles, and suggested the potential of PLNs as oral carriers of BCS II drugs.

  2. Design, characterization, and clinical evaluation of argan oil nanostructured lipid carriers to improve skin hydration.

    Science.gov (United States)

    Tichota, Deise Michele; Silva, Ana Catarina; Sousa Lobo, José Manuel; Amaral, Maria Helena

    2014-01-01

    Given its advantages in skin application (eg, hydration, antiaging, and protection), argan oil could be used in both dermatological and cosmetic formulations. Therefore, the preparation of nanostructured lipid carriers (NLCs) using argan oil as a liquid lipid is a promising technique, since the former constitute well-established systems for dermal delivery. The aim of this work was to develop a topical formulation of argan oil NLCs to improve skin hydration. Firstly an NLC dispersion was developed and characterized, and afterward an NLC-based hydrogel was prepared. The in vivo evaluation of the suitability of the prepared formulation for the proposed application was assessed in volunteers, by measuring different skin-surface parameters for 1 month. An argan oil NLC-based hydrogel formulation was successfully prepared and characterized. Moreover, the entrapment of the NLCs in the hydrogel net did not affect their colloidal sizes. Additionally, it was observed that this formulation precipitated an increase in skin hydration of healthy volunteers. Therefore, we concluded that the preparation of NLC systems using argan oil as the liquid lipid is a promising strategy, since a synergistic effect on the skin hydration was obtained (ie, NLC occlusion plus argan oil hydration).

  3. Control of Lipid Synthesis during Soybean Seed Development: Enzymic and Immunochemical Assay of Acyl Carrier Protein.

    Science.gov (United States)

    Ohlrogge, J B; Kuo, T M

    1984-03-01

    During soybean seed (Glycine max, var Am Soy 71) development, the rate of lipid biosynthesis per seed increases greatly. As the seed reaches maturity, lipid synthesis declines. To study the controls over the oil synthesis and storage process, we have chosen acyl carrier protein (ACP) as a representative marker for the fatty acid synthetase pathway. We have quantitated soybean ACP levels by both enzymic and immunochemical methods. Escherichia coli acyl-ACP synthetase was used as an assay for enzymically active ACP. Total ACP protein was determined by immunoassay using antibodies prepared in rabbits against spinach ACP. These antibody preparations also bind ACP isolated from soybeans, allowing development of a radioimmunoassay based on competition with [(3)H]palmitoyl-ACP. The enzymic and immunochemical measurement of ACP at various stages of seed development have indicated that ACP activity and ACP antigen increase markedly in correlation with the in vivo increase in lipid synthesis. These results indicate that a major control over the increase in lipid synthesis arises through regulation of the levels of the fatty acid biosynthetic proteins. However, as the seed reaches maturity and lipid biosynthesis declines, ACP per seed remains relatively high. In the mature seed, we found that more than 95% of the ACP is localized in the cotyledons, less than 5% is in the axis, and less than 1% is in the seed coat.

  4. RES and brain targeting stavudine-loaded solid lipid nanoparticles for AIDS therapy

    Directory of Open Access Journals (Sweden)

    Panchaxari M Dandagi

    2012-01-01

    Full Text Available Cells of the reticuloendothelial system (RES, e.g., macrophages play an important role in the immunopathogenesis of Acquired Immunodeficiency Syndrome (AIDS. The objective of the present study was to investigate the possibility of specifically targeting antiviral drugs Stavudine to RES (like Liver, Spleen etc. and brain using solid lipid nanoparticles (SLNs as colloidal drug carriers. Various lipids like stearic acid, cetyl palmitate, glyceryl behenate and phospholipid in combination have been used and effect of lipid on properties of SLNs has been investigated. The SLNs of Stavudine were prepared by double emulsion solvent evaporation method. The diameter of SLNs was determined and found in range of 175 ± 6.027 to 393 ± 2.309 nm depending on the type of lipid used. Percentage drug entrapment was found to be influenced by the concentration and type of lipid used, which was found in the range of 18.1 to 65.2%. The drug release behavior was studied by dialysis bag method and the release pattern of drug was found to follow Higuchi model. Results of stability evaluation showed a relatively long-term stability after storage at 4°C for 1 month. Stavudine-loaded SLNs were successfully prepared, optimized and effectively targeted to RES and brain. SLNs of Stavudine have been shown to be taken up by brain 11 fold greater as compared to pure Stavudine. This finding is more important since Human Immunodeficiency Syndrome (HIV infect the central nervous system.

  5. A method for detergent-free isolation of membrane proteins in their local lipid environment.

    Science.gov (United States)

    Lee, Sarah C; Knowles, Tim J; Postis, Vincent L G; Jamshad, Mohammed; Parslow, Rosemary A; Lin, Yu-Pin; Goldman, Adrian; Sridhar, Pooja; Overduin, Michael; Muench, Stephen P; Dafforn, Timothy R

    2016-07-01

    Despite the great importance of membrane proteins, structural and functional studies of these proteins present major challenges. A significant hurdle is the extraction of the functional protein from its natural lipid membrane. Traditionally achieved with detergents, purification procedures can be costly and time consuming. A critical flaw with detergent approaches is the removal of the protein from the native lipid environment required to maintain functionally stable protein. This protocol describes the preparation of styrene maleic acid (SMA) co-polymer to extract membrane proteins from prokaryotic and eukaryotic expression systems. Successful isolation of membrane proteins into SMA lipid particles (SMALPs) allows the proteins to remain with native lipid, surrounded by SMA. We detail procedures for obtaining 25 g of SMA (4 d); explain the preparation of protein-containing SMALPs using membranes isolated from Escherichia coli (2 d) and control protein-free SMALPS using E. coli polar lipid extract (1-2 h); investigate SMALP protein purity by SDS-PAGE analysis and estimate protein concentration (4 h); and detail biophysical methods such as circular dichroism (CD) spectroscopy and sedimentation velocity analytical ultracentrifugation (svAUC) to undertake initial structural studies to characterize SMALPs (∼2 d). Together, these methods provide a practical tool kit for those wanting to use SMALPs to study membrane proteins.

  6. Antithrombotic lipids from Semen Persicae.

    Science.gov (United States)

    Yang, Nian-Yun; Liu, Li; Tao, Wei-Wei; Duan, Jin-Ao; Liu, Xun-Hong; Huang, Su-Ping

    2011-10-01

    Chemical investigation of Semen Persicae has led to the isolation of decane (1), triolein (2), nonacosanoic acid (3), oleic acid ethyl ester (4), palmitic acid (5), oleic acid (6) and 15,16-dihydroxy-9Z,12Z-octadecadienoic acid 2,3-dihydroxypropyl ester (7). Amongst these, compound 7 is a new lipid. Their structures were elucidated by chemical and extensive spectral analysis. Their anticoagulative activities were also evaluated in vitro, which showed that petroleum ether extract and compounds 5-6 could significantly prolong thrombin time while methanol extract could obviously inhibit platelet aggregation.

  7. Superdiffusion in supported lipid bilayers

    CERN Document Server

    Campagnola, Grace; Schroder, Bryce W; Peersen, Olve B; Krapf, Diego

    2015-01-01

    We study the diffusion of membrane-targeting C2 domains using single-molecule tracking in supported lipid bilayers. The ensemble-averaged mean square displacement (MSD) exhibits superdiffusive behavior. However, the time-averaged MSD of individual trajectories is found to be linear with respect to lag time, as in Brownian diffusion. These observations are explained in terms of bulk excursions that introduce jumps with a heavy-tail distribution. Our experimental results are shown to agree with analytical models of bulk-mediated diffusion and with numerical simulations.

  8. Effect of brown seaweed lipids on fatty acid composition and lipid hydroperoxide levels of mouse liver.

    Science.gov (United States)

    Airanthi, M K Widjaja-Adhi; Sasaki, Naoya; Iwasaki, Sayaka; Baba, Nobuko; Abe, Masayuki; Hosokawa, Masashi; Miyashita, Kazuo

    2011-04-27

    Brown seaweed lipids from Undaria pinnatifida (Wakame), Sargassum horneri (Akamoku), and Cystoseira hakodatensis (Uganomoku) contained several bioactive compounds, namely, fucoxanthin, polyphenols, and omega-3 polyunsaturated fatty acids (PUFA). Fucoxanthin and polyphenol contents of Akamoku and Uganomoku lipids were higher than those of Wakame lipids, while Wakame lipids showed higher total omega-3 PUFA content than Akamoku and Uganomoku lipids. The levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) in liver lipids of KK-A(y) mouse significantly increased by Akamoku and Uganomoku lipid feeding as compared with the control, but not by Wakame lipid feeding. Fucoxanthin has been reported to accelerate the bioconversion of omega-3 PUFA and omega-6 PUFA to DHA and AA, respectively. The higher hepatic DHA and AA level of mice fed Akamoku and Uganomoku lipids would be attributed to the higher content of fucoxanthin of Akamoku and Uganomoku lipids. The lipid hydroperoxide levels of the liver of mice fed brown seaweed lipids were significantly lower than those of control mice, even though total PUFA content was higher in the liver of mice fed brown seaweed lipids. This would be, at least in part, due to the antioxidant activity of fucoxanthin metabolites in the liver.

  9. Lipid Disturbances in Psoriasis: An Update

    Directory of Open Access Journals (Sweden)

    Aldona Pietrzak

    2010-01-01

    Full Text Available Psoriasis is a common disease with the population prevalence ranging from 2% to 3%. Its prevalence in the population is affected by genetic, environmental, viral, infectious, immunological, biochemical, endocrinological, and psychological factors, as well as alcohol and drug abuse. In the recent years, psoriasis has been recognised as a systemic disease associated with numerous multiorgan abnormalities and complications. Dyslipidemia is one of comorbidities in psoriatic patients. Lipid metabolism studies in psoriasis have been started at the beginning of the 20th century and are concentrated on skin surface lipids, stratum corneum lipids and epidermal phospholipids, serum lipids, dermal low-density lipoproteins in the psoriatic skin, lipid metabolism, oxidative stress and correlations between inflammatory parameters, lipid parameters and clinical symptoms of the disease. On the basis of the literature data, psoriasis can be described as an immunometabolic disease.

  10. Highly antioxidant carotene-lipid nanocarriers: synthesis and antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Lacatusu, Ioana; Badea, Nicoleta, E-mail: nicoleta.badea@gmail.com; Ovidiu, Oprea [University POLITEHNICA of Bucharest, Faculty of Applied Chemistry and Materials Science (Romania); Bojin, Dionezie [Faculty of Engineering and Materials Science (Romania); Meghea, Aurelia [University POLITEHNICA of Bucharest, Faculty of Applied Chemistry and Materials Science (Romania)

    2012-06-15

    The objective of this study was to explore the potential of two natural oils (squalene-Sq and grape seed oil-GSO) to prepare biocompatible antioxidant nanostructured lipid carriers-NLCs as a safety and protective formulation for sensitive {beta}-carotene. For this purpose different oil-in-water nanoemulsions stabilized by a combination of alkylpolyoxy ethylene sorbitans, lecithin and a block copolymer, were prepared using a melt high-shear homogenization process. The physico-chemical characteristics of the carotene-loaded NLCs were firstly investigated in detail. The smaller lipid nanoparticles have been obtained by using Tween 20 as main non-ionic surfactant, with average diameters of about 85 nm for GSO and 89 nm for Sq, with a polydispersity index <0.19. The developed carotene-NLCs presented an excellent physical stability with almost all zeta potential values ranging between -29 Division-Sign -40 mV. The differential scanning calorimetry analysis showed that the {beta}-carotene incorporation has led to a perturbation of solid lipid matrix with a less ordered arrangement. By UV-Vis spectroscopy it was evidenced that after encapsulation {beta}-carotene adopts a supramolecular structure demonstrated by appearance of a shoulder at 530 nm related to a {beta}-carotene triplet-triplet absorption. The carotene-NLCs have been also evaluated in terms of in vitro antioxidant properties. The presence of Sq and GSO produced a significant effect on the antioxidant capacity of developed NLCs. The samples prepared with GSO and Tween 80 as main surfactant showed the highest antioxidant activity (AA %) against free oxygen radicals, exhibiting an enhancement of 35 % for loaded NLCs, as comparing to pure carotene. In addition to these properties, the ability of NLCs to manifest antibacterial activity was tested against Escherichiacoli bacteria. The antibacterial analysis shown that loaded-NLCs develop an effective inhibition zone against bacteria growth and it was dependent in a

  11. Preparation of microsomes to study Ca2+ channels.

    Science.gov (United States)

    Bezprozvanny, Ilya

    2013-11-01

    Native cerebellar microsomes are used to study the properties of native cerebellar inositol(1,4,5)-trisphosphate receptor 1 (InsP3R1) and ryanodine receptor 1 (RyanR1) Ca(2+) release channels. Additionally, microsomes prepared from Sf9 cells infected with InsP3R- or RyanR-expressing recombinant baculoviruses can be used to compare properties of different InsP3R and RyanR isoforms and to perform structure-function studies of both types of receptors. This protocol describes how to prepare ER microsomes from native cerebellar tissue or Sf9 cells infected with InsP3R- or RyanR-expressing recombinant baculoviruses for planar lipid bilayer (also called black lipid membranes or BLM) experiments. Prepared material is aliquoted and can be stored at -80°C freezer for many months before BLM experiments.

  12. Circadian regulators of intestinal lipid absorption

    OpenAIRE

    Hussain, M. Mahmood; Pan, Xiaoyue

    2015-01-01

    Among all the metabolites present in the plasma, lipids, mainly triacylglycerol and diacylglycerol, show extensive circadian rhythms. These lipids are transported in the plasma as part of lipoproteins. Lipoproteins are synthesized primarily in the liver and intestine and their production exhibits circadian rhythmicity. Studies have shown that various proteins involved in lipid absorption and lipoprotein biosynthesis show circadian expression. Further, intestinal epithelial cells express circa...

  13. APP Function and Lipids: A Bidirectional Link.

    Science.gov (United States)

    Grimm, Marcus O W; Mett, Janine; Grimm, Heike S; Hartmann, Tobias

    2017-01-01

    Extracellular neuritic plaques, composed of aggregated amyloid-β (Aβ) peptides, are one of the major histopathological hallmarks of Alzheimer's disease (AD), a progressive, irreversible neurodegenerative disorder and the most common cause of dementia in the elderly. One of the most prominent risk factor for sporadic AD, carrying one or two aberrant copies of the apolipoprotein E (ApoE) ε4 alleles, closely links AD to lipids. Further, several lipid classes and fatty acids have been reported to be changed in the brain of AD-affected individuals. Interestingly, the observed lipid changes in the brain seem not only to be a consequence of the disease but also modulate Aβ generation. In line with these observations, protective lipids being able to decrease Aβ generation and also potential negative lipids in respect to AD were identified. Mechanistically, Aβ peptides are generated by sequential proteolytic processing of the amyloid precursor protein (APP) by β- and γ-secretase. The α-secretase appears to compete with β-secretase for the initial cleavage of APP, preventing Aβ production. All APP-cleaving secretases as well as APP are transmembrane proteins, further illustrating the impact of lipids on Aβ generation. Beside the pathological impact of Aβ, accumulating evidence suggests that Aβ and the APP intracellular domain (AICD) play an important role in regulating lipid homeostasis, either by direct effects or by affecting gene expression or protein stability of enzymes involved in the de novo synthesis of different lipid classes. This review summarizes the current literature addressing the complex bidirectional link between lipids and AD and APP processing including lipid alterations found in AD post mortem brains, lipids that alter APP processing and the physiological functions of Aβ and AICD in the regulation of several lipid metabolism pathways.

  14. FORMULATION AND EVALUATION OF SOLID LIPID NANOPARTICLES OF A POORLY WATER SOLUBLE MODEL DRUG, IBUPROFEN

    Directory of Open Access Journals (Sweden)

    De Pintu Kumar

    2012-12-01

    Full Text Available Approximately 40% of lipophilic drug candidates fail to comply the commercial requirements of solubility and formulation stability, prompting significant research activity in advanced lipophile delivery technologies. Solid lipid nanoparticle (SLN technology represents a promising new approach to lipophile drug delivery. Solid lipid nanoparticles typically are spherical with average diameters between 1 to 1000 nanometers. SLNs possess a solid lipid core matrix that can solubilize lipophilic molecules. The lipid core is stabilized by surfactants. Primary objective of this study is to enhance the solubility and dissolution rate of Ibuprofen by formulation into SLN using hot homogenization method. Further, this study also investigates the effect of various formulation parameters like stabilizer concentration, surfactant ratio, Lipid ratio and drug loading. SLNs were characterized for size distribution, entrapment efficiency, drug release and stability. SLN of Ibuprofen was prepared using stearic acid (lipid Phospholipon 80 H (surfactant and Tween-80 as stabilizer. The FTIR study shows no major interaction of Ibuprofen with other formulation ingredients, and the Differential Scanning Calorimetry (DSC study revealed that the drug is molecularly dispersed into the lipid. The particle size determinations confirm the particle size distribution in the nanoparticular range (27% Volume to 56% volume. In-vitro drug release through the dialysis membrane from the prepared SLNs is much higher than the pure drug. The stability study indicates the stability of the formulations without changing its performance on storage. Hence formulation of Ibuprofen in SLN enhances the dissolution rate as well as it will enhance the bioavailability of the drug which could be stabilized during storage.

  15. Chitosan-coupled solid lipid nanoparticles: Tuning nanostructure and mucoadhesion.

    Science.gov (United States)

    Sandri, Giuseppina; Motta, Simona; Bonferoni, Maria Cristina; Brocca, Paola; Rossi, Silvia; Ferrari, Franca; Rondelli, Valeria; Cantù, Laura; Caramella, Carla; Del Favero, Elena

    2017-01-01

    Solid Lipid Nanoparticles (SLNs) composed of biodegradable physiological lipids have been widely proposed as efficient drug delivery systems, also for ophthalmic administration. Recently, chitosan-associated-SLNs have been developed to further improve the residence time of these colloidal systems in the precorneal area by means of mucoadhesive interaction. In the present study, a one-step preparation protocol was used aiming both at scale-up ease and at stronger coupling between chitosan and SLNs. The resulting particles were chitosan associated-SLNs (CS-SLNs). These nanoparticles were characterized, as compared to both the chitosan-free and the usual chitosan-coated ones, by applying a multi-technique approach: light, neutron and X-ray scattering, Zeta-potential, AFM, calorimetry. It was assessed that, while keeping the features of nano-size and surface-charge required for an efficient vector, these new nanoparticles display a strong and intimate interaction between chitosan and SLNs, far more settled than the usual simple coverage. Moreover, this one-step preparation method allows to obtain a strong and intimate interaction between chitosan and SLNs, firmer than the usual simple coating. This confers to the CS-SLNs an improved mucoadhesion, opening the way for a high-performing ophthalmic formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Cholesterylbutyrate Solid Lipid Nanoparticles as a Butyric Acid Prodrug

    Directory of Open Access Journals (Sweden)

    Alessandro Mauro

    2008-02-01

    Full Text Available Cholesterylbutyrate (Chol-but was chosen as a prodrug of butyric acid.Butyrate is not often used in vivo because its half-life is very short and therefore too largeamounts of the drug would be necessary for its efficacy. In the last few years butyric acid'santi-inflammatory properties and its inhibitory activity towards histone deacetylases havebeen widely studied, mainly in vitro. Solid Lipid Nanoparticles (SLNs, whose lipid matrixis Chol-but, were prepared to evaluate the delivery system of Chol-but as a prodrug and totest its efficacy in vitro and in vivo. Chol-but SLNs were prepared using the microemulsionmethod; their average diameter is on the order of 100-150 nm and their shape is spherical.The antineoplastic effects of Chol-but SLNs were assessed in vitro on different cancer celllines and in vivo on a rat intracerebral glioma model. The anti-inflammatory activity wasevaluated on adhesion of polymorphonuclear cells to vascular endothelial cells. In thereview we will present data on Chol-but SLNs in vitro and in vivo experiments, discussingthe possible utilisation of nanoparticles for the delivery of prodrugs for neoplastic andchronic inflammatory diseases.

  17. Lipid bilayer composition influences small multidrug transporters

    Directory of Open Access Journals (Sweden)

    Curnow Paul

    2008-11-01

    Full Text Available Abstract Background Membrane proteins are influenced by their surrounding lipids. We investigate the effect of bilayer composition on the membrane transport activity of two members of the small multidrug resistance family; the Escherichia coli transporter, EmrE and the Mycobacterium tuberculosis, TBsmr. In particular we address the influence of phosphatidylethanolamine and anionic lipids on the activity of these multidrug transporters. Phosphatidylethanolamine lipids are native to the membranes of both transporters and also alter the lateral pressure profile of a lipid bilayer. Lipid bilayer lateral pressures affect membrane protein insertion, folding and activity and have been shown to influence reconstitution, topology and activity of membrane transport proteins. Results Both EmrE and TBsmr are found to exhibit a similar dependence on lipid composition, with phosphatidylethanolamine increasing methyl viologen transport. Anionic lipids also increase transport for both EmrE and TBsmr, with the proteins showing a preference for their most prevalent native anionic lipid headgroup; phosphatidylglycerol for EmrE and phosphatidylinositol for TBsmr. Conclusion These findings show that the physical state of the membrane modifies drug transport and that substrate translocation is dependent on in vitro lipid composition. Multidrug transport activity seems to respond to alterations in the lateral forces exerted upon the transport proteins by the bilayer.

  18. Lipid Nanoparticles for Ocular Gene Delivery

    Directory of Open Access Journals (Sweden)

    Yuhong Wang

    2015-06-01

    Full Text Available Lipids contain hydrocarbons and are the building blocks of cells. Lipids can naturally form themselves into nano-films and nano-structures, micelles, reverse micelles, and liposomes. Micelles or reverse micelles are monolayer structures, whereas liposomes are bilayer structures. Liposomes have been recognized as carriers for drug delivery. Solid lipid nanoparticles and lipoplex (liposome-polycation-DNA complex, also called lipid nanoparticles, are currently used to deliver drugs and genes to ocular tissues. A solid lipid nanoparticle (SLN is typically spherical, and possesses a solid lipid core matrix that can solubilize lipophilic molecules. The lipid nanoparticle, called the liposome protamine/DNA lipoplex (LPD, is electrostatically assembled from cationic liposomes and an anionic protamine-DNA complex. The LPD nanoparticles contain a highly condensed DNA core surrounded by lipid bilayers. SLNs are extensively used to deliver drugs to the cornea. LPD nanoparticles are used to target the retina. Age-related macular degeneration, retinitis pigmentosa, and diabetic retinopathy are the most common retinal diseases in humans. There have also been promising results achieved recently with LPD nanoparticles to deliver functional genes and micro RNA to treat retinal diseases. Here, we review recent advances in ocular drug and gene delivery employing lipid nanoparticles.

  19. DMSO Induces Dehydration near Lipid Membrane Surfaces

    Science.gov (United States)

    Cheng, Chi-Yuan; Song, Jinsuk; Pas, Jolien; Meijer, Lenny H.H.; Han, Songi

    2015-01-01

    Dimethyl sulfoxide (DMSO) has been broadly used in biology as a cosolvent, a cryoprotectant, and an enhancer of membrane permeability, leading to the general assumption that DMSO-induced structural changes in cell membranes and their hydration water play important functional roles. Although the effects of DMSO on the membrane structure and the headgroup dehydration have been extensively studied, the mechanism by which DMSO invokes its effect on lipid membranes and the direct role of water in this process are unresolved. By directly probing the translational water diffusivity near unconfined lipid vesicle surfaces, the lipid headgroup mobility, and the repeat distances in multilamellar vesicles, we found that DMSO exclusively weakens the surface water network near the lipid membrane at a bulk DMSO mole fraction (XDMSO) of DMSO was found to effectively destabilize the hydration water structure at the lipid membrane surface at XDMSO 0.1, DMSO enters the lipid interface and restricts the lipid headgroup motion. We postulate that DMSO acts as an efficient cryoprotectant even at low concentrations by exclusively disrupting the water network near the lipid membrane surface, weakening the cohesion between water and adhesion of water to the lipid headgroups, and so mitigating the stress induced by the volume change of water during freeze-thaw. PMID:26200868

  20. Lipid peroxides level in the Indonesian elderly

    Directory of Open Access Journals (Sweden)

    Purwantyastuti Purwantyastuti

    2005-06-01

    Full Text Available A cross-sectional study was done to see the possible association of plasma lipid peroxides in the elderly with age and other factors. Plasma lipid peroxides is a product of free radical reactions which according to the latest theory of aging is the cause of aging process. Lipid peroxides were also found high in coronary heart disease. Four hundred forty relatively healthy elderly, age 55-85 years, were randomly chosen from free living elderly under guidance of health care centers (PUSKESMAS in Jakarta. Anamnesis and physical examination were done in the morning in the health centers. Blood samples were taken in fasting conditions, plasma lipids and lipid peroxides were measured according to standard methods. There was an age difference of lipid peroxides level in the elderly, which increased with age up to 70 years old. Elderly 70 years old and over had low plasma lipid peroxides. The level was not related to high plasma lipids. Higher level was found when more chronic degenerative diseases were found. (Med J Indones 2005; 14: 71-7Keywords: lipid peroxides, aging

  1. Electrodiffusion of lipids on membrane surfaces

    Science.gov (United States)

    Zhou, Y. C.

    2012-05-01

    Lateral translocation of lipids and proteins is a universal process on membrane surfaces. Local aggregation or organization of lipids and proteins can be induced when the random lateral motion is mediated by the electrostatic interactions and membrane curvature. Although the lateral diffusion rates of lipids on membranes of various compositions are measured and the electrostatic free energies of predetermined protein-membrane-lipid systems can be computed, the process of the aggregation and the evolution to the electrostatically favorable states remain largely undetermined. Here we propose an electrodiffusion model, based on the variational principle of the free energy functional, for the self-consistent lateral drift-diffusion of multiple species of charged lipids on membrane surfaces. Finite sizes of lipids are modeled to enforce the geometrical constraint of the lipid concentration on membrane surfaces. A surface finite element method is developed to appropriate the Laplace-Beltrami operators in the partial differential equations of the model. Our model properly describes the saturation of lipids on membrane surfaces, and correctly predicts that the MARCKS peptide can consistently sequester three multivalent phosphatidylinositol 4,5-bisphosphate lipids through its basic amino acid residues, regardless of a wide range of the percentage of monovalent phosphatidylserine in the membrane.

  2. Lipid transport in cholecystokinin knockout mice.

    Science.gov (United States)

    King, Alexandra; Yang, Qing; Huesman, Sarah; Rider, Therese; Lo, Chunmin C

    2015-11-01

    Cholecystokinin (CCK) is released in response to lipid feeding and regulates pancreatic digestive enzymes vital to the absorption of nutrients. Our previous reports demonstrated that cholecystokinin knockout (CCK-KO) mice fed for 10 weeks of HFD had reduced body fat mass, but comparable glucose uptake by white adipose tissues and skeletal muscles. We hypothesized that CCK is involved in energy homeostasis and lipid transport from the small intestine to tissues in response to acute treatment with dietary lipids. CCK-KO mice with comparable fat absorption had increased energy expenditure and were resistant to HFD-induced obesity. Using intraduodenal infusion of butter fat and intravenous infusion using Liposyn III, we determined the mechanism of lipid transport from the small intestine to deposition in lymph and adipocytes in CCK-KO mice. CCK-KO mice had delayed secretion of Apo B48-chylomicrons, lipid transport to the lymphatic system, and triglyceride (TG)-derived fatty acid uptake by epididymal fat in response to acute treatment of intraduodenal lipids. In contrast, CCK-KO mice had comparable TG clearance and lipid uptake by white adipocytes in response to TGs in chylomicron-like emulsion. Thus, we concluded that CCK is important for lipid transport and energy expenditure to control body weight in response to dietary lipid feeding.

  3. Lipid Metabolism, Apoptosis and Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Chunfa Huang

    2015-01-01

    Full Text Available Lipid metabolism is regulated by multiple signaling pathways, and generates a variety of bioactive lipid molecules. These bioactive lipid molecules known as signaling molecules, such as fatty acid, eicosanoids, diacylglycerol, phosphatidic acid, lysophophatidic acid, ceramide, sphingosine, sphingosine-1-phosphate, phosphatidylinositol-3 phosphate, and cholesterol, are involved in the activation or regulation of different signaling pathways. Lipid metabolism participates in the regulation of many cellular processes such as cell growth, proliferation, differentiation, survival, apoptosis, inflammation, motility, membrane homeostasis, chemotherapy response, and drug resistance. Bioactive lipid molecules promote apoptosis via the intrinsic pathway by modulating mitochondrial membrane permeability and activating different enzymes including caspases. In this review, we discuss recent data in the fields of lipid metabolism, lipid-mediated apoptosis, and cancer therapy. In conclusion, understanding the underlying molecular mechanism of lipid metabolism and the function of different lipid molecules could provide the basis for cancer cell death rationale, discover novel and potential targets, and develop new anticancer drugs for cancer therapy.

  4. Retroviral vector production under serum deprivation: The role of lipids.

    Science.gov (United States)

    Rodrigues, A F; Carmo, M; Alves, P M; Coroadinha, A S

    2009-12-15

    The use of retroviral vectors for gene therapy applications demands high titer preparations and stringent quality standards. However, the manufacturing of these vectors still represents a highly challenging task due to the low productivity of the cell lines and reduced stability of the vector infectivity, particularly under serum-free conditions. With the objective of understanding the major limitations of retroviral vector production under serum deprivation, a thorough study of viral production kinetics, vector characterization and cell growth and metabolic behavior was conducted, for 293 FLEX 18 and Te Fly Ga 18 producer cell lines using different serum concentrations. The reduction of serum supplementation in the culture medium resulted in pronounced decreases in cell productivity of infectious vector, up to ninefold in 293 FLEX 18 cells and sevenfold in Te Fly Ga 18 cells. Total particles productivity was maintained, as assessed by measuring viral RNA; therefore, the decrease in infectious vector production could be attributed to higher defective particles output. The absence of the serum lipid fraction was found to be the major cause for this decrease in cell viral productivity. The use of delipidated serum confirmed the requirement of serum lipids, particularly cholesterol, as its supplementation not only allowed the total recovery of viral titers as well as additional production increments in both cell lines when comparing with the standard 10% (v/v) FBS supplementation. This work identified lower production ratios of infectious particles/total particles as the main restraint of retroviral vector production under serum deprivation; this is of the utmost importance concerning the clinical efficacy of the viral preparations. Lipids were confirmed as the key serum component correlated with the production of infective retroviral vectors and this knowledge can be used to efficiently design medium supplementation strategies for serum-free production. Biotechnol

  5. Design and evaluation of lidocaine- and prilocaine-coloaded nanoparticulate drug delivery systems for topical anesthetic analgesic therapy: a comparison between solid lipid nanoparticles and nanostructured lipid carriers

    Directory of Open Access Journals (Sweden)

    You P

    2017-09-01

    Full Text Available Peijun You,1 Ran Yuan,2 Chuanyu Chen1 1Department of Anesthesiology, Shandong Jining No 1 People’s Hospital, Shandong, People’s Republic of China; 2Department of Anesthesiology, Affiliated Hospital of Jining Medical College, Jining, Shandong, People’s Republic of China Purpose: Topical anesthesia analgesic therapy has diverse applicability in solving the barrier properties of skin and unfavorable physicochemical properties of drugs. Lidocaine (LID combined with prilocaine (PRI has been used as a topical preparation for dermal anesthesia for treatment of conditions such as paresthesia. Materials and methods: In this study, for combination anesthesia and overcoming the drawbacks of LID and PRI, respectively, LID- and PRI-loaded solid lipid nanoparticles (SLNs and nanostructured lipid carriers (NLCs were prepared and characterized by determination of their particle size, drug loading capacity, stability, in vitro drug release behavior and in vitro cellular viability. Ex vivo skin permeation and in vivo anesthesia analgesic efficiency of these two systems were also evaluated and compared. Results: Results revealed that combination delivery of the dual drugs exhibited more remarkable efficiency than signal drug-loaded systems. SLN systems have better ex vivo skin permeation ability than NLCs. NLC systems revealed a stronger in vivo anesthesia analgesic effect than SLN systems. Conclusion: It can be concluded that SLNs and NLCs have different advantages, and that both carriers are promising dual drug delivery systems for topical anesthetic analgesic therapy. Keywords: topical anesthesia, prilocaine, lidocaine, solid lipid nanoparticles, nanostructured lipid carriers

  6. Impact of lipid content and composition on lipid oxidation and protein carbonylation in experimental fermented sausages.

    Science.gov (United States)

    Fuentes, Verónica; Estévez, Mario; Ventanas, Jesús; Ventanas, Sonia

    2014-03-15

    This study aims to investigate the effect of lipid content (∼4%, ∼10% and ∼15%) and composition (different lipid sources; animal fat and sunflower oil) on the oxidative stability of proteins and lipids in experimental fermented sausages. Increasing the lipid content of sausages enhanced the susceptibility of lipids to oxidation whereas the effect on the formation of specific carbonyls from protein oxidation was not so evident. Sausages manufactured with different lipid sources affected the susceptibility of lipids and proteins to oxidation as a likely result of the modifications in the fatty acid profile, as well as to the presence of antioxidant compounds. While the fatty acid profile had a major effect on the occurrence and extent of lipid oxidation, the presence of compounds with potential antioxidant activity may be more influential on the extent of protein carbonylation.

  7. Fabrication of pseudo-ceramide-based lipid microparticles for recovery of skin barrier function.

    Science.gov (United States)

    Kim, Do-Hoon; Park, Woo Ram; Kim, Jeong Hwan; Cho, Eun Chul; An, Eun Jung; Kim, Jin-Woong; Oh, Seong-Geun

    2012-06-01

    The recovery of skin barrier functions was investigated with pseudo-ceramide-based lipid microparticles. The microparticles were prepared by using a fluid bed technique where lipid components (a pseudo-ceramide, cholesterol and a fatty acid) were coated on a sugar seed, and a polymer was subsequently coated on the lipid microparticles. The microparticles contained large amount of pseudo-ceramide, and the pseudo-ceramide was in the form of lamellar structures mixed with other lipid components. In addition, the microparticles were stably dispersed in aqueous media or emulsion systems without any disruption of the microparticles' structures, thereby supplying sufficient amount of the pseudo-ceramide to skins for improving skin barrier functions such as preventing water loss. Such a role of the microparticles was proven by evaluating in vivo the efficacy of the lipid microparticles in reducing a trans-epidermal water loss (TEWL) of impaired murine skins. As a result, the novel pseudo-ceramide-based lipid microparticles for barrier recovery may potentially be applied in the field of dermatology, cosmetics and pharmaceuticals. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Thermally-induced aggregation and fusion of protein-free lipid vesicles.

    Science.gov (United States)

    Ibarguren, Maitane; Bomans, Paul H H; Ruiz-Mirazo, Kepa; Frederik, Peter M; Alonso, Alicia; Goñi, Félix M

    2015-12-01

    Membrane fusion is an important phenomenon in cell biology and pathology. This phenomenon can be modeled using vesicles of defined size and lipid composition. Up to now fusion models typically required the use of chemical (polyethyleneglycol, cations) or enzymatic catalysts (phospholipases). We present here a model of lipid vesicle fusion induced by heat. Large unilamellar vesicles consisting of a phospholipid (dioleoylphosphatidylcholine), cholesterol and diacylglycerol in a 43:57:3 mol ratio were employed. In this simple system, fusion was the result of thermal fluctuations, above 60 °C. A similar system containing phospholipid and cholesterol but no diacylglycerol was observed to aggregate at and above 60 °C, in the absence of fusion. Vesicle fusion occurred under our experimental conditions only when (31)P NMR and cryo-transmission electron microscopy of the lipid mixtures used in vesicle preparation showed non-lamellar lipid phase formation (hexagonal and cubic). Non-lamellar structures are probably the result of lipid reassembly of the products of individual fusion events, or of fusion intermediates. A temperature-triggered mechanism of lipid reassembly might have occurred at various stages of protocellular evolution.

  9. Optimization of LDL targeted nanostructured lipid carriers of 5-FU by a full factorial design

    Directory of Open Access Journals (Sweden)

    Sare Andalib

    2012-01-01

    Full Text Available Background: Nanostructured lipid carriers (NLC are a mixture of solid and liquid lipids or oils as colloidal carrier systems that lead to an imperfect matrix structure with high ability for loading water soluble drugs. The aim of this study was to find the best proportion of liquid and solid lipids of different types for optimization of the production of LDL targeted NLCs used in carrying 5-Fu by the emulsification-solvent evaporation method. Materials and Methods: The influence of the lipid type, cholesterol or cholesteryl stearate for targeting LDL receptors, oil type (oleic acid or octanol, lipid and oil% on particle size, surface charge, drug loading efficiency, and drug released percent from the NLCs were studied by a full factorial design. Results: The NLCs prepared by 54.5% cholesterol and 25% of oleic acid, showed optimum results with particle size of 105.8 nm, relatively high zeta potential of −25 mV, drug loading efficiency of 38% and release efficiency of about 40%. Scanning electron microscopy of nanoparticles confirmed the results of dynamic light scattering method used in measuring the particle size of NLCs. Conclusions: The optimization method by a full factorial statistical design is a useful optimization method for production of nanostructured lipid carriers.

  10. Effect of diurnal temperature difference on lipid accumulation and development in Calanus sinicus (Copepoda: Calanoida)

    Science.gov (United States)

    Zhou, Konglin; Sun, Song

    2016-08-01

    Calanus sinicus, the dominant copepod in the Yellow Sea, develops a large oil sac in late spring to prepare for over-summering in the Yellow Sea Cold Water Mass (YSCWM). The lipid accumulation mechanism for the initiation of over-summering is unknown. Here, we cultured C3 copepodites at four constant temperatures (10, 13, 16, and 19°C) and at three temperature regimes that mimicked the temperature variations experienced during diurnal vertical migration (10-13°C, 10-16°C, and 10-19°C) for 18 days to explore the effects of temperature differences on copepod development and lipid accumulation. C. sinicus stored more lipid at low than at high temperatures. A diurnal temperature difference (10-16°C and 10-19°C) promoted greater lipid accumulation (1.9-2.1 times) than a constant temperature of either 16°C or 19°C, by reducing the energy cost at colder temperatures and lengthening copepodite development. Thereafter, the lipid reserve supported gonad development after final molting. Only one male developed in these experiments. This highly female-skewed sex ratio may have been the result of the monotonous microalgae diet fed to the copepodites. This study provides the first evidence that diurnal temperature differences may promote lipid accumulation in C. sinicus, and provides a foundation for future investigations into the mechanisms involved in over-summering in the YSCWM.

  11. Clinical controversies in lipid management.

    Science.gov (United States)

    Tziomalos, K

    2015-06-01

    Even though it is firmly established that statins are the cornerstone of management of dyslipidemias, several controversies still exist in this area. In the present review, the most pertinent controversies in lipid management are discussed and the current evidence is summarized. Treatment with statins increases the risk for type 2 diabetes mellitus (T2DM) but this increase appears to be small and outweighed by the benefits of statins on cardiovascular disease prevention. Accordingly, statin treatment-associated T2DM should not affect management decisions. In patients who cannot achieve low-density lipoprotein cholesterol (LDL-C) targets despite treatment with the maximum tolerated dose of a potent statin, adding ezetimibe appears to be the treatment of choice. Finally, patients who achieved LDL-C targets with a statin but have elevated triglyceride levels appear to have increased cardiovascular risk and adding fenofibrate appears to reduce this risk. Even though additional large randomized controlled trials are unlikely to be performed with the existing lipid-lowering agents, mechanistic, genetic and epidemiological studies, as well as careful analyses of the existing trials will provide further insights in these controversial issues and will allow the optimization of the management of dyslipidemia aiming at further reductions in cardiovascular morbidity.

  12. Electroporation of heterogeneous lipid membranes.

    Science.gov (United States)

    Reigada, Ramon

    2014-03-01

    Electroporation is the basis for the transfection of genetic material and for drug delivery to cells, including electrochemotherapy for cancer. By means of molecular dynamics many aspects of membrane electroporation have been unveiled at the molecular detail in simple, homogeneous, lipid bilayers. However, the correspondence of these findings \\with the process happening in cell membranes requires, at least, the consideration of laterally structured membranes. Here, I present a systematic molecular dynamics study of bilayers composed of different liquid-ordered and liquid-disordered lipid phases subjected to a transversal electric field. The simulations reveal two significant results. First, the electric field mainly affects the properties of the disordered phases, so that electroporation takes place in these membrane regions. Second, the smaller the disordered domains are, the faster they become electroporated. These findings may have a relevant significance in the experimental application of cell electroporation in vivo since it implies that electro-induced and pore-mediated transport processes occur in particularly small disordered domains of the plasma membrane, thus locally affecting only specific regions of the cell.

  13. Identification of components of Prunus africana extract that inhibit lipid peroxidation.

    Science.gov (United States)

    Hass, M A; Nowak, D M; Leonova, E; Levin, R M; Longhurst, P A

    1999-11-01

    Extractive and chromatographic separations were performed on V-1326, a chloroform extract from the bark of Prunus africana (also referred to as Pygeum africanum), which is used to treat the symptoms associated with benign prostate hyperplasia (BPH). The relative amounts of eleven identified constituents in crude V-1326 and in separated fractions were determined using gas chromatographic analysis. The ability of V-1326 and its separated fractions to inhibit ferrous ion-induced stimulation of lipid peroxidation in microsomal preparations from rabbit livers was evaluated. The extract, V-1326, and fractions containing high levels of myristic acid potently inhibited lipid peroxidation.

  14. Mechanistic profiling of the siRNA delivery dynamics of lipid-polymer hybrid nanoparticles

    DEFF Research Database (Denmark)

    Colombo, Stefano; Cun, Dongmei; Remaut, Katrien

    2015-01-01

    Understanding the delivery dynamics of nucleic acid nanocarriers is fundamental to improve their design for therapeutic applications. We investigated the carrier structure-function relationship of lipid-polymer hybrid nanoparticles (LPNs) consisting of poly(dl-lactic-co-glycolic acid) (PLGA......) nanocarriers modified with the cationic lipid dioleoyltrimethyl-ammoniumpropane (DOTAP). A library of siRNA-loaded LPNs was prepared by systematically varying the nitrogen-to-phosphate (N/P) ratio. Atomic force microscopy (AFM) and cryo-transmission electron microscopy (cryo-TEM) combined with small angle X...

  15. Gelatin coated hybrid lipid nanoparticles for oral delivery of amphotericin B

    DEFF Research Database (Denmark)

    Jain, Sanyog; Valvi, Pankaj U; Swarnakar, Nitin K

    2012-01-01

    Amphotericin B (AmB) loaded polymer lipid hybrid nanoparticles (AmB-PLNs) comprised of lecithin (anionic lipid) and gelatin (Type A, cationic below its isoelectric point 7.0-9.0) were prepared by a two-step desolvation method to improve the oral bioavailability of AmB. The optimized AmB-PLNs were......) and fluorescent resonance energy transfer (FRET) analysis confirmed the orientation of the lecithin (located in the core) and gelatin (exterior coat) within the system. The developed formulation exhibited a sustained drug release profile with a release pattern best fitted to Higuchi kinetics. Experiments on Caco...

  16. Nanostructured lipid carriers as a potential vehicle for Carvedilol delivery: Application of factorial design approach.

    Science.gov (United States)

    Patil, Ganesh B; Patil, Nandkishor D; Deshmukh, Prashant K; Patil, Pravin O; Bari, Sanjay B

    2016-01-01

    Present invention relates to design of nanostructured lipid carriers (NLC) to augment oral bioavailability of Carvedilol (CAR). In this attempt, formulations of CAR-NLCs were prepared with glyceryl-monostearate (GMS) as a lipid, poloxamer 188 as a surfactant and tween 80 as a co-surfactant using high pressure homogenizer by 2(3) factorial design approach. Formed CAR-NLCs were assessed for various performance parameters. Accelerated stability studies demonstrated negligible change in particle size and entrapment efficiency, after storage at specified time up to 3 months. The promising findings in this investigation suggest the practicability of these systems for enhancement of bioavailability of drugs like CAR.

  17. Resveratrol-loaded solid lipid nanoparticles versus nanostructured lipid carriers: evaluation of antioxidant potential for dermal applications

    Directory of Open Access Journals (Sweden)

    Sandri G

    2012-04-01

    Full Text Available Evren H Gokce1, Emrah Korkmaz1, Eleonora Dellera2, Giuseppina Sandri2, M Cristina Bonferoni2, Ozgen Ozer11Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Ege, Izmir, Turkey; 2Department of Drug Sciences, University of Pavia, Pavia, ItalyBackground: Excessive generation of radical oxygen species (ROS is a contributor to skin pathologies. Resveratrol (RSV is a potent antioxidant. Solid lipid nanoparticles (SLN and nanostructured lipid carriers (NLC can ensure close contact and increase the amount of drug absorbed into the skin. In this study, RSV was loaded into SLN and NLC for dermal applications.Methods: Nanoparticles were prepared by high shear homogenization using Compritol 888ATO, Myglyol, Poloxamer188, and Tween80. Particle size (PS, polydispersity index (PI, zeta potential (ZP, drug entrapment efficiency (EE, and production yield were determined. Differential scanning calorimetry (DSC analysis and morphological transmission electron microscopy (TEM examination were conducted. RSV concentration was optimized with cytotoxicity studies, and net intracellular accumulation of ROS was monitored with cytofluorimetry. The amount of RSV was determined from different layers of rat abdominal skin.Results: PS of uniform RSV-SLN and RSV-NLC were determined as 287.2 nm ± 5.1 and 110.5 nm ± 1.3, respectively. ZP was –15.3 mV ± 0.4 and –13.8 mV ± 0.1 in the same order. The drug EE was 18% higher in NLC systems. TEM studies showed that the drug in the shell model was relevant for SLN, and that the melting point of the lipid in NLC was slightly lower. Concentrations below 50 µM were determined as suitable RSV concentrations for both SLN and NLC in cell culture studies. RSV-NLC showed less fluorescence, indicating less ROS production in cytofluorometric studies. Ex vivo skin studies revealed that NLC are more efficient in carrying RSV to the epidermis.Conclusion: This study suggests that both of the lipid nanoparticles had

  18. Lipid-Mediated Clusters of Guest Molecules in Model Membranes and Their Dissolving in the Presence of Lipid Rafts.

    Science.gov (United States)

    Kardash, Maria E; Dzuba, Sergei A

    2017-05-25

    The clustering of molecules is an important feature of plasma membrane organization. It is challenging to develop methods for quantifying membrane heterogeneities because of their transient nature and small size. Here, we obtained evidence that transient membrane heterogeneities can be frozen at cryogenic temperatures which allows the application of solid-state experimental techniques sensitive to the nanoscale distance range. We employed the pulsed version of electron paramagnetic resonance (EPR) spectroscopy, the electron spin echo (ESE) technique, for spin-labeled molecules in multilamellar lipid bilayers. ESE decays were refined for pure contribution of spin-spin magnetic dipole-dipolar interaction between the labels; these interactions manifest themselves at a nanometer distance range. The bilayers were prepared from different types of saturated and unsaturated lipids and cholesterol (Chol); in all cases, a small amount of guest spin-labeled substances 5-doxyl-stearic-acid (5-DSA) or 3β-doxyl-5α-cholestane (DChl) was added. The local concentration found of 5-DSA and DChl molecules was remarkably higher than the mean concentration in the bilayer, evidencing the formation of lipid-mediated clusters of these molecules. To our knowledge, formation of nanoscale clusters of guest amphiphilic molecules in biological membranes is a new phenomenon suggested only recently. Two-dimensional 5-DSA molecular clusters were found, whereas flat DChl molecules were found to be clustered into stacked one-dimensional structures. These clusters disappear when the Chol content is varied between the boundaries known for lipid raft formation at room temperatures. The room temperature EPR evidenced entrapping of DChl molecules in the rafts.

  19. Inclusion of the helper lipid dioleoyl-phosphatidylethanolamine in solid lipid nanoparticles inhibits their transfection efficiency

    NARCIS (Netherlands)

    de Jesus, Marcelo B.; Radaic, Allan; Hinrichs, Wouter L J; Ferreira, Carmen V; de Paula, Eneida; Hoekstra, Dirk; Zuhorn, Inge S

    2014-01-01

    Solid lipid nanoparticles (SLNs) are a promising system for the delivery of lipophilic and hydrophilic drugs. They consist of a solid lipid core that is stabilized by a layer of surfactants. By the incorporation of cationic lipids in the formulation, positively charged SLNs can be generated, that ar

  20. Lipids, lipid droplets and lipoproteins in their cellular context; an ultrastructural approach

    NARCIS (Netherlands)

    Mesman, R.J.

    2013-01-01

    Lipids are essential for cellular life, functioning either organized as bilayer membranes to compartmentalize cellular processes, as signaling molecules or as metabolic energy storage. Our current knowledge on lipid organization and cellular lipid homeostasis is mainly based on biochemical data. How

  1. ``Sheddable'' PEG-lipid to balance the contradiction of PEGylation between long circulation and poor uptake

    Science.gov (United States)

    Zhao, Caiyan; Deng, Hongzhang; Xu, Jing; Li, Shuyi; Zhong, Lin; Shao, Leihou; Wu, Yan; Liang, Xing-Jie

    2016-05-01

    PEGylated lipids confer longer systemic circulation and tumor accumulation via the enhanced permeability and retention (EPR) effect. However, PEGylation inhibits cellular uptake and subsequent endosomal escape. In order to balance the contradiction between the advantages of long circulation and the disadvantages of poor uptake of PEGylated lipids, we prepared a ``sheddable'' PEG-lipid micelle system based on the conjugation of PEG and phosphatidyl ethanolamine (DSPE) with a pH sensitive benzoic imine bond. In a physiological environment, the PEG-protected micelles were not readily taken up by the reticuloendothelial system (RES) and could be successfully delivered to tumor tissue by the EPR effect. In a tumor acidic microenvironment, the PEG chains detached from the surfaces of the micelles while the degree of linker cleavage could not cause a significant particle size change, which facilitated the carrier binding to tumor cells and improved the cellular uptake. Subsequently, the ``sheddable'' PEG-lipid micelles easily internalized into cells and the increased acidity in the lysosomes further promoted drug release. Thus, this ``sheddable'' PEG-lipid nanocarrier could be a good candidate for effective intracellular drug delivery in cancer chemotherapy.PEGylated lipids confer longer systemic circulation and tumor accumulation via the enhanced permeability and retention (EPR) effect. However, PEGylation inhibits cellular uptake and subsequent endosomal escape. In order to balance the contradiction between the advantages of long circulation and the disadvantages of poor uptake of PEGylated lipids, we prepared a ``sheddable'' PEG-lipid micelle system based on the conjugation of PEG and phosphatidyl ethanolamine (DSPE) with a pH sensitive benzoic imine bond. In a physiological environment, the PEG-protected micelles were not readily taken up by the reticuloendothelial system (RES) and could be successfully delivered to tumor tissue by the EPR effect. In a tumor acidic

  2. Fluorescent lipid probes : some properties and applications (a review)

    NARCIS (Netherlands)

    Maier, O; Oberle, [No Value; Hoekstra, D

    2002-01-01

    Odd as it may seem, experimental challenges in lipid research are often hampered by the simplicity of the lipid structure. Since, as in protein research. mutants or overexpression of lipids are not realistic, a considerable amount of lipid research relies on the use Of tagged lipid analogues. Howeve

  3. Fluorescent lipid probes : some properties and applications (a review)

    NARCIS (Netherlands)

    Maier, O; Oberle, [No Value; Hoekstra, D

    Odd as it may seem, experimental challenges in lipid research are often hampered by the simplicity of the lipid structure. Since, as in protein research. mutants or overexpression of lipids are not realistic, a considerable amount of lipid research relies on the use Of tagged lipid analogues.

  4. [Nitric oxide and lipid peroxidation].

    Science.gov (United States)

    Cristol, J P; Maggi, M F; Guérin, M C; Torreilles, J; Descomps, B

    1995-01-01

    Nitric oxide (NO) is a free radical produced enzymatically in biological systems from the guanidino group of L-arginine. Its large spectrum of biological effects is achieved through chemical interactions with different targets including oxygen (O2), superoxide (O2o-) and other oxygen reactive species (ROS), transition metals and thiols. Superoxide anions and other ROS have been reported to react with NO to produce peroxynitrite anions that can decompose to form nitrogen dioxide (NO2) and hydroxyl radial (OHo). Thus, NO has been reported to have a dual effect on lipid peroxidation (prooxidant via the peroxynitrite or antioxydant via the chelation of ROS). In the present study we have investigated in different models the in vitro and in vivo action of NO on lipid peroxidation. Copper-induced LDL oxidation were used as an in vitro model. Human LDL (100 micrograms ApoB/ml) were incubated in oxygene-saturated PBS buffer in presence or absence of Cu2+ (2.5 microM) with increasing concentrations of NO donnors (sodium nitroprussiate or nitroso-glutathione). LDL oxidation was monitored continuously for conjugated diene formation (234 nm) and 4-hydroxynonenal (HNE) accumulation. Exogenous NO prevents in a dose dependent manner the progress of copper-induced oxidation. Ischaemia-reperfusion injury (I/R), characterized by an overproduction of ROS, is used as an in vivo model. Anaesthetized rats were submitted to 1 hour renal ischaemia following by 2 hours of reperfusion. Sham-operated rats (SOP) were used as control. Lipid peroxidation was evaluated by measuring the HNE accumulated in rats kidneys in presence or absence of L-arginine or D-arginine infusion. L-arginine, but not D-arginine, enhances HNE accumulation in I/R but not in SOP (< 0.050 pmol/g tissue in SOP versus 0.6 nmol/g tissue in I/R), showing that, in this experimental conditions, NO produced from L-arginine, enhances the toxicity of ROS. This study shows that the pro- or antioxydant effects of NO are different

  5. Real-time monitoring of lipid transfer between vesicles and hybrid bilayers on Au nanoshells using surface enhanced Raman scattering (SERS)

    Science.gov (United States)

    Kundu, Janardan; Levin, Carly S.; Halas, Naomi J.

    2009-09-01

    To investigate the dynamics of exchange/transfer of lipids between membranes, we have studied the interaction of donor-deuterated DMPC vesicles with DMPC hybrid bilayers on Au nanoshells using SERS. Experimental data confirm partial lipid exchange/transfer in the outer leaflet of the hybrid bilayer. The kinetics of the exchange/transfer process follows a first order process with a rate constant of 1.3 × 10-4 s-1. Changes in lipid phase behavior caused by the exchange/transfer process were characterized using generalized polarization measurements. In situ lipid transfer can potentially be utilized for preparation of asymmetric supported lipid bilayers and for incorporation of reporter lipids in biological membranes.To investigate the dynamics of exchange/transfer of lipids between membranes, we have studied the interaction of donor-deuterated DMPC vesicles with DMPC hybrid bilayers on Au nanoshells using SERS. Experimental data confirm partial lipid exchange/transfer in the outer leaflet of the hybrid bilayer. The kinetics of the exchange/transfer process follows a first order process with a rate constant of 1.3 × 10-4 s-1. Changes in lipid phase behavior caused by the exchange/transfer process were characterized using generalized polarization measurements. In situ lipid transfer can potentially be utilized for preparation of asymmetric supported lipid bilayers and for incorporation of reporter lipids in biological membranes. Electronic supplementary information (ESI) available: Nanoshell extinction spectra and SEM, SERS spectral reproducibility, and details of experimental procedures. See DOI: 10.1039/b9nr00063a

  6. Dithranol-loaded lipid-core nanocapsules improve the photostability and reduce the in vitro irritation potential of this drug

    Energy Technology Data Exchange (ETDEWEB)

    Savian, Ana L. [Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal de Santa Maria, Av. Roraima, 1000, Santa Maria, RS 97105-900 (Brazil); Rodrigues, Daiane [Curso de Farmácia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Av. Roraima, 1000, Santa Maria, RS 97105-900 (Brazil); Weber, Julia; Ribeiro, Roseane F. [Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal de Santa Maria, Av. Roraima, 1000, Santa Maria, RS 97105-900 (Brazil); Motta, Mariana H. [Curso de Farmácia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Av. Roraima, 1000, Santa Maria, RS 97105-900 (Brazil); Schaffazick, Scheila R.; Adams, Andréa I.H. [Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal de Santa Maria, Av. Roraima, 1000, Santa Maria, RS 97105-900 (Brazil); Andrade, Diego F. de; Beck, Ruy C.R. [Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Av. Ipiranga, 2752, Porto Alegre, RS 90610-000 (Brazil); and others

    2015-01-01

    Dithranol is a very effective drug for the topical treatment of psoriasis. However, it has some adverse effects such as irritation and stain in the skin that make its application and patient adherence to treatment difficult. The aims of this work were to prepare and characterize dithranol-loaded nanocapsules as well as to evaluate the photostability and the irritation potential of these nanocarriers. Lipid-core nanocapsules containing dithranol (0.5 mg/mL) were prepared by interfacial deposition of preformed polymer. EDTA (0.05%) or ascorbic acid (0.02%) was used as antioxidants. After preparation, dithranol-loaded lipid-core nanocapsules showed satisfactory characteristics: drug content close to the theoretical concentration, encapsulation efficiency of about 100%, nanometric mean size (230–250 nm), polydispersity index below 0.25, negative zeta potential, and pH values from 4.3 to 5.6. In the photodegradation study against UVA light, we observed a higher stability of the dithranol-loaded lipid-core nanocapsules comparing to the solution containing the free drug (half-life times around 4 and 1 h for the dithranol-loaded lipid-core nanocapsules and free drug solution containing EDTA, respectively; half-life times around 17 and 7 h for the dithranol-loaded lipid-core nanocapsules and free drug solution containing ascorbic acid, respectively). Irritation test by HET-CAM method was conducted to evaluate the safety of the formulations. From the results it was found that the nanoencapsulation of the drug decreased its toxicity compared to the effects observed for the free drug. - Highlights: • Strategy to prepare lipid-core nanocapsules containing dithranol • Evaluation of the nanoencapsulation effect on the photostability and irritation • Evaluation of the in vitro release of dithranol-loaded lipid-core nanocapsules.

  7. Thematic review series: systems biology approaches to metabolic and cardiovascular disorders. Lipidomics: a global approach to lipid analysis in biological systems.

    Science.gov (United States)

    Watson, Andrew D

    2006-10-01

    Lipids are water-insoluble molecules that have a wide variety of functions within cells, including: 1) maintenance of electrochemical gradients; 2) subcellular partitioning; 3) first- and second-messenger cell signaling; 4) energy storage; and 5) protein trafficking and membrane anchoring. The physiological importance of lipids is illustrated by the numerous diseases to which lipid abnormalities contribute, including atherosclerosis, diabetes, obesity, and Alzheimer's disease. Lipidomics, a branch of metabolomics, is a systems-based study of all lipids, the molecules with which they interact, and their function within the cell. Recent advances in soft-ionization mass spectrometry, combined with established separation techniques, have allowed the rapid and sensitive detection of a variety of lipid species with minimal sample preparation. A "lipid profile" from a crude lipid extract is a mass spectrum of the composition and abundance of the lipids it contains, which can be used to monitor changes over time and in response to particular stimuli. Lipidomics, integrated with genomics, proteomics, and metabolomics, will contribute toward understanding how lipids function in a biological system and will provide a powerful tool for elucidating the mechanism of lipid-based disease, for biomarker screening, and for monitoring pharmacologic therapy.

  8. Intravenous lipid emulsion in clinical toxicology

    Directory of Open Access Journals (Sweden)

    Oswald Sarah

    2010-10-01

    Full Text Available Abstract Intravenous lipid emulsion is an established, effective treatment for local anesthetic-induced cardiovascular collapse. The predominant theory for its mechanism of action is that by creating an expanded, intravascular lipid phase, equilibria are established that drive the offending drug from target tissues into the newly formed 'lipid sink'. Based on this hypothesis, lipid emulsion has been considered a candidate for generic reversal of toxicity caused by overdose of any lipophilic drug. Recent case reports of successful resuscitation suggest the efficacy of lipid emulsion infusion for treating non-local anesthetic overdoses across a wide spectrum of drugs: beta blockers, calcium channel blockers, parasiticides, herbicides and several varieties of psychotropic agents. Lipid emulsion therapy is gaining acceptance in emergency rooms and other critical care settings as a possible treatment for lipophilic drug toxicity. While protocols exist for administration of lipid emulsion in the setting of local anesthetic toxicity, no optimal regimen has been established for treatment of acute non-local anesthetic poisonings. Future studies will shape the evolving recommendations for lipid emulsion in the setting of non-local anesthetic drug overdose.

  9. Stratum Corneum Barrier Lipids in Cholesteatoma

    DEFF Research Database (Denmark)

    Svane-Knudsen, V; Halkier-Sørensen, L; Rasmussen, G

    2000-01-01

    emerged. When the corneocyte reaches the transitional stage to the stratum corneum, the Odland bodies accumulate near the cell membrane and discharge their contents of lipid and enzymes. The lipids are reorganized into multiple long sheets of lamellar structures that embrace the keratinized corneocytes...

  10. Lipids of the living coelacanth, Latimeria chalumnae.

    Science.gov (United States)

    Nevenzel, J C; Rodegker, W; Mead, J F; Gordon, M S

    1966-06-24

    The muscle of Latimeria chalumnae contains 30 to 71 percent (dry weight) of lipid deposited extracellularly. Wax esters constituted 90 percent or more of the lipids from muscle and fat storage tissues. These esters, by gaschromatographic analysis, consisted of C(30) to C(40) ho