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Sample records for aerosolized drugs encapsulated

  1. Delivery of aerosolized drugs encapsulated in liposomes

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yung-Sung; Lyons, C.R. [Univ. of New Mexico, Albuquerque, NM (United States); Schmid, M.H.

    1995-12-01

    Mycobacterium tuberculosis (Mtb) is an infectious disease that resides in the human lung. Due to the difficulty in completely killing off the disease in infected individuals, Mtb has developed drug-resistant forms and is on the rise in the human population. Therefore, ITRI and the University of New Mexico are collaborating to explore the treatment of Mtb by an aerosolized drug delivered directly to the lungs. In conclusion, it is feasible to obtain an appropriate size and concentration of the liposomes before and after aerosolization.

  2. Encapsulation effects on carbonaceous aerosol light absorption

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, A.J.; Onasch, T.; Davidovits, P.; Cross, E.; Mazzoleni, C.

    2010-03-15

    The contribution of aerosol absorption on direct radiative forcing is still an active area of research, in part, because aerosol extinction is dominated by light scattering and, in part, because the primary absorbing aerosol of interest, soot, exhibits complex aging behavior that alters its optical properties. The consequences of this can be evidenced by the work of Ramanathan and Carmichael (2008) who suggest that incorporating the atmospheric heating due to brown clouds (plumes containing soot byproducts from automobiles, biomass burning, wood-burning kitchen stoves, and coal-fired power plants) will increase black carbon (BC) radiative forcing from the Intergovernmental Panel on Climate Change best estimate of 0.34 Wm-2 (±0.25 Wm-2) (IPCC 2007) to 0.9 Wm-2. This noteworthy degree of uncertainty is due largely to the interdependence of BC optical properties on particle mixing state and aggregate morphology, each of which changes as the particle ages in the atmosphere and becomes encapsulated within a coating of inorganic and/or organic substances. In July 2008, a laboratory-based measurement campaign, led by Boston College and Aerodyne, was initiated to begin addressing this interdependence. To achieve insights into the interdependence of BC optical properties on particle mixing state and aggregate morphology, measurements of both the optical and physical properties of flame-generated soot under nascent, coated, and denuded conditions were conducted. This poster presents data on black carbon (BC) light absorption measured by Photothermal Interferometry (Sedlacek and Lee 2007). In addition to examining nascent BC—to provide a baseline measurement—encapsulation with varying thicknesses of either dioctyl sebacate (DOS) or sulfuric acid was conducted to glean insights into the interplay between particle mixing state and optical properties. Additionally, some experiments were carried out where BC was coated and then denuded. In the case of DOS-coated soot, a

  3. Patient's Guide to Aerosol Drug Delivery

    Science.gov (United States)

    ... Table of Contents Page Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ................................................................ 1. Aerosol Drug Delivery: The Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Aerosol Drugs: The Major Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 3. Aerosol Drug Delivery Devices: Small-Volume Nebulizers . . . . . . . . . . . . .17 4. Aerosol Drug ...

  4. Generation of aerosolized drugs.

    Science.gov (United States)

    Wolff, R K; Niven, R W

    1994-01-01

    The expanding use of inhalation therapy has placed demands on current aerosol generation systems that are difficult to meet with current inhalers. The desire to deliver novel drug entities such as proteins and peptides, as well as complex formulations including liposomes and microspheres, requires delivery systems of improved efficiency that will target the lung in a reproducible manner. These efforts have also been spurred by the phase out of chlorofluorocarbons (CFCs) and this has included a directed search for alternative propellants. Consequently, a variety of new aerosol devices and methods of generating aerosols are being studied. This includes the use of freon replacement propellants, dry powder generation systems, aqueous unit spray systems and microprocessor controlled technologies. Each approach has advantages and disadvantages depending upon each principle of action and set of design variables. In addition, specific drugs may be better suited for one type of inhaler device vs. another. The extent to which aerosol generation systems achieve their goals is discussed together with a summary of selected papers presented at the recent International Congress of Aerosols in Medicine.

  5. Liposomal Encapsulated Rhodomyrtone: A Novel Antiacne Drug

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    Julalak Chorachoo

    2013-01-01

    Full Text Available Rhodomyrtone isolated from the leaves of Rhodomyrtus tomentosa possesses antibacterial, anti-inflammatory, and anti-oxidant activities. Since rhodomyrtone is insoluble in water, it is rather difficult to get to the target sites in human body. Liposome exhibited ability to entrap both hydrophilic and hydrophobic compounds and easily penetrate to the target site. The present study aimed to develop a novel liposomal encapsulated rhodomyrtone formulations. In addition, characterization of liposome, stability profiles, and their antiacne activity were performed. Three different formulations of total lipid concentrations 60, 80, and 100 μmol/mL were used. Formulation with 60 μmol/mL total lipid (phosphatidylcholine from soybean and cholesterol from lanolin in 4 : 1, w/w exhibited the highest rhodomyrtone encapsulation efficacy (65.47 ± 1.7%, average particle size (209.56 ± 4.8 nm, and ζ-potential (–41.19 ± 1.3 mV. All formulations demonstrated good stability when stored for 2 months in dark at 4°C as well as room temperature. Minimal inhibitory concentration and minimal bactericidal concentration values of liposomal formulation against 11 clinical bacterial isolates and reference strains ranged from 1 to 4 and from 4 to 64 μg/mL, respectively, while those of rhodomyrtone were 0.25–1 and 0.5–2 μg/mL, respectively. The MIC and MBC values of liposome formulation were more effective than topical drugs against Staphylococcus aureus and Staphylococcus epidermidis.

  6. Application of supercritical antisolvent method in drug encapsulation: a review

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    Kalani M

    2011-07-01

    Full Text Available Mahshid Kalani, Robiah YunusChemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, Selangor Darul Ehsan, MalaysiaAbstract: The review focuses on the application of supercritical fluids as antisolvents in the pharmaceutical field and demonstrates the supercritical antisolvent method in the use of drug encapsulation. The main factors for choosing the solvent and biodegradable polymer to produce fine particles to ensure effective drug delivery are emphasized and the effect of polymer structure on drug encapsulation is illustrated. The review also demonstrates the drug release mechanism and polymeric controlled release system, and discusses the effects of the various conditions in the process, such as pressure, temperature, concentration, chemical compositions (organic solvents, drug, and biodegradable polymer, nozzle geometry, CO2 flow rate, and the liquid phase flow rate on particle size and its distribution.Keywords: supercritical antisolvent method, drug encapsulation, particle size, drug release mechanisms, drug delivery

  7. The interaction of encapsulated pharmaceutical drugs with a silica matrix.

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    Morais, Everton C; Correa, Gabriel G; Brambilla, Rodrigo; Radtke, Claudio; Baibich, Ione Maluf; dos Santos, João Henrique Z

    2013-03-01

    A series of seven drugs, namely, fluoxetine, gentamicin, lidocaine, morphine, nifedipine, paracetamol and tetracycline, were encapsulated. The encapsulated systems were characterized using a series of complementary techniques: Fourier-transform infrared spectroscopy (FT-IR), diffusive reflectance spectroscopy in the UV-vis region (DRS) and X-ray photoelectron spectroscopy (XPS). According to the DRS spectra, most of the encapsulated systems showed a band shift of the maximum absorption when compared with the corresponding bare pharmaceutical. Additionally, after encapsulation, the drugs exhibited infrared band shifts toward higher wavenumbers, which in turn provided insight into potential sites for interaction with the silica framework. The amine group showed a band shift in the spectra of almost all the drugs (except nifedipine and tetracycline). This finding indicates the possibility of a hydrogen bonding interaction between the drug and the silica via electron donation from the amine group to the silica framework. XPS confirmed this interaction between the pharmaceuticals and the silica through the amine group. A correlation was observed between the textural characteristics of the solids and the spectroscopic data, suggesting that the amine groups from the pharmaceuticals were more perturbed upon encapsulation.

  8. Enhancement of anticancer efficacy using modified lipophilic nanoparticle drug encapsulation

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    Lee P

    2012-02-01

    Full Text Available Puiyan Lee1, Ruizhong Zhang1, Vincent Li1, Xuelai Liu1, Raymond WY Sun2, Chi-Ming Che2, Kenneth KY Wong11Department of Surgery, Li Ka Shing Faculty of Medicine, 2Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular Technology for Drug Discovery and Synthesis, The University of Hong Kong, Hong KongBackground: Development of anticancer drugs is challenging. Indeed, much research effort has been spent in the development of new drugs to improve clinical outcomes with minimal toxicity. We have previously reported that a formulation of lipid gold porphyrin nanoparticles reduced systemic drug toxicity when compared with free gold porphyrin. In this study, we investigated the delivery and treatment efficiency of PEG surface-modified lipid nanoparticles as a carrier platform.Methods: We encapsulated antitumor drugs into PEG-modified lipid nanoparticles and these were characterized by size, zeta potential, and encapsulation efficiency. The delivery efficiency into tumor tissue was evaluated using a biodistribution study. To evaluate antitumor efficacy, gold porphyrin or camptothecin (a DNA topoisomerase I inhibitor were encapsulated and compared using an in vivo neuroblastoma (N2A model.Results: We showed that drug encapsulation into PEG-modified lipid nanoparticles enhanced the preferential uptake in tumor tissue. Furthermore, higher tumor killing efficiency was observed in response to treatment with PEG-modified lipid nanoparticles encapsulating gold porphyrin or camptothecin when compared with free gold porphyrin or free camptothecin. The in vivo antitumor effect was further confirmed by study of tumor inhibition and positive apoptosis activity. Surface modification of lipophilic nanoparticles with PEG increased the efficiency of drug delivery into tumor tissue and subsequently more effective antitumor activity.Conclusion: This specific design of a chemotherapeutic agent using nanotechnology is important in the

  9. Application of supercritical antisolvent method in drug encapsulation: a review.

    Science.gov (United States)

    Kalani, Mahshid; Yunus, Robiah

    2011-01-01

    The review focuses on the application of supercritical fluids as antisolvents in the pharmaceutical field and demonstrates the supercritical antisolvent method in the use of drug encapsulation. The main factors for choosing the solvent and biodegradable polymer to produce fine particles to ensure effective drug delivery are emphasized and the effect of polymer structure on drug encapsulation is illustrated. The review also demonstrates the drug release mechanism and polymeric controlled release system, and discusses the effects of the various conditions in the process, such as pressure, temperature, concentration, chemical compositions (organic solvents, drug, and biodegradable polymer), nozzle geometry, CO(2) flow rate, and the liquid phase flow rate on particle size and its distribution.

  10. Pulmonary drug delivery by powder aerosols.

    Science.gov (United States)

    Yang, Michael Yifei; Chan, John Gar Yan; Chan, Hak-Kim

    2014-11-10

    The efficacy of pharmaceutical aerosols relates to its deposition in the clinically relevant regions of the lungs, which can be assessed by in vivo lung deposition studies. Dry powder formulations are popular as devices are portable and aerosolisation does not require a propellant. Over the years, key advancements in dry powder formulation, device design and our understanding on the mechanics of inhaled pharmaceutical aerosol have opened up new opportunities in treatment of diseases through pulmonary drug delivery. This review covers these advancements and future directions for inhaled dry powder aerosols.

  11. Delivery of Encapsulated Drugs to Cancer Cells and Tissue: The Impact of Ultrasound

    OpenAIRE

    Afadzi, Mercy

    2013-01-01

    Encapsulated drugs have improved tumor to normal tissue uptake compared to free drugs, however, the concentration of drugs at the tumor site is still low and heterogeneous due to the tumor microenvironment which serves as barriers for the delivery to the target site. Combining ultrasound (US) with encapsulated drugs might enhance the transport of the encapsulated drug across the vasculature and into tumor tissues. US can also increase local drug release and the uptake of the drug into cancer ...

  12. Mathematical model for drug molecules encapsulated in lipid nanotube

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    Putthikorn, Sasipim; Baowan, Duangkamon

    2016-11-01

    Lipid nanotube is considered as a nanocontainer for drug and gene delivery. It is important to understand a basic idea of the encapsulation process. In this paper, we use the Lennard-Jones potential function and the continuous approximation to explain the energy behaviour of three hollow shapes of Doxorubicin (DOX) clusters that are a sphere, a cylinder, and an ellipsoid interacting with the lipid nanotube. On assuming that the surface areas of the three structures are equal, we can find the minimum size of the lipid nanotube that encapsulates DOX inside by determining the suction energy. Moreover, we find that a long cylindrical drug provides the largest suction energy among other structures studied here due to the perfect fit between the cylindrical drug and the cylindrical tube. This investigation is the first step to develop the design of nanocapsule for medical application.

  13. Principles of encapsulating hydrophobic drugs in PLA/PLGA microparticles.

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    Wischke, Christian; Schwendeman, Steven P

    2008-12-08

    Injectable biodegradable and biocompatible copolymers of lactic and glycolic acid (PLGA) are an important advanced delivery system for week-to-month controlled release of hydrophobic drugs (e.g., from biopharmaceutical classification system class IV), which often display poor oral bioavailability. The basic principles and considerations to develop such microparticle formulations is reviewed here based on a comprehensive study of papers and patents from the beginnings of hydrophobic drug encapsulation in polylactic acid and PLGA up through the very recent literature. Challenges with the diversity of drug properties, microencapsulation methods, and organic solvents are evaluated in light of the precedence of commercialized formulations and with a focus on decreasing the time to lab-scale encapsulation of water-insoluble drug candidates in the early stage of drug development. The influence of key formulation variables on final microparticle characteristics, and how best to avoid undesired microparticle properties, is analyzed mechanistically. Finally, concepts are developed to manage the common issues of maintaining sink conditions for in vitro drug release assays of hydrophobic compounds. Overall, against the backdrop of an increasing number of new, poorly orally available drug entities entering development, microparticle delivery systems may be a viable strategy to rescue an otherwise undeliverable substance.

  14. Internalized compartments encapsulated nanogels for targeted drug delivery

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    Yu, Jicheng; Zhang, Yuqi; Sun, Wujin; Wang, Chao; Ranson, Davis; Ye, Yanqi; Weng, Yuyan; Gu, Zhen

    2016-04-01

    Drug delivery systems inspired by natural particulates hold great promise for targeted cancer therapy. An endosome formed by internalization of plasma membrane has a massive amount of membrane proteins and receptors on the surface, which is able to specifically target the homotypic cells. Herein, we describe a simple method to fabricate an internalized compartments encapsulated nanogel with endosome membrane components (EM-NG) from source cancer cells. Following intracellular uptake of methacrylated hyaluronic acid (m-HA) adsorbed SiO2/Fe3O4 nanoparticles encapsulating a crosslinker and a photoinitiator, EM-NG was readily prepared through in situ crosslinking initiated under UV irradiation after internalization. The resulting nanogels loaded with doxorubicin (DOX) displayed enhanced internalization efficiency to the source cells through a specific homotypic affinity in vitro. However, when treated with the non-source cells, the EM-NGs exhibited insignificant difference in therapeutic efficiency compared to a bare HA nanogel with DOX. This study illustrates the potential of utilizing an internalized compartments encapsulated formulation for targeted cancer therapy, and offers guidelines for developing a natural particulate-inspired drug delivery system.Drug delivery systems inspired by natural particulates hold great promise for targeted cancer therapy. An endosome formed by internalization of plasma membrane has a massive amount of membrane proteins and receptors on the surface, which is able to specifically target the homotypic cells. Herein, we describe a simple method to fabricate an internalized compartments encapsulated nanogel with endosome membrane components (EM-NG) from source cancer cells. Following intracellular uptake of methacrylated hyaluronic acid (m-HA) adsorbed SiO2/Fe3O4 nanoparticles encapsulating a crosslinker and a photoinitiator, EM-NG was readily prepared through in situ crosslinking initiated under UV irradiation after internalization. The

  15. Modelled radiative effects of sea spray aerosol using a source function encapsulating wave state

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    Partanen, Antti-Ilari; Dunne, Eimear M.; Bergman, Tommi; Laakso, Anton; Kokkola, Harri; Ovadnevaite, Jurgita; Sogacheva, Larisa; Baisnée, Dominique; Sciare, Jean; Manders, Astrid; O'Dowd, Colin; de Leeuw, Gerrit; Korhonen, Hannele

    2014-05-01

    Sea spray aerosol particles have significant effects on global climate by scattering solar radiation (direct effect) and modifying cloud properties (indirect effect). Sea spray consists mainly of sea salt, but in biologically active regions, major fraction of sea spray may come in the form of primary marine organic matter (PMOM). Traditionally, sea spray flux has been parameterized in global models in terms of wind speed, and organic fraction of sea spray in terms of chlorophyll-a concentration. In this study, we have incorporated recently developed parameterizations for the sea spray aerosol source flux into the global aerosol-climate model ECHAM-HAMMOZ. The parameterizations encapsulate the wave state via Reynolds number, and predict the organic fraction of the sea spray aerosol source flux. The model was then used to investigate the direct and indirect effects of sea spray aerosol particles. We compared simulated sea spray concentrations with in-situ measurements from Mace Head (North Atlantic), Point Reyes (North Pacific), and Amsterdam Island (Southern Indian Ocean). Aerosol optical depth (AOD) was compared with satellite measurements from PARASOL. Modelled annual mean global emissions of sea salt and PMOM were 805 Tg yr-1 (uncertainty range of 378-1233 Tg yr-1) and 1.1 Tg yr-1 (0.5-1.8 Tg yr-1), respectively. Sea salt emissions were considerably lower than the majority of previous estimates, but PMOM was in the range of previous studies. The model captured sea salt concentrations fairly well in the smaller size ranges at Mace Head (annual normalized mean bias of -13% for particles with vacuum aerodynamic diameter Dva

  16. Encapsulation of Alpha-1 antitrypsin in PLGA nanoparticles: In Vitro characterization as an effective aerosol formulation in pulmonary diseases

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    Pirooznia Nazanin

    2012-05-01

    Full Text Available Abstract Background Alpha 1- antitrypsin (α1AT belongs to the superfamily of serpins and inhibits different proteases. α1AT protects the lung from cellular inflammatory enzymes. In the absence of α1AT, the degradation of lung tissue results to pulmonary complications. The pulmonary route is a potent noninvasive route for systemic and local delivery. The aerosolized α1AT not only affects locally its main site of action but also avoids remaining in circulation for a long period of time in peripheral blood. Poly (D, L lactide-co glycolide (PLGA is a biodegradable and biocompatible polymer approved for sustained controlled release of peptides and proteins. The aim of this work was to prepare a wide range of particle size as a carrier of protein-loaded nanoparticles to deposit in different parts of the respiratory system especially in the deep lung. Various lactide to glycolide ratio of the copolymer was used to obtain different release profile of the drug which covers extended and rapid drug release in one formulation. Results Nonaqueous and double emulsion techniques were applied for the synthesis of nanoparticles. Nanoparticles were characterized in terms of surface morphology, size distribution, powder X-ray diffraction (XRD, encapsulation efficiency, in vitro drug release, FTIR spectroscopy and differential scanning calorimetry (DSC. To evaluate the nanoparticles cytotoxicity, cell cytotoxicity test was carried out on the Cor L105 human epithelial lung cancer cell line. Nanoparticles were spherical with an average size in the range of 100 nm to 1μ. The encapsulation efficiency was found to be higher when the double emulsion technique was applied. XRD and DSC results indicated that α1AT encapsulated in the nanoparticles existed in an amorphous or disordered-crystalline status in the polymer matrix. The lactic acid to glycolic acid ratio affects the release profile of α1AT. Hence, PLGA with a 50:50 ratios exhibited the ability to release

  17. Agarose encapsulated mesoporous carbonated hydroxyapatite nanocomposites powder for drug delivery.

    Science.gov (United States)

    Kolanthai, Elayaraja; Abinaya Sindu, P; Thanigai Arul, K; Sarath Chandra, V; Manikandan, E; Narayana Kalkura, S

    2017-01-01

    The powder composites are predominantly used for filling of voids in bone and as drug delivery carrier to prevent the infection or inflammatory reaction in the damaged tissues. The objective of this work was to study the synthesis of agarose encapsulation on carbonated hydroxyapatite powder and their biological and drug delivery properties. Mesoporous, nanosized carbonated hydroxyapatite/agarose (CHAp/agarose) powder composites were prepared by solvothermal method and subsequently calcined to study the physico-chemical changes, if it subjected to thermal exposure. The phase of the as-synthesized powder was CHAp/agarose whereas the calcinated samples were non-stoichiometric HAp. The CHAp/agarose nanorods were of length 10-80nm and width 40-190nm for the samples synthesized at temperatures 120°C (ST120) and 150°C (ST150). The calcination process produced spheres (10-50nm) and rods with reduced size (40-120nm length and 20-30nm width). Composites were partially dissolved in SBF solution followed by exhibited better bioactivity than non-stoichiometric HAp confirmed by gravimetric method. Hemo and biocompatibility remained unaffected by presence of agarose or carbonate in the HAp. Specific surface area of the composites was high and exhibited an enhanced amoxicillin and 5-fluorouracil release than the calcined samples. The composites demonstrated a strong antimicrobial activity against E. coli, S. aureus and S. epidermidis. The ST120 showed prolonged drug (AMX and 5-Fcil) release and antimicrobial efficacy than ST150 and calcined samples. This technique would be simple and rapid for composites preparation, to produce high quality crystalline, resorbable, mesoporous and bioactive nanocomposite (CHAp/agarose) powders. This work provides new insight into the role of agarose coated on bioceramics by solvothermal technique and suggests that CHAp/agarose composites powders are promising materials for filling of void in bone and drug delivery applications.

  18. Folate receptor targeted liposomes encapsulating anti-cancer drugs.

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    Chaudhury, Anumita; Das, Surajit

    2015-01-01

    Among all available lipid based nanoparticulate systems, the success of liposomal drug delivery system is evident by the number of liposomal products available in the market or under advanced stages of preclinical and clinical trials. Liposome has the ability to deliver chemotherapeutic agents to the targeted tissues or even inside the cancerous cells by enhanced intracellular penetration or improved tumour targeting. In the last decade, folate receptor mediated tumour targeting has emerged as an attractive alternative method of active targeting of cancer cells through liposomes due to its numerous advantages over other targeting methods. Folate receptors, also known as folate binding proteins, allow the binding and internalization of folate or folic acid into the cells by a method called folate receptor mediated endocytosis. They have restricted presence in normal cells and are mostly expressed during malignant transformation. In this review article, folate receptor targeting capability of liposomes has been described. This review article has focussed on the different cancer drugs which have been encapsulated in folate receptor targeted liposomes and their in vitro as well as in vivo efficacies in several tumour models.

  19. Multiscale modeling of drug-polymer nanoparticle assembly identifies parameters influencing drug encapsulation efficiency.

    Science.gov (United States)

    Mackenzie, R; Booth, J; Alexander, C; Garnett, M C; Laughton, C A

    2015-06-09

    Using a multiscale (dual resolution) approach combining an atomistic (GROMOS96) and coarse-grain (MARTINI) force field, we have been able to simulate the process of drug-polymer nanoparticle assembly by nanoprecipitation from mixed solvents. Here, we present the development and application of this method to the interaction of three poly(glycerol adipate) polymer variants with the anticancer drug dexamethasone phosphate. Differences in encapsulation efficiency and drug loading between the polymers are in agreement with the experimental trend. Reference atomistic simulations at key points along the predicted aggregation pathway support the accuracy of the much more computationally efficient multiscale methodology.

  20. Encapsulation of poorly water-soluble drugs into organic nanotubes for improving drug dissolution.

    Science.gov (United States)

    Moribe, Kunikazu; Makishima, Takashi; Higashi, Kenjirou; Liu, Nan; Limwikrant, Waree; Ding, Wuxiao; Masuda, Mitsutoshi; Shimizu, Toshimi; Yamamoto, Keiji

    2014-07-20

    Hydrocortisone (HC), a poorly water-soluble drug, was encapsulated within organic nanotubes (ONTs), which were formed via the self-assembly of N-{12-[(2-α,β-d-glucopyranosyl) carbamoyl]dodecanyl}-glycylglycylglycine acid. The stability of the ONTs was evaluated in ten organic solvents, of differing polarities, by field emission transmission electron microscopy. The ONTs maintained their stable tubular structure in the highly polar solvents, such as ethanol and acetone. Furthermore, solution-state (1)H-NMR spectroscopy confirmed that they were practically insoluble in acetone at 25°C (0.015 mg/mL). HC-loaded ONTs were prepared by solvent evaporation using acetone. A sample with a 3/7 weight ratio of HC/ONT was analyzed by powder X-ray diffraction, which confirmed the presence of a halo pattern and the absence of any crystalline HC peak. HC peak broadening, observed by solid-state (13)C-NMR measurements of the evaporated sample, indicated the absence of HC crystals. These results indicated that HC was successfully encapsulated in ONT as an amorphous state. Improvements of the HC dissolution rate were clearly observed in aqueous media at both pH 1.2 and 6.8, probably due to HC amorphization in the ONTs. Phenytoin, another poorly water-soluble drug, also showed significant dissolution improvement upon ONT encapsulation. Therefore, ONTs can serve as an alternative pharmaceutical excipient to enhance the bioavailability of poorly water-soluble drugs.

  1. LIPOSOMAL ENCAPSULATION TECHNOLOGY A NOVEL DRUG DELIVERY SYSTEM DESIGNED FOR AYURVEDIC DRUG PREPARATION

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    M. Hemanth kumar

    2011-10-01

    Full Text Available Liposomal Encapsulation Technology (LET is the newest delivery method used by medical researchers to transfer drugs that act as healing promoters to the definite body organs. This form of delivery system offers targeted delivery of vital compounds to the body. It has been in existence since the early 70’s. Liposomal Encapsulation Technology is a state of the art method of producing sub-microscopic bubbles called liposomes, which encapsulate various substances. These phospholipids or “liposomes” form a barrier around their contents that is resistant to enzymes in the mouth and stomach, digestive juices, alkaline solutions, bile salts, and intestinal flora, found in the human body as well as free radicals. The contents of the liposomes are therefore shielded from degradation and oxidation. This protective phospholipid shield or barrier remains unharmed until the contents of the liposome are delivered right to the target organ, gland, or system where the contents will be utilized. Natural extracts are generally degraded because of oxidation and other chemical reactions before they delivered to the target site. Our research has shown liposomal encapsulated ayurvedic preparations have shown more stability and also more efficiency when compared to traditional preparations. Size of liposomes were measured around 85-200 nm.

  2. Encapsulation of methotrexate loaded magnetic microcapsules for magnetic drug targeting and controlled drug release

    Energy Technology Data Exchange (ETDEWEB)

    Chakkarapani, Prabu [Department of Pharmaceutical Technology & Centre for Excellence in Nanobio Translational Research, Anna University, Bharathidasan Institute of Technology Campus, Tiruchirappalli 620024, Tamil Nadu (India); Subbiah, Latha, E-mail: lathasuba2010@gmail.com [Department of Pharmaceutical Technology & Centre for Excellence in Nanobio Translational Research, Anna University, Bharathidasan Institute of Technology Campus, Tiruchirappalli 620024, Tamil Nadu (India); Palanisamy, Selvamani; Bibiana, Arputha [Department of Pharmaceutical Technology & Centre for Excellence in Nanobio Translational Research, Anna University, Bharathidasan Institute of Technology Campus, Tiruchirappalli 620024, Tamil Nadu (India); Ahrentorp, Fredrik; Jonasson, Christian; Johansson, Christer [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden)

    2015-04-15

    We report on the development and evaluation of methotrexate magnetic microcapsules (MMC) for targeted rheumatoid arthritis therapy. Methotrexate was loaded into CaCO{sub 3}-PSS (poly (sodium 4-styrenesulfonate)) doped microparticles that were coated successively with poly (allylamine hydrochloride) and poly (sodium 4-styrenesulfonate) by layer-by-layer technique. Ferrofluid was incorporated between the polyelectrolyte layers. CaCO{sub 3}-PSS core was etched by incubation with EDTA yielding spherical MMC. The MMC were evaluated for various physicochemical, pharmaceutical parameters and magnetic properties. Surface morphology, crystallinity, particle size, zeta potential, encapsulation efficiency, loading capacity, drug release pattern, release kinetics and AC susceptibility studies revealed spherical particles of ~3 µm size were obtained with a net zeta potential of +24.5 mV, 56% encapsulation and 18.6% drug loading capacity, 96% of cumulative drug release obeyed Hixson-Crowell model release kinetics. Drug excipient interaction, surface area, thermal and storage stability studies for the prepared MMC was also evaluated. The developed MMC offer a promising mode of targeted and sustained release drug delivery for rheumatoid arthritis therapy. - Highlights: • Development of methotrexate magnetic microcapsules (MMC) by layer-by-layer method. • Characterization of physicochemical, pharmaceutical and magnetic properties of MMC. • Multiple layers of alternative polyelectrolytes prolongs methotrexate release time. • MMC is capable for targeted and sustained release rheumatoid arthritis therapy.

  3. Simulating the co-encapsulation of drugs in a "smart" core-shell-shell polymer nanoparticle.

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    Buxton, Gavin A

    2014-03-01

    A coarse-grained lattice Monte Carlo method is used to simulate co-encapsulation and delivery of both a hydrophilic and hydrophobic drug from polymer nanoparticles. In particular, core-shell-shell polymer nanoparticles with acid-labile bonds are simulated, and the preferential release of the encapsulated drugs near more acidic tumors is captured. While these simple models lack the molecular details of a real system, they can reveal interesting insights concerning the effects of entropy and enthalpy in these systems.

  4. Encapsulation of Liposomes within pH Responsive Microspheres for Oral Colonic Drug Delivery

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    M. J. Barea

    2012-01-01

    Full Text Available A novel liposome-in-microsphere (LIM formulation has been created comprising drug-loaded liposomes within pH responsive Eudragit S100 microspheres. The liposomes contained the model drug 5-ASA and were coated with chitosan in order to protect them during encapsulation within the microspheres and to improve site-specific release characteristics. In vitro drug release studies showed that LIMs prevented drug release within simulated stomach and small intestine conditions with subsequent drug release occurring in large intestine conditions. The formulation therefore has potential for oral colonic drug delivery.

  5. Encapsulation of liver microsomes into a thermosensitive hydrogel for characterization of drug metabolism and toxicity.

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    Yang, Huiying; Zheng, Yuanting; Zhao, Bei; Shao, Tengfei; Shi, Qingling; Zhou, Ning; Cai, Weimin

    2013-12-01

    This study reported the encapsulation of liver microsomes into a thermosensitive hydrogel to characterize drug metabolism and predict drug effects. Pluronic(®)F-127 (F127) and acrylamide-bisacrylamide (Acr-Bis) were utilized as the two precursors. After chemical crosslinking catalyzed by ammonium persulfate (APS) and N,N,N',N'-tetramethylethylenediamine (TEMED), the resulting Pluronic F127-acrylamide-bisacrylamide (FAB) hydrogel could encapsulate microsomes at 4 °C and facilitate metabolic reactions at 37 °C. The gel morphology at different Acr-Bis concentrations was characterized using field emission scanning electron microscopy (FE-SEM). Higher concentrations of Acr-Bis could lead to higher degrees of cross-linking of the gel. A fluorescent staining assay was subsequently used to demonstrate successful encapsulation of microsomes into the gel as well as the free diffusion process of micromolecular substrates. The thermosensitivity of the FAB gel was studied using swelling ratio and protein release assay to verify its ability to encapsulate microsomes. The metabolic activity of microsomes encapsulated in gels was investigated by detecting the metabolites of FDA-approved substrates, including dextromethorphan, chlorzoxazone and testosterone. Compared with the traditional method of microsomal incubation, the FAB gel maintained 60%-70% of microsome activity. Lastly, the classic anticancer prodrug cyclophosphamide (CTX) was chosen as a model drug for the study of drug metabolism and the prediction of drug effects. When the microsomes encapsulated in the FAB gel were used in the cell culture system, CTX induced a higher level of apoptosis in MCF-7 cells compared with traditional microsomes.

  6. Global modelling of direct and indirect effects of sea spray aerosol using a source function encapsulating wave state

    Science.gov (United States)

    Partanen, A.-I.; Dunne, E. M.; Bergman, T.; Laakso, A.; Kokkola, H.; Ovadnevaite, J.; Sogacheva, L.; Baisnée, D.; Sciare, J.; Manders, A.; O'Dowd, C.; de Leeuw, G.; Korhonen, H.

    2014-11-01

    Recently developed parameterizations for the sea spray aerosol source flux, encapsulating wave state, and its organic fraction were incorporated into the aerosol-climate model ECHAM-HAMMOZ to investigate the direct and indirect radiative effects of sea spray aerosol particles. Our simulated global sea salt emission of 805 Tg yr-1 (uncertainty range 378-1233 Tg yr-1) was much lower than typically found in previous studies. Modelled sea salt and sodium ion concentrations agreed relatively well with measurements in the smaller size ranges at Mace Head (annual normalized mean model bias -13% for particles with vacuum aerodynamic diameter Dva particles with aerodynamic diameter Da particles with Da particles with 2.5 μm biologically active months, suggesting a need to improve the parameterization of the organic sea spray fraction. Globally, the satellite-retrieved AOD over the oceans, using PARASOL data, was underestimated by the model (means over ocean 0.16 and 0.10, respectively); however, in the pristine region around Amsterdam Island the measured AOD fell well within the simulated uncertainty range. The simulated sea spray aerosol contribution to the indirect radiative effect was positive (0.3 W m-2), in contrast to previous studies. This positive effect was ascribed to the tendency of sea salt aerosol to suppress both the in-cloud supersaturation and the formation of cloud condensation nuclei from sulfate. These effects can be accounted for only in models with sufficiently detailed aerosol microphysics and physics-based parameterizations of cloud activation. However, due to a strong negative direct effect, the simulated effective radiative forcing (total radiative) effect was -0.2 W m-2. The simulated radiative effects of the primary marine organic emissions were small, with a direct effect of 0.03 W m-2 and an indirect effect of -0.07 W m-2.

  7. Grafting β-Cyclodextrins to Silicone, Formulation of Emulsions and Encapsulation of Antifungal Drug

    Science.gov (United States)

    Noomen, Ahlem; Penciu, Alexandra; Hbaieb, Souhaira; Parrot-Lopez, Hélène; Amdouni, Noureddine; Chevalier, Yves; Kalfat, Rafik

    Emulsions of silicone polymers having β-cyclodextrin units as lateral chains have been prepared and used for the encapsulation of the antifungal drug griseofulvin. Such technology enables the formulation of active substances that are not soluble in water as dosage forms for topical administration.

  8. Massage-induced release of subcutaneously injected liposome-encapsulated drugs to the blood.

    Science.gov (United States)

    Trubetskoy, V S; Whiteman, K R; Torchilin, V P; Wolf, G L

    1998-01-01

    Liposome-based, externally regulated drug delivery system is described in which liposome-encapsulated bioactive molecules can be delivered into the blood in response to simple mechanical action. Without any mechanical stimulation, subcutaneously injected 200 mm liposomes are usually trapped in the interstitial for prolonged time. However, upon lymphotropic stimulation (such as manual massage of the injection site), the liposomes can be mobilized into the blood via lymphatic pathway. Up to 40% of the injection dose can be delivered to the blood via lymphatic pathway from the injection site at the rabbit's front paw dorsum during 5 min manual massage cycle. Using vasoconstricting hormone angiotensin II as liposome-encapsulated pharmacological marker, we demonstrated that physiological response to encapsulated drug (average blood pressure increase) can also induced and modulated by massage. Massage itself was found to have no effect on the blood pressure. Modification of liposome surface with polyethylene glycol was found to increase blood localization of the liposome-encapsulated drug presumably due to decreasing the uptake of the drug carrier by lymph node macrophages. Pressure-dependent gaps between lymphatic capillary endothelial cells are thought to play the role of the size discrimination device allowing larger particulates into the lymphatics and, eventually into the blood after increase of interstitial pressure caused by injection site massage.

  9. The production of volvox spheres and their potential application in multi-drugs encapsulation and release

    Energy Technology Data Exchange (ETDEWEB)

    Teong, Benjamin; Chang, Shwu Jen [Department of Biomedical Engineering, I-Shou University, College of Medicine, No. 8, Yida Rd., Jiaosu Village, Yanchao District, Kaohsiung City 82445, Taiwan (China); Chuang, Chin Wen [Department of Electrical Engineering, I-Shou University, No. 1, Sec. 1, Syuecheng Rd., Dashu District, Kaohsiung City 84001, Taiwan (China); Kuo, Shyh Ming, E-mail: smkuo@isu.edu.tw [Department of Biomedical Engineering, I-Shou University, College of Medicine, No. 8, Yida Rd., Jiaosu Village, Yanchao District, Kaohsiung City 82445, Taiwan (China); Manousakas, Ioannis, E-mail: i.manousakas@ieee.org [Department of Biomedical Engineering, I-Shou University, College of Medicine, No. 8, Yida Rd., Jiaosu Village, Yanchao District, Kaohsiung City 82445, Taiwan (China)

    2013-12-01

    Volvox sphere is a bio-mimicking concept of an innovative biomaterial structure of a sphere that contains smaller microspheres which then encapsulate chemicals, drugs and/or cells. The volvox spheres were produced via a high-voltage electrostatic field system, using alginate as the primary material. Encapsulated materials tested in this study include staining dyes, nuclear fast red and trypan blue, and model drugs, bovine serum albumin (BSA) and cytochrome c (CytC). The external morphology of the volvox spheres was observed via electron microscopy whereas the internal structure of the volvox spheres was observed via an optical microscope with the aid of the staining dyes, since alginate is colorless and transparent. The diameter of the microspheres was about 200 to 300 μm, whereas the diameter of the volvox spheres was about 1500 μm. Volvox spheres were durable, retaining about 95% of their mass after 4 weeks. Factors affecting entrapment efficiency, such as temperature and concentration of the bivalent cross-linker, were compared followed by a 7-day in vitro release study. The encapsulation efficiency of CytC within the microspheres was higher at cold (∼ 4 °C) and warm (∼ 50 °C) temperatures whereas temperature has no obvious effect on the BSA encapsulation. High crosslinking concentration (25% w/v) of calcium chloride has resulted higher entrapment efficiency for BSA but not for CytC. Furthermore, volvox spheres showed a different release pattern of BSA and CytC when compared to microspheres encapsulating BSA and CytC. Despite the fact that the mechanisms behind remain unclear and further investigation is required, this study demonstrates the potential of the volvox spheres for drug delivery. - Highlights: • Volvox spheres contain smaller microspheres which can encapsulate drugs and/or cells. • Alginate is the primary material for the inner and outer spheres. • Encapsulation is affected by the crosslinking, temperature and the selection of drugs.

  10. Evaluation of Lactobacillus rhamnosus GG and Lactobacillus acidophilus NCFM encapsulated using a novel impinging aerosol method in fruit food products.

    Science.gov (United States)

    Sohail, Asma; Turner, Mark S; Prabawati, Elisabeth Kartika; Coombes, Allan G A; Bhandari, Bhesh

    2012-07-02

    This study investigated the effect of microencapsulation on the survival of Lactobacillus rhamnosus GG and Lactobacillus acidophilus NCFM and their acidification in orange juice at 25°C for nine days and at 4°C over thirty five days of storage. Alginate micro beads (10-40 μm) containing the probiotics were produced by a novel dual aerosol method of alginate and CaCl(2) cross linking solution. Unencapsulated L. rhamnosus GG was found to have excellent survivability in orange juice at both temperatures. However unencapsulated L. acidophilus NCFM showed significant reduction in viability. Encapsulation of these two bacteria did not significantly enhance survivability but did reduce acidification at 25°C and 4°C. In agreement with this, encapsulation of L. rhamnosus GG also reduced acidification in pear and peach fruit-based foods at 25°C, however at 4°C difference in pH was insignificant between free and encapsulated cells. In conclusion, L. rhamnosus GG showed excellent survival in orange juice and microencapsulation has potential in reducing acidification and possible negative sensory effects of probiotics in orange juice and other fruit-based products.

  11. Nanoformulation and encapsulation approaches for poorly water-soluble drug nanoparticles

    Science.gov (United States)

    Wais, Ulrike; Jackson, Alexander W.; He, Tao; Zhang, Haifei

    2016-01-01

    During the last few decades the nanomedicine sector has emerged as a feasible and effective solution to the problems faced by the high percentage of poorly water-soluble drugs. Decreasing the size of such drug compounds to the nanoscale can significantly change their physical properties, which lays the foundation for the use of nanomedicine for pharmaceutical applications. Various techniques have been developed to produce poorly water-soluble drug nanoparticles, mainly to address the poor water-soluble issues but also for the efficient and targeted delivery of such drugs. These techniques can be generally categorized into top-down, bottom-up and encapsulation approaches. Among them, the top-down approaches have been the main choice for industrial preparation of drug nanoparticles while other methods are actively investigated by researchers. In this review, we aim to give a comprehensive overview and latest progress of the top-down, bottom-up, and encapsulation methods for the preparation of poorly water-soluble drug nanoparticles and how solvents and additives can be selected for these methods. In addition to the more industrially applied top-down approaches, the review is focused more on bottom-up and encapsulation methods, particularly covering supercritical fluid-related methods, cryogenic techniques, and encapsulation with dendrimers and responsive block copolymers. Some of the approved and mostly used nanodrug formulations on the market are also covered to demonstrate the applications of poorly water-soluble drug nanoparticles. This review is complete with perspectives on the development and challenges of fabrication techniques for more effective nanomedicine.

  12. Multilayer encapsulated mesoporous silica nanospheres as an oral sustained drug delivery system for the poorly water-soluble drug felodipine

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Liang [Department of Pharmaceutics, Shenyang Pharmaceutical University, P.O. Box 32, Liaoning Province, Shenyang 110016 (China); Sun, Hongrui [English Teaching Department, School of Basic Courses, Shenyang Pharmaceutical University, Wenhua Road 103, Shenyang 110016 (China); Zhao, Qinfu; Han, Ning; Bai, Ling; Wang, Ying; Jiang, Tongying [Department of Pharmaceutics, Shenyang Pharmaceutical University, P.O. Box 32, Liaoning Province, Shenyang 110016 (China); Wang, Siling, E-mail: silingwang@syphu.edu.cn [Department of Pharmaceutics, Shenyang Pharmaceutical University, P.O. Box 32, Liaoning Province, Shenyang 110016 (China)

    2015-02-01

    We used a combination of mesoporous silica nanospheres (MSN) and layer-by-layer (LBL) self-assembly technology to establish a new oral sustained drug delivery system for the poorly water-soluble drug felodipine. Firstly, the model drug was loaded into MSN, and then the loaded MSN were repeatedly encapsulated by chitosan (CHI) and acacia (ACA) via LBL self-assembly method. The structural features of the samples were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption. The encapsulating process was monitored by zeta-potential and surface tension measurements. The physical state of the drug in the samples was characterized by differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). The influence of the multilayer with different number of layers on the drug release rate was studied using thermal gravimetric analysis (TGA) and surface tension measurement. The swelling effect and the structure changes of the multilayer were investigated to explore the relationship between the drug release behavior and the state of the multilayer under different pH conditions. The stability and mucosa adhesive ability of the prepared nanoparticles were also explored. After multilayer coating, the drug release rate was effectively controlled. The differences in drug release behavior under different pH conditions could be attributed to the different states of the multilayer. And the nanoparticles possessed good stability and strong mucosa adhesive ability. We believe that this combination offers a simple strategy for regulating the release rate of poorly water-soluble drugs and extends the pharmaceutical applications of inorganic materials and polymers. - Highlights: • A combination of inorganic and organic materials was applied. • Mesoporous silica nanospheres (MSN) were used as drug carriers. • Chitosan and acacia were encapsulated through layer-by-layer self-assembly. • The release rate of the poorly

  13. A new technique for the encapsulation of water insoluble drugs using ethyl cellulose.

    Science.gov (United States)

    Sheorey, D S; Sai, M S; Dorle, A K

    1991-01-01

    A new technique for encapsulation of water insoluble drugs has been developed utilizing ethyl cellulose as a wall forming material. Ethyl cellulose was dissolved in a water immiscible, volatile organic solvent, containing sulphadiazine as a model drug. This dispersion was emulsified into an aqueous bentonite suspension and phase separation was induced by solvent evaporation. The effect of bentonite concentration, core to coat ratio, organic solvent, speed of agitation and temperature was studied with respect to the microcapsule size and size distribution, drug content, in vitro release and surface characteristics.

  14. Mathematical modeling of coupled drug and drug-encapsulated nanoparticle transport in patient-specific coronary artery walls

    KAUST Repository

    Hossain, Shaolie S.

    2011-08-20

    The majority of heart attacks occur when there is a sudden rupture of atherosclerotic plaque, exposing prothrombotic emboli to coronary blood flow, forming clots that can cause blockages of the arterial lumen. Diseased arteries can be treated with drugs delivered locally to vulnerable plaques. The objective of this work was to develop a computational tool-set to support the design and analysis of a catheter-based nanoparticulate drug delivery system to treat vulnerable plaques and diffuse atherosclerosis. A threedimensional mathematical model of coupled mass transport of drug and drug-encapsulated nanoparticles was developed and solved numerically utilizing isogeometric finite element analysis. Simulations were run on a patient-specific multilayered coronary artery wall segment with a vulnerable plaque and the effect of artery and plaque inhomogeneity was analyzed. The method captured trends observed in local drug delivery and demonstrated potential for optimizing drug design parameters, including delivery location, nanoparticle surface properties, and drug release rate. © Springer-Verlag 2011.

  15. Mathematical modeling of coupled drug and drug-encapsulated nanoparticle transport in patient-specific coronary artery walls

    Science.gov (United States)

    Hossain, Shaolie S.; Hossainy, Syed F. A.; Bazilevs, Yuri; Calo, Victor M.; Hughes, Thomas J. R.

    2012-02-01

    The majority of heart attacks occur when there is a sudden rupture of atherosclerotic plaque, exposing prothrombotic emboli to coronary blood flow, forming clots that can cause blockages of the arterial lumen. Diseased arteries can be treated with drugs delivered locally to vulnerable plaques. The objective of this work was to develop a computational tool-set to support the design and analysis of a catheter-based nanoparticulate drug delivery system to treat vulnerable plaques and diffuse atherosclerosis. A three-dimensional mathematical model of coupled mass transport of drug and drug-encapsulated nanoparticles was developed and solved numerically utilizing isogeometric finite element analysis. Simulations were run on a patient-specific multilayered coronary artery wall segment with a vulnerable plaque and the effect of artery and plaque inhomogeneity was analyzed. The method captured trends observed in local drug delivery and demonstrated potential for optimizing drug design parameters, including delivery location, nanoparticle surface properties, and drug release rate.

  16. Electrohydrodynamic encapsulation of cisplatin in poly (lactic-co-glycolic acid) nanoparticles for controlled drug delivery.

    OpenAIRE

    Parhizkar, M.; Reardon, PJT; Knowles, JC; Browning, RJ; Stride, E.; Pedley, RB; Harker, AH; Edirisinghe, M.

    2016-01-01

    Targeted delivery of potent, toxic chemotherapy drugs, such as cisplatin, is a significant area of research in cancer treatment. In this study, cisplatin was successfully encapsulated with high efficiency (>70%) in Poly (lactic-co-glycolic acid) polymeric nanoparticles by using electrohydrodynamic atomization (EHDA) where applied voltage and solution flow rate as well as the concentration of cisplatin and polymer were varied to control the size of the p...

  17. A facile method to prepare superparamagnetic iron oxide and hydrophobic drug-encapsulated biodegradable polyurethane nanoparticles

    Directory of Open Access Journals (Sweden)

    Cheng K

    2017-03-01

    Full Text Available Kuo-Wei Cheng, Shan-hui Hsu Institute of Polymer Science and Engineering, College of Engineering, National Taiwan University, Taipei, Taiwan, Republic of China Abstract: Superparamagnetic iron oxide nanoparticles (SPIO NPs have a wide range of biomedical applications such as in magnetic resonance imaging, targeting, and hyperthermia therapy. Aggregation of SPIO NPs can occur because of the hydrophobic surface and high surface energy of SPIO NPs. Here, we developed a facile method to encapsulate SPIO NPs in amphiphilic biodegradable polymer. Anionic biodegradable polyurethane nanoparticles (PU NPs with ~35 nm size and different chemistry were prepared by waterborne processes. SPIO NPs were synthesized by chemical co-precipitation. SPIO NPs were then added to the aqueous dispersion of PU NPs, followed by application of high-frequency (~20 kHz ultrasonic vibration for 3 min. This method rendered SPIO-PU hybrid NPs (size ~110 nm suspended in water. SPIO-PU hybrid NPs contained ~50–60 wt% SPIO and retained the superparamagnetic property (evaluated by a magnetometer as well as high contrast in magnetic resonance imaging. SPIO-PU NPs also showed the ability to provide cell hyperthermic treatment. Using the same ultrasonic method, hydrophobic drug (Vitamin K3 [VK3] or (9-(methylaminomethylanthracene [MAMA] could also be encapsulated in PU NPs. The VK3-PU or MAMA-PU hybrid NPs had ~35 nm size and different release profiles for PUs with different chemistry. The encapsulation efficiency for VK3 and MAMA was high (~95% without burst release. The encapsulation mechanism may be attributed to the low glass transition temperature (Tg and good mechanical compliance of PU NPs. The new encapsulation method involving waterborne biodegradable PU NPs is simple, rapid, and effective to produce multimodular NP carriers. Keywords: superparamagnetic iron oxide, polyurethane, drug release, hybrid nanoparticles

  18. Hydrophilic drug encapsulation in shell-core microcarriers by two stage polyelectrolyte complexation method.

    Science.gov (United States)

    Dalmoro, Annalisa; Sitenkov, Alexander Y; Cascone, Sara; Lamberti, Gaetano; Barba, Anna Angela; Moustafine, Rouslan I

    2017-02-25

    In this study a protocol exploiting the combination of the ultrasonic atomization and the complexation between polyelectrolytes was developed to efficiently encapsulate a hydrophilic chemotherapeutic agent essentially used in the treatment of colon cancer, 5-fluorouracil, in enteric shell-core alginate-based microcarriers. The atomization assisted by ultrasound allowed to obtain small droplets by supplying low energy and avoiding drug degradation. In particular microcarriers were produced in a home-made apparatus where both the core (composed of alginate, drug, and Pluronic F127) and shell (composed of only alginate) feed were separately sent to the coaxial ultrasonic atomizer where they were nebulized and placed in contact with the complexation bulk. With the aim to obtain microstructured particles of alginate encapsulating 5-fluorouracil, different formulations of the first complexation bulk were tested; at last an emulsion made of a calcium chloride aqueous solution and dichloromethane allowed to reach an encapsulation efficiency of about 50%. This result can be considered very interesting considering that in literature similar techniques gave 5-fluorouracil encapsulation efficiencies of about 10%. Since a single complexation stage was not able to assure microcarriers gastroresistance, the formulation of a second complexation bulk was evaluated. The solution of cationic and pH-insoluble Eudragit® RS 100 in dichloromethane was chosen as bulk of second-stage complexation obtaining good enteric properties of shell-core microcarriers, i.e. a 5-FU cumulative release at pH 1 (simulating gastric pH) lower than 35%. The formation of interpolyelectrolyte complex (IPEC) between countercharged polymers and the chemical stability of 5-FU in microcarriers were confirmed by FTIR analysis, the presence of an amorphous dispersion of 5-FU in prepared microparticles was also confirmed by DSC. Finally, shell-core enteric coated microcarriers encapsulating 5-fluorouracil were used

  19. Alginate encapsulated mesoporous silica nanospheres as a sustained drug delivery system for the poorly water-soluble drug indomethacin

    Directory of Open Access Journals (Sweden)

    Liang Hu

    2014-08-01

    Full Text Available We applied a combination of inorganic mesoporous silica material, frequently used as drug carriers, and a natural organic polymer alginate (ALG, to establish a sustained drug delivery system for the poorly water-soluble drug Indomethacin (IND. Mesoporous silica nanospheres (MSNs were synthesized using an organic template method and then functionalized with aminopropyl groups through postsynthesis. After drug loading into the pores of aninopropyl functionalized MSNs (AP-MSNs, IND loaded AP-MSNs (IND-AP-MSNs were encapsulated by ALG through the ionic interaction. The effects of surface chemical groups and ALG layer on IND release were systematically studied using scanning electron microscopy (SEM, transmission electron microscopy (TEM, nitrogen adsorption, zeta-potential analysis and TGA analysis. The surface structure and surface charge changes of the ALG encapsulated AP-MSNs (ALG-AP-MSNs were also investigated. The results showed that sustained release of IND from the designed drug delivery system was mainly due to the blockage effect from the coated ALG. We believe that this combination will help designing oral sustained drug delivery systems for poorly water-soluble drugs.

  20. Aerosol flow reactor method for synthesis of drug nanoparticles.

    Science.gov (United States)

    Eerikäinen, Hannele; Watanabe, Wiwik; Kauppinen, Esko I; Ahonen, P Petri

    2003-05-01

    An aerosol flow reactor method, a one-step continuous process to produce nanometer-sized drug particles with unimodal size distribution, was developed. This method involves first dissolving the drug material in question into a suitable solvent, which is then followed by atomising the solution as fine droplets into carrier gas. A heated laminar flow reactor tube is used to evaporate the solvent, and solid drug nanoparticles are formed. In this study, the effect of drying temperature on the particle size and morphology was examined. A glucocorticosteroid used for asthma therapy, beclomethasone dipropionate, was selected as an experimental model drug. The geometric number mean particle diameter increases significantly with increasing reactor temperatures due to formation of hollow nanoparticles. Above 160 degrees C, however, further increase in temperature results in decreasing particle size. The produced nanoparticles are spherical and show smooth surfaces at all studied experimental conditions.

  1. A Method to Co-encapsulate Gas and Drugs in Liposomes for Ultrasound-Controlled Drug Delivery

    OpenAIRE

    2008-01-01

    A novel method for the facile production of gas-containing liposomes with simultaneous drug encapsulation is described. Liposomes of phospholipid and cholesterol were prepared by conventional procedures of hydrating the lipid film, sonicating, freezing and thawing. A single, but critical modification of this procedure generates liposomes that contain gas (air, perfluorocarbon, argon); after sonication, the lipid is placed under pressure with the gas of interest. After equilibration, the sampl...

  2. Fabrication of hydrogel-encapsulated silica core bound with chitosan chains for efficient drug delivery

    Science.gov (United States)

    Byeol Bae, Saet; Lee, Sang Wha

    2016-06-01

    In this study, hydrogel-encapsulated silica nanoparticles were facilely prepared through the following three consecutive steps: i) silica nanoparticles (SNPs) were synthesized via a sol-gel reaction of tetraethyl orthosilicate (TEOS) with ammonium hydroxide, ii) the resulting SNPs were functionalized with 3-(trimethoxysilyl)-propylmethacrylate (TPM) ligand with an olefin group, and iii) the TPM-functionalized SNPs were encapsulated with poly(N-isopropylacrylamide-co-acrylic acid), NIPAM-co-AAc hydrogels by using a radical polymerization reaction of the co-monomers at the following ratio: \\text{NIPAM}:\\text{AAc} = 91:9 wt %. The lower critical solution temperature (LCST) of the encapsulated hydrogels with a moiety of carboxylic groups was slightly above physiological temperature and they demonstrated a thermo-sensitive variation of particle size. The hydrogel-encapsulated SNPs (SNPs@Hyd) were finally bound with chitosan chains, which are bio-friendly and non-toxic polymers. When compared to SNPs@Hyd, chitosan-coated SNPs@Hyd (SNPs@Hyd@Chi) exhibited prolonged drug (ibuprofen) release and stable structural integrity during the release test.

  3. Marbofloxacin-encapsulated microparticles provide sustained drug release for treatment of veterinary diseases.

    Science.gov (United States)

    Lee, Joohyeon; Kwon, Ho Jin; Ji, Hyunggun; Cho, Sun Hang; Cho, Eun-Haeng; Han, Hee Dong; Shin, Byung Cheol

    2016-03-01

    Fluoroquinolone antibiotics with concentration-dependent killing effects and a well-established broad spectrum of activity are used commonly to treat infectious diseases caused by bacteria. However, frequent and excessive administration of these antibiotics is a serious problem, and leads to increased number of drug-resistant bacteria. Thus, there is an urgent need for novel fluoroquinolone antibiotic formulations that minimize the risk of resistance while maximizing their efficacy. In this study, we developed intramuscularly injectable polymeric microparticles (MPs) that encapsulated with marbofloxacin (MAR) and were composed of poly(D,L-lactide-co-glycolic acid) (PLGA) and poloxamer (POL). MAR-encapsulated MP (MAR-MP) had a spherical shape with particle size ranging from 80 μm to 120 μm. Drug loading efficiency varied from 55 to 85% (w/w) at increasing amount of hydrophilic agent, POL. Drug release from MAR-MP demonstrated a significant and sustained increase at increased ratios of POL to PLGA. These results indicate that MAR-MP is an improved drug delivery carrier for fluoroquinolone antibiotics, which can reduce the number of doses needed and sustain a high release rate of MAR for 2-3 days. As a novel and highly effective drug delivery platform, MAR-MP has great potential for use in a broad range of applications for the treatment of various veterinary diseases.

  4. A facile method to prepare superparamagnetic iron oxide and hydrophobic drug-encapsulated biodegradable polyurethane nanoparticles

    Science.gov (United States)

    Cheng, Kuo-Wei; Hsu, Shan-hui

    2017-01-01

    Superparamagnetic iron oxide nanoparticles (SPIO NPs) have a wide range of biomedical applications such as in magnetic resonance imaging, targeting, and hyperthermia therapy. Aggregation of SPIO NPs can occur because of the hydrophobic surface and high surface energy of SPIO NPs. Here, we developed a facile method to encapsulate SPIO NPs in amphiphilic biodegradable polymer. Anionic biodegradable polyurethane nanoparticles (PU NPs) with ~35 nm size and different chemistry were prepared by waterborne processes. SPIO NPs were synthesized by chemical co-precipitation. SPIO NPs were then added to the aqueous dispersion of PU NPs, followed by application of high-frequency (~20 kHz) ultrasonic vibration for 3 min. This method rendered SPIO-PU hybrid NPs (size ~110 nm) suspended in water. SPIO-PU hybrid NPs contained ~50–60 wt% SPIO and retained the superparamagnetic property (evaluated by a magnetometer) as well as high contrast in magnetic resonance imaging. SPIO-PU NPs also showed the ability to provide cell hyperthermic treatment. Using the same ultrasonic method, hydrophobic drug (Vitamin K3 [VK3]) or (9-(methylaminomethyl) anthracene [MAMA]) could also be encapsulated in PU NPs. The VK3-PU or MAMA-PU hybrid NPs had ~35 nm size and different release profiles for PUs with different chemistry. The encapsulation efficiency for VK3 and MAMA was high (~95%) without burst release. The encapsulation mechanism may be attributed to the low glass transition temperature (Tg) and good mechanical compliance of PU NPs. The new encapsulation method involving waterborne biodegradable PU NPs is simple, rapid, and effective to produce multimodular NP carriers. PMID:28280341

  5. Multilayer encapsulated mesoporous silica nanospheres as an oral sustained drug delivery system for the poorly water-soluble drug felodipine.

    Science.gov (United States)

    Hu, Liang; Sun, Hongrui; Zhao, Qinfu; Han, Ning; Bai, Ling; Wang, Ying; Jiang, Tongying; Wang, Siling

    2015-02-01

    We used a combination of mesoporous silica nanospheres (MSN) and layer-by-layer (LBL) self-assembly technology to establish a new oral sustained drug delivery system for the poorly water-soluble drug felodipine. Firstly, the model drug was loaded into MSN, and then the loaded MSN were repeatedly encapsulated by chitosan (CHI) and acacia (ACA) via LBL self-assembly method. The structural features of the samples were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption. The encapsulating process was monitored by zeta-potential and surface tension measurements. The physical state of the drug in the samples was characterized by differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). The influence of the multilayer with different number of layers on the drug release rate was studied using thermal gravimetric analysis (TGA) and surface tension measurement. The swelling effect and the structure changes of the multilayer were investigated to explore the relationship between the drug release behavior and the state of the multilayer under different pH conditions. The stability and mucosa adhesive ability of the prepared nanoparticles were also explored. After multilayer coating, the drug release rate was effectively controlled. The differences in drug release behavior under different pH conditions could be attributed to the different states of the multilayer. And the nanoparticles possessed good stability and strong mucosa adhesive ability. We believe that this combination offers a simple strategy for regulating the release rate of poorly water-soluble drugs and extends the pharmaceutical applications of inorganic materials and polymers.

  6. Anticancer studies of drug encapsulated polyethylene terephthalate-Co-polylactic acid nanocapsules

    Directory of Open Access Journals (Sweden)

    K Sathish Kumar

    2011-01-01

    Full Text Available Objectives: The purpose of this study was to investigate the anticancer activity of anticancer drugs (5-fluorouracil and 6-thioguanine in polymeric nanocapsules in the presence and in the absence of gold and iron oxide nanoparticles toward Hep2 cancer cells. Materials and Methods: MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay was used for quantitative measurements for the anticancer cell activity. Encapsulated drug in polyethylene terephthalate-polylactic acid copolymer (PET-co-PLA nanocapsules in the presence and absence of gold and iron oxide nanoparticles were prepared via the W/O/W emulsification solvent-evaporation method. Morphology of the nanoparticles was characterized by transmission electron microscopy and scanning electron microscopy. Conclusion: The average size of the polymeric nanocapsules, gold nanoparticles, and iron oxide nanoparticles were found to be in range of 230-260, 18 -20 nm, 5-10 nm, respectively. The findings in this study inferred that incorporated drug in polymeric nanocapsules with gold nanoparticles and iron oxide nanoparticles show better anticancer activity when compared with encapsulated drug in polymeric nanocapsules.

  7. Solid lipid nanoparticles for encapsulation of hydrophilic drugs by an organic solvent free double emulsion technique.

    Science.gov (United States)

    Becker Peres, Luana; Becker Peres, Laize; de Araújo, Pedro Henrique Hermes; Sayer, Claudia

    2016-04-01

    Encapsulation of hydrophilic compounds for drug delivery systems with high loading efficiency is not easily feasible and remains a challenge, mainly due to the leaking of the drug to the outer aqueous phase during nanoparticle production. Usually, encapsulation of hydrophilic drugs is achieved by using double emulsion or inverse miniemulsion systems that often require the use of organic solvents, which may generate toxicological issues arising from solvent residues. Herein, we present the preparation of solid lipid nanoparticles loaded with a hydrophilic compound by a novel organic solvent free double emulsion/melt dispersion technique. The main objective of this study was to investigate the influence of important process and formulation variables, such as lipid composition, surfactant type, sonication parameters and lipid solidification conditions over physicochemical characteristics of SLN dispersion. Particle size and dispersity, as well as dispersion stability were used as responses. SLN dispersions with average size ranging from 277 to 550 nm were obtained, showing stability for over 60 days at 4 °C depending on the chosen emulsifying system. Entrapment efficiency of fluorescent dyes used as model markers was assessed by fluorescence microscopy and UV-vis spectrophotometry and results suggest that the obtained lipid based nanoparticles could be potentially applied as a delivery system of water soluble drugs.

  8. Protein encapsulated magnetic carriers for micro/nanoscale drug delivery systems.

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Y.; Kaminski, M. D.; Mertz, C. J.; Finck, M. R.; Guy, S. G.; Chen, H.; Rosengart, A. J.; Chemical Engineering; Univ. of Chicago, Pritzker School of Medicine

    2005-01-01

    Novel methods for drug delivery may be based on nanotechnology using non-invasive magnetic guidance of drug loaded magnetic carriers to the targeted site and thereafter released by external ultrasound energy. The key building block of this system is to successfully synthesize biodegradable, magnetic drug carriers. Magnetic carriers using poly(D,L-lactide-co-glycolide) (PLGA) or poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) as matrix materials were loaded with bovine serum albumin (BSA) by a double-emulsion technique. BSA-loaded magnetic microspheres were characterized for size, morphology, surface charge, and magnetization. The BSA encapsulation efficiency was determined by recovering albumin from the microspheres using dimethyl sulfoxide and 0.05N NaOH/0.5% SDS then quantifying with the Micro-BCA protein assay. BSA release profiles were also determined by the Micro-BCA protein assay. The microspheres had drug encapsulation efficiencies up to 90% depending on synthesis parameters. Particles were spherical with a smooth or porous surface having a size range less than 5 {mu}m. The surface charge (expressed as zeta potential) was near neutral, optimal for prolonged intravascular survival. The magnetization of these BSA loaded magnetic carriers was 2 to 6 emu/g, depending on the specific magnetic materials used during synthesis.

  9. Electrohydrodynamic encapsulation of cisplatin in poly (lactic-co-glycolic acid) nanoparticles for controlled drug delivery.

    Science.gov (United States)

    Parhizkar, Maryam; Reardon, Philip J T; Knowles, Jonathan C; Browning, Richard J; Stride, Eleanor; Barbara, Pedley R; Harker, Anthony H; Edirisinghe, Mohan

    2016-10-01

    Targeted delivery of potent, toxic chemotherapy drugs, such as cisplatin, is a significant area of research in cancer treatment. In this study, cisplatin was successfully encapsulated with high efficiency (>70%) in poly (lactic-co-glycolic acid) polymeric nanoparticles by using electrohydrodynamic atomization (EHDA) where applied voltage and solution flow rate as well as the concentration of cisplatin and polymer were varied to control the size of the particles. Thus, nanoparticles were produced with three different drug:polymer ratios (2.5, 5 and 10wt% cisplatin). It was shown that smaller nanoparticles were produced with 10wt% cisplatin. Furthermore, these demonstrated the best sustained release (smallest burst release). By fitting the experimental data with various kinetic models it was concluded that the release is dependent upon the particle morphology and the drug concentration. Thus, these particles have significant potential for cisplatin delivery with controlled dosage and release period that are crucial chemotherapy parameters.

  10. Energetics investigation on encapsulation of protein/peptide drugs in carbon nanotubes.

    Science.gov (United States)

    Chen, Qu; Wang, Qi; Liu, Ying-Chun; Wu, Tao; Kang, Yu; Moore, Joshua D; Gubbins, Keith E

    2009-07-07

    This work focuses on the dynamic properties and energetics of the protein/peptide drug during its transport through carbon nanotubes (CNTs). A systematic study was performed on the interaction between the peptide and the CNTs. In the molecular dynamics (MD) simulations, the protein/peptide molecule Zadaxin is observed to be encapsulated inside the nanotube after its spontaneous insertion and oscillates around the center of the tube, where the van der Waals interaction energy is observed to be a minimum. Furthermore, it is found by performing steered MD simulations that the pulling force applied to the peptide reaches a maximum value, which demonstrates the ability of the CNTs to trap protein/peptide drugs. Such effects, attributed to van der Waals interactions, can be influenced by varying the lengths and diameters of the CNTs. Longer nanotubes provide a broader area to trap the peptide, while smaller nanotubes are able to encapsulate the peptide with a deeper interaction energy well. This investigation provides insights into nanoscale pharmaceutical drug delivery devices.

  11. Receptor binding peptides for target-selective delivery of nanoparticles encapsulated drugs

    Directory of Open Access Journals (Sweden)

    Accardo A

    2014-03-01

    Full Text Available Antonella Accardo,1 Luigi Aloj,2 Michela Aurilio,2 Giancarlo Morelli,1 Diego Tesauro11Centro interuniversitario di Ricerca sui Peptidi Bioattivi (CIRPeB, Department of Pharmacy and Istituto di Biostrutture e Bioimmagini - Consiglio Nazionale delle Ricerche (IBB CNR, University of Naples “Federico II”, 2Department of Nuclear Medicine, Istituto Nazionale per lo Studio e la Cura dei Tumori, Fondazione “G. Pascale”, Napoli, ItalyAbstract: Active targeting by means of drug encapsulated nanoparticles decorated with targeting bioactive moieties represents the next frontier in drug delivery; it reduces drug side effects and increases the therapeutic index. Peptides, based on their chemical and biological properties, could have a prevalent role to direct drug encapsulated nanoparticles, such as liposomes, micelles, or hard nanoparticles, toward the tumor tissues. A considerable number of molecular targets for peptides are either exclusively expressed or overexpressed on both cancer vasculature and cancer cells. They can be classified into three wide categories: integrins; growth factor receptors (GFRs; and G-protein coupled receptors (GPCRs. Therapeutic agents based on nanovectors decorated with peptides targeting membrane receptors belonging to the GPCR family overexpressed by cancer cells are reviewed in this article. The most studied targeting membrane receptors are considered: somatostatin receptors; cholecystokinin receptors; receptors associated with the Bombesin like peptides family; luteinizing hormone-releasing hormone receptors; and neurotensin receptors. Nanovectors of different sizes and shapes (micelles, liposomes, or hard nanoparticles loaded with doxorubicin or other cytotoxic drugs and externally functionalized with natural or synthetic peptides are able to target the overexpressed receptors and are described based on their formulation and in vitro and in vivo behaviors.Keywords: receptors binding peptides, drug delivery

  12. Self-degrading niosomes for encapsulation of hydrophilic and hydrophobic drugs: An efficient carrier for cancer multi-drug delivery.

    Science.gov (United States)

    Sharma, Varsha; Anandhakumar, Sundaramurthy; Sasidharan, Manickam

    2015-11-01

    In this study, we have examined the encapsulation and release of hydrophilic and hydrophobic drugs in self-degrading niosomes as a unique method for anticancer therapy. Niosomes were prepared by amphiphilic self-assembly of Tween 80 and cholesterol through film hydration method. Encapsulation studies with two active molecules curcumin and doxorubicin hydrochloride (Dox) showed that curcumin is supposed to accumulate in the shell whereas Dox accumulates in the inner aqueous core of the niosome. Confocal studies indicated that nile red adsorbs preferentially to the head group of the Tween 80 and forms two separate layers in the shell. It was also seen that the niosomes undergo self-degradation in PBS through a sequential process, forming interconnected pores followed by complete collapse after 1week. The release profile shows two phases: i) initial Dox release in the first two days, followed by ii) curcumin release over 7days. Enhanced (synergistic) cytotoxicity was observed for dual-drug loaded niosomes against HeLa cell lines. Thus these niosomes are shown to offer a promising delivery system for hydrophobic and hydrophilic drugs collectively.

  13. Novel 'nano in nano' composites for sustained drug delivery: biodegradable nanoparticles encapsulated into nanofiber non-wovens.

    Science.gov (United States)

    Beck-Broichsitter, Moritz; Thieme, Marcel; Nguyen, Juliane; Schmehl, Thomas; Gessler, Tobias; Seeger, Werner; Agarwal, Seema; Greiner, Andreas; Kissel, Thomas

    2010-12-08

    Novel 'nano in nano' composites consisting of biodegradable polymer nanoparticles incorporated into polymer nanofibers may efficiently modulate drug delivery. This is shown here using a combination of model compound-loaded biodegradable nanoparticles encapsulated in electrospun fibers. The dye coumarin 6 is used as model compound for a drug in order to simulate drug release from loaded poly(lactide-co-glycolide) nanoparticles. Dye release from the nanoparticles occurs immediately in aqueous solution. Dye-loaded nanoparticles which are encapsulated by electrospun polymer nanofibers display a significantly retarded release.

  14. Structural, energetic and electrical properties of encapsulation of penicillamine drug into the CNTs based on vdW-DF perspective

    Science.gov (United States)

    Khorsand, Ameneh; Jamehbozorgi, Saeid; Ghiasi, Reza; Rezvani, Mahyar

    2015-08-01

    First-principles van der Waals density functional (vdW-DF) calculation using GGA/PBE functional and DZP basis set implemented in the SIESTA package was carried out to investigation the encapsulation of penicillamine drug into the both armchair and zigzag single wall carbon nanotubes (SWCNTs). The results reveal that the drug encapsulated inside the CNT cavity is weakly bounded. The obtained results of binding energies indicated that incorporation of drug is favored inside the zigzag SWCNTs compared with armchair counterparts. We address here the role of vdW interaction for penicillamine drug when inclusion in the CNTs. It worth mentioning that encapsulation of vdW forces can be effects on the binding properties. The electronic structures and Mulliken charge population are analysed for the energetically most favorable complexes which shows that encapsulated penicillamine changes slightly the electronic properties of SWCNTs and trivial charges are transferred from drug to CNTs during encapsulation process. Global reactivity descriptor values such as electronegativity (χ), global hardness (η), global softness (S), electronic chemical potential (μ), and electrophilicity index (ω) were calculated. We anticipated that these findings supply the new way and value information for help in the experimental study and future applications.

  15. Parylene-encapsulated copolymeric membranes as localized and sustained drug delivery platforms.

    Science.gov (United States)

    Chen, Mark; Huang, Houjin; Pierstorff, Erik; Shin, Eric; Robinson, Erik; Ho, Dean

    2009-10-01

    Parylene is a biologically inert material capable of being deposited in conformal nanoscale layers on virtually any surface, making it a viable structural material for the fabrication of drug delivery devices, as well as implant coatings, sensors, and other biomedical technologies. Here we explore its novel drug delivery applications by using parylene to package the polymethyloxazoline-polydimethylsiloxane-polymethyloxazoline (PMOXA-PDMS-PMOXA) block copolymer membrane of a nanoscale thickness (approximately 4 nm/layer) mixed with a therapeutic element, creating an active parylene-encapsulated copolymeric (APC) membrane for slow release drug delivery of dexamethasone (Dex), a potent anti-inflammatory and immunosuppressant synthetic glucocorticoid. Given current needs for localized therapeutic release for conditions such as cancer, post-surgical inflammation, wound healing, regenerative medicine, to name a few, this stand-alone and minimally invasive implantable technology may impact a broad range of medical scenarios. To evaluate the applicability of the APC membrane as a biocompatible drug delivery system, real-time polymerase chain reaction (RT-PCR) was performed to investigate the expression of cytokines that regulate cellular stress and inflammation as a result of in vitro RAW264.7 macrophage cell growth on the APC membrane. Significant decreases in relative mRNA levels of IL-6, TNF-alpha, and iNOS were observed. Dex functionalized APC membranes were further found to effectively slow-elute the drug via confocal microscopy, with a confirmed extended elution capability over a period of several days, undergoing phosphate buffered saline washes between time points. In addition, we examined the membrane surface through atomic force microscopy (AFM) to examine Dex/copolymer deposition, and to characterize the surface of the APC membrane. Furthermore, we evaluated the effects of incubation with the APC membrane in solution on macrophage growth behavior and cellular

  16. Microparticles prepared from biodegradable polyhydroxyalkanoates as matrix for encapsulation of cytostatic drug.

    Science.gov (United States)

    Murueva, A V; Shishatskaya, E I; Kuzmina, A M; Volova, T G; Sinskey, A J

    2013-08-01

    Microparticles made from degradable polyhydroxyalkanoates of different chemical compositions a homopolymer of 3-hydroxybutyric acid, copolymers of 3-hydroxybutyric and 4-hydroxybutyric acids (P3HB/4HB), 3-hydroxybutyric and 3-hydroxyvaleric acids (P3HB/3HV), 3-hydroxybutyric and 3-hydroxyhexanoic acids (P3HB/3HHx) were prepared using the solvent evaporation technique, from double emulsions. The study addresses the influence of the chemical compositions on the size and ξ-potential of microparticles. P3HB microparticles loaded with doxorubicin have been prepared and investigated. Their average diameter and ξ-potential have been found to be dependent upon the level of loading (1, 5, and 10 % of the polymer mass). Investigation of the in vitro drug release behavior showed that the total drug released from the microparticle into the medium increased with mass concentration of the drug. In this study mouse fibroblast NIH 3T3 cells were cultivated on PHA microparticles, and results of using fluorescent DAPI DNA stain, and MTT assay showed that microparticles prepared from PHAs of different chemical compositions did not exhibit cytotoxicity to cells cultured on them and proved to be highly biocompatible. Cell attachment and proliferation on PHA microparticles were similar to those on polystyrene. The cytostatic drug encapsulated in P3HB/3HV microparticles has been proven to be effective against HeLa tumor cells.

  17. 5-Fluorouracil Encapsulated Chitosan Nanoparticles for pH-Stimulated Drug Delivery: Evaluation of Controlled Release Kinetics

    Directory of Open Access Journals (Sweden)

    R. Seda Tığlı Aydın

    2012-01-01

    Full Text Available Nanoparticles consisting of human therapeutic drugs are suggested as a promising strategy for targeted and localized drug delivery to tumor cells. In this study, 5-fluorouracil (5-FU encapsulated chitosan nanoparticles were prepared in order to investigate potentials of localized drug delivery for tumor environment due to pH sensitivity of chitosan nanoparticles. Optimization of chitosan and 5-FU encapsulated nanoparticles production revealed 148.8±1.1 nm and 243.1±17.9 nm particle size diameters with narrow size distributions, which are confirmed by scanning electron microscope (SEM images. The challenge was to investigate drug delivery of 5-FU encapsulated chitosan nanoparticles due to varied pH changes. To achieve this objective, pH sensitivity of prepared chitosan nanoparticle was evaluated and results showed a significant swelling response for pH 5 with particle diameter of ∼450 nm. In vitro release studies indicated a controlled and sustained release of 5-FU from chitosan nanoparticles with the release amounts of 29.1–60.8% due to varied pH environments after 408 h of the incubation period. pH sensitivity is confirmed by mathematical modeling of release kinetics since chitosan nanoparticles showed stimuli-induced release. Results suggested that 5-FU encapsulated chitosan nanoparticles can be launched as pH-responsive smart drug delivery agents for possible applications of cancer treatments.

  18. Fabrication of supramolecular hydrogels for drug delivery and stem cell encapsulation.

    Science.gov (United States)

    Wu, De-Qun; Wang, Tao; Lu, Bo; Xu, Xiao-Ding; Cheng, Si-Xue; Jiang, Xue-Jun; Zhang, Xian-Zheng; Zhuo, Ren-Xi

    2008-09-16

    Supramolecular hydrogels self-assembled by alpha-cyclodextrin and methoxypolyethylene glycol-poly(caprolactone)-(dodecanedioic acid)-poly(caprolactone)-methoxypolyethylene glycol (MPEG-PCL-MPEG) triblock polymers were prepared and characterized in vitro and in vivo. The sustained release of dextran-fluorescein isothiocyanate (FITC) from the hydrogels lasted for more than 1 month, which indicated that the hydrogels were promising for controlled drug delivery. ECV304 cells and marrow mesenchymal stem cells (MSC) were encapsulated and cultured in the hydrogels, during which the morphologies of the cells could be kept. The in vitro cell viability studies and the in vivo histological studies demonstrated that the hydrogels were non-cytotoxic and biocompatible, which indicated that the hydrogels prepared were promising candidates as injectable scaffolds for tissue engineering applications.

  19. STUDY OF THE PROLONGED RELEASE OF A DRUG FROM ENCAPSULATED GRANULES PREPARED WITH BEESWAX

    Directory of Open Access Journals (Sweden)

    N. A. Elechi* and H. C. Mital

    2012-06-01

    Full Text Available The in vitro dissolution studies of encapsulated sodium salicylate granules coated with beeswax is presented. The factors investigated were the effects of concentration, presence of a hydrophilic fatty material, polyethylene glycol 6000 (PEG 6000, and technique (pan-coating, fusion and granulation on the sustained release of drug when coated with beeswax. Comparison of release rates was based on the use of a parameter, t70% (time for 70% of drug to be released. The greater the concentration of beeswax, ranging from 13.04 to 28.75%, the more prolonged the release. The presence of PEG 6000 at a concentration of 1:9 beeswax in the coating fluid significantly (p<0.05 increased the release rate, and at a concentration of 1:1 nullified the sustained release effect of beeswax. The t70% for the fusion, granulated and pan-coated batches were in the increasing order of 25min., 1hr.35min. and 2hr.45min, respectively.

  20. Encapsulation of anticancer drug and magnetic particles in biodegradable polymer nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Koneracka, M; Zavisova, V; Tomasovicova, N; Kopcansky, P; Timko, M; JurIkova, A; Csach, K; Kavecansky, V; Lancz, G [Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, Kosice (Slovakia); Muckova, M [Hameln rds a.s., Horna 36, Modra (Slovakia)], E-mail: konerack@saske.sk

    2008-05-21

    In this study, we have prepared PLGA (poly-D,L-lactide-co-glycolide) nanospheres loaded with biocompatible magnetic fluid and anticancer drug taxol by a modified nanoprecipitation technique and investigated their magnetic properties. A magnetic fluid, MF-PEG, with a biocompatible layer of polyethylene glycol (PEG), was chosen as a magnetic carrier. The PLGA, whose copolymer ratio of D,L-lactide to glycolide is 85:15, was utilized as a capsulation material. Taxol, as an important anticancer drug, was chosen for its significant role against a wide range of tumours. The morphology and particle size distributions of the prepared nanospheres were investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) and showed a spherical shape of prepared nanospheres with size 250 nm. Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetry (TGA) analysis confirmed incorporation of magnetic particles and taxol into the PLGA polymer. The results showed good encapsulation with magnetite content 21.5 wt% and taxol 0.5 wt%. Magnetic properties of magnetic fluids and taxol within the PLGA polymer matrix were investigated by SQUID magnetometry from 4.2 to 300 K. The SQUID measurements showed superparamagnetism of prepared nanospheres with a blocking temperature of 160 K and saturation magnetization 1.4 mT.

  1. Production of Inhalable Submicrometer Aerosols from Conventional Mesh Nebulizers for Improved Respiratory Drug Delivery.

    Science.gov (United States)

    Longest, P Worth; Spence, Benjamin M; Holbrook, Landon T; Mossi, Karla M; Son, Yoen-Ju; Hindle, Michael

    2012-09-01

    Submicrometer and nanoparticle aerosols may significantly improve the delivery efficiency, dissolution characteristics, and bioavailability of inhaled pharmaceuticals. The objective of this study was to explore the formation of submicrometer and nanometer aerosols from mesh nebulizers suitable for respiratory drug delivery using experiments and computational fluid dynamics (CFD) modeling. Mesh nebulizers were coupled with add-on devices to promote aerosol drying and the formation of submicrometer particles, as well as to control the inhaled aerosol temperature and relative humidity. Cascade impaction experiments were used to determine the initial mass median aerodynamic diameters of 0.1% albuterol aerosols produced by the AeroNeb commercial (4.69 μm) and lab (3.90 μm) nebulizers and to validate the CFD model in terms of droplet evaporation. Through an appropriate selection of flow rates, nebulizers, and model drug concentrations, submicrometer and nanometer aerosols could be formed with the three devices considered. Based on CFD simulations, a wire heated design was shown to overheat the airstream producing unsafe conditions for inhalation if the aerosol was not uniformly distributed in the tube cross-section or if the nebulizer stopped producing droplets. In comparison, a counter-flow heated design provided sufficient thermal energy to produce submicrometer particles, but also automatically limited the maximum aerosol outlet temperature based on the physics of heat transfer. With the counter-flow design, submicrometer aerosols were produced at flow rates of 5, 15, and 30 LPM, which may be suitable for various forms of oral and nasal aerosol delivery. Thermodynamic conditions of the aerosol stream exiting the counter-flow design were found be in a range of 21-45 °C with relative humidity greater than 40% in some cases, which was considered safe for direct inhalation and advantageous for condensational growth delivery.

  2. Spectral, thermal, and molecular modeling studies on the encapsulation of selected sulfonamide drugs in β-cyclodextrin nano-cavity.

    Science.gov (United States)

    Bani-Yaseen, Abdulilah Dawoud; Mo'ala, Abeer

    2014-10-15

    In the present work the inclusion complexation of three sulfonamide (SA) drugs, namely sulfisoxazole (SSX), sulfamethizole (SMZ), and Sulfamethazine (STM) with β-cyclodextrin (β-CD) has been investigated using UV-Vis spectroscopy, DSC, (1)H NMR spectroscopy, and molecular modeling methods. The binding constant (Kb) of SA:β-CD inclusion complexation was determined via applying the modified form of Benesi-Hildebrand equation employing the changes in absorbance at λmax. Obtained results revealed that SA drugs form 1:1 inclusion complex with β-CD with Kb of 650, 1532, 714M(-1) at 25°C for SSX, SMZ, and STM, respectively. The UV-Vis absorption spectra displayed solvatochromic behavior of bathochromic shift with decreasing solvent polarity that in turn is good agreement with their behavior in the presence of β-CD in terms of environment polarity dependency. The inclusion complex formation between β-CD and tested SA drugs in liquid and solid states was confirmed by (1)H NMR and DSC, respectively. Using semi-empirical quantum chemistry methods at PM3 theoretical level, inclusion complexes' structures as well as energetic and thermodynamic parameters of encapsulation were elucidated. Obtained results revealed that the encapsulation is favorably energetic and enthalpic in nature with the inclusion of the aniline moiety through the wide rim side of β-CD nano-cavity. Further, molecular modeling revealed that β-CD encapsulation of SA drugs reduced their (EHOMO-ELUMO) gap.

  3. Cationic vesicles based on biocompatible diacyl glycerol-arginine surfactants: physicochemical properties, antimicrobial activity, encapsulation efficiency and drug release.

    Science.gov (United States)

    Tavano, L; Pinazo, A; Abo-Riya, M; Infante, M R; Manresa, M A; Muzzalupo, R; Pérez, L

    2014-08-01

    Physicochemical characteristics of cationic vesicular systems prepared from biocompatible diacyl glycerol-arginine surfactants are investigated. These systems form stable cationic vesicles by themselves and the average diameter of the vesicles decreases as the alkyl chain length of the surfactant increases. The addition of DPPC also modifies the physicochemical properties of these vesicles. Among the drugs these cationic formulations can encapsulate, we have considered Ciprofloxacin and 5-Fluorouracil (5-FU). We show that the percentage of encapsulated drug depends on both the physicochemical properties of the carrier and the type of drug. The capacity of these systems to carry different molecules was evaluated performing in vitro drug release studies. Finally, the antimicrobial activity of empty and Ciprofloxacin-loaded vesicles against Gram-positive and Gram-negative bacteria has been determined. Three bacteria were tested: Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. The in vitro drug release from all formulations was effectively delayed. Empty cationic vesicles showed antimicrobial activity and Ciprofloxacin-loaded vesicles showed similar or higher antimicrobial activity than the free drug solution. These results suggest that our formulations represent a great innovation in the pharmaceutical field, due to their dual pharmacological function: one related to the nature of the vehiculated drug and the other related to the innate antibacterial properties of the surfactant-based carriers.

  4. New generation of β-cyclodextrin-chitosan nanoparticles encapsulated quantum dots loaded with anticancer drug for tumor-target drug delivery and imaging of cancer cells

    Science.gov (United States)

    Shu, Chang; Li, Ruixin; Guo, Jin; Ding, Li; Zhong, Wenying

    2013-12-01

    The objective of this study was to report the drug delivery system that can integrate the functional building blocks for optical pH-sensing, cancer cell imaging and controlled drug release into a single nanoparticle. The CD/SAHA-QDs-CS/FA nanoparticles were prepared by in-situ immobilization of ZnSe/ZnS quantum dots (QDs) in β-cyclodextrin (CD) and chitosan (CS) polymer loaded with suberoylanilide hydroxamic acid (SAHA). Synthetic CD/SAHA-QDs-CS/FA nanoparticles were approximately 100 nm in size and with blue fluorescence. The drug encapsulation efficiency of nanoparticles was 22.36 % and the encapsulated drug was released via a controlled release mechanism after a 9 h plateau was reached. The efficiency of the drug release in tumor microenvironments (pH 5.3 buffer solutions) was higher than that in physiological pH 7.4. In vitro cytotoxicity assay results showed that the blank nanoparticles had no cytotoxicity and therefore can be used as the fluorescence tracer, and the SAHA-encapsulated nanoparticles expressed an anticancer effect. Confocal microscopy and in vivo imaging studies showed that the developed nanoparticles had cytotoxicity in resistant cancer cells and preferentially accumulated in tumors. CD/SAHA-QDs-CS/FA nanoparticles with excellent long-term optical properties have great prospects for the development of targeting tracers and anti-tumor biomedical research.

  5. Shea butter solid nanoparticles for curcumin encapsulation: Influence of nanoparticles size on drug loading

    OpenAIRE

    Hajj Ali, Hassan; Michaux, Florentin; Bouelet Ntsama, Isabelle Sandrine; Durand, Pierrick; Jasniewski, Jordane; Linder, Michel

    2015-01-01

    International audience; In the present work, shea butter solid lipid nanoparticles (SLN) were prepared by sonication using nonionic surfactants as stabilizers without organic solvent. The mixture design methodology enabled to control particles size from 50?nm to more than 1?µm according to the mixture composition. Then, curcumin, a natural polyphenol, has been encapsulated in nanoparticles with a wide range of diameters (50–230?nm) and the encapsulation efficiency has been related to the part...

  6. In vivo-in vitro correlations: predicting pulmonary drug deposition from pharmaceutical aerosols.

    Science.gov (United States)

    Byron, Peter R; Hindle, Michael; Lange, Carlos F; Longest, P Worth; McRobbie, Donald; Oldham, Michael J; Olsson, Bo; Thiel, Charles G; Wachtel, Herbert; Finlay, Warren H

    2010-12-01

    In order to answer the question "what research remains to be done?" we review the current state of the art in pharmaceutical aerosol deposition modeling and explore possible in vivo- in vitro correlations (IVIVC) linking drug deposition in the human lung to predictions made using in vitro physical airway models and in silico computer models. The use of physical replicas of portions of the respiratory tract is considered, alongside the advantages and disadvantages of the different imaging methods used to obtain their dimensions. The use of airway replicas to determine drug deposition in vitro is discussed and compared with the predictions from different empirical curve fits to long-standing in vivo deposition data for monodisperse aerosols. The use of improved computational models and three-dimensional computational fluid dynamics (CFD) to predict aerosol deposition within the respiratory tract is examined. CFD's ability to predict both drug deposition from pharmaceutical aerosol sprays and powder behavior in dry powder inhalers is examined; both were highlighted as important areas for future research. Although the authors note the abilities of current in vitro and in silico methods to predict in vivo data, a number of limitations remain. These include our present inability to either image or replicate all but the most proximal airways in sufficient spatial and temporal detail to allow full capture of the fluid and aerosol mechanics in these regions. In addition, the highly complex microscale behavior of aerosols within inhalers and the respiratory tract places extreme computational demands on in silico methods. When the complexity of variations in respiratory tract geometry is associated with additional factors such as breathing pattern, age, disease state, postural position, and patient-device interaction are all considered, it is clear that further research is required before the prediction of all aspects of inhaled pharmaceutical aerosol deposition is possible.

  7. Folic acid-targeted disulfide-based cross-linking micelle for enhanced drug encapsulation stability and site-specific drug delivery against tumors

    Directory of Open Access Journals (Sweden)

    Zhang Y

    2016-03-01

    Full Text Available Yumin Zhang,1,* Junhui Zhou,2,* Cuihong Yang,1 Weiwei Wang,3 Liping Chu,1 Fan Huang,1 Qiang Liu,1 Liandong Deng,2 Deling Kong,3 Jianfeng Liu,1 Jinjian Liu1 1Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, 2Department of Polymer Science and Technology, School of Chemical Engineering and Technology, Tianjin University, 3Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Science and Peking Union Medical College, Tianjin, People’s Republic of China *These authors contributed equally in this work Abstract: Although the shortcomings of small molecular antitumor drugs were efficiently improved by being entrapped into nanosized vehicles, premature drug release and insufficient tumor targeting demand innovative approaches that boost the stability and tumor responsiveness of drug-loaded nanocarriers. Here, we show the use of the core cross-linking method to generate a micelle with enhanced drug encapsulation ability and sensitivity of drug release in tumor. This kind of micelle could increase curcumin (Cur delivery to HeLa cells in vitro and improve tumor accumulation in vivo. We designed and synthesized the core cross-linked micelle (CCM with polyethylene glycol and folic acid-polyethylene glycol as the hydrophilic units, pyridyldisulfide as the cross-linkable and hydrophobic unit, and disulfide bond as the cross-linker. CCM showed spherical shape with a diameter of 91.2 nm by the characterization of dynamic light scattering and transmission electron microscope. Attributed to the core cross-linking, drug-loaded CCM displayed higher Nile Red or Cur-encapsulated stability and better sensitivity to glutathione than noncross-linked micelle (NCM. Cellular uptake and in vitro antitumor studies proved the enhanced endocytosis and better cytotoxicity of CCM-Cur against

  8. 5-Fluorouracil-lipid conjugate: potential candidate for drug delivery through encapsulation in hydrophobic polyester-based nanoparticles.

    Science.gov (United States)

    Ashwanikumar, N; Kumar, Nisha Asok; Nair, S Asha; Kumar, G S Vinod

    2014-11-01

    The encapsulation of 5-fluorouracil (5-FU) in hydrophobic polymeric materials is made feasible by a lipid-based prodrug approach. A lipid-5-FU conjugate of 5-FU with palmitic acid was synthesized in two-step process. A synthesized dipalmitoyl derivative (5-FUDIPAL) was characterized using Fourier transform infrared spectroscopy and (1)H-nuclear magnetic resonance. The 5-FUDIPAL was encapsulated in polyester-based polymers by the double emulsion-solvent evaporation method. The nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy and dynamic light scattering. The thermal stability was assessed by differential scanning calorimetry data. In vitro release kinetics measurements of the drug from nanoparticles showed the controlled release pattern over a period of time. Cytotoxicity measurements by MTT assay confirmed that dipalmitoyl derivative in nano formulation successfully inhibited the cell growth. Thus the combined physical and biological evaluation of the different polyester-based nanoparticle containing the modified drug showed a facile approach to delivering 5-FU to the tumour site with enhanced efficacy.

  9. Copper ion-mediated liposomal encapsulation of mitoxantrone: the role of anions in drug loading, retention and release.

    Science.gov (United States)

    Li, Chunlei; Cui, Jingxia; Li, Yingui; Wang, Caixia; Li, Yanhui; Zhang, Lan; Zhang, Li; Guo, Wenmin; Wang, Jinxu; Zhang, Hongwu; Hao, Yanli; Wang, Yongli

    2008-08-01

    Besides pH gradient, other transmembrane gradients such as metal ion gradient could be also employed to load drugs into liposomes. In pH gradient method, anions have an important role since they could form specific aggregates with drugs, and then affect drug release kinetics from vesicles. To explore the role of anions in metal ion gradient method, copper ion-mediated mitoxantrone (MIT) loading was investigated systematically. When empty liposomes exhibiting a transmembrane copper ion gradient (300 mM) were mixed with MIT in a molar ratio of 0.2:1, after 5 min incubation at 60 degrees C, >95% MIT could be loaded into vesicles and the encapsulation was stable, regardless of the kinds of anions and initial intraliposomal pH values. The encapsulation ratio decreased with increased MIT/lipid molar ratio. But even when the molar ratio increased to 0.4, >90% encapsulation could still be achieved. In the presence of nigericin and ammonium, the drug loading profiles were affected to different degree with respect to both drug loading rate and encapsulation ratio. Relative to CuSO(4)-containing systems, CuCl(2) mediated MIT loading was unstable. Both nigericin and ammonium could alter the absorption spectra of liposomal MITs loaded with CuSO(4) gradient. In vitro release studies were performed in glucose/histidine buffer and in 50% human plasma using a dialysis method. In both of release media, CuCl(2)-containing vesicles displayed rapid release kinetics in comparison with CuSO(4) systems; and during the experiment period, MIT was lost from the vesicles continuously. When the formulations were injected into BDF1 mice at a dose of 4 mg/kg, all the liposomal formulations exhibited enhanced blood circulation time, with half-life values of 6.8-7.2h, significantly compared to the rapid clearance of free-MIT. In L1210 ascitic model, CuCl(2) formulation was more therapeutically active than CuSO(4) formulation. At a dose of 6 mg/kg, the treatment with CuCl(2) formulation resulted in

  10. Evaluation of Aerosol Delivery of Nanosuspension for Pre-clinical Pulmonary Drug Delivery

    Directory of Open Access Journals (Sweden)

    Chiang Po-Chang

    2009-01-01

    Full Text Available Abstract Asthma and chronic obstructive pulmonary disease (COPD are pulmonary diseases that are characterized by inflammatory cell infiltration, cytokine production, and airway hyper-reactivity. Most of the effector cells responsible for these pathologies reside in the lungs. One of the most direct ways to deliver drugs to the target cells is via the trachea. In a pre-clinical setting, this can be achieved via intratracheal (IT, intranasal (IN, or aerosol delivery in the desired animal model. In this study, we pioneered the aerosol delivery of a nanosuspension formulation in a rodent model. The efficiency of different dosing techniques and formulations to target the lungs were compared, and fluticasone was used as the model compound. For the aerosol particle size determination, a ten-stage cascade impactor was used. The mass median aerodynamic diameter (MMAD was calculated based on the percent cumulative accumulation at each stage. Formulations with different particle size of fluticasone were made for evaluation. The compatibility of regular fluticasone suspension and nanosuspension for aerosol delivery was also investigated. The in vivo studies were conducted on mice with optimized setting. It was found that the aerosol delivery of fluticasone with nanosuspension was as efficient as intranasal (IN dosing, and was able to achieve dose dependent lung deposition.

  11. Evaluation of Aerosol Delivery of Nanosuspension for Pre-clinical Pulmonary Drug Delivery

    Science.gov (United States)

    Chiang, Po-Chang; Alsup, Jason W.; Lai, Yurong; Hu, Yiding; Heyde, Bruce R.; Tung, David

    2009-03-01

    Asthma and chronic obstructive pulmonary disease (COPD) are pulmonary diseases that are characterized by inflammatory cell infiltration, cytokine production, and airway hyper-reactivity. Most of the effector cells responsible for these pathologies reside in the lungs. One of the most direct ways to deliver drugs to the target cells is via the trachea. In a pre-clinical setting, this can be achieved via intratracheal (IT), intranasal (IN), or aerosol delivery in the desired animal model. In this study, we pioneered the aerosol delivery of a nanosuspension formulation in a rodent model. The efficiency of different dosing techniques and formulations to target the lungs were compared, and fluticasone was used as the model compound. For the aerosol particle size determination, a ten-stage cascade impactor was used. The mass median aerodynamic diameter (MMAD) was calculated based on the percent cumulative accumulation at each stage. Formulations with different particle size of fluticasone were made for evaluation. The compatibility of regular fluticasone suspension and nanosuspension for aerosol delivery was also investigated. The in vivo studies were conducted on mice with optimized setting. It was found that the aerosol delivery of fluticasone with nanosuspension was as efficient as intranasal (IN) dosing, and was able to achieve dose dependent lung deposition.

  12. Development of novel encapsulated formulations using albumin-chitosan as a polymer matrix for ocular drug delivery

    Science.gov (United States)

    Addo, Richard Tettey

    Designing formulations for ophthalmic drug delivery is one of the most challenging endeavors facing the pharmaceutical scientist due to the unique anatomy, physiology, and biochemistry of the eye. Current treatment protocols for administration of drugs in eye diseases are primarily solution formulations, gels or ointments. However, these modes of delivery have several drawbacks such as short duration of exposure, need for repeated administrations and non-specific toxicity. We hypothesize that development of ocular drugs in microparticles will overcome the deficiencies of the current modalities of treatment. We based the hypothesis on the preliminary studies conducted with encapsulated tetracaine, an anesthetic used for surgical purposes and atropine, a medication used for several ophthalmic indications including mydriatic and cycloplegic effects. However, atropine is well absorbed into the systemic circulation and has been reported to exert severe systemic side effects after ocular administration (Hoefnagel D. 1961, Morton H. G. 1939 and Lang J. C. 1995) and may lead to serious side effects including death in extreme cases with pediatric use. Based on these observations, the focus of this dissertation is to formulate microparticulate drug carrier for treatment of various conditions of the eye. Purpose: To prepare, characterize, study the in vitro and in vivo interaction of albumin-chitosan microparticles (BSA-CSN MS), a novel particulate drug carrier for ocular drug delivery. Method: Microparticle formulations were prepared by method of spray drying. The percentage drug loading and efficiency were assessed using USP (I) dissolution apparatus. Using Malvern Zeta-Sizer, we determined size and surface charge of the fabrication. Surface morphology of the microparticles was examined using Scanning Electron Microscopy. Microparticles were characterized in terms of thermal properties using Differential Scanning Calorimetry. Human corneal epithelial cells (HCET-1) were

  13. Poly(ethylene glycol)-poly(lactic-co-glycolic acid) core-shell microspheres with enhanced controllability of drug encapsulation and release rate.

    Science.gov (United States)

    Cha, Chaenyung; Jeong, Jae Hyun; Kong, Hyunjoon

    2015-01-01

    Poly(lactic-co-glycolic acid) (PLGA) microspheres have been widely used as drug carriers for minimally invasive, local, and sustained drug delivery. However, their use is often plagued by limited controllability of encapsulation efficiency, initial burst, and release rate of drug molecules, which cause unsatisfactory outcomes and several side effects including inflammation. This study presents a new strategy of tuning the encapsulation efficiency and the release rate of protein drugs from a PLGA microsphere by filling the hollow core of the microsphere with poly(ethylene glycol) (PEG) hydrogels of varying cross-linking density. The PEG gel cores were prepared by inducing in situ cross-linking reactions of PEG monoacrylate solution within the PLGA microspheres. The resulting PEG-PLGA core-shell microspheres exhibited (1) increased encapsulation efficiency, (2) decreased initial burst, and (3) a more sustained release of protein drugs, as the cross-linking density of the PEG gel core was increased. In addition, implantation of PEG-PLGA core-shell microspheres encapsulated with vascular endothelial growth factor (VEGF) onto a chicken chorioallantoic membrane resulted in a significant increase in the number of new blood vessels at an implantation site, while minimizing inflammation. Overall, this strategy of introducing PEG gel into PLGA microspheres will be highly useful in tuning release rates and ultimately in improving the therapeutic efficacy of a wide array of protein drugs.

  14. Effects of Formulation Variables on the Particle Size and Drug Encapsulation of Imatinib-Loaded Solid Lipid Nanoparticles.

    Science.gov (United States)

    Gupta, Biki; Poudel, Bijay Kumar; Pathak, Shiva; Tak, Jin Wook; Lee, Hee Hyun; Jeong, Jee-Heon; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

    2016-06-01

    Imatinib (IMT), an anticancer agent, inhibits receptor tyrosine kinases and is characterized by poor aqueous solubility, extensive first-pass metabolism, and rapid clearance. The aims of the current study are to prepare imatinib-loaded solid lipid nanoparticles (IMT-SLN) and study the effects of associated formulation variables on particle size and drug encapsulation on IMT-SLN using an experimental design. IMT-SLN was optimized by use of a "combo" approach involving Plackett-Burman design (PBD) and Box-Behnken design (BBD). PBD screening resulted in the determination of organic-to-aqueous phase ratio (O/A), drug-to-lipid ratio (D/L), and amount of Tween® 20 (Tw20) as three significant variables for particle size (S z), drug loading (DL), and encapsulation efficiency (EE) of IMT-SLN, which were used for optimization by BBD, yielding an optimized criteria of O/A = 0.04, D/L = 0.03, and Tw20 = 2.50% w/v. The optimized IMT-SLN exhibited monodispersed particles with a size range of 69.0 ± 0.9 nm, ζ-potential of -24.2 ± 1.2 mV, and DL and EE of 2.9 ± 0.1 and 97.6 ± 0.1% w/w, respectively. Results of in vitro release study showed a sustained release pattern, presumably by diffusion and erosion, with a higher release rate at pH 5.0, compared to pH 7.4. In conclusion, use of the combo experimental design approach enabled clear understanding of the effects of various formulation variables on IMT-SLN and aided in the preparation of a system which exhibited desirable physicochemical and release characteristics.

  15. Photoclick Hydrogels Prepared from Functionalized Cyclodextrin and Poly(ethylene glycol) for Drug Delivery and in Situ Cell Encapsulation.

    Science.gov (United States)

    Shih, Han; Lin, Chien-Chi

    2015-07-13

    Polymers or hydrogels containing modified cyclodextrin (CD) are highly useful in drug delivery applications, as CD is a cytocompatible amphiphilic molecule that can complex with a variety of hydrophobic drugs. Here, we designed modular photoclick thiol-ene hydrogels from derivatives of βCD and poly(ethylene glycol) (PEG), including βCD-allylether (βCD-AE), βCD-thiol (βCD-SH), PEG-thiol (PEGSH), and PEG-norbornene (PEGNB). Two types of CD-PEG hybrid hydrogels were prepared using radical-mediated thiol-ene photoclick reactions. Specifically, thiol-allylether hydrogels were formed by reacting multiarm PEGSH and βCD-AE, and thiol-norbornene hydrogels were formed by cross-linking βCD-SH and multiarm PEGNB. We characterized the properties of these two types of thiol-ene hydrogels, including gelation kinetics, gel fractions, hydrolytic stability, and cytocompatibility. Compared with thiol-allylether hydrogels, thiol-norbornene photoclick reaction formed hydrogels with faster gelation kinetics at equivalent macromer contents. Using curcumin, an anti-inflammatory and anticancer hydrophobic molecule, we demonstrated that CD-cross-linked PEG-based hydrogels, when compared with pure PEG-based hydrogels, afforded higher drug loading efficiency and prolonged delivery in vitro. Cytocompatibility of these CD-cross-linked hydrogels were evaluated by in situ encapsulation of radical sensitive pancreatic MIN6 β-cells. All formulations and cross-linking conditions tested were cytocompatible for cell encapsulation. Furthermore, hydrogels cross-linked by βCD-SH showed enhanced cell proliferation and insulin secretion as compared to gels cross-linked by either dithiothreitol (DTT) or βCD-AE, suggesting the profound impact of both macromer compositions and gelation chemistry on cell fate in chemically cross-linked hydrogels.

  16. Hyperthermia-Induced Drug Delivery from Thermosensitive Liposomes Encapsulated in an Injectable Hydrogel for Local Chemotherapy

    NARCIS (Netherlands)

    López-Noriega, Adolfo; Hastings, Conn L.; Ozbakir, Burcin; O'Donnell, Kathleen E.; O'Brien, Fergal J.; Storm, Gert; Hennink, Wim E.; Duffy, Garry P.; Ruiz-Hernåndez, Eduardo

    2014-01-01

    A novel drug delivery system, enabling an in situ, thermally triggered drug release is described, consisting of an injectable thermoresponsive chitosan hydrogel containing doxorubicin-loaded thermosensitive liposomes. The design, fabrication, characterization, and an assessment of in vitro bioactivi

  17. Modeling of drug and drug-encapsulated nanoparticle transport in patient-specific coronary artery walls to treat vulnerable plaques

    KAUST Repository

    Hossain, Shaolie S.

    2010-01-01

    The main objective of this work is to develop computational tools to support the design of a catheter-based local drug delivery system that uses nanoparticles as drug carriers in order to treat vulnerable plaques and diffuse atherosclerotic disease.

  18. Synthesis of Poly(N-isopropylacrylamide) Microcapsules for Drug Delivery Applications via UV Aerosol Photopolymerization

    Science.gov (United States)

    Roberson, Nicole; Denmark, Daniel; Witanachchi, Sarath

    Hybrid drug delivery systems composed of thermoresponsive polymers and magnetic nanoparticles have been developed using chemical methods to deliver controlled amounts of a biotherapeutic to target tissue. These methods can be expensive, time intensive, and produce impure composites due to the use of surfactants during polymer synthesis. In this study, UV aerosol photopolymerization is used to synthesize N-isoplopylacrylamide (NIPAM) monomers, N,N-methylenebisacrylamide (MBA) crosslinker, and irgacure 2959 photoinitiator into the transporting microcapsule for drug delivery. The method of UV aerosol photopolymerization allows for the continuous, cost effective, and time efficient synthesis of a high concentration of pure polymers in a short amount of time; toxic surfactants are not necessary. Optimal NIPAM monomer, MBA crosslinker, and irgacure 2959 photoinitiator concentrations were tested and analyzed to synthesize a microcapsule with optimal conditions for controlled drug delivery. Scanning Electron Microscope (SEM) imaging reveals that synthesis of polymer microcapsules of about 30 micrometers in size is effective through UV aerosol photopolymerization. Findings will contribute greatly to the field of emergency medicine. This work was supported by the United States Army (Grant No. W81XWH1020101/3349).

  19. Microfluidics-assisted engineering of polymeric microcapsules with high encapsulation efficiency for protein drug delivery.

    Science.gov (United States)

    Pessi, Jenni; Santos, Hélder A; Miroshnyk, Inna; JoukoYliruusi; Weitz, David A; Mirza, Sabiruddin

    2014-09-10

    In this study, microfluidic technology was employed to develop protein formulations. The microcapsules were produced with a biphasic flow to create water-oil-water (W/O/W) double emulsion droplets with ultrathin shells. Optimized microcapsule formulations containing 1% (w/w) bovine serum albumin (BSA) in the inner phase were prepared with poly(vinyl alcohol), polycaprolactone and polyethylene glycol. All the particles were found to be intact and with a particle size of 23-47 μm. Furthermore, the particles were monodisperse, non-porous and stable up to 4 weeks. The encapsulation efficiency of BSA in the microcapsules was 84%. The microcapsules released 30% of their content within 168 h. This study demonstrates that microfluidics is a powerful technique for engineering formulations for therapeutic proteins.

  20. Comparison of in vitro dialysis release methods of loperamide-encapsulated liposomal gel for topical drug delivery

    Directory of Open Access Journals (Sweden)

    Hua S

    2014-01-01

    Full Text Available Susan HuaThe School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, AustraliaBackground: The purpose of this study was to determine the most appropriate dialysis equilibrium method to assess liposomal gel formulations containing hydrophobic drugs, to give the most accurate indication of drug release.Methods: Loperamide hydrochloride-encapsulated liposomes, composed of L-α-phosphatidylcholine and cholesterol (molar ratio of 2:1, were prepared according to the method of dried lipid film hydration. The liposomes were incorporated into a carbopol gel (0.5%, weight/weight. The release of the drug from the nanoparticles was assessed using a number of variations of the dialysis technique, taking into account solubility parameters and formulation. Method 1 (below saturation point and Method 2 (above saturation point used a dilution method to evaluate how drug concentration and solubility affects the in vitro drug-release profile of loperamide hydrochloride, while Methods 3 (below saturation point and 4 (above saturation point evaluated how drug concentration and the gel base affect the release profile.Results: In Method 1, the liposomes showed a rapid release of just over 60% in the first 3 hours and then a slower, sustained release to just over 70% at 24 hours. Method 2 showed a gradual, sustained release profile with the liposomes with 55% release at 24 hours. In Method 3, the liposomes showed a rapid burst release of 98% at 2 hours. In Method 4, the liposomal gel had a rapid release of 60% within 3 hours and then a more gradual, sustained release with 86% release at 24 hours. The free drug suspension in Methods 2 and 4 showed a limited release across the dialysis membrane, in comparison to Methods 1 and 3, which showed a complete release in a timely manner.Conclusion: This study has demonstrated that the actual method used for equilibrium dialysis plays a significant role in determining the true characteristics of a

  1. Impedimetric toxicity assay in microfluidics using free and liposome-encapsulated anticancer drugs

    DEFF Research Database (Denmark)

    Caviglia, Claudia; Zor, Kinga; Montini, Lucia;

    2015-01-01

    In this work, we have developed a microfluidic cytotoxicity assay for a cell culture and detection platform, which enables both fluid handling and electrochemical/optical detection. The cytotoxic effect of anticancer drugs doxorubicin (DOX), oxaliplatin (OX) as well as OX-loaded liposomes......, developed for targeted drug delivery, was evaluated using real-time impedance monitoring. The time-dependent effect of DOX on HeLa cells was monitored and found to have a delayed onset of cytotoxicity in microfluidics compared with static culture conditions based on data obtained in our previous study......-dependent cytotoxic response of fibrosarcoma cells (HT1080) to free OX and OX-loaded liposomes was observed and attributed to incomplete degradation of the liposomes, which results in lower drug availability. The matrix metalloproteinase (MMP)-dependent release of OX from OX-loaded liposomes was also confirmed using...

  2. Montelukast-loaded nanostructured lipid carriers: part II pulmonary drug delivery and in vitro-in vivo aerosol performance.

    Science.gov (United States)

    Patil-Gadhe, Arpana; Kyadarkunte, Abhay; Patole, Milind; Pokharkar, Varsha

    2014-09-01

    The aim of the present study was to establish the potential of montelukast loaded nanostructured lipid carrier (MNLC) for pulmonary application. The formulated nanoparticles were evaluated in vitro for aerodynamic characterization and in vivo for pulmokinetics in Wistar rats. The in vitro cytotoxicity was performed on A549 cell line and compared with montelukast-aqueous solution. MNLC was prepared with montelukast (0.2%), Precirol ATO5 (solid lipid), and Capryol-90 (liquid lipid) in the ratio of 7:3 using melt-emulsification-homogenization method. dl-Pyrrolidonecarboxylic acid salt of l-cocyl arginine ethyl ester (CAE), a biodegradable surfactant in the concentration of 1% was used to stabilize the nanoparticles. The particle size and encapsulation efficiency (EE) were 184.6 ± 2.7 nm and >95%, respectively. MNLC-Dry powder for inhalation (DPI) was prepared by lyophilization using 3% mannitol as cryoprotectant and carrier. MNLC-DPI was evaluated for flow, crystallographic and thermal properties. Mass median diameters (MMD) and density for MNLC-DPI were found to be 15.1 ± 1.4 μm and 0.051 ± 0.002 g/cc, respectively. In vitro aerosol performance study indicated more than 95% of the emitted dose (ED) at both the flow rates studied. Mass median aerodynamic diameters (MMAD) of 3.24 ± 0.67 μm with 69.98 ± 1.9% fine particle fraction (FPF) were obtained at 30 L/min flow rate, whereas at 60 L/min MMAD and FPF were found to be 2.83 ± 0.46 μm and 90.22 ± 2.6%, respectively. In vitro cytotoxicity study on A549 cells revealed higher safety of MNLC than pure drug. The pulmonary pharmacokinetic study demonstrated improved bioavailability, longer residence of drug in the lung and targeting factor of 11.76 for MNLC as compared to montelukast-aqueous solution. Thus, the results of the study demonstrated the potential of montelukast lipidic nanoparticulate formulation to improve the efficacy with reduced toxicity leading to better performance of drug as MNLC-DPI for

  3. Nanohybrid based on antibiotic encapsulated layered double hydroxide as a drug delivery system.

    Science.gov (United States)

    Khan, Sher Bahadar; Alamry, Khalid A; Alyahyawi, Nedaa A; Asiri, Abdullah M; Arshad, Muhammad Nadeem; Marwani, Hadi M

    2015-02-01

    Nanohybrid of cefuroxime (CFO) with layered double hydroxide (LDH) has been prepared, and the rate of dissolution and bioavailability of CFO using nanohybrid as a drug delivery system has been broadly studied. The intercalation process was confirmed by X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The CFO contents were found to be 19.0 wt% in the nanohybrid. The release mechanism of CFO was investigated with respect to anion and pH of the dissolution media such as gastric, intestinal and blood simulated media. The effect of pH was evaluated on the release of CFO from nanohybrid, and the dissolution of CFO from the nanohybrid was found to be a slow process at pH 4.0, 6.8, and 7.4. Further the addition of Cl ion and PAM in release media did not affect the release rate of drug at pH 4.0 and 6.8, while at pH 7.4, Cl ion and PAM have significant role on the drug release. At pH 1.2, the release study shows that LDH dissolved in the acidic medium and CFO released in its molecular form. The release behavior suggests two mechanisms that are responsible for the release of CFO from nanohybrid: weathering (dependent on the pH) and ion exchange (highly dependent on the anions). Surface reactions mediated by solid weathering ruled the release in gastric fluid, whereas anion exchange determined CFO release in lysosomal, intestinal, and blood medium. In order to evaluate the drug release mechanism, the released data were fitted by mathematical models describing various kinetic.

  4. Visualized intravesical floating hydrogel encapsulating vaporized perfluoropentane for controlled drug release.

    Science.gov (United States)

    Zhu, Guanchen; Zhang, Yifan; Wang, Kaikai; Zhao, Xiaozhi; Lian, Huibo; Wang, Wei; Wang, Haoran; Wu, Jinhui; Hu, Yiqiao; Guo, Hongqian

    2016-10-01

    Intravesical drug delivery is the main strategy for the treatment of bladder disorders. To reduce the relief arising from frequent intravesical instillation, mucoadhesive hydrogel was used for the controlled release of the drug. However, the viscosity of mucoadhesive gel might cause severe urinary obstruction and bladder irritation. To solve all these problems, a floating hydrogel delivery system was developed using perfluoropentane (PFP) as the floating agent. After intravesical instillation of the floating hydrogel, the increased temperature in bladder vaporized PFP, resulting in the generation of microbubbles in the hydrogel. Then, it can float in urine to avoid the urinary obstruction and bladder irritation. In this study, systematic experiments were conducted to investigate the influences of PFP vaporization on the morphology and floating ability of hydrogels. The floating process is much milder and safer than other floating methods published before. In addition, PFP had been used as contrast agent, which affiliated the monitoring of gels during the operation. Therefore, this new drug delivery system addresses the problems of conventional intravesical instillation and is promising for clinic use.

  5. Control of encapsulation efficiency and drug loading in PLGA microsphere%PLGA微球载药量和包封率的影响因素及控制

    Institute of Scientific and Technical Information of China (English)

    孙美丽; 班俊峰; 黄思玉; 吕竹芬

    2011-01-01

    Poly( D,L-lactide-co-glycolide) (PLGA) has attracted much attention due to its good biodegradable and biocompatible properties. PLGA has been shown great clinical application of controlled drug delivery systems. Focusing on the low drug loading and encapsulation efficiency of PLGA microspheres, this article reviews the variables influencing the drug loading and encapsulation efficiency, which may have significant implications for the research on the drug loading and encapsulation efficiency.%PLGA是乳酸和羟基乙酸的共聚物,具有良好的生物相容性和生物可降解性,已经广泛应用于缓控释给药系统的研究.针对目前PLGA微球存在载药量和包封率低的问题,根据国内外文献,综述了影响PLGA微球载药量和包封率的因素,包括PLGA、药物、溶剂、添加剂等方面,为研究PLGA微球载药量和包封率提供思路.

  6. Encapsulation of nabumetone by means of -drug: ({beta}-cyclodextrin){sub 2}:polyvinylpyrrolidone ternary complex formation

    Energy Technology Data Exchange (ETDEWEB)

    Valero, Margarita [Departamento de Quimica Fisica, Facultad de Farmacia, Universidad de Salamanca, Salamanca (Spain)]. E-mail: mvalero@usal.es; Tejedor, Javier [Departamento de Quimica Fisica, Facultad de Farmacia, Universidad de Salamanca, Salamanca (Spain); Rodriguez, Licesio J. [Departamento de Quimica Fisica, Facultad de Farmacia, Universidad de Salamanca, Salamanca (Spain)

    2007-10-15

    The aim of the present study was to investigate the effect of the presence of the water-soluble polymer polyvinylpyrrolidone (PVP) MW=24,000 g/mol, on the complexing of the anti-inflammatory drug nabumetone, with {beta}-cyclodextrin ({beta}-CD). The data show that the polymer interacts with the free nabumetone and with the nabumetone:{beta}-CD inclusion complex, in both cases with a stoichiometry of 1:1. The interaction constants are 1.3x10{sup 4} M{sup -1} and 1.6x10{sup 4} M{sup -1}, respectively. The presence of PVP, changes the drug:cyclodextrin interaction, a nabumetone:({beta}-CD){sub 2}:PVP complex being formed. In addition, the presence of PVP, produces a strong increase in the global binding constant, {beta} {sub 2}=(22.12{+-}0.22)x10{sup 6} M{sup -2} at 1% PVP. In the ternary complex, the nabumetone is wrapped at both ends for the {beta}-CD. In this complex the polymer seems to act as a bridge between both {beta}-CD molecules that bind the nabumetone.

  7. Co-encapsulation of magnetic Fe3O4 nanoparticles and doxorubicin into biodegradable PLGA nanocarriers for intratumoral drug delivery

    Directory of Open Access Journals (Sweden)

    Jia Y

    2012-03-01

    Full Text Available Yanhui Jia1, Mei Yuan1, Huidong Yuan1, Xinglu Huang2, Xiang Sui1, Xuemei Cui1, Fangqiong Tang2, Jiang Peng1, Jiying Chen1, Shibi Lu1, Wenjing Xu1, Li Zhang1, Quanyi Guo11Institute of Orthopedics, General Hospital of the Chinese People's Liberation Army, Beijing, People's Republic of China; 2Laboratory of Controllable Preparation and Application of Nanomaterials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, People's Republic of ChinaAbstract: In this study, the authors constructed a novel PLGA [poly(D,L-lactic-co-glycolic acid]-based polymeric nanocarrier co-encapsulated with doxorubicin (DOX and magnetic Fe3O4 nanoparticles (MNPs using a single emulsion evaporation method. The DOX-MNPs showed high entrapment efficiency, and they supported a sustained and steady release of DOX. Moreover, the drug release was pH sensitive, with a faster release rate in an acidic environment than in a neutral environment. In vitro, the DOX-MNPs were easily internalized into murine Lewis lung carcinoma cells and they induced apoptosis. In vivo, the DOX-MNPs showed higher antitumor activity than free DOX solution. Furthermore, the antitumor activity of the DOX-MNPs was higher with than without an external magnetic field; they were also associated with smaller tumor volume and a lower metastases incidence rate. This work may provide a new modality for developing an effective drug delivery system.Keywords: antitumor activity, external magnetic field, intratumoral injection, apoptosis, Lewis lung carcinoma

  8. Synthesis of silica nanoparticles for encapsulation of oncology drugs with low water solubility: effect of processing parameters on structural evolution

    Science.gov (United States)

    Bürglová, Kristýna; Hlaváč, Jan; Bartlett, John R.

    2015-12-01

    Silica nanoparticles with tailored properties have been developed for a variety of biomedical applications, with particular emphasis on their use as carriers for the encapsulation and controlled release of bioactive species. Among the various strategies described, silica nanoparticles with uniform mesoporosity (MSN) prepared in aqueous solution at elevated temperatures using cetyltrimethylammonium bromide as a template have a range of desirable properties. However, the processing windows available to control the dimensions and other key properties of such nanoparticles prepared using fluoride salts as catalysts have not been elucidated, with mixed products containing gel fragments and non-uniform products obtained under many conditions. Here, we present a parametric study of the synthesis of MSN under fluoride-catalysed conditions using tetraethylorthosilicate as silica precursor. The processing conditions required to produce uniform nanoparticles with controlled dimensions are elucidated, together with the conditions under which dried powders can be re-dispersed in aqueous solution after long-term storage to regenerate unaggregated nanospheres with dimensions (as measured by dynamic light scattering) comparable to those measured via scanning electron microscopy analysis of the dried material. The ability to dry and store such powders for extended periods of time is an important requirement for the use of such materials in drug delivery applications. Preliminary results demonstrating the use of such MSNs as hosts for oncology drugs [substituted 3-hydroxyquinolinones ( 3-HQ)] with low water solubility (≪1 µg/g H2O) are presented, with loadings of several wt% demonstrated. The ability of the silica host to protect the 3-HQ from oxidative degradation during impregnation and release is discussed.

  9. Synthesis of silica nanoparticles for encapsulation of oncology drugs with low water solubility: effect of processing parameters on structural evolution

    Energy Technology Data Exchange (ETDEWEB)

    Bürglová, Kristýna; Hlaváč, Jan [Institute of Molecular and Translational Medicine, Palacký University Olomouc, Faculty of Medicine and Dentistry (Czech Republic); Bartlett, John R., E-mail: JBartlett@usc.edu.au [University of the Sunshine Coast, Faculty of Science, Health, Education and Engineering (Australia)

    2015-12-15

    Silica nanoparticles with tailored properties have been developed for a variety of biomedical applications, with particular emphasis on their use as carriers for the encapsulation and controlled release of bioactive species. Among the various strategies described, silica nanoparticles with uniform mesoporosity (MSN) prepared in aqueous solution at elevated temperatures using cetyltrimethylammonium bromide as a template have a range of desirable properties. However, the processing windows available to control the dimensions and other key properties of such nanoparticles prepared using fluoride salts as catalysts have not been elucidated, with mixed products containing gel fragments and non-uniform products obtained under many conditions. Here, we present a parametric study of the synthesis of MSN under fluoride-catalysed conditions using tetraethylorthosilicate as silica precursor. The processing conditions required to produce uniform nanoparticles with controlled dimensions are elucidated, together with the conditions under which dried powders can be re-dispersed in aqueous solution after long-term storage to regenerate unaggregated nanospheres with dimensions (as measured by dynamic light scattering) comparable to those measured via scanning electron microscopy analysis of the dried material. The ability to dry and store such powders for extended periods of time is an important requirement for the use of such materials in drug delivery applications. Preliminary results demonstrating the use of such MSNs as hosts for oncology drugs [substituted 3-hydroxyquinolinones (3-HQ)] with low water solubility (≪1 µg/g H{sub 2}O) are presented, with loadings of several wt% demonstrated. The ability of the silica host to protect the 3-HQ from oxidative degradation during impregnation and release is discussed.

  10. Encapsulation of cisplatin as an anti-cancer drug into boron-nitride and carbon nanotubes: Molecular simulation and free energy calculation

    Energy Technology Data Exchange (ETDEWEB)

    Roosta, Sara [Molecular Simulation Research Laboratory, Department of Chemistry, Iran University of Science & Technology, Tehran (Iran, Islamic Republic of); Hashemianzadeh, Seyed Majid, E-mail: hashemianzadeh@iust.ac.ir [Molecular Simulation Research Laboratory, Department of Chemistry, Iran University of Science & Technology, Tehran (Iran, Islamic Republic of); Ketabi, Sepideh, E-mail: sepidehketabi@yahoo.com [Department of Chemistry, East Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2016-10-01

    Encapsulation of cisplatin anticancer drug into the single walled (10, 0) carbon nanotube and (10, 0) boron-nitride nanotube was investigated by quantum mechanical calculations and Monte Carlo Simulation in aqueous solution. Solvation free energies and complexation free energies of the cisplatin@ carbon nanotube and cisplatin@ boron-nitride nanotube complexes was determined as well as radial distribution functions of entitled compounds. Solvation free energies of cisplatin@ carbon nanotube and cisplatin@ boron-nitride nanotube were − 4.128 kcal mol{sup −1} and − 2457.124 kcal mol{sup −1} respectively. The results showed that cisplatin@ boron-nitride nanotube was more soluble species in water. In addition electrostatic contribution of the interaction of boron- nitride nanotube complex and solvent was − 281.937 kcal mol{sup −1} which really more than Van der Waals and so the electrostatic interactions play a distinctive role in the solvation free energies of boron- nitride nanotube compounds. On the other hand electrostatic part of the interaction of carbon nanotube complex and solvent were almost the same as Van der Waals contribution. Complexation free energies were also computed to study the stability of related structures and the free energies were negative (− 374.082 and − 245.766 kcal mol{sup −1}) which confirmed encapsulation of drug into abovementioned nanotubes. However, boron-nitride nanotubes were more appropriate for encapsulation due to their larger solubility in aqueous solution. - Highlights: • Solubility of cisplatin@ boron-nitride nanotube is larger than cisplatin@ carbon nanotube. • Boron- nitride nanotube complexes have larger electrostatic contribution in solvation free energy. • Complexation free energies confirm encapsulation of drug into the nanotubes in aqueous solution. • Boron- nitride nanotubes are appropriate drug delivery systems compared with carbon nanotubes.

  11. Fabrication of a multifunctional nano-in-micro drug delivery platform by microfluidic templated encapsulation of porous silicon in polymer matrix.

    Science.gov (United States)

    Zhang, Hongbo; Liu, Dongfei; Shahbazi, Mohammad-Ali; Mäkilä, Ermei; Herranz-Blanco, Bárbara; Salonen, Jarno; Hirvonen, Jouni; Santos, Hélder A

    2014-07-01

    A multifunctional nano-in-micro drug delivery platform is developed by conjugating the porous silicon nanoparticles with mucoadhesive polymers and subsequent encapsulation into a pH-responsive polymer using microfluidics. The multistage platform shows monodisperse size distribution and pH-responsive payload release, and the released nanoparticles are mucoadhesive. Moreover, this platform is capable of simultaneously loading and releasing multidrugs with distinct properties.

  12. Ketoprofen encapsulated cucurbit[6]uril nanoparticles: a new exploration of macrocycles for drug delivery

    Science.gov (United States)

    Hoai, Nguyen To; Tuyen Thi Dao, Phuong; Phu, Quoc Nam; Dam Le, Duy; Nguyen, Tuan Anh; Nguyen, Tai Chi; Chien Dang, Mau

    2012-12-01

    The aim of this study is (i) to fabricate a nanoparticle formulation of ketoprofen (Keto) using a relatively new family of macrocycles as the carrier for drug delivery: cucurbit[6]uril (CB[6]), (ii) to evaluate its in vitro dissolution and (iii) to investigate its in vivo pharmaceutical property. The CB[6]-Keto nanoparticles were prepared by emulsion solvent evaporation method. Morphology and size of the successfully prepared nanoparticles were then confirmed using a transmission electron microscope and dynamic light scattering. It was shown that they are spherical with hydrodynamic diameter of 200-300 nm. The in vitro dissolution studies of CB[6]-Keto nanoparticles were conducted at pH 1.2 and 7.4. The results indicated that there is a significant increase in Keto concentration at pH 7.4 compared to pH 1.2. For the in vivo assessment, CB[6]-Keto nanoparticles and referential profenid were administered by oral gavages to rabbits. The results implied that CB[6]-Keto nanoparticles remarkably increased area under the curve compared to profenid.

  13. Phytosome and Liposome: The Beneficial Encapsulation Systems in Drug Delivery and Food Application

    Directory of Open Access Journals (Sweden)

    Nayyer Karimi

    2015-06-01

    Full Text Available Due to poor solubility in lipids, many of bioactive components (Nutraceutical materials show less bioactivity than optimal state in water solution. Phytosomes improve absorption and bioavailability of biomaterials. Liposomes, spherical shaped nanocarriers, were discovered in the 1960s by bangham. Due to their composition, variability and structural properties, liposomes and phytosomes are extremely versatile, leading to a large number of applications including pharmaceutical, cosmetics and food industrial fields. They are advanced forms of herbal formulations containing the bioactive phytoconstituents of herb extracts such as flavonoids, glycosides and terpenoids, which have good ability to transit from a hydrophilic environment into the lipid friendly environment of the outer cell membrane. They have better bioavailability and actions than the conventional herbal extracts containing dosage. Phytosome technology has increasing effect on the bioavailability of herbal extracts including ginkgo biloba, grape seed, green tea, milk thistle, ginseng, etc., and can be developed for various therapeutic uses or dietary supplements. Liposomes are composed of bilayer membranes, which are made of lipid molecules. They form when phospholipids are dispersed in aqueous media and exposed to high shear rates by using micro-fluidization or colloid mill. The mechanism for formation of liposomes is mainly the hydrophilic–hydrophobic interactions between phospholipids and water molecules. Here, we attempt to review the features of phytosomes and liposomes as well as their preparation methods and capacity in food and drug applications. Generally, it is believed that phytosomes and liposomes are suitable delivery systems for nutraceuticals, and can be widely used in food industry.

  14. Encapsulation of paclitaxel into lauric acid-O-carboxymethyl chitosan-transferrin micelles for hydrophobic drug delivery and site-specific targeted delivery.

    Science.gov (United States)

    Nam, Joung-Pyo; Park, Seong-Cheol; Kim, Tae-Hun; Jang, Jae-Yeang; Choi, Changyong; Jang, Mi-Kyeong; Nah, Jae-Woon

    2013-11-30

    Transferrin/PEG/O-carboxymethyl chitosan/fatty acid/paclitaxel (TPOCFP) micelles were tested for suitability as a drug carrier characterized by low cytotoxicity, sustained release, high cellular uptake, and site-specific targeted delivery of hydrophobic drugs. Characterization, drug content, encapsulation efficiency, and in vitro drug release were investigated. When the feeding amount of paclitaxel (PTX) was increased, the drug content increased, but loading efficiency decreased. TPOCFP micelles had a spherical shape, with a particle size of approximately 140-649 nm. In vitro cell cytotoxicity and hemolysis assays were conducted to confirm the safety of the micelles. Anticancer activity and confocal laser scanning microscopy (CLSM) were used to confirm the targeting efficiency of target ligand-modified TPOCFP micelles. Anticancer activity and CLSM results clearly demonstrated that transferrin-modified TPOCFP micelles were quickly taken up by the cell. The endocytic pathway of TPOCFP micelles was analyzed by flow cytometry, revealing transfection via receptor-mediated endocytosis. These results suggest that PTX-encapsulated TPOCFP micelles may be used as an effective cancer-targeting drug delivery system for chemotherapy.

  15. Antibody-drug conjugates: targeting melanoma with cisplatin encapsulated in protein-cage nanoparticles based on human ferritin

    Science.gov (United States)

    Falvo, Elisabetta; Tremante, Elisa; Fraioli, Rocco; Leonetti, Carlo; Zamparelli, Carlotta; Boffi, Alberto; Morea, Veronica; Ceci, Pierpaolo; Giacomini, Patrizio

    2013-11-01

    A novel antibody-drug conjugate (ADC) was synthesized incorporating ferritin-based nanoparticles. An average of three molecules of monoclonal antibody (mAb) Ep1 to the human melanoma-specific antigen CSPG4 were conjugated to a single ferritin cage encapsulating about 50 cisplatin molecules (HFt-Pt-Ep1). The HFt-Pt-Ep1 nanoparticle had an estimated molecular size of about 900 kD and 33 nm, and flow cytometry demonstrated specific binding to a CSPG4+ melanoma cell line, but not to a CSPG4- breast carcinoma cell line. As compared to the cisplatin-containing ferritin nanoparticle alone (HFt-Pt), which inhibited thymidine incorporation more efficiently in breast carcinoma than melanoma cells, the mAb-derivatized HFt-Pt-Ep1 nanoparticle had a 25-fold preference for the latter. A similar preference for melanoma was observed upon systemic intravenous administration of HFt-Pt-Ep1 to nude mice xenotransplanted with pre-established, palpable melanoma and breast carcinoma tumors. Thus, we have been able to determine precise combinations and stoichiometric relationships between mAbs and nanoparticle protein cages, whereby the latter lose their tropism for ubiquitously distributed cellular receptors, and acquire instead remarkably lineage-selective binding. HFt-Pt-Ep1 is therefore an interesting model to improve the therapeutic index of antiblastic therapy in a tumor such as melanoma, which at its advanced stages is totally refractory to mono- and combination-chemotherapy.A novel antibody-drug conjugate (ADC) was synthesized incorporating ferritin-based nanoparticles. An average of three molecules of monoclonal antibody (mAb) Ep1 to the human melanoma-specific antigen CSPG4 were conjugated to a single ferritin cage encapsulating about 50 cisplatin molecules (HFt-Pt-Ep1). The HFt-Pt-Ep1 nanoparticle had an estimated molecular size of about 900 kD and 33 nm, and flow cytometry demonstrated specific binding to a CSPG4+ melanoma cell line, but not to a CSPG4- breast carcinoma cell

  16. Encapsulation of cisplatin as an anti-cancer drug into boron-nitride and carbon nanotubes: Molecular simulation and free energy calculation.

    Science.gov (United States)

    Roosta, Sara; Hashemianzadeh, Seyed Majid; Ketabi, Sepideh

    2016-10-01

    Encapsulation of cisplatin anticancer drug into the single walled (10, 0) carbon nanotube and (10, 0) boron-nitride nanotube was investigated by quantum mechanical calculations and Monte Carlo Simulation in aqueous solution. Solvation free energies and complexation free energies of the cisplatin@ carbon nanotube and cisplatin@ boron-nitride nanotube complexes was determined as well as radial distribution functions of entitled compounds. Solvation free energies of cisplatin@ carbon nanotube and cisplatin@ boron-nitride nanotube were -4.128kcalmol(-1) and -2457.124kcalmol(-1) respectively. The results showed that cisplatin@ boron-nitride nanotube was more soluble species in water. In addition electrostatic contribution of the interaction of boron- nitride nanotube complex and solvent was -281.937kcalmol(-1) which really more than Van der Waals and so the electrostatic interactions play a distinctive role in the solvation free energies of boron- nitride nanotube compounds. On the other hand electrostatic part of the interaction of carbon nanotube complex and solvent were almost the same as Van der Waals contribution. Complexation free energies were also computed to study the stability of related structures and the free energies were negative (-374.082 and -245.766kcalmol(-1)) which confirmed encapsulation of drug into abovementioned nanotubes. However, boron-nitride nanotubes were more appropriate for encapsulation due to their larger solubility in aqueous solution.

  17. Continuous-flow encapsulation of ketoprofen in copolymer microbeads via co-axial microfluidic device: influence of operating and material parameters on drug carrier properties.

    Science.gov (United States)

    Khan, Ikram Ullah; Serra, Christophe A; Anton, Nicolas; Vandamme, Thierry

    2013-01-30

    Microchannels based microfluidic systems are able to obtain monodispersed microparticles but are limited by cost, time and channel clogging. We succeeded in on the fly encapsulation of high ketoprofen contents in acrylate-based copolymer microbeads by environment friendly UV induced free radical polymerization in off-the-shelf co-axial microfluidic device. FTIR shows complete polymerization of acrylate monomers and interaction between carboxylic group of ketoprofen and ester group of monomers. DSC and XRD confirm amorphous nature of drug in microbeads. Different comonomer content formulations show limited drug release at low pH, a helpful properties to avoid gastric irritating effect of ketoprofen associated with conventional dosage forms. At pH 6.8 microbeads release higher content of drug by a non-Fickian diffusion mechanism. Their drug release rate depends upon the weight content of ethyl acrylate in the formulation as well as their size, increasing by increasing the former and decreasing the later.

  18. Encapsulation of Platelet in Kefiran Polymer and Detection of Bioavailability of Immobilized Platelet in Probiotic Kefiran as A New Drug for Surface Bleeding

    Directory of Open Access Journals (Sweden)

    Anahita Jenab

    2015-11-01

    Full Text Available Background : Kefir contains lactic acid bacteria (Lactobacillus, Lactococcus, Leuconostoc, Acetobacter and Streptococcus and yeasts (Kluyveromyces, Torula, Candida, Saccharomyces .Kefiran is the polysaccharide produced by lactic acid bacteria in kefir.Methods : Kefiran was prepared from milk containing 0.5% fat and 10 grams kefir grains and was separated from kefir by ethanol (0.02 gram following entrapping the platelets to this polymer. Ligand of the platelet-polysaccharide was studied by FTIR.Results : FTIR results showed that the bands of C-O and C-O-C connections were formed and the polysaccharides had been attached to the receptors of the platelet glycoproteins (GP Ib,GPIIb / IIIa. Stability and encapsulation of the platelet and kefiran were assessed by Coulter Counter. Encapsulation of the platelets by polysaccharide at the beginning caused to reduce the number of platelets following by releasing of 50% of the platelets after 3 hours.Conclusion : The platelets were encapsulated in kefiran polymer and detected for bioavailability as new drug for surface bleeding. Also, kefiran has antimicrobial and antifungal properties. On the other hand, the existence of nisin in kefiran could be useful as an antibacterial lantibiotic. 

  19. Intravenous pretreatment with empty pH gradient liposomes alters the pharmacokinetics and toxicity of doxorubicin through in vivo active drug encapsulation.

    Science.gov (United States)

    Mayer, L D; Reamer, J; Bally, M B

    1999-01-01

    Liposomes have been used widely to improve the therapeutic activity of pharmaceutical agents. The traditional approach for such applications has been to formulate the pharmaceutical agent in liposomes prior to administration in vivo. In this report we demonstrate that liposomes exhibiting a transmembrane pH gradient injected intravenously (iv) can actively encapsulate doxorubicin in the circulation after iv administration of free drug. Small (110 nm) liposomes composed of phosphatidylcholine (PC)/cholesterol (Chol, 55:45 mol:mol) exhibiting a pH gradient (inside acidic) were administered iv 1 h prior to free doxorubicin, and plasma drug levels as well as toxicity and efficacy were evaluated. Predosing with egg PC/Chol pH gradient liposomes increased the plasma concentration of doxorubicin as much as 200-fold compared to free drug alone as well as to predosing with dipalmitoyl PC/Chol pH gradient liposomes or EPC/Chol liposomes without a pH gradient. The ability of the liposomes to alter the pharmacokinetics of doxorubicin was dependent on the presence of a transmembrane pH gradient and correlated with the extent of doxorubicin uptake into the liposomes at 37 degreesC in pH 7.5 buffer, indicating that doxorubicin was being actively accumulated in the circulating liposomes. This in vivo drug loading was achieved over a range of doxorubicin doses (5 mg/kg-40 mg/kg) and was dependent on the dose of EPC/Chol liposomes administered prior to free doxorubicin injection. The altered pharmacokinetic properties of doxorubicin associated with in vivo doxorubicin encapsulation were accompanied by a decrease in drug toxicity and maintained antitumor potency. These results suggest that pretreatment with empty liposomes exhibiting a pH gradient may provide a versatile and straightforward method for enhancing the pharmacological properties of many drugs that can accumulate into such vesicle systems at physiological temperatures.

  20. Influence of inspiratory flow rate, particle size, and airway caliber on aerosolized drug delivery to the lung.

    Science.gov (United States)

    Dolovich, M A

    2000-06-01

    A number of studies in the literature support the use of fine aerosols of drug, inhaled at low IFRs to target peripheral airways, with the objective of improving clinical responses to inhaled therapy (Fig. 8). Attempts have been made to separate response due to changes in total administered dose or the surface concentration of the dose from response due to changes in site of deposition--both are affected by the particle size of the aerosol, with IFR additionally influencing the latter. The tools for measuring dose and distribution have improved over the last 10-15 years, and thus we should expect greater accuracy in these measurements for assessing drug delivery to the lung. There are still issues, though, in producing radiolabeled (99m)technetium aerosols that are precise markers for the pharmaceutical product being tested and in quantitating absolute doses deposited in the lung. PET isotopes may provide the means for directly labelling a drug and perhaps can offer an alternative for making these measurements in the future, but deposition measurements should not be used in isolation; protocols should incorporate clinical tests to provide parallel therapeutic data in response to inhalation of the drug by the various patient populations being studied.

  1. Challenges and Successes Using Nanomedicines for Aerosol Delivery to the Airways.

    Science.gov (United States)

    Resnier, P; Mottais, A; Sibiril, Y; Le Gall, T; Montier, T

    2016-01-01

    Numerous diseases affect the respiratory tract and the aerosol administration has been widely considered as an adapted and non-invasive method for local delivery. This pathway induces a lung concentration and thus also limits, systemic side effects. However, aerosol delivery of active pharmaceutical ingredients represents a real challenge, due to numerous obstacles such as the specific respiratory movement, the presence of mucus or surfactant, and the mucociliary clearance. Nanomedicines, such as liposomes, micelles or nanoparticles, offer the possibility to increase bioavailability and favor intracellular penetration of specific drugs into lung tissue. This review focuses on the description of aerosol formulations and cellular barriers including design, characteristics and progressive adaptation to airways anatomy. Then, aerosolized formulations currently clinically approved, or in clinical trial are summarized according to the encapsulated drug. In a final section, promising aerosol formulations in pre-clinical studies are detailed.

  2. Small angle neutron scattering study of doxorubicin–surfactant complexes encapsulated in block copolymer micelles

    Indian Academy of Sciences (India)

    Jayita Bhattacharjee; Gunjan Verma; V K Aswal; P A Hassan

    2008-11-01

    Self-assembling behaviour of block copolymers and their ability to evade the immune system through polyethylene oxide stealth makes it an attractive candidate for drug encapsulation. Micelles formed by polyethylene oxide–polypropylene oxide–polyethylene oxide triblock copolymers (PEO–PPO–PEO), pluronic P123, have been employed for encapsulating the anti-cancer drug doxorubicin hydrochloride. The binding affinity of doxorubicin within the micelle carrier is enhanced through complex formation of drug and anionic surfactant, aerosol OT (AOT). Electrostatic binding of doxorubicin with negatively charged surfactants leads to the formation of hydrophobic drug–surfactant complexes. Surfactant-induced partitioning of the anti-cancer drug into nonpolar solvents such as chloroform is investigated. SANS measurements were performed on pluronic P123 mi-celles in the presence of drug–surfactant complex. No significant changes in the structure of the micelles are observed upon drug encapsulation. This demonstrates that surfactant–drug complexes can be encapsulated in block copolymer micelles without disrupting the structure of aggregates.

  3. Neuropeptide Y Y1 receptors meditate targeted delivery of anticancer drug with encapsulated nanoparticles to breast cancer cells with high selectivity and its potential for breast cancer therapy.

    Science.gov (United States)

    Li, Juan; Shen, Zheyu; Ma, Xuehua; Ren, Wenzhi; Xiang, Lingchao; Gong, An; Xia, Tian; Guo, Junming; Wu, Aiguo

    2015-03-11

    By enabling nanoparticle-based drug delivery system to actively target cancer cells with high selectivity, active targeted molecules have attracted great attention in the application of nanoparticles for anticancer drug delivery. However, the clinical application of most active targeted molecules in breast cancer therapy is limited, due to the low expression of their receptors in breast tumors or coexpression in the normal and tumor breast tissues. Here, a neuropeptide Y Y1 receptors ligand PNBL-NPY, as a novel targeted molecule, is conjugated with anticancer drug doxorubicin encapsulating albumin nanoparticles to investigate the effect of Y1 receptors on the delivery of drug-loaded nanoparticles to breast cancer cells and its potential for breast cancer therapy. The PNBL-NPY can actively recognize and bind to the Y1 receptors that are significantly overexpressed on the surface of the breast cancer cells, and the drug-loaded nanoparticles are delivered directly into the cancer cells through internalization. This system is highly selective and able to distinguish the breast cancer cells from the normal cells, due to normal breast cells that express Y2 receptors only. It is anticipated that this study may provide a guidance in the development of Y1 receptor-based nanoparticulate drug delivery system for a safer and more efficient breast cancer therapy.

  4. Aerosol-Assisted Fast Formulating Uniform Pharmaceutical Polymer Microparticles with Variable Properties toward pH-Sensitive Controlled Drug Release

    Directory of Open Access Journals (Sweden)

    Hong Lei

    2016-05-01

    Full Text Available Microencapsulation is highly attractive for oral drug delivery. Microparticles are a common form of drug carrier for this purpose. There is still a high demand on efficient methods to fabricate microparticles with uniform sizes and well-controlled particle properties. In this paper, uniform hydroxypropyl methylcellulose phthalate (HPMCP-based pharmaceutical microparticles loaded with either hydrophobic or hydrophilic model drugs have been directly formulated by using a unique aerosol technique, i.e., the microfluidic spray drying technology. A series of microparticles of controllable particle sizes, shapes, and structures are fabricated by tuning the solvent composition and drying temperature. It is found that a more volatile solvent and a higher drying temperature can result in fast evaporation rates to form microparticles of larger lateral size, more irregular shape, and denser matrix. The nature of the model drugs also plays an important role in determining particle properties. The drug release behaviors of the pharmaceutical microparticles are dependent on their structural properties and the nature of a specific drug, as well as sensitive to the pH value of the release medium. Most importantly, drugs in the microparticles obtained by using a more volatile solvent or a higher drying temperature can be well protected from degradation in harsh simulated gastric fluids due to the dense structures of the microparticles, while they can be fast-released in simulated intestinal fluids through particle dissolution. These pharmaceutical microparticles are potentially useful for site-specific (enteric delivery of orally-administered drugs.

  5. Dry powder aerosols generated by standardized entrainment tubes from drug blends with lactose monohydrate: 1. Albuterol sulfate and disodium cromoglycate.

    Science.gov (United States)

    Xu, Zhen; Mansour, Heidi M; Mulder, Tako; McLean, Richard; Langridge, John; Hickey, Anthony J

    2010-08-01

    The major objective of this study was: discriminatory assessment of dry powder aerosol performance using standardized entrainment tubes (SETs) and lactose-based formulations with two model drugs. Drug/lactose interactive physical mixtures (2%w/w) were prepared. Their properties were measured: solid-state characterization of phase behavior and molecular interactions by differential scanning calorimetry and X-ray powder diffraction; particle morphology and size by scanning electron microscopy and laser diffraction; aerosol generation by SETs and characterization by twin-stage liquid impinger and Andersen cascade impactor operated at 60 L/min. The fine particle fraction (FPF) was correlated with SET shear stress (tau(s)), using a novel powder aerosol deaggregation equation (PADE). Drug particles were <5 microm in volume diameter with narrow unimodal distribution (Span <1). The lowest shear SET (tau(s) = 0.624 N/m(2)) gave a higher emitted dose (ED approximately 84-93%) and lower FPF (FPF(6.4) approximately 7-25%). In contrast, the highest shear SET (tau(s) = 13.143 N/m(2)) gave a lower ED (ED approximately 75-89%) and higher FPF (FPF(6.4) approximately 15-46%). The performance of disodium cromoglycate was superior to albuterol sulfate at given tau(s), as was milled with respect to sieved lactose monohydrate. Excellent correlation was observed (R(2) approximately 0.9804-0.9998) when pulmonary drug particle release from the surface of lactose carriers was interpreted by PADE linear regression for dry powder formulation evaluation and performance prediction.

  6. On the accessibility of surface-bound drugs on magnetic nanoparticles. Encapsulation of drugs loaded on modified dextran-coated superparamagnetic iron oxide by β-cyclodextrin.

    Science.gov (United States)

    Sudha, Natesan; Yousuf, Sameena; Israel, Enoch V M V; Paulraj, Mosae Selvakumar; Dhanaraj, Premnath

    2016-05-01

    We report the loading of drugs on aminoethylaminodextran-coated iron oxide nanoparticles, their superparamagnetic behavior, loading of drugs on them, and the β-cyclodextrin-complex formation of the drugs on the surface of the nanoparticles. The magnetic behavior is studied using vibrating sample magnetometry and X-ray photoelectron spectroscopy is used to analyze the elemental composition of drug-loaded nanoparticles. Scanning electron microscopy shows ordered structures of drug-loaded nanoparticles. UV-visible absorption and fluorescence spectroscopy are used to study the binding of the surface-loaded drugs to β-cyclodextrin. All of the drugs form 1:1 host-guest complexes. The iodide ion quenching of fluorescence of free- and iron oxide-attached drugs are compared. The binding strengths of the iron oxide surface-loaded drugs-β-cyclodextrin binding are smaller than those of the free drugs.

  7. Diffusion loading and drug delivery characteristics of alginate gel microparticles produced by a novel impinging aerosols method.

    Science.gov (United States)

    Hariyadi, Dewi M; Lin, Sharon Chien-Yu; Wang, Yiwei; Bostrom, Thor; Turner, Mark S; Bhandari, Bhesh; Coombes, Allan G A

    2010-12-01

    Microencapsulation of a hydrophilic active (gentamicin sulphate (GS)) and a hydrophobic non-steroidal anti-inflammatory drug (ibuprofen) in alginate gel microparticles was accomplished by molecular diffusion of the drug species into microparticles produced by impinging aerosols of alginate solution and CaCl(2) cross-linking solution. A mean particle size in the range of 30-50 µm was measured using laser light scattering and high drug loadings of around 35 and 29% weight/dry microparticle weight were obtained for GS and ibuprofen respectively. GS release was similar in simulated intestinal fluid (phosphate buffer saline (PBS), pH 7.4, 37°C) and simulated gastric fluid (SGF) (HCl, pH 1.2, 37°C) but was accelerated in PBS following incubation of microparticles in HCl. Ibuprofen release was restricted in SGF but occurred freely on transfer of microparticles into PBS with almost 100% efficiency. GS released in PBS over 7 h, following incubation of microparticles in HCl for 2 h was found to retain at least 80% activity against Staphylococcus epidermidis while Ibuprofen retained around 50% activity against Candida albicans. The impinging aerosols technique shows potential for producing alginate gel microparticles of utility for protection and controlled delivery of a range of therapeutic molecules.

  8. Formulation and evaluation of gelatin micropellets of aceclofenac: Effect of process variables on encapsulation efficiency, particle size and drug release

    Directory of Open Access Journals (Sweden)

    Sahoo S

    2008-01-01

    Full Text Available In the present study aceclofenac-gelatin micropellets were prepared by the cross linking technique using gluteraldehyde as cross linking agent and characterized by X-ray diffractometry, differential scanning calorimetry and scanning electron microscopy. The effect of drug: polymer ratio, temperature of oil phase, amount of gluteraldehyde and stirring time was studied with respect to entrapment efficiency, micropellet size and drug release characteristics. Spherical micropellets having an entrapment efficiency of 57% to 97% were obtained. Differential scanning calorimetric analysis confirmed the absence of any drug-polymer interaction. The micromeritic studies of micropellets show improved flow property. The entrapment efficiency, micropellet size and drug release profile was altered significantly by changing various processing parameters.

  9. Silica encapsulated lipid-based drug delivery systems for reducing the fed/fasted variations of ziprasidone in vitro.

    Science.gov (United States)

    Dening, Tahnee J; Rao, Shasha; Thomas, Nicky; Prestidge, Clive A

    2016-04-01

    Ziprasidone is a poorly water-soluble antipsychotic drug that demonstrates low fasted state oral bioavailability and a clinically significant two-fold increase in absorption when dosed postprandially. Owing to significant compliance challenges faced by schizophrenic patients, a novel oral formulation of ziprasidone that demonstrates improved fasted state absorption and a reduced food effect is of major interest, and is therefore the aim of this research. Three lipid-based drug delivery systems (LBDDS) were developed and investigated: (a) a self-nanoemulsifying drug delivery system (SNEDDS), (b) a solid SNEDDS formulation, and (c) silica-lipid hybrid (SLH) microparticles. SNEDDS was developed using Capmul MCM® and Tween 80®, and solid SNEDDS was fabricated by spray-drying SNEDDS with Aerosil 380® silica nanoparticles as the solid carrier. SLH microparticles were prepared in a similar manner to solid SNEDDS using a precursor lipid emulsion composed of Capmul MCM® and soybean lecithin. The performance of the developed formulations was evaluated under simulated digesting conditions using an in vitro lipolysis model, and pure (unformulated) ziprasidone was used as a control. While pure ziprasidone exhibited the lowest rate and extent of drug solubilization under fasting conditions and a significant 2.4-fold increase in drug solubilization under fed conditions, all three LBDDS significantly enhanced the extent of drug solubilization under fasting conditions between 18- and 43-folds in comparison to pure drug. No significant difference in drug solubilization for the fed and fasted states was observed for the three LBDDS systems. To highlight the potential of LBDDS, mechanism(s) of action and various performance characteristics are discussed. Importantly, LBDDS are identified as an appropriate formulation strategy to explore further for the improved oral delivery of ziprasidone.

  10. Synthesis of mesoporous SiO{sub 2}-ZnO nanocapsules: encapsulation of small biomolecules for drugs and 'SiOZO-plex' for gene delivery

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vijay Bhooshan [School of Engineering Sciences and Technology, University of Hyderabad (India); Annamanedi, Madhavi [School of Life Sciences, University of Hyderabad, Department of Animal Sciences (India); Prashad, Muvva Durga [University of Hyderabad, Centre for Nanoscience and Nanotechnology (India); Arunasree, Kalle M. [School of Life Sciences, University of Hyderabad, Department of Animal Sciences (India); Mastai, Yitzhak; Gedanken, Aharon, E-mail: gedanken@mail.biu.ac.il [Bar-Ilan University, Department of Chemistry, Institute for Nanotechnology and Advanced Materials (Israel); Paik, Pradip, E-mail: ppse@uohyd.ernet.in [School of Engineering Sciences and Technology, University of Hyderabad (India)

    2013-09-15

    This work presents a new synthesis of mesoporous SiO{sub 2}-ZnO composite nanocapsules with sizes of 90-150 nm and represents their applications in encapsulation of small biomolecules (fluorescent molecules, drugs, and DNA) for uses in medical biotechnology (e.g., drug and gene delivery) for the first time. The nanocapsule size and morphology have been confirmed through the HRSEM and HRTEM. The mesoporous structure of the novel materials has been confirmed through both BET and HRTEM, and the pore diameter observed to be ca. 2-8 nm with an average diameter of 5.1 nm. The BET surface area of mesoporous SiO{sub 2}-ZnO was found to be {approx}230 m{sup 2} g{sup -1}. Three different types of pores were detected through HRTEM: type-I, normal pores in silica matrix, pore with ZnO nanoparticles at the boundary (type-II) and type-III, the pores with tiny ZnO nanoparticles ({approx}5-7 nm) inside them. To demonstrate the biocompatibility and cell viability of the nanocapsules, normal and cancerous lymphocyte cells have been chosen and investigated in a systematic way. Fluorescent dye (Rhodamine 6G), anticancer drug e.g., Doxorubicin (DOX) were loaded in all types of pores, and EtBr-labeled DNA molecules were loaded efficiently into the mesopores of second and third types of the composite nanocapsules to manifest the characteristic of mesoporous, and to find out its loading efficacy. The release kinetics of Rhodamine 6G and DOX were studied. The results highlight the potential of novel functional mesoporous SiO{sub 2}-ZnO nanoparticles for using as the carrier of drugs and formation of 'SiOZO-plex', a complex of mesoporous SiO{sub 2}-ZnO with DNA for gene delivery applications.Graphical Abstract.

  11. 植物固醇在脂质体中的应用研究进展%Application of plant sterols in liposome-encapsulated drugs

    Institute of Scientific and Technical Information of China (English)

    邬瑞光; 李维峰; 侯俊玲; 吴富根

    2011-01-01

    脂质体作为药物载体,由于其具有靶向性、可降低药物毒性等优点而备受关注.本文在阐述固醇分子在脂质体中的作用、脂质体液态有序相的特征、脂筏定义的基础上综述了植物细胞中脂筏的发现及植物固醇代替胆固醇作为脂质体膜材的必要性和可行性等相关问题的研究进展.%As a new kind of drug carries, liposomes have been widely studied for their benefits of selectivity and low toxicity. In the paper we introduced the roles of sterols in liposomes, the characteristics of liquid-ordered phase of liposomes, and the concept of lipid raft. We also reviewed the discovery of plant lipid raft and the progress of application of the plant sterols in liposome-encapsulated drugs.

  12. Potentiation of 5-fluorouracil encapsulated in zeolites as drug delivery systems for in vitro models of colorectal carcinoma.

    Science.gov (United States)

    Vilaça, Natália; Amorim, Ricardo; Machado, Ana F; Parpot, Pier; Pereira, Manuel F R; Sardo, Mariana; Rocha, João; Fonseca, António M; Neves, Isabel C; Baltazar, Fátima

    2013-12-01

    The studies of potentiation of 5-fluorouracil (5-FU), a traditional drug used in the treatment of several cancers, including colorectal (CRC), were carried out with zeolites Faujasite in the sodium form, with different particle sizes (NaY, 700nm and nanoNaY, 150nm) and Linde type L in the potassium form (LTL) with a particle size of 80nm. 5-FU was loaded into zeolites by liquid-phase adsorption. Characterization by spectroscopic techniques (FTIR, (1)H NMR and (13)C and (27)Al solid-state MAS NMR), chemical analysis, thermal analysis (TGA), nitrogen adsorption isotherms and scanning electron microscopy (SEM), demonstrated the successful loading of 5-FU into the zeolite hosts. In vitro drug release studies (PBS buffer pH 7.4, 37°C) revealed the release of 80-90% of 5-FU in the first 10min. To ascertain the drug release kinetics, the release profiles were fitted to zero-order, first-order, Higuchi, Hixson-Crowell, Korsmeyer-Peppas and Weibull kinetic models. The in vitro dissolution from the drug delivery systems (DDS) was explained by the Weibull model. The DDS efficacy was evaluated using two human colorectal carcinoma cell lines, HCT-15 and RKO. Unloaded zeolites presented no toxicity to both cancer cells, while all DDS allowed an important potentiation of the 5-FU effect on the cell viability. Immunofluorescence studies provided evidence for zeolite-cell internalization.

  13. Protein encapsulation in polymeric microneedles by photolithography

    Directory of Open Access Journals (Sweden)

    Kochhar JS

    2012-06-01

    Full Text Available Jaspreet Singh Kochhar,1 Shui Zou,2 Sui Yung Chan,1 Lifeng Kang11Department of Pharmacy, 2Department of Chemistry, National University of Singapore, SingaporeBackground: Recent interest in biocompatible polymeric microneedles for the delivery of biomolecules has propelled considerable interest in fabrication of microneedles. It is important that the fabrication process is feasible for drug encapsulation and compatible with the stability of the drug in question. Moreover, drug encapsulation may offer the advantage of higher drug loading compared with other technologies, such as drug coating.Methods and results: In this study, we encapsulated a model protein drug, namely, bovine serum albumin, in polymeric microneedles by photolithography. Drug distribution within the microneedle array was found to be uniform. The encapsulated protein retained its primary, secondary, and tertiary structural characteristics. In vitro release of the encapsulated protein showed that almost all of the drug was released into phosphate buffered saline within 6 hours. The in vitro permeation profile of encapsulated bovine serum albumin through rat skin was also tested and shown to resemble the in vitro release profile, with an initial release burst followed by a slow release phase. The cytotoxicity of the microneedles without bovine serum albumin was tested in three different cell lines. High cell viabilities were observed, demonstrating the innocuous nature of the microneedles.Conclusion: The microneedle array can potentially serve as a useful drug carrier for proteins, peptides, and vaccines.Keywords: poly (ethylene glycol diacrylate, microneedles, protein stability, photolithography, biocompatibility

  14. In vitro evaluation of the effect of metered-dose inhaler administration technique on aerosolized drug delivery.

    Science.gov (United States)

    Shalansky, K F; Htan, E Y; Lyster, D M; Mouat, B; Tweeddale, M G

    1993-01-01

    The administration of aerosolized metered-dose inhalers (MDIs) to mechanically ventilated patients is labor intensive due to the large number of activations required and the currently recommended 30- to 60-second "wait and shake" between each puff. No studies have been published that assess the relationship between this delay between puffs and drug delivery. To address this issue, we conducted an in vitro, randomized, single-blind study using fenoterol MDI containing technetium-99m pertechnetate. Four modes of MDI administration were tested in triplicate by random sequence. Eight activations of the MDI were performed for each mode according to the following procedures: rapid succession (5 sec apart); 30-second intervals and shaking MDI between two rapid activations; 30-second intervals and shaking between each activation; and 60-second intervals and shaking between each activation. Two closed in vitro systems were designed to collect and measure the radiolabeled aerosol. In the first system, the MDI was activated into a plastic collection container; with the second system, the MDI was administered through an aerosol holding chamber with attached circuit filter positioned on the inspiratory line of the ventilator circuit. Sixty-second intervals between each activation were not tested with the second system. Radioactivity was measured before and after each mode of testing. No difference was found between the various modes of administration other than a 14% decrease in the amount of radioactivity released with the 60-second waiting period between puffs, compared with their rapid succession when using the plastic collection container system. Our results support the hypothesis that the delay after each activation of a MDI may not be necessary.

  15. Evaluating the Properties of Poly(lactic-co-glycolic acid) Nanoparticle Formulations Encapsulating a Hydrophobic Drug by Using the Quality by Design Approach.

    Science.gov (United States)

    Kozaki, Masato; Kobayashi, Shin-Ichiro; Goda, Yukihiro; Okuda, Haruhiro; Sakai-Kato, Kumiko

    2017-01-01

    We applied the Quality by Design (QbD) approach to the development of poly(lactic-co-glycolic acid) (PLGA) nanoparticle formulations encapsulating triamcinolone acetonide, and the critical process parameters (CPPs) were identified to clarify the correlations between critical quality attributes and CPPs. Quality risk management was performed by using an Ishikawa diagram and experiments with a fractional factorial design (ANOVA). The CPPs for particle size were PLGA concentration and rotation speed, and the CPP for relative drug loading efficiency was the poor solvent to good solvent volume ratio. By assessing the mutually related factors in the form of ratios, many factors could be efficiently considered in the risk assessment. We found a two-factor interaction between rotation speed and rate of addition of good solvent by using a fractional factorial design with resolution V. The system was then extended by using a central composite design, and the results obtained were visualized by using the response surface method to construct a design space. Our research represents a case study of the application of the QbD approach to pharmaceutical development, including formulation screening, by taking actual production factors into consideration. Our findings support the feasibility of using a similar approach to nanoparticle formulations under development. We could establish an efficient method of analyzing the CPPs of PLGA nanoparticles by using a QbD approach.

  16. In vitro and in vivo imaging of peptide-encapsulated polymer nanoparticles for cancer biomarker activated drug delivery.

    Science.gov (United States)

    Kulsharova, Gulsim K; Lee, Matthew B; Cheng, Felice; Haque, Munima; Choi, Hyungsoo; Kim, Kyekyoon; O'Brien, William D; Liu, G Logan

    2013-12-01

    Gelatin nanoparticles coated with Cathepsin D-specific peptides were developed as a vehicle for the targeted delivery of the cancer drug doxorubicin (DOX) to treat breast malignancy. Cathepsin D, a breast cancer cell secretion enzyme, triggered the release of DOX by digesting the protective peptide-coating layer of nanoparticles. Fabricated nanoparticles were successfully detected with ultrasound imaging in both in vitro conditions and in vivo mouse cancer models. Cell viability experiments were conducted to determine the efficacy of biomarker activation specific to breast cancer cell lines. These experimental results were compared with the outcome of a viability experiment conducted on noncancerous cells. Viability decreased in human MCF7 mammary adenocarcinoma and mouse 4T1 mammary carcinoma cells, while that of noncancerous 3T3 fibroblast cells remained unaffected. Next, a real-time video of nanoparticle flow in mouse models was obtained using in vivo ultrasound imaging. The fluorescent profile of DOX was used as a means to examine nanoparticle localization in vivo. Results show the distribution of nanoparticles concentrated primarily within bladder and tumor sites of subject mice bodies. These findings support the use of biomarker coated nanoparticles in target specific therapy for breast cancer treatment.

  17. Endogenous lung surfactant inspired pH responsive nanovesicle aerosols: Pulmonary compatible and site-specific drug delivery in lung metastases

    Science.gov (United States)

    Joshi, Nitin; Shirsath, Nitesh; Singh, Ankur; Joshi, Kalpana S.; Banerjee, Rinti

    2014-11-01

    Concerns related to pulmonary toxicity and non-specificity of nanoparticles have limited their clinical applications for aerosol delivery of chemotherapeutics in lung cancer. We hypothesized that pulmonary surfactant mimetic nanoparticles that offer pH responsive release specifically in tumor may be a possible solution to overcome these issues. We therefore developed lung surfactant mimetic and pH responsive lipid nanovesicles for aerosol delivery of paclitaxel in metastatic lung cancer. 100-200 nm sized nanovesicles showed improved fusogenicity and cytosolic drug release, specifically with cancer cells, thereby resulting in improved cytotoxicity of paclitaxel in B16F10 murine melanoma cells and cytocompatibility with normal lung fibroblasts (MRC 5). The nanovesicles showed airway patency similar to that of endogenous pulmonary surfactant and did not elicit inflammatory response in alveolar macrophages. Their aerosol administration while significantly improving the biodistribution of paclitaxel in comparison to Taxol (i.v.), also showed significantly higher metastastes inhibition (~75%) in comparison to that of i.v. Taxol and i.v. Abraxane. No signs of interstitial pulmonary fiborisis, chronic inflammation and any other pulmonary toxicity were observed with nanovesicle formulation. Overall, these nanovesicles may be a potential platform to efficiently deliver hydrophobic drugs as aerosol in metastatic lung cancer and other lung diseases, without causing pulmonary toxicity.

  18. The effect of surfactant and solid phase concentration on drug aggregates in model aerosol propellent suspensions.

    Science.gov (United States)

    Bower, C; Washington, C; Purewal, T S

    1996-04-01

    The effect of increasing solid phase concentration on the morphology and flocculation rate of model aerosol suspensions has been investigated. Suspensions of micronized salbutamol sulphate and lactose in trichlorotrifluoroethane (P113) were studied under conditions of increasing shear stress. By use of image analysis techniques, measurement of aggregate size, fractal dimension and rate of aggregation was performed. The effect of the surfactant sorbitan monooleate on morphology and flocculation rate was also studied. Increased solid phase concentration caused an increase in the rate of aggregation and average aggregate size at a given value of shear stress. Surfactant addition retarded the aggregation rate, and caused a shift from a diffusion-limited cluster aggregation to a reaction-limited cluster aggregation mechanism. The aggregate profiles showed a corresponding change from rugged and crenellated without surfactant, to increasingly smooth and Euclidian with increasing surfactant concentration. The morphological changes were characterized by a decrease in the average boundary fractal dimension which also correlated well with the corresponding reduction in aggregation rate.

  19. In vitro confirmation of the quantitative differentiation of liposomal encapsulated and non-encapsulated prednisolone (phosphate) tissue concentrations by murine phosphatases

    NARCIS (Netherlands)

    Smits, Evelien A W; Soetekouw, José A; Vromans, Herman

    2014-01-01

    The quantitative differentiation of liposomal encapsulated and non-encapsulated drug tissue concentrations is desirable, since the efficacy and toxicity are only related to the level of non-encapsulated drug. However, such separate concentration profiles in tissues have still not been reported due t

  20. Smart Magnetically Responsive Hydrogel Nanoparticles Prepared by a Novel Aerosol-Assisted Method for Biomedical and Drug Delivery Applications

    Directory of Open Access Journals (Sweden)

    Ibrahim M. El-Sherbiny

    2011-01-01

    Full Text Available We have developed a novel spray gelation-based method to synthesize a new series of magnetically responsive hydrogel nanoparticles for biomedical and drug delivery applications. The method is based on the production of hydrogel nanoparticles from sprayed polymeric microdroplets obtained by an air-jet nebulization process that is immediately followed by gelation in a crosslinking fluid. Oligoguluronate (G-blocks was prepared through the partial acid hydrolysis of sodium alginate. PEG-grafted chitosan was also synthesized and characterized (FTIR, EA, and DSC. Then, magnetically responsive hydrogel nanoparticles based on alginate and alginate/G-blocks were synthesized via aerosolization followed by either ionotropic gelation or both ionotropic and polyelectrolyte complexation using CaCl2 or PEG-g-chitosan/CaCl2 as crosslinking agents, respectively. Particle size and dynamic swelling were determined using dynamic light scattering (DLS and microscopy. Surface morphology of the nanoparticles was examined using SEM. The distribution of magnetic cores within the hydrogels nanoparticles was also examined using TEM. In addition, the iron and calcium contents of the particles were estimated using EDS. Spherical magnetic hydrogel nanoparticles with average particle size of 811 ± 162 to 941 ± 2 nm were obtained. This study showed that the developed method is promising for the manufacture of hydrogel nanoparticles, and it represents a relatively simple and potential low-cost system.

  1. Microencapsulation techniques, factors influencing encapsulation efficiency.

    Science.gov (United States)

    Jyothi, N Venkata Naga; Prasanna, P Muthu; Sakarkar, Suhas Narayan; Prabha, K Surya; Ramaiah, P Seetha; Srawan, G Y

    2010-05-01

    Microencapsulation is one of the quality preservation techniques of sensitive substances and a method for production of materials with new valuable properties. Microencapsulation is a process of enclosing micron-sized particles in a polymeric shell. There are different techniques available for the encapsulation of drug entities. The encapsulation efficiency of the microparticle or microsphere or microcapsule depends upon different factors like concentration of the polymer, solubility of polymer in solvent, rate of solvent removal, solubility of organic solvent in water, etc. The present article provides a literature review of different microencapsulation techniques and different factors influencing the encapsulation efficiency of the microencapsulation technique.

  2. Inhaler technique: facts and fantasies. A view from the Aerosol Drug Management Improvement Team (ADMIT).

    Science.gov (United States)

    Levy, Mark L; Dekhuijzen, P N R; Barnes, P J; Broeders, M; Corrigan, C J; Chawes, B L; Corbetta, L; Dubus, J C; Hausen, Th; Lavorini, F; Roche, N; Sanchis, J; Usmani, Omar S; Viejo, J; Vincken, W; Voshaar, Th; Crompton, G K; Pedersen, Soren

    2016-04-21

    Health professionals tasked with advising patients with asthma and chronic obstructive pulmonary disease (COPD) how to use inhaler devices properly and what to do about unwanted effects will be aware of a variety of commonly held precepts. The evidence for many of these is, however, lacking or old and therefore in need of re-examination. Few would disagree that facilitating and encouraging regular and proper use of inhaler devices for the treatment of asthma and COPD is critical for successful outcomes. It seems logical that the abandonment of unnecessary or ill-founded practices forms an integral part of this process: the use of inhalers is bewildering enough, particularly with regular introduction of new drugs, devices and ancillary equipment, without unnecessary and pointless adages. We review the evidence, or lack thereof, underlying ten items of inhaler 'lore' commonly passed on by health professionals to each other and thence to patients. The exercise is intended as a pragmatic, evidence-informed review by a group of clinicians with appropriate experience. It is not intended to be an exhaustive review of the literature; rather, we aim to stimulate debate, and to encourage researchers to challenge some of these ideas and to provide new, updated evidence on which to base relevant, meaningful advice in the future. The discussion on each item is followed by a formal, expert opinion by members of the ADMIT Working Group.

  3. Characterization Methods of Encapsulates

    Science.gov (United States)

    Zhang, Zhibing; Law, Daniel; Lian, Guoping

    Food active ingredients can be encapsulated by different processes, including spray drying, spray cooling, spray chilling, spinning disc and centrifugal co-extrusion, extrusion, fluidized bed coating and coacervation (see Chap. 2 of this book). The purpose of encapsulation is often to stabilize an active ingredient, control its release rate and/or convert a liquid formulation into a solid which is easier to handle. A range of edible materials can be used as shell materials of encapsulates, including polysaccharides, fats, waxes and proteins (see Chap. 3 of this book). Encapsulates for typical industrial applications can vary from several microns to several millimetres in diameter although there is an increasing interest in preparing nano-encapsulates. Encapsulates are basically particles with a core-shell structure, but some of them can have a more complex structure, e.g. in a form of multiple cores embedded in a matrix. Particles have physical, mechanical and structural properties, including particle size, size distribution, morphology, surface charge, wall thickness, mechanical strength, glass transition temperature, degree of crystallinity, flowability and permeability. Information about the properties of encapsulates is very important to understanding their behaviours in different environments, including their manufacturing processes and end-user applications. E.g. encapsulates for most industrial applications should have desirable mechanical strength, which should be strong enough to withstand various mechanical forces generated in manufacturing processes, such as mixing, pumping, extrusion, etc., and may be required to be weak enough in order to release the encapsulated active ingredients by mechanical forces at their end-user applications, such as release rate of flavour by chewing. The mechanical strength of encapsulates and release rate of their food actives are related to their size, morphology, wall thickness, chemical composition, structure etc. Hence

  4. Encapsulation plant at Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Nystroem, Anders

    2007-08-15

    SKB has already carried out a preliminary study of an encapsulation plant detached from Clab (Central interim storage for spent fuels). This stand-alone encapsulation plant was named FRINK and its assumed siting was the above-ground portion of the final repository, irrespective of the repository's location. The report previously presented was produced in cooperation with BNFL Engineering Ltd in Manchester and the fuel reception technical solution was examined by Gesellschaft fuer Nuklear-Service mbH (GNS) in Hannover and by Societe Generale pour les Techniques Nouvelles (SGN) in Paris. This report is an update of the earlier preliminary study report and is based on the assumption that the encapsulation plant and also the final repository will be sited in the Forsmark area. SKB's main alternative for siting the encapsulation plant is next to Clab. Planning of this facility is ongoing and technical solutions from the planning work have been incorporated in this report. An encapsulation plant placed in proximity to any final repository in Forsmark forms part of the alternative presentation in the application for permission to construct and operate an installation at Clab. The main technical difference between the planned encapsulation plant at Clab and an encapsulation plant at a final repository at Forsmark is how the fuel is managed and prepared before actual encapsulation. Fuel reception at the encapsulation plant in Forsmark would be dry, i.e. there would be no water-filled pools at the facility. Clab is used for verificatory fuel measurements, sorting and drying of the fuel before transport to Forsmark. This means that Clab will require a measure of rebuilding and supplementary equipment. In purely technical terms, the prospects for building an encapsulation plant sited at Forsmark are good. A description of the advantages and drawbacks of siting the encapsulation plant at Clab as opposed to any final repository at Forsmark is presented in a separate

  5. Improvement in UV protection retention capability and reduction in skin penetration of benzophenone-3 with mesoporous silica as drug carrier by encapsulation.

    Science.gov (United States)

    Li, C C; Lin, Y T; Chen, Y T; Sie, S F; Chen-Yang, Y W

    2015-07-01

    In this study, various amounts of benzophenone-3 (BP-3), a solid-type of organic UV-filter, were encapsulated in mesoporous silica (MS) to form the BP-3 encapsulated by MS UV-filters (BESs), BES-1 and BES-2, via in-situ sol-gel process. The characterization of BESs was completed using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results showed that of the BES filters, BES-2 containing emulsion (BES-2-E) exhibited about 2 times and 1.64 times higher SPF and erythemal UV-A PF values, respectively, and after 3 months about 7-8 times higher protection retention capability than the free BP-3 containing emulsion (BP-3-E). Moreover, the result of the in vitro skin penetration test using Franz glass diffusion cell indicated that the skin permeation of BP-3 from BESs was about 3 times lower than from BP-3-E. This property is particularly important for sunscreens because the amount of sunscreen penetration inside the stratum corneum directly correlates to its UV protection ability, and consequently its ability to reduce phototoxic and photo-allergic reactions that are damaging to the skin. The results of this study demonstrated the potential of as-prepared BES-2 as a UV-filter for cosmetic products.

  6. Enhanced encapsulation of metoprolol tartrate with carbon nanotubes as adsorbent

    Science.gov (United States)

    Garala, Kevin; Patel, Jaydeep; Patel, Anjali; Dharamsi, Abhay

    2011-12-01

    A highly water-soluble antihypertensive drug, metoprolol tartrate (MT), was selected as a model drug for preparation of multi-walled carbon nanotubes (MWCNTs)-impregnated ethyl cellulose (EC) microspheres. The present investigation was aimed to increase encapsulation efficiency of MT with excellent adsorbent properties of MWCNTs. The unique surface area, stiffness, strength and resilience of MWCNTs have drawn much anticipation as carrier for highly water-soluble drugs. Carbon nanotubes drug adsorbate (MWCNTs:MT)-loaded EC microspheres were further optimized by the central composite design of the experiment. The effects of independent variables (MWCNTs:MT and EC:adsorbate) were evaluated on responses like entrapment efficiency (EE) and t 50 (time required for 50% drug release). The optimized batch was compared with drug alone EC microspheres. The results revealed high degree of improvement in encapsulation efficiency for MWCNTs:MT-loaded EC microspheres. In vitro drug release study exhibited complete release form drug alone microspheres within 15 h, while by the same time only 50-60% drug was released for MWCNTs-impregnated EC microspheres. The optimized batch was further characterized by various instrumental analyses such as scanning electron microscopy, powder X-ray diffraction and differential scanning calorimetry. The results endorse encapsulation of MWCNTs:MT adsorbate inside the matrix of EC microspheres, which might have resulted in enhanced encapsulation and sustained effect of MT. Hence, MWCNTs can be utilized as novel carriers for extended drug release and enhanced encapsulation of highly water-soluble drug, MT.

  7. Encapsulation of a flavonoid-rich Allium cepa L. var. agrogatum don extract in β-cyclodextrin for transdermal drug delivery.

    Science.gov (United States)

    Ding, Zhiying; Wu, Min; Guo, Qiushi; Yang, Xiaohong; Zhang, Bingren

    2013-05-22

    This work aims to evaluate the encapsulation of a flavonoid-rich Allium cepa L. var. agrogatum Don extract (ACADFE) in β-cyclodextrin (β-CD) by analyzing the percutaneous penetration in vitro and in vivo, leading to an explanation of the physical mechanism during transdermal transport. The optimal inclusion compound containing ACADFE in β-CD was prepared in a 1:3 molar ratio. The physicochemical characterization of the inclusion complex was performed using IR, UV-vis, simultaneous thermogravimetry (TG), and differential thermal analysis (DTA) studies. It was concluded that the inclusion complex could improve the aqueous solubility and bioavailability of ACADFE. The inclusion complex exhibited significant enhancement of percutaneous absorption both in vitro and in vivo. The dorsal skins of hairless mice were photographed using a confocal scanning laser microscope. Confocal scanning laser microscopy shows that penetration of the ACADFE-β-CD inclusion complex proceeds across skin via both follicular and transcellular routes.

  8. Emerging technologies: Polymer-free phospholipid encapsulated sirolimus nanocarriers for the controlled release of drug from a stent-plus-balloon or a stand-alone balloon catheter

    NARCIS (Netherlands)

    P.A. Lemos Neto (Pedro); V. Farooq (Vasim); C.K. Takimura (Celso); P.S. Gutierrez (Paulo); R. Virmani (Renu); F. Kolodgie (Frank); U. Christians (Uwe); A.N. Kharlamov (Alexander ); M. Doshi (Manish); P. Sojitra (Prakash); H.M.M. van Beusekom (Heleen); P.W.J.C. Serruys (Patrick)

    2013-01-01

    textabstractDrug-eluting stents have proven to be effective in reducing the risk of late restenosis. In order to achieve a controlled and prolonged release of the antiproliferative agent, current drug-eluting stents utilise various biodegradable as well as non-erodible polymeric blends to coat the s

  9. Effect of Polyethylene Glycol on Properties and Drug Encapsulation-Release Performance of Biodegradable/Cytocompatible Agarose-Polyethylene Glycol-Polycaprolactone Amphiphilic Co-Network Gels.

    Science.gov (United States)

    Chandel, Arvind K Singh; Kumar, Chinta Uday; Jewrajka, Suresh K

    2016-02-10

    We synthesized agarose-polycaprolactone (Agr-PCL) bicomponent and Agr-polyethylene glycol-PCL (Agr-PEG-PCL) tricomponent amphiphilic co-network (APCN) gels by the sequential nucleophilic substitution reaction between amine-functionalized Agr and activated halide terminated PCL or PCL-b-PEG-b-PCL copolymer for the sustained and localized delivery of hydrophilic and hydrophobic drugs. The biodegradability of the APCNs was confirmed using lipase and by hydrolytic degradation. These APCN gels displayed good cytocompatibility and blood compatibility. Importantly, these APCN gels exhibited remarkably high drug loading capacity coupled with sustained and triggered release of both hydrophilic and hydrophobic drugs. PEG in the APCNs lowered the degree of phase separation and enhanced the mechanical property of the APCN gels. The drug loading capacity and the release kinetics were also strongly influenced by the presence of PEG, the nature of release medium, and the nature of the drug. Particularly, PEG in the APCN gels significantly enhanced the 5-fluorouracil loading capacity and lowered its release rate and burst release. Release kinetics of highly water-soluble gemcitabine hydrochloride and hydrophobic prednisolone acetate depended on the extent of water swelling of the APCN gels. Cytocompatibility/blood compatibility and pH and enzyme-triggered degradation together with sustained release of drugs show great promise for the use of these APCN gels in localized drug delivery and tissue engineering applications.

  10. Encapsulation with structured triglycerides

    Science.gov (United States)

    Lipids provide excellent materials to encapsulate bioactive compounds for food and pharmaceutical applications. Lipids are renewable, biodegradable, and easily modified to provide additional chemical functionality. The use of structured lipids that have been modified with photoactive properties are ...

  11. Determination of Drug Encapsulation Efficiency of Baicalin Liposomes by HPLC%高效液相色谱法测定黄芩苷脂质体药物包封率

    Institute of Scientific and Technical Information of China (English)

    李红燕; 薛大权; 洪怡

    2015-01-01

    目的:建立测定黄芩苷脂质体中药物包封率的高效液相色谱(HPLC)法。方法色谱柱为Fortis Xi C18柱(250 mm ×4.6 mm,5μm ),流动相为乙腈-0.2%磷酸溶液(35∶65),柱温为25℃,流速为1.0 mL/min,检测波长为278 nm。结果黄芩苷质量浓度在6~100μg/mL范围内与峰面积线性关系良好( r=0.9998,n=5),平均回收率为99.51%,RSD为2.09%( n=9)。结论该法准确、简便、快速,可用于黄芩苷脂质体包封率的测定。%Objective To establish an HPLC method for the determination of drug encapsulation efficiency of baicalin liposomes. Methods The chromatographic column was Fortis Xi C18 column ( 250 mm × 4. 6 mm,5 μm ) ,the mobile phase was acetonitrile-0. 2%phosphoric acid solution(35 ∶65),the column temperature was 25 ℃,the flow rate was 1. 0 mL/min,the UV detection wavelength was 278 nm. Results The baicalin concentration showed a good linear relationship in the range of 6-100 μg/mL( r=0. 999 8,n=5). The average recovery rate was 99. 51%,RSD was 2. 09%( n=9 ) . Conclusion This method is accurate,simple,rapid and can be used for the determination of baicalin liposomes encapsulation efficiency.

  12. Effect of novel curcumin-encapsulated chitosan-bioglass drug on bone and skin repair after gamma radiation: experimental study on a Wistar rat model.

    Science.gov (United States)

    Jebahi, S; Saoudi, M; Farhat, L; Oudadesse, H; Rebai, T; Kabir, A; El Feki, A; Keskes, H

    2015-04-01

    Radiation therapy contributes to a significant increase in bone osteoporosis and skin loss. Various natural health products might be beneficial to reduce bone and skin alterations. Curcumin (CUR) medicines derived from natural plants have played an important role in health care. This study aims at synthesizing and evaluating the performance therapy of CUR-encapsulated bioglass-chitosan (CUR-BG-CH). In vitro, the antioxidant assay was evaluated by using 1,1-diphenyl-2-picrylhydrazyl free-radical (DPPH) scavenging and the nitroblue tetrazolium reduction. The CUR-BG-CH antimicrobial effects were tested in liquid media. In vivo, after rat (60) Co γ-radiation, the tissue wound-healing process was studied by grafting CUR and CUR-BG-CH in femoral condyle and dorsal skin rat tissue. The antioxidant studies indicated that CUR-BG-CH quenches free radicals more efficiently than unmodified CUR and had effective DPPH (91%) and superoxide anion (51%) radical scavenging activities. The CUR-BG-CH biomaterial exhibited an important antimicrobial activity against Staphylococcus aureus. The histomorphometric parameters showed amelioration in CUR-BG-CH-treated rats. An improved mechanical property was noticed (33.16 ± 5.0 HV) when compared with that of unmodified CUR group (23.15 ± 4.9 HV). A significant decrease in tumour necrosis factor-α cytokine production was noted in the CUR-BG-CH rats (90 pg/ml) as compared with that of unmodified CUR group (240 pg/ml). The total amount of hydroxyproline was significantly enhanced (33.5%) in CUR-BG-CH group as compared with that of control. Our findings suggested that CUR-BG-CH might have promising potential applications for wound healing.

  13. Superparamagnetic Iron Oxide Nanoparticles Encapsulated in Biodegradable Thermosensitive Polymeric Micelles: Toward a Targeted Nanomedicine Suitable for Image-Guided Drug Delivery

    NARCIS (Netherlands)

    Talelli, M.; Rijcken, C.J.F.; Lammers, T.; Seevinck, P.R.; Storm, G.; van Nostrum, C.F.; Hennink, W.E.

    2009-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) have been receiving great attention lately due to their various biomedical applications, such as in MR imaging and image guided drug delivery. However, their systemic administration still remains a challenge. In this study, the ability of biodegrad

  14. NH2基修饰SiO2包覆的Fe3O4纳米管药物载体的制备及载药研究%Preparation and drug loading study on amino modified silica encapsulated magnetite nanotubes drug carrier

    Institute of Scientific and Technical Information of China (English)

    王丹; 吕敏婷; 谭钊杰

    2012-01-01

    Objective To prepare amino modified and silica encapsulated magnetite nanotubes drug carrier and study its drug loading properties. Methods Firstly,the hematite (Fe2O3) nanotubes were prepared by hydrothermal method,which were coated with SiO2 and reduced in H2 atmosphere. After that,the surface amino modification was carried out with 3-aminopropyltriethoxysilane. At last,the drug-loading properties of the prepared drug carrier were investigated with salicylic acid as a model drug. Results Amino modified and silica encapsulated magnetite nanotubes drug carrier had been prepared successfully. The entrapment efficiency and the drug loading ratio in water were 54.7% and 55.8% .respectively,and in ethanol were 22.4% and 49. 1% .respectively. Conclusion Nano Fe,O4 agnetic drug carrier with novel shape and high drug loading ratio has been prepared successfully.%目的 制备NH2基修饰SiO2包覆的Fe3O4纳米管药物载体并研究其载药性能.方法 使用水热法制备Fe2O3纳米管,然后用SiO2对其表面进行包覆,再使用H2还原制备SiO2包覆的Fe3O4纳米管,接着用3-氨丙基三乙氧基硅烷对其表面进行—NH2修饰,以水杨酸为模型药物研究所制备载体的载药性能.结果 成功制备出NH2基修饰SiO2包覆的Fe3O4纳米管药物载体,载药实验显示:以水为溶剂时,所制备的载体的包封率和载药率分别为54.7%和55.8%;以体积分数50%乙醇为溶剂时,所制备的载体的包封率和载药率分别为22.4%和49.1%.结论 成功制备得到形状新颖的载药率高的纳米Fe3O4磁性药物载体.

  15. Core-shell magnetite nanoparticles surface encapsulated with smart stimuli-responsive polymer: synthesis, characterization, and LCST of viable drug-targeting delivery system.

    Science.gov (United States)

    Zhang, J L; Srivastava, R S; Misra, R D K

    2007-05-22

    We describe here the synthesis of a novel magnetic drug-targeting carrier characterized by a core-shell structure. The core-shell carrier combines the advantages of a magnetic core and the stimuli-responsive property of the thermosensitive biodegradable polymer shell (e.g., an on-off mechanism responsive to external temperature change). The composite nanoparticles are approximately 8 nm in diameter with approximately 3 nm shell. The lower critical solution temperature (LCST) is approximately 38 degrees C as determined by UV-vis absorption spectroscopy. The carrier is composed of cross-linked dextran grafted with a poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) [dextran-g-poly(NIPAAm-co-DMAAm)] shell and superparamagnetic Fe3O4 core. Fourier transform infrared spectroscopy (FTIR) confirmed the composition of the carrier. The synthesized magnetic carrier system has potential applications in magnetic drug-targeting delivery and magnetic resonance imaging.

  16. Silica Micro Encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, P.; Whitbread-Jordan, M. [KEECO (United Kingdom)

    2001-04-01

    The article explains how Silica Micro Encapsulation (SME) water treatment technology may be transferred from metal mining to coal mining operations. KEECO has been developing a unique solution for treating acid rock drainage in the metal sulphide mining sector and following trials in metal mining operations (described in the article), is preparing to transfer the technology to the coal industry. SME technology comprises metal precipitation and encapsulation accomplished with proprietary chemical, KB-1, and a group of patented chemical dosing systems, the K-series, to dose KB-1 into contaminated liquid wastes as a dry powder. 4 figs., 4 tabs.

  17. Subcutaneous encapsulated fat necrosis

    DEFF Research Database (Denmark)

    Aydin, Dogu; Berg, Jais O

    2016-01-01

    We have described subcutaneous encapsulated fat necrosis, which is benign, usually asymptomatic and underreported. Images have only been published on two earlier occasions, in which the necrotic nodules appear "pearly" than the cloudy yellow surface in present case. The presented image may help f...... future surgeons to establish the diagnosis peroperatively....

  18. Poly(DL-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate): synthesis, characterization, micellization behavior in aqueous solutions, and encapsulation of the hydrophobic drug dipyridamole.

    Science.gov (United States)

    Karanikolopoulos, Nikos; Zamurovic, Miljana; Pitsikalis, Marinos; Hadjichristidis, Nikos

    2010-02-08

    We synthesized a series of well-defined poly(dl-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate) (PDLLA-b-PDMAEMA) amphiphilic diblock copolymers by employing a three-step procedure: (a) ring-opening polymerization (ROP) of dl-lactide using n-decanol and stannous octoate, Sn(Oct)(2), as the initiating system, (b) reaction of the PDLLA hydroxyl end groups with bromoisobutyryl bromide, and (c) atom transfer radical polymerization, ATRP, of DMAEMA with the newly created bromoisobutyryl initiating site. The aggregation behavior of the prepared block copolymers was investigated by dynamic light scattering and zeta potential measurements at 25 degrees C in aqueous solutions of different pH values. The hydrophobic drug dipyridamole was efficiently incorporated into the copolymer aggregates in aqueous solutions of pH 7.40. High partition coefficient values were determined by fluorescence spectroscopy.

  19. Controlled Release of Multiple Hydrophilic and Hydrophobic Drugs and in vitro Cytotoxicity of Electrospun Poly(lactic-co-glycolic acid)/ZnO Nanofibers Encapsulated with Dual Drugs%聚乳酸-乙醇酸/纳米氧化锌复合电纺纤维装载亲疏水药物的控释及体外细胞毒性

    Institute of Scientific and Technical Information of China (English)

    曾莉; 胡俊; 魏俊超

    2014-01-01

    利用静电纺丝技术制备了负载亲水性药物阿霉素( DOX)以及疏水性药物喜树碱( CPT)的复合纳米纤维。先用巯基封端的普朗尼克(F127)修饰纳米氧化锌(FZnO),再将FZnO负载盐酸阿霉素(DOX@FZnO),最后将DOX@FZnO与CPT一起纺入聚乳酸-乙醇酸( PLGA)纤维中。体外药物释放结果表明,复合纳米纤维能够减小亲水性药物的突释,减缓药物释放速率,延长药物释放时间。体外细胞活性结果表明,双载药复合纤维比单载药复合纤维具有更强的细胞毒性,能够有效抑制癌细胞生长。%A novel poly( lactic-co-glycolic acid) ( PLGA)/ZnO electrospun composite fibers encapsulated with both hydrophilic drug(doxorubicin hydrochloride, DOX) and hydrophobic drug(camptothecin, CPT) were fabricated via electrospinning method. Primarily, the ZnO was decorat with F127 and then used to encapsulate DOX. Finally, the DOX-loaded ZnO( DOX@ZnO) and CPT were mixed with PLGA solution to fabricate elec-trospun hybrid nanofibers. The in vitro release results demonstrated the composite fibers decreased the burst release and increased the time of release, which showed a long-term and sustained release. The cell cytotoxici-ty test demonstated that the composite nanofiber with two drugs showed stronger antitumor efficacy against HepG-2 cells than the nanofiber with single drug. Thus, the composite nanofibers with two anticancer drugs could be a versatile drug delivery system as local implantable scaffolds for potential postsurgical cancer treat-ment.

  20. A mathematical model of aerosol holding chambers

    DEFF Research Database (Denmark)

    Zak, M; Madsen, J; Berg, E

    1999-01-01

    A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol...... in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London...

  1. Influence of Formulation Components on Aerosolization Properties of Isoniazid Loaded Chitosan Microspheres

    Directory of Open Access Journals (Sweden)

    Aliasgar J. Kundawala

    2011-10-01

    Full Text Available The objective of the present study was to prepare microspheres with small size and good sphericity by spray drying technology using Isoniazid (INH as model drug, chitosan as encapsulating polymer; lactose and L Leucine as bulking and dispersing agent respectively. Influence of formulation components on physical properties and aerosol performance were studied. The spray dried powders obtained were characterized for morphological characteristics, compatibility using scanning electron microscopy and Differential Scanning calorimetery respectively. Tapped density; bulk density and aerosol properties like Fine particle fraction, mass median aerodynamic diameter etc were also evaluated. The smooth microspheres with particle size ranging between 4 to 6 µm were obtained. The drug content of chitosan microspheres loaded with Isoniazid were in the range of 88 % to 108 %. The drug release studies showed that more than 90% of drug released from the chitosan microsphere matrix within one hour. The fine particle fraction observed between 55 to 67 % which indicate good lung deposition. Results of Fine particle fraction also revealed addition of L Leucine found to enhance powder dispersibility.

  2. Factors determining the stability, size distribution, and cellular accumulation of small, monodisperse chitosan nanoparticles as candidate vectors for anticancer drug delivery: application to the passive encapsulation of [14C]-doxorubicin

    Directory of Open Access Journals (Sweden)

    Masarudin MJ

    2015-12-01

    readily accumulate the nanoparticles 30 minutes posttreatment and that nanoparticles persisted within cells for up to 24 hours posttreatment. As a proof of principle for use in anticancer therapeutic applications, a [14C]-radiolabeled form of the anticancer agent doxorubicin was efficiently encapsulated within the CNP, confirming the feasibility of using this system as a drug delivery vector. Keywords: nanobiotechnology, drug delivery, chitosan, chitosan nanoparticles, doxorubicin, FITC

  3. Anisotropic silica mesostructures for DNA encapsulation

    Indian Academy of Sciences (India)

    Aparna Ganguly; Ashok K Ganguli

    2013-04-01

    The encapsulation of biomolecules in inert meso or nanostructures is an important step towards controlling drug delivery agents. Mesoporous silica nanoparticles (MSN) are of immense importance owing to their high surface area, large pore size, uniform particle size and chemical inertness. Reverse micellar method with CTAB as the surfactant has been used to synthesize anisotropic mesoporous silica materials. We have used the anisotropic silica nanostructures for DNA encapsulation studies and observed a loading capacity of ∼8 g mg-1 of the sample. On functionalizing the pores of silica with amine group, the amount of DNA loaded on the rods decreases which is due to a reduction in the pore size upon grafting of amine groups.

  4. Novel methods for the encapsulation of meglumine antimoniate into liposomes

    Directory of Open Access Journals (Sweden)

    F. Frézard

    2000-07-01

    Full Text Available The antimonial drug, meglumine antimoniate, was successfully encapsulated in dehydration-rehydration vesicles and in freeze-dried empty liposomes (FDELs. High encapsulation efficiencies (from 28 to 58% and low weight ratios of lipids to encapsulated antimony (from 1:0.15 to 1:0.3 were achieved. These formulations, contrary to those obtained by conventional methods, can be stored as intermediate lyophilized forms and reconstituted just before use. The efficacy of FDEL-encapsulated meglumine antimoniate was evaluated in hamsters experimentally infected with Leishmania chagasi. A significant reduction of liver parasite burdens was observed in animals treated with this preparation, when compared to control animals treated with empty liposomes. In contrast, free meglumine antimoniate was found to be inefficient when administered at a comparable dose of antimony. This novel liposome-based meglumine antimoniate formulation appears to be promising as a pharmaceutical product for the treatment of visceral leishmaniasis.

  5. Encapsulation of graphene in Parylene

    Science.gov (United States)

    Skoblin, Grigory; Sun, Jie; Yurgens, August

    2017-01-01

    Graphene encapsulated between flakes of hexagonal boron nitride (hBN) demonstrates the highest known mobility of charge carriers. However, the technology is not scalable to allow for arrays of devices. We are testing a potentially scalable technology for encapsulating graphene where we replace hBN with Parylene while still being able to make low-ohmic edge contacts. The resulting encapsulated devices show low parasitic doping and a robust Quantum Hall effect in relatively low magnetic fields <5 T.

  6. Congenital peritoneal encapsulation

    Institute of Scientific and Technical Information of China (English)

    Diana; Teixeira; Vítor; Costa; Paula; Costa; Carlos; Alpoim; Pinto; Correia

    2015-01-01

    Peritoneal encapsulation(PE) is a rare congenital malformation, characterized by a thin accessory peritoneal membrane which covers all or part of the small bowel, forming an accessory peritoneal sac. Most cases areasymptomatic and diagnosed incidentally during surgery and/or autopsy. Clinical presentation with intestinal obstruction is extremely rare and we report a case. A 25-year-old male, referred to emergency department with diffuse abdominal pain, crampy, with 8 h evolution, associated with nausea, vomiting and constipation in the last 48 h. The abdominal examination revealed an asymmetric and fixed distension, with hard consistency on palpation of lower abdominal quadrants. The abdominal radiography reveals a small bowel distension and fluid levels. Submitted to laparoscopic surgery that recourse to conversion because there is a total peritoneal encapsulation of the small bowel. After opening the peritoneal sac, we find a rotation of mesentery, at its root, conditioning twisting of small bowel and consequently occlusion. Uneventful postoperative with discharged at the 6th day. The PE is a very rare congenital anomaly characterized by abnormal bowel back into the abdominal cavity in the early stages of development. Your knowledge becomes important because, although rare, it might be diagnosis in patients with intestinal obstruction, in the absence of other etiologic factors.

  7. Polymer encapsulation of amoxicillin microparticles by SAS process.

    Science.gov (United States)

    Montes, A; Baldauf, E; Gordillo, M D; Pereyra, C M; Martínez de la Ossa, E J

    2014-01-01

    Encapsulation of amoxicillin (AMC) with ethyl cellulose (EC) by a supercritical antisolvent process (SAS) was investigated. AMC microparticles obtained previously by an SAS process were used as host particles and EC, a biodegradable polymer used for the controlled release of drugs, was chosen as the coating material. In this work, a suspension of AMC microparticles in a solution of ethyl cellulose in dichloromethane (DCM) was sprayed through a nozzle into supercritical CO2. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and HPLC analyses were carried out. The effects of AMC:EC ratio, the initial polymer concentration of the solution, temperature and pressure on the encapsulation process were investigated. Although all the experiments led to powder precipitation, the AMC encapsulation was achieved in only half of the cases, particularly when the lower drug:polymer ratios were assayed. In general, it was observed that the percentages of AMC present in the precipitates were higher on increasing the AMC:EC ratio. In these cases composites rather than encapsulates were obtained. The in vitro release profiles of the resulting materials were evaluated in order to ascertain whether composites can be used as encapsulated systems for drug delivery systems.

  8. Hydrophobic encapsulation of hydrocarbon gases.

    Science.gov (United States)

    Leontiev, Alexander V; Saleh, Anas W; Rudkevich, Dmitry M

    2007-04-26

    [reaction: see text] Encapsulation data for hydrophobic hydrocarbon gases within a water-soluble hemicarcerand in aqueous solution are reported. It is concluded that hydrophobic interactions serve as the primary driving force for the encapsulation, which can be used for the design of gas-separating polymers with intrinsic inner cavities.

  9. Micro-Encapsulation of Probiotics

    Science.gov (United States)

    Meiners, Jean-Antoine

    Micro-encapsulation is defined as the technology for packaging with the help of protective membranes particles of finely ground solids, droplets of liquids or gaseous materials in small capsules that release their contents at controlled rates over prolonged periods of time under the influences of specific conditions (Boh, 2007). The material encapsulating the core is referred to as coating or shell.

  10. Encapsulation of isohexenylnaphthazarins in cyclodextrins.

    Science.gov (United States)

    Assimopoulou, A N; Papageorgiou, V P

    2004-05-01

    Naturally occurring isohexenylnaphthazarins (IHN), such as Alkannin, Shikonin (A/S) and their derivatives, are potent pharmaceutical substances with a wide spectrum of biological activity. In the present study, inclusion complexes of alkannin and shikonin commercial samples and IHN derivatives in the form of an oily extract of Alkanna tinctoria roots were formed with beta-cyclodextrin (CD) and beta-HPCD. These complexes were investigated to evaluate the effect of complexation on their aqueous solubility, decoloration, and also the percentage of polymeric A/S and IHN derivatives enclosed in the CDs cavity, since these decrease the active monomeric IHN. Both beta-CD and beta-HPCD increased the aqueous solubility of A/S and IHN derivatives and thus inclusion complexes can be used as drug delivery systems for A/S in both internal (capsules, tablets) and external hydrophilic pharmaceutical and cosmetic preparations (creams, gels, sprays) with enhanced bioavailability. The inclusion complexes formed had a pale purple colour, contributing to the partial decoloration of the A/S and thus of the fi nal pharmaceutical preparations. Finally, CDs selectively included more monomeric and less polymeric IHN, compared with the initial each time sample that is encapsulated; thus inclusion complexes may present enhanced biological activity.

  11. Aerosolized Antibiotics.

    Science.gov (United States)

    Restrepo, Marcos I; Keyt, Holly; Reyes, Luis F

    2015-06-01

    Administration of medications via aerosolization is potentially an ideal strategy to treat airway diseases. This delivery method ensures high concentrations of the medication in the targeted tissues, the airways, with generally lower systemic absorption and systemic adverse effects. Aerosolized antibiotics have been tested as treatment for bacterial infections in patients with cystic fibrosis (CF), non-CF bronchiectasis (NCFB), and ventilator-associated pneumonia (VAP). The most successful application of this to date is treatment of infections in patients with CF. It has been hypothesized that similar success would be seen in NCFB and in difficult-to-treat hospital-acquired infections such as VAP. This review summarizes the available evidence supporting the use of aerosolized antibiotics and addresses the specific considerations that clinicians should recognize when prescribing an aerosolized antibiotic for patients with CF, NCFB, and VAP.

  12. Encapsulation of Aroma

    Science.gov (United States)

    Zuidam, Nicolaas Jan; Heinrich, Emmanuel

    Flavor is one of the most important characteristics of a food product, since people prefer to eat only food products with an attractive flavor (Voilley and Etiévant 2006). Flavor can be defined as a combination of taste, smell and/or trigeminal stimuli. Taste is divided into five basic ones, i.e. sour, salty, sweet, bitter and umami. Components that trigger the so-called gustatory receptors for these tastes are in general not volatile, in contrast to aroma. Aroma molecules are those that interact with the olfactory receptors in the nose cavity (Firestein 2001). Confusingly, aroma is often referred to as flavor. Trigeminal stimuli cause sensations like cold, touch, and prickling. The current chapter only focuses on the encapsulation of the aroma molecules.

  13. Palisaded encapsulated neuroma

    Directory of Open Access Journals (Sweden)

    Adesh S Manchanda

    2015-01-01

    Full Text Available Palisaded encapsulated neuroma (PEN is a benign cutaneous or mucosal neural tumor which, usually, presents as a solitary, firm, asymptomatic, papule or nodule showing striking predilection for the face. It occurs commonly in middle age, and there is no sex predilection. Oral PEN are not common, and these lesions must be distinguished from other peripheral nerve sheath tumors such as the neurofibroma, neurilemma (schwannoma, and traumatic neuroma. The major challenge in dealing with lesions of PEN is to avoid the misdiagnosis of neural tumors that may be associated with systemic syndromes such as neurofibromatosis and multiple endocrine neoplasia syndrome type 2B. Here, we present a case of benign PEN of the gingiva in the left anterior mandibular region, laying importance on immunohistochemical staining in diagnosing such lesions.

  14. Sclerosing encapsulating peritonitis

    Directory of Open Access Journals (Sweden)

    Jen-Jung Pan

    2012-03-01

    Full Text Available Sclerosing encapsulating peritonitis (SEP is a rare cause of intestinal obstruction. This entity has been reported as either primary idiopathic or secondary to other diseases. We report SEP in 2 cirrhotic patients and review the literature. Both patients had decompensated cirrhosis and episodes of spontaneous bacterial peritonitis. One patient underwent a Denver shunt placement before developing SEP. This patient remains alive and is managed conservatively. The other patient deceased from multi-organ failure after the resection of gangrened small bowel. The manifestations of SEP are often nonspecific that leads to misdiagnosis and/or delayed diagnosis. Early diagnosis of SEP is difficult but not impossible. Surgical treatment is often required when intestinal obstruction is present. Nevertheless, patients with this problem can be treated conservatively with immunosuppressive therapy with or without total parenteral nutrition (TPN before going for surgery.

  15. Mechanically invisible encapsulations

    DEFF Research Database (Denmark)

    Mazurek, Piotr Stanislaw

    the commercialisation of such devices. Therefore, this project was dedicated to exploring the possibility of using polar liquids as high dielectric constant fillers for dielectric PDMS-based elastomers. Incorporating polar liquids in the form of discrete droplets into nonpolar membrane swas expected to produce a two......-fold improvement with respect to a reference material. Firstly, dielectric constant enhancement and, secondly, a Young’s modulus decrease were anticipated. In the first approach a flow-focusing microfluidic technique was employed, in order to encapsulate polar liquids within a soft elastomeric shell. The produced...... core-shell microspheres served as a carrier for liquids, enabling the uniform dispersion of the filler droplets within PDMS prepolymer. The dielectric constant of the prepared water-PDMS composite was proven to be enhanced by 30% following the incorporation of 4.5 wt.% of water. Due to the favourable...

  16. Stabilization and encapsulation of magnetite nanoparticles

    Science.gov (United States)

    Kawni, Issmat Al; Garcia, Ricardo; Youssef, Sami; Abboud, Maher; Podlecki, Jean; Habchi, Roland

    2016-12-01

    The goal is to stabilize magnetite nanoparticles (NPs) in order to prepare them for encapsulation and to obtain a core–shell structure. Magnetite NPs were obtained by a co-precipitation method and then treated with different stabilizing agents in order to get a full dispersion in an aqueous medium. The dispersed particles were then coated with silica using a TEOS solution. The samples were characterized by Raman spectroscopy, TEM, EDX analysis, and FTIR measurements. The particles are the basis of a core–shell structure where a potential polymer or drug could be anchored on the surface.

  17. Cinnamomum casia Extract Encapsulated Nanochitosan as Antihypercholesterol

    Science.gov (United States)

    Ngadiwiyana; Purbowatiningrum; Fachriyah, Enny; Ismiyarto

    2017-02-01

    Atherosclerosis vascular disease with clinical manifestations such as cardiovascular disease and stroke are the leading cause of death in Indonesia. One solution to these problems is a natural antihypercholesterol medicine by utilizing Cinnamomum casia extract. However, the use of natural extracts to lower blood cholesterol levels do not provide optimal results because it is possible that the active components of extract have been degraded/damaged during the absorption process. So that, we need to do the research to get a combination of chitosan nanoparticles-Cinnamomum casia. extract as a compound which has an antihypercholesterol activity through the in vitro study. Modification of natural extracts encapsulated nanochitosan be a freshness in this study, which were conducted using the method of inclusion. The combination of both has the dual function of protecting the natural extracts from degradation and deliver the natural extracts to the target site. Analysis of nanochitosan using the Particle Size Analyzer (PSA) shows the particle size of synthesis product that is equal to 64.9 nm. Encapsulation efficiency of Cinnamomum casia extract-Chitosan Nanoparticles known through UV-VIS spectrophotometry test and obtained the efficiency encapsulation percentage of 84.93%. Zeta Potential at 193,3 mv that chitosan appropriate for a delivery drug. Antihypercholesterol activity tested in vitro assay that showed the extract-nanoparticle chitosan in concentration 150 ppm gave the highest cholesterol decreasing level in the amount of 49.66% w/v. So it can be concluded that Cinnamomum casia extract can be encapsulated in nanoparticles of chitosan and proved that it has a cholesterol-lowering effect through the in vitro study.

  18. Encapsulation and characterization of controlled release flurbiprofen loaded microspheres using beeswax as an encapsulating agent.

    Science.gov (United States)

    Ranjha, Nazar M; Khan, Hafeezullah; Naseem, Shahzad

    2010-05-01

    The aim of the present study was to extend the use of flurbiprofen in clinical settings by avoiding its harmful gastric effects. For this purpose, we designed the controlled release solid lipid flurbiprofen microspheres (SLFM) by emulsion congealing technique. Drug was entrapped into gastro resistant biodegradable beeswax microspheres which were prepared at different drug/beeswax ratios 1:1, 1:2 and 1:3 using gelatin and tween 20 as emulsifying agents. The effect of emulsifiers and the effect drug/beeswax ratios were studied on hydration rate, encapsulating efficiency, micromeritic properties, scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (X-RD) analysis and in vitro drug release at pH 1.2 for 2 h and at pH 6.8 for 10 h. SEM revealed that microspheres made with tween 20 were smooth while microspheres made with gelatin showed porous morphology, however, they were all spherical in nature. The practical yield (recovery) showed a dependence on drug-beeswax ratio and it was variable from 53 to 84%. High loading encapsulating efficiency of flurbiprofen from 8 to 94% was achieved. FTIR and DSC analysis confirmed the absence of any drug polymer interaction indicating drug stability during microencapsulation. X-RD of pure flurbiprofen shows sharp peaks, which decreases on encapsulation, indicating decrease in the crystallinity of drug in microspheres. The micromeritic studies confirmed the presence of excellent and good flow properties of microspheres. Entrapment efficiency, morphology, practical yield, hydration rate, flow properties demonstrated their dependence on the HLB value of emulsifiers and emulsifiers with higher HLB were found more appropriate for effective microencapsulation of flurbiprofen. The release kinetics followed zero order mechanism of drug release at pH 6.8. Release pattern depends on the morphology of flurbiprofen microspheres and amount of beeswax used in

  19. Sclerosing Encapsulating Peritonitis; Review

    Directory of Open Access Journals (Sweden)

    Norman O. Machado

    2016-05-01

    Full Text Available Sclerosing encapsulating peritonitis (SEP is a rare chronic inflammatory condition of the peritoneum with an unknown aetiology. Also known as abdominal cocoon, the condition occurs when loops of the bowel are encased within the peritoneal cavity by a membrane, leading to intestinal obstruction. Due to its rarity and nonspecific clinical features, it is often misdiagnosed. The condition presents with recurrent episodes of small bowel obstruction and can be idiopathic or secondary; the latter is associated with predisposing factors such as peritoneal dialysis or abdominal tuberculosis. In the early stages, patients can be managed conservatively; however, surgical intervention is necessary for those with advanced stage intestinal obstruction. A literature review revealed 118 cases of SEP; the mean age of these patients was 39 years and 68.0% were male. The predominant presentation was abdominal pain (72.0%, distension (44.9% or a mass (30.5%. Almost all of the patients underwent surgical excision (99.2% without postoperative complications (88.1%.

  20. Modelling encapsulation of gold and silver nanoparticles inside lipid nanotubes

    Science.gov (United States)

    Baowan, Duangkamon; Thamwattana, Ngamta

    2014-02-01

    Lipid nanotubes are of particular interest for use as a template to create various one-dimensional nanostructures and as a carrier for drug and gene delivery. Understanding the encapsulation process is therefore crucial for such development. This paper models the interactions between lipid nanotubes and spheres of gold and silver nanoparticles and determines the critical dimension of lipid nanotubes that maximises the interaction with the nanoparticles. Our results confirm the acceptance of gold and silver nanoparticles inside lipid nanotubes. Further, we find that the lipid nanotube of radius approximately 10.23 nm is most favourable to encapsulate both types of nanoparticles.

  1. Encapsulated microsensors for reservoir interrogation

    Science.gov (United States)

    Scott, Eddie Elmer; Aines, Roger D.; Spadaccini, Christopher M.

    2016-03-08

    In one general embodiment, a system includes at least one microsensor configured to detect one or more conditions of a fluidic medium of a reservoir; and a receptacle, wherein the receptacle encapsulates the at least one microsensor. In another general embodiment, a method include injecting the encapsulated at least one microsensor as recited above into a fluidic medium of a reservoir; and detecting one or more conditions of the fluidic medium of the reservoir.

  2. Characterization of different vitamin E carriers intended for pulmonary drug delivery.

    Science.gov (United States)

    Laouini, A; Andrieu, V; Vecellio, L; Fessi, H; Charcosset, C

    2014-08-25

    The targeted release of drugs intended for pulmonary delivery is a research field which has been so far rather unexploited but is currently becoming increasingly attractive. Liquid dispersions encapsulating vitamin E (liposomes, micelles, nano-emulsion, and solid lipid particles) were prepared using various methods based on membrane contactor. The dispersions were nebulized and aerodynamic characteristics of the generated aerosols were assessed using two different methods: laser light scattering and cascade impaction. When the laser diffraction technique was used, results showed that fine particle fractions (<5 μm) were 19, 29, 38 and 71% for solid lipid particles, micelles, nano-emulsion and liposomes, respectively. When the impaction method was applied, using a next generation pharmaceutical impactor operated at 30 l/min, results showed that fine particle fractions were 39, 78, 82 and 87% for solid lipid particles, micelles, nano-emulsion and liposomes, respectively. The differences observed between the results obtained from both methods confirm that the laser diffraction method is not always suitable for aerodynamic characterization of aerosols and should be validated against an impaction method. Nebulization of the drug-carrier systems led to an increase of their size most likely due to aggregation phenomena. The size was increased by a factor of 2-26 depending on the encapsulation system. The most important aggregation was obtained with nano-emulsion; the less one with solid lipid particles. The mass median aerodynamic diameter (MMAD) of the generated aerosols ranged from 1.76 to 6.10 μm. The application of a mathematical model, the Multiple-Path Particle Dosimetry (MPPD), for the prediction of the pulmonary deposit gave encouraging results. The rate of vitamin E able to reach the lung ranged from 37.6 (for the liposomes) to 51.6% (for the micelles). The obtained results showed that the different systems developed for vitamin E encapsulation were suitable to

  3. An evaluation of transmembrane ion gradient-mediated encapsulation of topotecan within liposomes.

    Science.gov (United States)

    Abraham, Sheela A; Edwards, Katarina; Karlsson, Göran; Hudon, Norma; Mayer, Lawrence D; Bally, Marcel B

    2004-05-18

    Topotecan can be encapsulated in liposomes, however little is known about the role encapsulated counter ions play in drug loading efficiency and drug release. Using 1,2-distearoyl-sn-glycero-3 phosphatidylcholine and cholesterol liposomes (55:45 mole ratio), encapsulation was achieved using manganese ion gradients (MnSO(4) or MnCl(2)), with the addition of A23187, a divalent cation/proton exchanger, to maintain a pH gradient. This methodology was compared to procedures where the pH gradient was generated by use of encapsulated (NH(4))(2)SO(4) or citrate (300 mM, pH 3.5). All methods facilitated topotecan encapsulation. Liposomes prepared in the presence of the citrate and MnCl(2) (+A23187) exhibited reduced loading capacities. Liposomes prepared in the presence of (NH(4))(2)SO(4) and MnSO(4) (+A23187) could be used to generate liposomes exhibiting a drug-to-lipid ratio of 0.3 (wt/wt) with an encapsulation efficiency of >90%. In vitro drug release data suggested that the (NH(4))(2)SO(4) and MnSO(4) (+A23187) formulations released drug at a reduced rate. For these formulations, the drug release rates decreased as the drug-to-lipid ratio (wt/wt) increased from 0.1 to 0.2. Cryo-electron micrographs indicated that encapsulated topotecan precipitated as linear particles within liposomes. The stability of topotecan loaded liposomes appeared to be dependent on the presence of both a pH gradient and encapsulated sulfate.

  4. Aerosolized antimicrobial agents based on degradable dextran nanoparticles loaded with silver carbene complexes

    KAUST Repository

    Ornelas-Megiatto, Cátia

    2012-11-05

    Degradable acetalated dextran (Ac-DEX) nanoparticles were prepared and loaded with a hydrophobic silver carbene complex (SCC) by a single-emulsion process. The resulting particles were characterized for morphology and size distribution using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The average particle size and particle size distribution were found to be a function of the ratio of the organic phase to the surfactant containing aqueous phase with a 1:5 volume ratio of Ac-DEX CH2Cl2 (organic):PBS (aqueous) being optimal for the formulation of nanoparticles with an average size of 100 ± 40 nm and a low polydispersity. The SCC loading was found to increase with an increase in the SCC quantity in the initial feed used during particle formulation up to 30% (w/w); however, the encapsulation efficiency was observed to be the best at a feed ratio of 20% (w/w). In vitro efficacy testing of the SCC loaded Ac-DEX nanoparticles demonstrated their activity against both Gram-negative and Gram-positive bacteria; the nanoparticles inhibited the growth of every bacterial species tested. As expected, a higher concentration of drug was required to inhibit bacterial growth when the drug was encapsulated within the nanoparticle formulations compared with the free drug illustrating the desired depot release. Compared with free drug, the Ac-DEX nanoparticles were much more readily suspended in an aqueous phase and subsequently aerosolized, thus providing an effective method of pulmonary drug delivery. © 2012 American Chemical Society.

  5. Innovative formulations for controlled drug delivery to the lungs and the technical and toxicological challenges to overcome(.).

    Science.gov (United States)

    Aragao-Santiago, Leticia; Bohr, Adam; Delaval, Mathilde; Dalla-Bona, Alexandra C; Gessler, Tobias; Seeger, Werner; Beck-Broichsitter, Moritz

    2016-01-01

    Inhalation of therapeutic aerosols has a long tradition and is, moreover, regarded as a safe and efficient route of drug administration to the respiratory tract. Especially, the targeting opportunities of this approach are beneficial for the treatment of numerous airway diseases. However, the rapid decay of local drug concentration and the resulting short-term duration of action of conventional medications necessitates several daily inhalations, which is clearly in conflict with a patients' convenience and compliance. Recent progress in pharmaceutical engineering has provided promising drug delivery vehicles (e.g., liposomes, nanoparticles and thermo-responsive preparations) allowing for a sustained release of the encapsulated medication at the target site. Nevertheless, aspects such as generating tailored aerosols from these formulations (including stability during aerosolization) and the choice of biocompatible excipients remain considerable challenges, which need to be addressed in order to optimize inhalation therapy. Therefore, toxicology issues raised by these novel drug delivery vehicles with respect to physicochemical and material properties and biocompatibility are described in this review. This brief overview is intended to serve as a foundation to prompt future advancement in the field of controlled drug delivery to the lungs.

  6. Process engineering of high voltage alginate encapsulation of mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Gryshkov, Oleksandr, E-mail: gryshkov@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany); Pogozhykh, Denys, E-mail: pogozhykh@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany); Zernetsch, Holger, E-mail: zernetsch@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany); Hofmann, Nicola, E-mail: hofmann@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany); Mueller, Thomas, E-mail: mueller.thomas@mh-hannover.de [Institute for Transfusion Medicine, Medical School Hannover, D-30625 Hannover (Germany); Glasmacher, Birgit, E-mail: glasmacher@imp.uni-hannover.de [Institute for Multiphase Processes, Leibniz University Hannover, D-30167 Hannover (Germany)

    2014-03-01

    Encapsulation of stem cells in alginate beads is promising as a sophisticated drug delivery system in treatment of a wide range of acute and chronic diseases. However, common use of air flow encapsulation of cells in alginate beads fails to produce beads with narrow size distribution, intact spherical structure and controllable sizes that can be scaled up. Here we show that high voltage encapsulation (≥ 15 kV) can be used to reproducibly generate spherical alginate beads (200–400 μm) with narrow size distribution (± 5–7%) in a controlled manner under optimized process parameters. Flow rate of alginate solution ranged from 0.5 to 10 ml/h allowed producing alginate beads with a size of 320 and 350 μm respectively, suggesting that this approach can be scaled up. Moreover, we found that applied voltages (15–25 kV) did not alter the viability and proliferation of encapsulated mesenchymal stem cells post-encapsulation and cryopreservation as compared to air flow. We are the first who employed a comparative analysis of electro-spraying and air flow encapsulation to study the effect of high voltage on alginate encapsulated cells. This report provides background in application of high voltage to encapsulate living cells for further medical purposes. Long-term comparison and work on alginate–cell interaction within these structures will be forthcoming. - Highlights: • High voltage alginate encapsulation of mesenchymal stem cells (MSCs) was designed. • Reproducible and spherical alginate beads were generated via high voltage. • Air flow encapsulation was utilized as a comparative approach to high voltage. • High voltage did not alter the viability and proliferation of encapsulated MSCs. • High voltage encapsulation can be scaled up and applied in cell-based therapy.

  7. Encapsulating contact allergens in liposomes, ethosomes, and polycaprolactone may affect their sensitizing properties.

    Science.gov (United States)

    Madsen, Jakob Torp; Vogel, Stefan; Johansen, Jeanne Duus; Andersen, Klaus Ejner

    2011-06-01

    Attempts to improve formulation of topical products are a continuing process and the development of micro- and nanovesicular systems as well as polymeric microparticles has led to marketing of topical drugs and cosmetics using these technologies. Encapsulation of some well-known contact allergens in ethanolic liposomes have been reported to enhance allergenicity compared with the allergens in similar vehicles without liposomes. The present report includes data on more sensitization studies using the mouse local lymph node assay with three contact allergens encapsulated in different dermal drug-delivery systems: liposomes, ethosomes, and polycaprolactone particles. The results show that the drug-delivery systems are not sensitizers in themselves. Encapsulating the hydrophilic contact allergen potassium dichromate in all three drug-delivery systems did not affect the sensitizing capacity of potassium dichromate compared with control solutions. However, encapsulating the lipophilic contact allergen dinitrochlorobenzene (DNCB) in polycaprolactone reduced the sensitizing capacity to 1211 ± 449 compared with liposomes (7602 ± 2658) and in acetone:olive oil (4:1) (5633 ± 666). The same trend was observed for encapsulating isoeugenol in polycaprolactone (1100 ± 406) compared with a formulation in acetone:olive oil (4491 ± 819) and in liposomes (3668 ± 950). Further, the size of DNCB-loaded liposomes did not affect the sensitizing properties. These results suggest that modern dermal drug-delivery systems may in some cases magnify or decrease the sensitizing capacity of the encapsulated contact allergen.

  8. LES of Laminar-to-Turbulent Particle-Fluid Dynamics in Human and Nonhuman Primate Airways: Applications to Aerosolized Drug Delivery Animal Testing

    Science.gov (United States)

    Geisler, Taylor; Padhy, Sourav; Shaqfeh, Eric; Iaccarino, Gianluca

    2016-11-01

    Both the human health benefit and risk from the inhalation of aerosolized medications is often predicted by extrapolating experimental data taken using nonhuman primates to human inhalation. In this study, we employ Large Eddy Simulation to simulate particle-fluid dynamics in realistic upper airway models of both humans and rhesus monkeys. We report laminar-to-turbulent flow transitions triggered by constrictions in the upper trachea and the persistence of unsteadiness into the low Reynolds number bifurcating lower airway. Micro-particle deposition fraction and locations are shown to depend significantly on particle size. In particular, particle filtration in the nasal airways is shown to approach unity for large aerosols (8 microns) or high-rate breathing. We validate the accuracy of LES mean flow predictions using MRV imaging results. Additionally, particle deposition fractions are validated against experiments in 3 model airways.

  9. TOMS Absorbing Aerosol Index

    Data.gov (United States)

    Washington University St Louis — TOMS_AI_G is an aerosol related dataset derived from the Total Ozone Monitoring Satellite (TOMS) Sensor. The TOMS aerosol index arises from absorbing aerosols such...

  10. Encapsulation of indomethacin in magnetic biodegradable polymer nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zavisova, Vlasta [Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Kosice (Slovakia)]. E-mail: zavisova@saske.sk; Koneracka, Martina [Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Kosice (Slovakia); Strbak, Oliver [Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Kosice (Slovakia); Tomasovicova, Natalia [Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Kosice (Slovakia); Kopcansky, Peter [Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Kosice (Slovakia); Timko, Milan [Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Kosice (Slovakia); Vavra, Ivo [Institute of Electrical Engineering, Slovak Academy of Science, Dubravska cesta 9, 841 04 Bratislava (Slovakia)

    2007-04-15

    In this study, indomethacin (IND), which is a poorly water-soluble anti-inflammatory drug, was encapsulated in magnetic biodegradable poly(D,L-lactide) polymer (PLA) by the nanoprecipitation method. The influence of aqueous phase pH on drug loading and maximum concentration of magnetic particles inside the polymer was investigated. Morphology and particle size of the prepared nanospheres were determined by atomic force microscopy and transmission electron microscopy. Drug release from the nanospheres was studied by external sink method. The diffusion and dissolution models were applied to the description of IND release from nanospheres.

  11. 硫酸香茅醛显色法测定莪术油微囊载药量与包封率%Determination of Drug Loading Capacity and Encapsulation Efficiency in Zedoary Turmericoil Microcapsules by Sulfuric Acid - vanillin Coloration Method

    Institute of Scientific and Technical Information of China (English)

    吴继龙; 张立华; 陈欢; 杨丽娜; 代英辉; 王东; 刘东春

    2014-01-01

    为评价莪术油/(麦芽糊精-Povacoat )微囊的质量,建立了硫酸香茅醛显色测定其载药量和包封率的方法。对莪术油乙醇溶液进行波长扫描,确定508nm为最大吸收波长,显色稳定性试验表明,反应液在150min内吸光度较稳定。莪术油检测浓度在0.1992μg/mL~9.960μg/mL范围内线性关系良好(A=0.0947C-0.0012,r=0.9993),微囊的载药量测定和包封率测定的方法回收率分别为99.6%和99.1%。经测定,3批微囊的载药量为51.5mg/g~53.2mg/g ,包封率为88.2%~90.7%。%In order to evaluate the quality of Zedoary turmeric oil/(maltodextrin-Povacoat) microcapsules(ZTO/M-P Mcs) ,a sulfuric acid-vanillin coloration method for determination of drug loading capacity and encapsulation efficiency was developed .Wavelength scanned on the ZTO ethanol solution was determined at 508nm as the maximum absorption wavelength .Color stability tests showed that the absorbance of reac-tion solutions was stabled at 150 minutes .Absorbance and concentration of ZTO had a good linear relationship in the range of 0.199 2μg/mL~9.96μg/mL (A=0.094 7C-0.001 2 ,r=0.999 3 ) ,the average recovery of determination of drug loading capacity and encapsulation efficien-cy were 99.6% and 99.1% respectively .According to assay results of 3 batches ,drug loading was 51.5mg/g~53.2mg/g;Encapsulation effi-ciency was 88.2% ~90.7% .

  12. Encapsulation of sorbitan ester-based organogels in alginate microparticles.

    Science.gov (United States)

    Sagiri, Sai S; Pal, Kunal; Basak, Piyali; Rana, Usman Ali; Shakir, Imran; Anis, Arfat

    2014-10-01

    Leaching of the internal apolar phase from the biopolymeric microparticles during storage is a great concern as it undoes the beneficial effects of encapsulation. In this paper, a novel formulation was prepared by encapsulating the sunflower oil-based organogels in alginate microparticles. Salicylic acid and metronidazole were used as the model drugs. The microparticles were prepared by double emulsion methodology. Physico-chemical characterization of the microparticles was done by microscopy, FTIR, XRD, and DSC studies. Oil leaching studies, biocompatibility, mucoadhesivity, in vitro drug release, and the antimicrobial efficiency of the microparticles were also performed. The microparticles were found to be spherical in shape. Gelation of the sunflower oil prevented leaching of the internal phase from the microparticles. Release of drugs from the microparticles followed Fickian kinetics and non-Fickian kinetics in gastric and intestinal environments, respectively. Microparticles showed good antimicrobial activity against both Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria. The results suggested that the developed formulations hold promise to carry oils without leakage of the internal phase. Encapsulation of organogels within the microparticles has improved the drug entrapment efficiency and improved characteristics for controlled delivery applications.

  13. Aerosol Observation System

    Data.gov (United States)

    Oak Ridge National Laboratory — The aerosol observation system (AOS) is the primary Atmospheric Radiation Measurement (ARM) platform for in situ aerosol measurements at the surface. The principal...

  14. Biodegradable core-shell carriers for simultaneous encapsulation of synergistic actives.

    Science.gov (United States)

    Windbergs, Maike; Zhao, Yuanjin; Heyman, John; Weitz, David A

    2013-05-29

    Simultaneous encapsulation of multiple active substances in a single carrier is essential for therapeutic applications of synergistic combinations of drugs. However, traditional carrier systems often lack efficient encapsulation and release of incorporated substances, particularly when combinations of drugs must be released in concentrations of a prescribed ratio. We present a novel biodegradable core-shell carrier system fabricated in a one-step, solvent-free process on a microfluidic chip; a hydrophilic active (doxorubicin hydrochloride) is encapsulated in the aqueous core, while a hydrophobic active (paclitaxel) is encapsulated in the solid shell. Particle size and composition can be precisely controlled, and core and shell can be individually loaded with very high efficiency. Drug-loaded particles can be dried and stored as a powder. We demonstrate the efficacy of this system through the simultaneous encapsulation and controlled release of two synergistic anticancer drugs using two cancer-derived cell lines. This solvent-free platform technology is also of high potential value for encapsulation of other active ingredients and chemical reagents.

  15. Drug delivery by lipid cochleates.

    Science.gov (United States)

    Zarif, Leila

    2005-01-01

    Drug delivery technology has brought additional benefits to pharmaceuticals such as reduction in dosing frequency and side effects, as well as the extension of patient life. To address this need, cochleates, a precipitate obtained as a result of the interaction between phosphatidylserine and calcium, have been developed and proved to have potential in encapsulating and delivering small molecule drugs. This chapter discusses the molecules that can be encapsulated in a cochleate system and describes in detail the methodology that can be used to encapsulate and characterize hydrophobic drugs such as amphotericin B, a potent antifungal agent. Some efficacy data in animal models infected with candidiasis or aspergillosis are described as well.

  16. Microbes encapsulated within crosslinkable polymers

    Energy Technology Data Exchange (ETDEWEB)

    Chidambaram, Devicharan; Liu, Ying; Rafailovich, Miriam H

    2013-02-05

    The invention relates to porous films comprising crosslinked electrospun hydrogel fibers. Viable microbes are encapsulated within the crosslinked electrospun hydrogel fibers. The crosslinked electrospun hydrogel fibers are water insoluble and permeable. The invention also relates to methods of making and using such porous films.

  17. Asbestos: The Case for Encapsulation.

    Science.gov (United States)

    Russek, William F.

    1980-01-01

    Encapsulation has proven to be the safest, surest, and most permanent method of treating sprayed asbestos on ceilings and walls. Federal aid is available to help pay for inspection of school buildings for asbestos and for asbestos removal. (Author/MLF)

  18. Encapsulation of polymer photovoltaic prototypes

    DEFF Research Database (Denmark)

    Krebs, Frederik C

    2006-01-01

    A simple and efficient method for the encapsulation of polymer and organic photovoltaic prototypes is presented. The method employs device preparation on glass substrates with subsequent sealing using glass fiber reinforced thermosetting epoxy (prepreg) against a back plate. The method allows...

  19. Technology of mammalian cell encapsulation

    NARCIS (Netherlands)

    Uludag, H; De Vos, P; Tresco, PA

    2000-01-01

    Entrapment of mammalian cells in physical membranes has been practiced since the early 1950s when it was originally introduced as a basic research tool. The method has since been developed based on the promise of its therapeutic usefulness in tissue transplantation. Encapsulation physically isolates

  20. Salinomycin encapsulated nanoparticles as a targeting vehicle for glioblastoma cells.

    Science.gov (United States)

    Tığlı Aydın, R Seda; Kaynak, Gökçe; Gümüşderelioğlu, Menemşe

    2016-02-01

    Salinomycin has been introduced as a novel alternative to traditional anti-cancer drugs. The aim of this study was to test a strategy designed to deliver salinomycin to glioblastoma cells in vitro. Salinomycin-encapsulated polysorbate 80-coated poly(lactic-co-glycolic acid) nanoparticles (P80-SAL-PLGA) were prepared and characterized with respect to particle size, morphology, thermal properties, drug encapsulation efficiency and controlled salinomycin-release behaviour. The in vitro cellular uptake of P80-SAL-PLGA (5 and 10 µM) or uncoated nanoparticles was assessed in T98G human glioblastoma cells, and the cell viability was investigated with respect to anti-growth activities. SAL, which was successfully transported to T98G glioblastoma cells via P80 coated nanoparticles (∼14% within 60 min), greatly decreased (p salinomycin delivery system in the treatment of human glioblastoma.

  1. Process engineering of high voltage alginate encapsulation of mesenchymal stem cells.

    Science.gov (United States)

    Gryshkov, Oleksandr; Pogozhykh, Denys; Zernetsch, Holger; Hofmann, Nicola; Mueller, Thomas; Glasmacher, Birgit

    2014-03-01

    Encapsulation of stem cells in alginate beads is promising as a sophisticated drug delivery system in treatment of a wide range of acute and chronic diseases. However, common use of air flow encapsulation of cells in alginate beads fails to produce beads with narrow size distribution, intact spherical structure and controllable sizes that can be scaled up. Here we show that high voltage encapsulation (≥ 15 kV) can be used to reproducibly generate spherical alginate beads (200-400 μm) with narrow size distribution (± 5-7%) in a controlled manner under optimized process parameters. Flow rate of alginate solution ranged from 0.5 to 10 ml/h allowed producing alginate beads with a size of 320 and 350 μm respectively, suggesting that this approach can be scaled up. Moreover, we found that applied voltages (15-25 kV) did not alter the viability and proliferation of encapsulated mesenchymal stem cells post-encapsulation and cryopreservation as compared to air flow. We are the first who employed a comparative analysis of electro-spraying and air flow encapsulation to study the effect of high voltage on alginate encapsulated cells. This report provides background in application of high voltage to encapsulate living cells for further medical purposes. Long-term comparison and work on alginate-cell interaction within these structures will be forthcoming.

  2. Efficiencies in alginate encapsulation of vegetative explants

    Science.gov (United States)

    The goal of this study was to improve a non-mechanized bulk encapsulation technique to standardize encapsulation procedures and reduce the labor time compared to encapsulating individual nodes. Four mm-long nodal segments from Stage II cultures of Hibiscus moscheutos L. ‘Lord Baltimore’ were encapsu...

  3. Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

    OpenAIRE

    Véronique Nardello-Rataj; Loïc Leclercq

    2014-01-01

    Host–guest chemistry is useful for the construction of nanosized objects. Some of the widely used hosts are probably the cyclodextrins (CDs). CDs can form water-soluble complexes with numerous hydrophobic compounds. They have been widespread used in medicine, drug delivery and are of interest for the biocides encapsulation. Indeed, this enables the development of more or less complex systems that release antimicrobial agents with time. In this paper, the general features of CDs and their appl...

  4. Preparation, characterization, and in vitro release study of albendazole-encapsulated nanosize liposomes

    OpenAIRE

    Panwar, Preety; Pandey, Bhumika; P C Lakhera; Singh, K. P.

    2010-01-01

    The purpose of the present study was to formulate effective and controlled release albendazole liposomal formulations. Albendazole, a hydrophobic drug used for the treatment of hydatid cysts, was encapsulated in nanosize liposomes. Rapid evaporation method was used for the preparation of albendazole-encapsulated conventional and PEGylated liposomes consisting of egg phosphatidylcholine (PC) and cholesterol (CH) in the molar ratios of (6:4) and PC:CH: polyethylene glycol (PEG) (5:4:1), respect...

  5. Self-assembled rosette nanotubes encapsulate and slowly release dexamethasone

    Directory of Open Access Journals (Sweden)

    Chen Y

    2011-05-01

    Full Text Available Yupeng Chen1,2, Shang Song2, Zhimin Yan3, Hicham Fenniri3, Thomas J Webster2,41Department of Chemistry, Brown University, Providence, RI, USA; 2School of Engineering, Brown University, Providence, RI, USA; 3National Institute for Nanotechnology and Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada; 4Department of Orthopedics, Brown University, Providence, RI, USAAbstract: Rosette nanotubes (RNTs are novel, self-assembled, biomimetic, synthetic drug delivery materials suitable for numerous medical applications. Because of their amphiphilic character and hollow architecture, RNTs can be used to encapsulate and deliver hydrophobic drugs otherwise difficult to deliver in biological systems. Another advantage of using RNTs for drug delivery is their biocompatibility, low cytotoxicity, and their ability to engender a favorable, biologically-inspired environment for cell adhesion and growth. In this study, a method to incorporate dexamethasone (DEX, an inflammatory and a bone growth promoting steroid into RNTs was developed. The drug-loaded RNTs were characterized using diffusion ordered nuclear magnetic resonance spectroscopy (DOSY NMR and UV-Vis spectroscopy. Results showed for the first time that DEX can be easily and quickly encapsulated into RNTs and released to promote osteoblast (bone-forming cell functions over long periods of time. As a result, RNTs are presented as a novel material for the targeted delivery of hydrophobic drugs otherwise difficult to deliver.Keywords: nanotubes, drug delivery, self-assembly, physiological conditions

  6. Encapsulation of Lactobacillus plantarum 423 and its Bacteriocin in Nanofibers.

    Science.gov (United States)

    Heunis, T D J; Botes, M; Dicks, L M T

    2010-03-01

    Plantaricin 423, produced by Lactobacillus plantarum 423, was encapsulated in nanofibers that were produced by the electrospinning of 18% (w/v) polyethylene oxide (200 000 Da). The average diameter of the nanofibers was 288 nm. Plantaricin 423 activity decreased from 51 200 AU/ml to 25 600 AU/ml and from 204 800 AU/ml to 51 200 AU/ml after electrospinning, as determined against Lactobacillus sakei DSM 20017 and Enterococcus faecium HKLHS, respectively. Cells of L. plantarum 423 encapsulated in nanofibers decreased from 2.3 × 10(10) cfu/ml before electrospinning to 4.7 × 10(8) cfu/ml thereafter. Cells entrapped in the nanofibers continued to produce plantaricin 423. This is the first report on the encapsulation of a bacteriocin and cells of L. plantarum in nanofibers. The method may be used to design a drug delivery system for bacteriocins and the encapsulation of probiotic lactic acid bacteria. The technology is currently being optimized.

  7. Cell-penetrating peptides meditated encapsulation of protein therapeutics into intact red blood cells and its application.

    Science.gov (United States)

    He, Huining; Ye, Junxiao; Wang, Yinsong; Liu, Quan; Chung, Hee Sun; Kwon, Young Min; Shin, Meong Cheol; Lee, Kyuri; Yang, Victor C

    2014-02-28

    Red blood cells (RBCs) based drug carrier appears to be the most appealing for protein drugs due to their unmatched biocompatability, biodegradability, and long lifespan in the circulation. Numerous methods for encapsulating protein drugs into RBCs were developed, however, most of them induce partial disruption of the cell membrane, resulting in irreversible alterations in both physical and chemical properties of RBCs. Herein, we introduce a novel method for encapsulating proteins into intact RBCs, which was meditated by a cell penetrating peptide (CPP) developed in our lab-low molecular weight protamine (LMWP). l-asparaginase, one of the primary drugs used in treatment of acute lymphoblastic leukemia (ALL), was chosen as a model protein to illustrate the encapsulation into erythrocytes mediated by CPPs. In addition current treatment of ALL using different l-asparaginase delivery and encapsulation methods as well as their associated problems were also reviewed.

  8. Drug: D00115 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D00115 Drug Gelatin (JP16/NF); Gelfilm (TN) Pharmaceutic aid [encapsulating agent]; Pharmaceutic aid [suspen...ding agent]; Pharmaceutic aid [tablet binder]; Pharmaceutic aid [tablet coating age

  9. Co-encapsulation of tamoxifen and quercetin in polymeric nanoparticles

    DEFF Research Database (Denmark)

    Jain, Amit K; Thanki, Kaushik; Jain, Sanyog

    2013-01-01

    (s) and their combination when tested against a DMBA-induced breast cancer model in female SD rats. Multiple oral administrations of Tmx-QT-NPs efficiently controlled the tumor angiogenesis as revealed by normalized levels of respective markers (MMP-2 and MMP-9). The safety profile of Tmx-QT-NPs was also established......, and no measurable hepatotoxicity or oxidative stress was observed when measured as a function of respective biochemical markers in contrast to free drug(s) and their combinations. In a nutshell, the co-encapsulation strategy with PLGA-NPs could be a promising approach in improving oral delivery of Tmx and QT...

  10. Hydrophobin-Encapsulated Quantum Dots.

    Science.gov (United States)

    Taniguchi, Shohei; Sandiford, Lydia; Cooper, Maggie; Rosca, Elena V; Ahmad Khanbeigi, Raha; Fairclough, Simon M; Thanou, Maya; Dailey, Lea Ann; Wohlleben, Wendel; von Vacano, Bernhard; de Rosales, Rafael T M; Dobson, Peter J; Owen, Dylan M; Green, Mark

    2016-02-01

    The phase transfer of quantum dots to water is an important aspect of preparing nanomaterials that are suitable for biological applications, and although numerous reports describe ligand exchange, very few describe efficient ligand encapsulation techniques. In this report, we not only report a new method of phase transferring quantum dots (QDs) using an amphiphilic protein (hydrophobin) but also describe the advantages of using a biological molecule with available functional groups and their use in imaging cancer cells in vivo and other imaging applications.

  11. Nanoparticle-mediated combination chemotherapy and photodynamic therapy overcomes tumor drug resistance in vitro.

    Science.gov (United States)

    Khdair, Ayman; Handa, Hitesh; Mao, Guangzhao; Panyam, Jayanth

    2009-02-01

    Drug resistance limits the success of many anticancer drugs. Reduced accumulation of the drug at its intracellular site of action because of overexpression of efflux transporters such as P-glycoprotein (P-gp) is a major mechanism of drug resistance. In this study, we investigated whether photodynamic therapy (PDT) using methylene blue, also a P-gp inhibitor, can be used to enhance doxorubicin-induced cytotoxicity in drug-resistant tumor cells. Aerosol OT (AOT)-alginate nanoparticles were used as a carrier for the simultaneous cellular delivery of doxorubicin and methylene blue. Methylene blue was photoactivated using light of 665 nm wavelength. Induction of apoptosis and necrosis following treatment with combination chemotherapy and PDT was investigated in drug-resistant NCI/ADR-RES cells using flow cytometry and fluorescence microscopy. Effect of encapsulation in nanoparticles on the intracellular accumulation of doxorubicin and methylene blue was investigated qualitatively using fluorescence microscopy and was quantitated using HPLC. Encapsulation in AOT-alginate nanoparticles significantly enhanced the cytotoxicity of combination therapy in resistant tumor cells. Nanoparticle-mediated combination therapy resulted in a significant induction of both apoptosis and necrosis. Improvement in cytotoxicity could be correlated with enhanced intracellular and nuclear delivery of the two drugs. Further, nanoparticle-mediated combination therapy resulted in significantly elevated reactive oxygen species (ROS) production compared to single drug treatment. In conclusion, nanoparticle-mediated combination chemotherapy and PDT using doxorubicin and methylene blue was able to overcome resistance mechanisms and resulted in improved cytotoxicity in drug-resistant tumor cells.

  12. Characterization of Chitosan Polymeric Ethosomes Capable of Encapsulating Hydrophobic and Hydrophilic Drugs Prepared by a Microemulsion Method%微乳液法制备可共载水溶和脂溶药物的壳聚糖季铵盐乙醇脂质体的载药性能表征

    Institute of Scientific and Technical Information of China (English)

    梁晓飞; 胡晶莹; 陈复华; 李宗海; 常津

    2012-01-01

    采用微乳液法制备了可包载脂溶性和水溶性药物的羧甲基壳聚糖十八烷基季铵盐(OQCMC)乙醇脂质体,研究了OQCMC乙醇高分子脂质体的相图、粒径和电位、对药物的包封及释放能力及共载水溶性和脂溶性荧光染料后的细胞内递送能力.结果表明:OQCMC上长链季铵盐分子的取代度和共乳化剂乙醇的加入量对相图中微乳区域的面积影响不大;微乳液法町制备包载水溶性长春新碱(VCR)、脂溶性消炎痛(IMC)或二者共载的OQCMC载药微球,微球粒径为(52.40+0.55) nm,分布均匀;微乳液体系对VCR的最大载药率为22.7%,对IMC的最大载药率为20.1%,二者共载时,VCR的最大载药率为12.2%,IMC的最大载药率为10.0%;载药微球对药物具有缓控释功能.OQCMC乙醇高聚物脂质体可有效地包载荧光染料异硫氰酸荧光素FITC(水溶性)和尼罗红(脂溶性),并将二者递送到卵巢癌H08901细胞内.%Polymeric ethosomes,formed from amphiphilic octadecyl quaternized carboxymethyl chitosan (OQCMC) with different degrees of quaternary substitution (DS),were prepared by the microemulsion (ME) method.These ethosomes could simultaneously encapsulate both the hydrophobic drug indomethacin (IMC) and the hydrophilic drug vincristine (VCR).The effects of the DS of the OQCMC and primary alcohols as cosurfactants on the phase diagram were elucidated.The prepared nanoparticles (NPs) were small ((52.40± 0.55) nm) and suitable as drug carriers for different drugs.The maximum drug loading efficiencies of VCR-loaded and IMC-Ioaded NPs were 22.7% and 20.1%,respectively.The drug loading capacities for co-delivery of VCR and IMC were 12.2% and 10.0%,respectively.OQCMC polymeric ethosomes were stable in aqueous solution and exhibited slow,steady drug release.Hydrophilic fluorescein isothiocyanate (FITC) and hydrophobic Nile Red were encapsulated by the OQCMC ME NPs and simultaneously delivered into HO8901 cells with green and

  13. Process for Encapsulating Protein Crystals

    Science.gov (United States)

    Morrison, Dennis R.; Mosier, Benjamin

    2003-01-01

    A process for growing protein crystals encapsulated within membranes has been invented. This process begins with the encapsulation of a nearly saturated aqueous protein solution inside semipermeable membranes to form microcapsules. The encapsulation is effected by use of special formulations of a dissolved protein and a surfactant in an aqueous first liquid phase, which is placed into contact with a second, immiscible liquid phase that contains one or more polymers that are insoluble in the first phase. The second phase becomes formed into the semipermeable membranes that surround microglobules of the first phase, thereby forming the microcapsules. Once formed, the microcapsules are then dehydrated osmotically by exposure to a concentrated salt or polymer solution. The dehydration forms supersaturated solutions inside the microcapsules, thereby enabling nucleation and growth of protein crystals inside the microcapsules. By suitable formulation of the polymer or salt solution and of other physical and chemical parameters, one can control the rate of transport of water out of the microcapsules through the membranes and thereby create physicochemical conditions that favor the growth, within each microcapsule, of one or a few large crystals suitable for analysis by x-ray diffraction. The membrane polymer can be formulated to consist of low-molecular-weight molecules that do not interfere with the x-ray diffraction analysis of the encapsulated crystals. During dehydration, an electrostatic field can be applied to exert additional control over the rate of dehydration. This protein-crystal-encapsulation process is expected to constitute the basis of protein-growth experiments to be performed on the space shuttle and the International Space Station. As envisioned, the experiments would involve the exposure of immiscible liquids to each other in sequences of steps under microgravitational conditions. The experiments are expected to contribute to knowledge of the precise

  14. Aerosol typing - key information from aerosol studies

    Science.gov (United States)

    Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina

    2016-04-01

    Aerosol typing is a key source of aerosol information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, aerosol typing can be used as input for retrievals or represents an output for other applications. Typically aerosol retrievals require some a priori or external aerosol type information. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different sensors can make use of different aerosol type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of aerosol types, showing for example the main source regions and typical transport paths. Climatological studies of aerosol load at global and regional scales often rely on inferred aerosol type. There is still a high degree of inhomogeneity among satellite aerosol typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d aerosol type distribution at these scales is essential for understanding the impact of different aerosol sources on climate, precipitation and air quality. All this information is needed for planning upcoming aerosol emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing aerosol type distribution uncertainties. Aerosol typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite Aerosol Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of aerosol typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the

  15. AN OVERVIEW ON: PHARMACEUTICAL AEROSOLS

    Directory of Open Access Journals (Sweden)

    Lahkar Sunita

    2012-09-01

    Full Text Available Pulmonary drug delivery system is found to have a wide range of application in the treatment of illness as well as in the research field due to its beneficial effect over the other dosage form. It is used not only in treatment of illness of asthma and chronic obstructive pulmonary disease (COPD but also finds its application in the treatment of diseases like diabetes, angina pectoris. This review article deals with an overview of one of the pulmonary drug delivery system called pharmaceutical aerosols.

  16. Nanocarriers from GRAS Zein Proteins to Encapsulate Hydrophobic Actives.

    Science.gov (United States)

    Weissmueller, Nikolas T; Lu, Hoang D; Hurley, Amanda; Prud'homme, Robert K

    2016-11-14

    One factor limiting the expansion of nanomedicines has been the high cost of the materials and processes required for their production. We present a continuous, scalable, low cost nanoencapsulation process, Flash Nanoprecipitation (FNP) that enables the production of nanocarriers (NCs) with a narrow size distribution using zein corn proteins. Zein is a low cost, GRAS protein (having the FDA status of "Generally Regarded as Safe") currently used in food applications, which acts as an effective encapsulant for hydrophobic compounds using FNP. The four-stream FNP configuration allows the encapsulation of very hydrophobic compounds in a way that is not possible with previous precipitation processes. We present the encapsulation of several model active compounds with as high as 45 wt % drug loading with respect to zein concentration into ∼100 nm nanocarriers. Three examples are presented: (1) the pro-drug antioxidant, vitamin E-acetate, (2) an anticholera quorum-sensing modulator CAI-1 ((S)-3-hydroxytridecan-4-one; CAI-1 that reduces Vibrio cholerae virulence by modulating cellular communication), and (3) hydrophobic fluorescent dyes with a range of hydrophobicities. The specific interaction between zein and the milk protein, sodium caseinate, provides stabilization of the NCs in PBS, LB medium, and in pH 2 solutions. The stability and size changes in the three media provide information on the mechanism of assembly of the zein/active/casein NC.

  17. Elevating bioavailability of curcumin via encapsulation with a novel formulation of artificial oil bodies.

    Science.gov (United States)

    Chang, Ming-Tsung; Tsai, Tong-Rong; Lee, Chun-Yann; Wei, Yu-Sheng; Chen, Ying-Jie; Chen, Chun-Ren; Tzen, Jason T C

    2013-10-09

    Utilization of curcumin has been limited due to its poor oral bioavailability. Oral bioavailability of hydrophobic compounds might be elevated via encapsulation in artificial seed oil bodies. This study aimed to improve oral bioavailability of curcumin via this encapsulation. Unfortunately, curcumin was indissoluble in various seed oils. A mixed dissolvent formula was used to dissolve curcumin, and the admixture was successfully encapsulated in artificial oil bodies stabilized by recombinant sesame caleosin. The artificial oil bodies of relatively small sizes (150 nm) were stably solidified in the forms of powder and tablet. Oral bioavailability of curcumin with or without encapsulation in artificial oil bodies was assessed in Sprague-Dawley male rats. The results showed that encapsulation of curcumin significantly elevated its bioavailability and provided the highest maximum whole blood concentration (Cmax), 37 ± 28 ng/mL, in the experimental animals 45 ± 17 min (t(max)) after oral administration. Relative bioavailability calculated on the basis of the area under the plasma concentration-time curve (AUC) was increased by 47.7 times when curcumin was encapsulated in the artificial oil bodies. This novel formulation of artificial oil bodies seems to possess great potential to encapsulate hydrophobic drugs for oral administration.

  18. Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

    Directory of Open Access Journals (Sweden)

    Véronique Nardello-Rataj

    2014-11-01

    Full Text Available Host–guest chemistry is useful for the construction of nanosized objects. Some of the widely used hosts are probably the cyclodextrins (CDs. CDs can form water-soluble complexes with numerous hydrophobic compounds. They have been widespread used in medicine, drug delivery and are of interest for the biocides encapsulation. Indeed, this enables the development of more or less complex systems that release antimicrobial agents with time. In this paper, the general features of CDs and their applications in the field of biocides have been reviewed. As the key point is the formation of biocide–CD inclusion complexes, this review deals with this in depth and the advantages of biocide encapsulation are highlighted throughout several examples from the literature. Finally, some future directions of investigation have been proposed. We hope that scientists studying biocide applications receive inspiration from this review to exploit the opportunities offered by CDs in their respective research areas.

  19. Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens.

    Science.gov (United States)

    Nardello-Rataj, Véronique; Leclercq, Loïc

    2014-01-01

    Host-guest chemistry is useful for the construction of nanosized objects. Some of the widely used hosts are probably the cyclodextrins (CDs). CDs can form water-soluble complexes with numerous hydrophobic compounds. They have been widespread used in medicine, drug delivery and are of interest for the biocides encapsulation. Indeed, this enables the development of more or less complex systems that release antimicrobial agents with time. In this paper, the general features of CDs and their applications in the field of biocides have been reviewed. As the key point is the formation of biocide-CD inclusion complexes, this review deals with this in depth and the advantages of biocide encapsulation are highlighted throughout several examples from the literature. Finally, some future directions of investigation have been proposed. We hope that scientists studying biocide applications receive inspiration from this review to exploit the opportunities offered by CDs in their respective research areas.

  20. Dynamic mechanism for encapsulating two HIV replication inhibitor peptides with carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Chen Bao-Dong; Yang Chuan-Lu; Wang Mei-Shan; Ma Xiao-Guang

    2012-01-01

    Encapsulation of biomolecules inside a carbon nanotube (CNT) has attracted great interest because it could enable the delivery of nanoscale pharmaceutical drugs with CNT-based devices.Using a molecular dynamics simulation,we investigate the dynamic process by which human immunodeficiency virus (HIV) replication inhibitor peptides (HRIPs)are encapsulated in a water solution contained inside a CNT.The van der Waals attraction between the HRIPs and the CNT and the root-mean-square deviation are used to analyse the evolution of the encapsulation.It is found that the interaction between the HRIPs and the CNT is the main driving force for the encapsulation process,which does not cause an obvious conformationai change to the HRIPs.

  1. Laser-triggered release of encapsulated molecules from polylactic-co-glycolic acid microcapsules

    Science.gov (United States)

    Ariyasu, Kazumasa; Ishii, Atsuhiro; Umemoto, Taiga; Terakawa, Mitsuhiro

    2016-08-01

    The controlled release of encapsulated molecules from a microcapsule is a promising method of targeted drug delivery. Laser-triggered methods for the release of encapsulated molecules have the advantage of spatial and temporal controllability. In this study, we demonstrated the release of encapsulated molecules from biodegradable polymer-based microcapsules using near-infrared femtosecond laser pulses. The polylactic-co-glycolic acid microcapsules encapsulating fluorescein isothiocyanate-dextran molecules were fabricated using a dual-coaxial nozzle system. Irradiation of femtosecond laser pulses enhanced the release of the molecules from the microcapsules, which was accompanied by a decrease in the residual ratio of the microcapsules. The laser-induced modification of the surface of the shell of the microcapsules indicated the potential for sustained release as well as burst release.

  2. Encapsulation methods for organic electrical devices

    Science.gov (United States)

    Blum, Yigal D.; Chu, William Siu-Keung; MacQueen, David Brent; Shi, Yijian

    2013-06-18

    The disclosure provides methods and materials suitable for use as encapsulation barriers in electronic devices. In one embodiment, for example, there is provided an electroluminescent device or other electronic device encapsulated by alternating layers of a silicon-containing bonding material and a ceramic material. The encapsulation methods provide, for example, electronic devices with increased stability and shelf-life. The invention is useful, for example, in the field of microelectronic devices.

  3. Aerosol mobility size spectrometer

    Science.gov (United States)

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  4. Encapsulation of curcumin in polyelectrolyte nanocapsules and their neuroprotective activity

    Science.gov (United States)

    Szczepanowicz, Krzysztof; Jantas, Danuta; Piotrowski, Marek; Staroń, Jakub; Leśkiewicz, Monika; Regulska, Magdalena; Lasoń, Władysław; Warszyński, Piotr

    2016-09-01

    Poor water solubility and low bioavailability of lipophilic drugs can be potentially improved with the use of delivery systems. In this study, encapsulation of nanoemulsion droplets was utilized to prepare curcumin nanocarriers. Nanosize droplets containing the drug were encapsulated in polyelectrolyte shells formed by the layer-by-layer (LbL) adsorption of biocompatible polyelectrolytes: poly-L-lysine (PLL) and poly-L-glutamic acid (PGA). The size of synthesized nanocapsules was around 100 nm. Their biocompatibility and neuroprotective effects were evaluated on the SH-SY5Y human neuroblastoma cell line using cell viability/toxicity assays (MTT reduction, LDH release). Statistically significant toxic effect was clearly observed for PLL coated nanocapsules (reduction in cell viability about 20%-60%), while nanocapsules with PLL/PGA coating did not evoke any detrimental effects on SH-SY5Y cells. Curcumin encapsulated in PLL/PGA showed similar neuroprotective activity against hydrogen peroxide (H2O2)-induced cell damage, as did 5 μM curcumin pre-dissolved in DMSO (about 16% of protection). Determination of concentration of curcumin in cell lysate confirmed that curcumin in nanocapsules has cell protective effect in lower concentrations (at least 20 times) than when given alone. Intracellular mechanisms of encapsulated curcumin-mediated protection engaged the prevention of the H2O2-induced decrease in mitochondrial membrane potential (MMP) but did not attenuate Reactive Oxygen Species (ROS) formation. The obtained results indicate the utility of PLL/PGA shell nanocapsules as a promising, alternative way of curcumin delivery for neuroprotective purposes with improved efficiency and reduced toxicity.

  5. Development of Novel Chitosan Microcapsules for Pulmonary Delivery of Dapsone: Characterization, Aerosol Performance, and In Vivo Toxicity Evaluation.

    Science.gov (United States)

    Ortiz, Manoel; Jornada, Denise Soledade; Pohlmann, Adriana Raffin; Guterres, Sílvia Stanisçuaski

    2015-10-01

    Pneumocystis carinii pneumonia (PCP) is a major opportunistic infection that affects patients with human immunodeficiency virus. Although orally administered dapsone leads to high hepatic metabolism, decreasing the therapeutic index and causing severe side effects, this drug is an effective alternative for the treatment of PCP. In this context, microencapsulation for pulmonary administration can offer an alternative to increase the bioavailability of dapsone, reducing its adverse effects. The aim of this work was to develop novel dapsone-loaded chitosan microcapsules intended for deep-lung aerosolized drug delivery. The geometric particle size (D 4,3) was approximately 7 μm, the calculated aerodynamic diameter (d aero) was approximately 4.5 μm, and the mass median aerodynamic diameter from an Andersen cascade impactor was 4.7 μm. The in vitro dissolution profile showed an efficient dapsone encapsulation, demonstrating the sustained release of the drug. The in vitro deposition (measured by the Andersen cascade impactor) showed an adequate distribution and a high fine particles fraction (FPF = 50%). Scanning electron microscopy of the pulmonary tissues demonstrated an adequate deposition of these particles in the deepest part of the lung. An in vivo toxicity experiment showed the low toxicity of the drug-loaded microcapsules, indicating a protective effect of the microencapsulation process when the particles are microencapsulated. In conclusion, the pulmonary administration of the novel dapsone-loaded microcapsules could be a promising alternative for PCP treatment.

  6. Aerosol distribution apparatus

    Science.gov (United States)

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  7. The influence of HLB on the encapsulation of oils by complex coacervation.

    Science.gov (United States)

    Rabisková, M; Valásková, J

    1998-01-01

    Microcapsules are used for the formulation of drug controlled release and drug targeting dosage forms. Encapsulated hydrophobic drugs are often applied as their solutions in plant oils. The uptake of the oils in the complex coacervate microcapsules can be improved by the addition of surfactants. In this study, soybean, olive and peanut oils were chosen as the representatives of plant oils. The well characterized complex coacervation of gelatin and acacia has been used to produce the microcapsules. The amount of encapsulated oil has been determined gravimetrically. The encapsulation of the oils was high (75-80%). When the surfactants with HLB values from 1.8 to 6.7 were used, the amount of encapsulated oil was high (65-85%). A significant decrease of the oil content in the microcapsules was found when Tween 61 with HLB = 9.6 had been added into the mixture. No oil was found inside the microcapsules from the coacervate emulsion mixture containing Tween 81 (HLB = 10) and Tween 80 (HLB = 15), respectively. The results of the experiment confirm the dependence of hydrophobic substance encapsulation on the HLB published recently for Squalan.

  8. Encapsulation of GFP in Complex Coacervate Core Micelles.

    Science.gov (United States)

    Nolles, Antsje; Westphal, Adrie H; de Hoop, Jacob A; Fokkink, Remco G; Kleijn, J Mieke; van Berkel, Willem J H; Borst, Jan Willem

    2015-05-11

    Protein encapsulation with polymers has a high potential for drug delivery, enzyme protection and stabilization. Formation of such structures can be achieved by the use of polyelectrolytes to generate so-called complex coacervate core micelles (C3Ms). Here, encapsulation of enhanced green fluorescent protein (EGFP) was investigated using a cationic-neutral diblock copolymer of two different sizes: poly(2-methyl-vinyl-pyridinium)41-b-poly(ethylene-oxide)205 and poly(2-methyl-vinyl-pyridinium)128-b-poly(ethylene-oxide)477. Dynamic light scattering and fluorescence correlation spectroscopy (FCS) revealed a preferred micellar composition (PMC) with a positive charge composition of 0.65 for both diblock copolymers and micellar hydrodynamic radii of approximately 34 nm. FCS data show that at the PMC, C3Ms are formed above 100 nM EGFP, independent of polymer length. Mixtures of EGFP and nonfluorescent GFP were used to quantify the amount of GFP molecules per C3M, resulting in approximately 450 GFPs encapsulated per micelle. This study shows that FCS can be successfully applied for the characterization of protein-containing C3Ms.

  9. Encapsulation of antioxidants in gastrointestinal-resistant nanoparticulate carriers.

    Science.gov (United States)

    Souto, Eliana B; Severino, Patrícia; Basso, Rafael; Santana, Maria Helena A

    2013-01-01

    Reactive oxygen species (ROS) are known to cause several human pathologies. For this reason, antioxidants have gained utmost importance because of their potential as prophylactic and therapeutic agents in many diseases. Examples of their application include their use in diabetic patients, as aging drugs, in cancer diseases, Parkinson's, Alzheimer's, autoimmune disorders, and also in inflammation. Antioxidants have limited absorption profiles, therefore low bioavailability and low concentrations at the target site. Efforts have been done towards loading antioxidant molecules in advanced nanoparticulate carriers, e.g., liposomes, polymeric nanoparticles, solid lipid nanoparticles, self-emulsifying drug delivery system. Examples of -successful achievements include the encapsulation of drugs and other active ingredients, e.g., coenzyme Q10, vitamin E and vitamin A, resveratrol and polyphenols, curcumin, lycopene, silymarin, and superoxide dismutase. This review focuses on the comprehensive analysis of using nanoparticulate carriers for loading these molecules for oral administration.

  10. Nano-encapsulated chlorophyllin significantly delays progression of lung cancer both in in vitro and in vivo models through activation of mitochondrial signaling cascades and drug-DNA interaction.

    Science.gov (United States)

    Das, Jayeeta; Samadder, Asmita; Mondal, Jesmin; Abraham, Suresh K; Khuda-Bukhsh, Anisur Rahman

    2016-09-01

    Chlorophyllin (CHL), a sodium-copper-salt derived from chlorophyll, has been widely used as a food-dye, also reportedly having some anti-cancer effect. We tested if PLGA-loaded CHL (NCHL) could have additional protective abilities through its faster and targeted drug delivery in cancer cells. Physico-chemical characterization of NCHL was done through atomic-force microscopy and UV-spectroscopy. NCHL demonstrated greater ability of drug uptake and strong anti-cancer potentials in non-small cell lung cancer cells, A549, as revealed from data of% cell viability, generation of reactive-oxygen-species and expression of bax, bcl2, caspase3, p53 and cytochrome c proteins. Circular dichroic spectral data indicated strong binding of NCHL with calf-thymus-DNA, causing a conformational/structural change in DNA. Further, NCHL could cross the blood-brain-barrier in mice and showed greater efficacy in recovery process of tissue damage, reduction in chromosomal aberrations and% of micronuclei in co-mutagens (Sodiumarsenite+Benzo[a]Pyrene)-treated mice at a much reduced dose, indicating its use in therapeutic oncology.

  11. Smart polyelectrolyte microcapsules as carriers for water-soluble small molecular drug.

    Science.gov (United States)

    Song, Weixing; He, Qiang; Möhwald, Helmuth; Yang, Yang; Li, Junbai

    2009-10-15

    Heat treatment is introduced as a simple method for the encapsulation of low molecular weight water-soluble drugs within layer-by-layer assembled microcapsules. A water-soluble drug, procainamide hydrochloride, could thus be encapsulated in large amount and enriched by more than 2 orders of magnitude in the assembled PDADMAC/PSS capsules. The shrunk capsules could control the unloading rate of drugs, and the drugs could be easily unloaded using ultrasonic treatment. The encapsulated amount could be quantitatively controlled via the drug concentration in the bulk. We also found that smaller capsules possess higher encapsulation capability.

  12. Point contacts in encapsulated graphene

    Energy Technology Data Exchange (ETDEWEB)

    Handschin, Clevin [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Swiss Nanoscience Institute, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Fülöp, Bálint; Csonka, Szabolcs [Department of Physics, Budapest University of Technology and Economics and Condensed Matter Research Group of the Hungarian Academy of Sciences, Budafoki ut 8, 1111 Budapest (Hungary); Makk, Péter; Blanter, Sofya; Weiss, Markus; Schönenberger, Christian, E-mail: Christian.Schoenenberger@unibas.ch [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Watanabe, Kenji; Taniguchi, Takashi [National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)

    2015-11-02

    We present a method to establish inner point contacts with dimensions as small as 100 nm on hexagonal boron nitride (hBN) encapsulated graphene heterostructures by pre-patterning the top-hBN in a separate step prior to dry-stacking. 2- and 4-terminal field effect measurements between different lead combinations are in qualitative agreement with an electrostatic model assuming point-like contacts. The measured contact resistances are 0.5–1.5 kΩ per contact, which is quite low for such small contacts. By applying a perpendicular magnetic field, an insulating behaviour in the quantum Hall regime was observed, as expected for inner contacts. The fabricated contacts are compatible with high mobility graphene structures and open up the field for the realization of several electron optical proposals.

  13. Liposomal nanoparticles encapsulating iloprost exhibit enhanced vasodilation in pulmonary arteries

    Directory of Open Access Journals (Sweden)

    Jain PP

    2014-07-01

    Full Text Available Pritesh P Jain,1 Regina Leber,1,2 Chandran Nagaraj,1 Gerd Leitinger,3 Bernhard Lehofer,4 Horst Olschewski,1,5 Andrea Olschewski,1,6 Ruth Prassl,1,4 Leigh M Marsh11Ludwig Boltzmann Institute for Lung Vascular Research, 2Biophysics Division, Institute of Molecular Biosciences, University of Graz, 3Research Unit Electron Microscopic Techniques, Institute of Cell Biology, Histology, and Embryology, 4Institute of Biophysics, 5Division of Pulmonology, Department of Internal Medicine, 6Department of Anesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, AustriaAbstract: Prostacyclin analogues are standard therapeutic options for vasoconstrictive diseases, including pulmonary hypertension and Raynaud’s phenomenon. Although effective, these treatment strategies are expensive and have several side effects. To improve drug efficiency, we tested liposomal nanoparticles as carrier systems. In this study, we synthesized liposomal nanoparticles tailored for the prostacyclin analogue iloprost and evaluated their pharmacologic efficacy on mouse intrapulmonary arteries, using a wire myograph. The use of cationic lipids, stearylamine, or 1,2-di-(9Z-octadecenoyl-3-trimethylammonium-propane (DOTAP in liposomes promoted iloprost encapsulation to at least 50%. The addition of cholesterol modestly reduced iloprost encapsulation. The liposomal nanoparticle formulations were tested for toxicity and pharmacologic efficacy in vivo and ex vivo, respectively. The liposomes did not affect the viability of human pulmonary artery smooth muscle cells. Compared with an equivalent concentration of free iloprost, four out of the six polymer-coated liposomal formulations exhibited significantly enhanced vasodilation of mouse pulmonary arteries. Iloprost that was encapsulated in liposomes containing the polymer polyethylene glycol exhibited concentration-dependent relaxation of arteries. Strikingly, half the concentration of iloprost in liposomes elicited

  14. Liposomal encapsulation of dexamethasone modulates cytotoxicity, inflammatory cytokine response, and migratory properties of primary human macrophages

    NARCIS (Netherlands)

    Bartneck, M.; Peters, F.M.; Warzecha, K.T.; Bienert, M.; Bloois, van L.; Trautwein, C.; Lammers, T.G.G.M.; Tacke, F.

    2014-01-01

    The encapsulation of drugs into liposomes aims to enhance their efficacy and reduce their toxicity. Corticosteroid-loaded liposomes are currently being evaluated in patients suffering from rheumatoid arthritis, atherosclerosis, colitis, and cancer. Here, using several different fluorophore-labeled f

  15. In-situ formation of growth-factor-loaded coacervate microparticle-embedded hydrogels for directing encapsulated stem cell fate.

    Science.gov (United States)

    Jeon, Oju; Wolfson, David W; Alsberg, Eben

    2015-04-01

    The spontaneous formation of coacervate microdroplet-laden photo-crosslinked hydrogels derived from the simple mixing of oxidized, methacrylated alginate (OMA) and methacrylated gelatin (GelMA) enables simultaneous creation of drug-laden microdroplets and encapsulation of stem cells in photopolymerized coacervate hydrogels under physiological conditions. This can be utilized as a novel platform for in situ formation of localized, sustained bioactive molecule delivery to encapsulate stem cells for therapeutic applications.

  16. Polysaccharide-based nanocomplexes for co-encapsulation and controlled release of 5-Fluorouracil and Temozolomide.

    Science.gov (United States)

    Di Martino, Antonio; Pavelkova, Alena; Maciulyte, Sandra; Budriene, Saulute; Sedlarik, Vladimir

    2016-09-20

    Polysaccharide-based nanocomplexes, intended for simultaneous encapsulation and controlled release of 5-Fluorouracil (5-FU) and Temozolomide (TMZ) were developed via the complexation method using chitosan, alginic and polygalacturonic acid. Investigation focused on the influence of polysaccharides on the properties of the system and amelioration of the stability of the drugs, in particular TMZ. The dimensions of particles and their ζ-potential were found to range between 100 and 200nm and -25 to +40mV, respectively. Encapsulation efficiency varied from 16% to over 70%, depending on the given system. The influence of pH on the release and co-release of TMZ and 5-FU was evaluated under different pH conditions. The stability of the loaded drug, in particular TMZ, after release was evaluated and confirmed by LC-MS analysis. Results suggested that the amount of loaded drug(s) and the release rate is connected with the weight ratio of polysaccharides and the pH of the media. One-way ANOVA analysis on the obtained data revealed no interference between the drugs during the encapsulation and release process, and in particular no hydrolysis of TMZ occurred suggesting that CS-ALG and CS-PGA would represent interesting carriers for multi-drug controlled release and drugs protection.

  17. Enhanced efficacy of clindamycin hydrochloride encapsulated in PLA/PLGA based nanoparticle system for oral delivery.

    Science.gov (United States)

    Rauta, Pradipta Ranjan; Das, Niladri Mohan; Nayak, Debasis; Ashe, Sarbani; Nayak, Bismita

    2016-08-01

    Clindamycin hydrochloride (CLH) is a clinically important oral antibiotic with wide spectrum of antimicrobial activity that includes gram-positive aerobes (staphylococci, streptococci etc.), most anaerobic bacteria, Chlamydia and certain protozoa. The current study was focused to develop a stabilised clindamycin encapsulated poly lactic acid (PLA)/poly (D,L-lactide-co-glycolide) (PLGA) nano-formulation with better drug bioavailability at molecular level. Various nanoparticle (NPs) formulations of PLA and PLGA loaded with CLH were prepared by solvent evaporation method varying drug: polymer concentration (1:20, 1:10 and 1:5) and characterised (size, encapsulation efficiency, drug loading, scanning electron microscope, differential scanning calorimetry [DSC] and Fourier transform infrared [FTIR] studies). The ratio 1:10 was found to be optimal for a monodispersed and stable nano formulation for both the polymers. NP formulations demonstrated a significant controlled release profile extended up to 144 h (both CLH-PLA and CLH-PLGA). The thermal behaviour (DSC) studies confirmed the molecular dispersion of the drug within the system. The FTIR studies revealed the intactness as well as unaltered structure of drug. The CLH-PLA NPs showed enhanced antimicrobial activity against two pathogenic bacteria Streptococcus faecalis and Bacillus cereus. The results notably suggest that encapsulation of CLH into PLA/PLGA significantly increases the bioavailability of the drug and due to this enhanced drug activity; it can be widely applied for number of therapies.

  18. Graphene-bonded and -encapsulated si nanoparticles for lithium ion battery anodes.

    Science.gov (United States)

    Wen, Yang; Zhu, Yujie; Langrock, Alex; Manivannan, Ayyakkannu; Ehrman, Sheryl H; Wang, Chunsheng

    2013-08-26

    Silicon (Si) has been considered a very promising anode material for lithium ion batteries due to its high theoretical capacity. However, high-capacity Si nanoparticles usually suffer from low electronic conductivity, large volume change, and severe aggregation problems during lithiation and delithiation. In this paper, a unique nanostructured anode with Si nanoparticles bonded and wrapped by graphene is synthesized by a one-step aerosol spraying of surface-modified Si nanoparticles and graphene oxide suspension. The functional groups on the surface of Si nanoparticles (50-100 nm) not only react with graphene oxide and bind Si nanoparticles to the graphene oxide shell, but also prevent Si nanoparticles from aggregation, thus contributing to a uniform Si suspension. A homogeneous graphene-encapsulated Si nanoparticle morphology forms during the aerosol spraying process. The open-ended graphene shell with defects allows fast electrochemical lithiation/delithiation, and the void space inside the graphene shell accompanied by its strong mechanical strength can effectively accommodate the volume expansion of Si upon lithiation. The graphene shell provides good electronic conductivity for Si nanoparticles and prevents them from aggregating during charge/discharge cycles. The functionalized Si encapsulated by graphene sample exhibits a capacity of 2250 mAh g⁻¹ (based on the total mass of graphene and Si) at 0.1C and 1000 mAh g⁻¹ at 10C, and retains 85% of its initial capacity even after 120 charge/discharge cycles. The exceptional performance of graphene-encapsulated Si anodes combined with the scalable and one-step aerosol synthesis technique makes this material very promising for lithium ion batteries.

  19. Potential Effect of Liposomes and Liposome-Encapsulated Botulinum Toxin and Tacrolimus in the Treatment of Bladder Dysfunction.

    Science.gov (United States)

    Janicki, Joseph J; Chancellor, Michael B; Kaufman, Jonathan; Gruber, Michele A; Chancellor, David D

    2016-03-18

    Bladder drug delivery via catheter instillation is a widely used treatment for recurrence of superficial bladder cancer. Intravesical instillation of liposomal botulinum toxin has recently shown promise in the treatment of overactive bladder and interstitial cystitis/bladder pain syndrome, and studies of liposomal tacrolimus instillations show promise in the treatment of hemorrhagic cystitis. Liposomes are lipid vesicles composed of phospholipid bilayers surrounding an aqueous core that can encapsulate hydrophilic and hydrophobic drug molecules to be delivered to cells via endocytosis. This review will present new developments on instillations of liposomes and liposome-encapsulated drugs into the urinary bladder for treating lower urinary tract dysfunction.

  20. The influence of feedstock and process variables on the encapsulation of drug suspensions by spray-drying in fast drying regime: the case of novel antitubercular drug–palladium complex containing polymeric microparticles.

    Science.gov (United States)

    Giovagnoli, Stefano; Palazzo, Francesco; Di Michele, Alessandro; Schoubben, Aurelie; Blasi, Paolo; Ricci, Maurizio

    2014-04-01

    The purpose of this study was to address the effect of feedstock properties and process variables on the characteristics of antitubercular drug–palladium (Pd) containing poly(lactic) acid (PLA) microparticles (MP) obtained by spray-drying of noncolloidal particle dispersions in fast drying regime. Two different systems were compared: capreomycin–Pd (C–Pd) and ofloxacin–Pd (Ofx–Pd) dispersions in acetonitrile PLA solution. Particle size, dynamic light scattering, differential scanning calorimetry, SEM–energy dispersive X-ray, and spectrophotometric methods were used for MP characterization. C–Pd-loaded MP were optimized preliminarily by experimental design and compared with Ofx–Pd-loaded MP investigated in our previous work. Morphology of feedstock particles had a dominant role in determining MP morphology. The Charlesworth and Marshall theory was used to explain such behavior. The smaller and homogeneous C–Pd microparticulates favored MP inflation and buckling by forming a thick and nonporous shell. A percolation effect was proposed for the larger and irregular Ofx–Pd particles that produced smaller MP with a more porous shell. Increasing feedstock concentration led to higher particle loss. A tentative descriptive scheme of MP formation according to feedstock particle arrangement was proposed. This work suggested that spray-drying of drug dispersions should carefully consider the morphology of feedstock particles as a major parameter influencing final MP properties.

  1. Poly(lactide-co-glycolide) encapsulated hydroxyapatite microspheres for sustained release of doxycycline

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaoyun [School of Pharmacy, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China); Department of Pharmacy, Shandong Drug and Food Vocational College, Science and Technology Town, Hightech Industrial Development Zone, Weihai 264210 (China); Xu Hui; Zhao Yanqiu [School of Pharmacy, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China); Wang Shaoning, E-mail: wsn-xh@126.com [School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China); Abe, Hiroya; Naito, Makio [Joining and Welding Research Institute, Osaka University, 11-1, Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Liu Yanli [School of Pharmacy, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China); Wang Guoqing [School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer PLGA encapsulated HAP-MSs were used for the sustained delivery of Doxycycline (Doxy, a broad spectrum tetracycline antibiotic). Black-Right-Pointing-Pointer Sustained Doxy release without obvious burst was observed. Black-Right-Pointing-Pointer Mechanism of the sustained Doxy release was illustrated. Black-Right-Pointing-Pointer Sustained Doxy release character in vivo was also obtained, the plasma Doxy levels were relatively lower and steady compared to that of the un-encapsulated HAP-MSs. - Abstract: The purpose of this study was to prepare a poly(lactide-co-glycolide) (PLGA) encapsulated hydroxyapatite microspheres (HAP-MSs) as injectable depot for sustained delivery of Doxycycline (Doxy). Doxy loaded HAP-MSs (Doxy-HAP-MSs) were encapsulated with PLGA by solid-in-oil-in-water (S/O/W) emulsion-solvent evaporation technique, the effects of the PLGA used (various intrinsic viscosity and LA/GA ratio) and ratio of PLGA/HAP-MSs on the formation of Doxy-HAP-MSs and in vitro release of Doxy were studied. The results showed that sustained drug release without obvious burst was obtained by using PLGA encapsulated HAP-MSs as the carrier, also the drug release rate could be tailored by changing the ratio of PLGA/HAP-MSs, or PLGA of various intrinsic viscosities or LA/GA ratio. Lower ratio of PLGA/HAP-MSs corresponded faster Doxy release, e.g. for the microspheres of PLGA/HAP-MSs ratio of 8 and 0.25, the in vitro Doxy release percents at the end of 7days were about 23% and 76%, respectively. Higher hydrophilicity (higher ratio of GA to LA) and lower molecular weight of PLGA corresponded to higher Doxy release rates. For in vivo release study, PLGA encapsulated HAP-MSs were subcutaneously injected to the back of mice, and the results showed good correlation between the in vivo and in vitro drug release. Meanwhile, the plasma Doxy levels after subcutaneous administration of PLGA encapsulated Doxy-HAP-MSs were relatively lower and steady

  2. Aerosol MTF revisited

    Science.gov (United States)

    Kopeika, Norman S.; Zilberman, Arkadi; Yitzhaky, Yitzhak

    2014-05-01

    Different views of the significance of aerosol MTF have been reported. For example, one recent paper [OE, 52(4)/2013, pp. 046201] claims that the aerosol MTF "contrast reduction is approximately independent of spatial frequency, and image blur is practically negligible". On the other hand, another recent paper [JOSA A, 11/2013, pp. 2244-2252] claims that aerosols "can have a non-negligible effect on the atmospheric point spread function". We present clear experimental evidence of common significant aerosol blur and evidence that aerosol contrast reduction can be extremely significant. In the IR, it is more appropriate to refer to such phenomena as aerosol-absorption MTF. The role of imaging system instrumentation on such MTF is addressed too.

  3. Encapsulation of the HDACi Ex527 into Liposomes and Polymer-Based Particles.

    Science.gov (United States)

    Hennig, Dorle; Imhof, Diana

    2017-01-01

    Incorporation of drugs into particles can improve their therapeutic effectiveness. Solubility, half-life time, targeting, and the release of the drug can be modified by the encapsulation into a particle. Histone deacetylase inhibitors have a great potential to be used as therapeutics for many different diseases. In this chapter, we describe the inclusion of the low molar mass HDACi Ex527 into polymer-based particles and liposomes.

  4. Aerosols Science and Technology

    CERN Document Server

    Agranovski, Igor

    2011-01-01

    This self-contained handbook and ready reference examines aerosol science and technology in depth, providing a detailed insight into this progressive field. As such, it covers fundamental concepts, experimental methods, and a wide variety of applications, ranging from aerosol filtration to biological aerosols, and from the synthesis of carbon nanotubes to aerosol reactors.Written by a host of internationally renowned experts in the field, this is an essential resource for chemists and engineers in the chemical and materials disciplines across multiple industries, as well as ideal supplementary

  5. Ultrasound-induced encapsulated microbubble phenomena

    NARCIS (Netherlands)

    Postema, Michiel; Wamel, van Annemieke; Lancée, Charles T.; Jong, de Nico

    2004-01-01

    When encapsulated microbubbles are subjected to high-amplitude ultrasound, the following phenomena have been reported: oscillation, translation, coalescence, fragmentation, sonic cracking and jetting. In this paper, we explain these phenomena, based on theories that were validated for relatively big

  6. Lipid encapsulated phenolic compounds by fluidization

    Science.gov (United States)

    Phenolic compounds exhibit antioxidant and antimicrobial activities with applications as functional food and feed additives. Ferulic acid, a phenolic compound present in grain crops and lignocellulose biomass, was encapsulated with saturated triglycerides using a laboratory fluidizer. Stability of t...

  7. Cisplatin encapsulated nanoparticle as a therapeutic agent for anticancer treatment

    Science.gov (United States)

    Eka Putra, Gusti Ngurah Putu; Huang, Leaf; Hsu, Yih-Chih

    2016-03-01

    The knowledge of manipulating size of biomaterials encapsulated drug into nano-scale particles has been researched and developed in treating cancer. Cancer is the second worldwide cause of death, therefore it is critical to treat cancers challenging with therapeutic modality of various mechanisms. Our preliminary investigation has studied cisplatin encapsulated into lipid-based nanoparticle and examined the therapeutic effect on xenografted animal model. We used mice with tumor volume ranging from 195 to 214 mm3 and then few mice were grouped into three groups including: control (PBS), lipid platinum chloride (LPC) nanoparticles and CDDP (cis-diamminedichloroplatinum(II) at dose of 3mg cisplatin /kg body weight. The effect of the treatment was observed for 12 days post-injection. It showed that LPC NPs demonstrated a better therapeutic effect compared to CDDP at same 3mg cisplatin/kg drug dose of tumor size reduction, 96.6% and 11.1% respectively. In addition, mouse body weight loss of LPC, CDDP and PBS treated group are 12.1%, 24.3% and 1.4%. It means that by compared to CDDP group, LPC group demonstrated less side effect as not much reduction of body weight have found. Our findings have shown to be a potential modality to further investigate as a feasible cancer therapy modality.

  8. Encapsulating contact allergens in liposomes, ethosomes, and polycaprolactone may affect their sensitizing properties

    DEFF Research Database (Denmark)

    Madsen, Jakob Torp; Vogel, Stefan; Johansen, Jeanne Duus

    2011-01-01

    dichromate compared with control solutions. However, encapsulating the lipophilic contact allergen dinitrochlorobenzene (DNCB) in polycaprolactone reduced the sensitizing capacity to 1211 ± 449 compared with liposomes (7602 ± 2658) and in acetone:olive oil (4:1) (5633 ± 666). The same trend was observed...... for encapsulating isoeugenol in polycaprolactone (1100 ± 406) compared with a formulation in acetone:olive oil (4491 ± 819) and in liposomes (3668 ± 950). Further, the size of DNCB-loaded liposomes did not affect the sensitizing properties. These results suggest that modern dermal drug-delivery systems may in some...

  9. Encapsulated Thermoelectric Modules for Advanced Thermoelectric Systems

    Science.gov (United States)

    Kambe, Mitsuru; Jinushi, Takahiro; Ishijima, Zenzo

    2014-06-01

    An encapsulated thermoelectric (TE) module consists of a vacuum-tight stainless-steel container in which an SiGe or BiTe TE module is encapsulated. This construction enables maximum performance and durability because: the thermal expansion mismatch between the hot and cold sides of the container can be accommodated by a sliding sheet in the container; the TE module inside is always kept in a vacuum environment, therefore no oxidation can occur; and the pressure difference between the inside and outside of the container reduces thermal contact resistance inside the container. Our encapsulated SiGe module features higher operating temperature—up to 650°C for both hot and cold sides. Other high-temperature modules and conventional BiTe modules, including both-sides and one-side skeleton types, have been encapsulated. Several variants of the encapsulated module are available. Encapsulated thermoelectric modules with integrated coolers contain cooling panels through which water can pass. If the module hot side is heated by a radiating heat source (radiation coupling) or convection of a hot gas or fluid (convection coupling), no pressing force on the module is necessary. It therefore features minimum contact resistance with the cooling duct, because no pressure is applied, maximum TE power, and minimum installation cost. Another, larger, variant is a quadruple flexible container in which four modules (each of maximum size 40 mm × 40 mm) are encapsulated. These encapsulated modules were used in a powder metallurgy furnace and were in use for more than 3000 h. Application to cryogenic temperatures simulating the liquid nitrogen gas vaporizer has been also attempted.

  10. Sclerosing encapsulating peritonitis: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Candido, Paula de Castro Menezes; Werner, Andrea de Freitas; Pereira, Izabela Machado Flores; Matos, Breno Assuncao; Pfeilsticker, Rudolf Moreira; Silva Filho, Raul, E-mail: paulacmcandido@yahoo.com.br [Hospital Felicio Rocho, Belo Horizonte, MG (Brazil)

    2015-01-15

    Sclerosing encapsulating peritonitis, a rare cause of bowel obstruction, was described as a complication associated with peritoneal dialysis which is much feared because of its severity. The authors report a case where radiological findings in association with clinical symptoms have allowed for a noninvasive diagnosis of sclerosing encapsulating peritonitis, emphasizing the high sensitivity and specificity of computed tomography to demonstrate the characteristic findings of such a condition. (author)

  11. Metallomics in drug development

    DEFF Research Database (Denmark)

    Nguyen, Trinh Thi Nhu Tam; Ostergaard, Jesper; Stürup, Stefan;

    2013-01-01

    A capillary electrophoresis inductively coupled plasma mass spectrometry method for separation of free cisplatin from liposome-encapsulated cisplatin and protein-bound cisplatin was developed. A liposomal formulation of cisplatin based on PEGylated liposomes was used as model drug formulation...... to plasma constituents in plasma samples. It was demonstrated that this approach is suitable for studies of the stability of liposome formulations as leakage of active drug from the liposomes and subsequent binding to biomolecules in plasma can be monitored. This methodology has not been reported before...... and will improve characterization of liposomal drugs during drug development and in studies on kinetics....

  12. High encapsulation efficiency of sodium alendronate in eudragit S100/HPMC blend microparticles

    Directory of Open Access Journals (Sweden)

    Letícia Cruz

    2009-01-01

    Full Text Available The hydrophilic drug sodium alendronate was encapsulated in blended microparticles of Eudragit® S100 and Methocel® F4M or Methocel® K100LV. Both formulations prepared by spray-drying showed spherical collapsed shape and smooth surface, encapsulation efficiencies of 85 and 82% and mean diameters of 11.7 and 8.4 µm, respectively. At pH 1.2, in vitro dissolution studies showed good gastro-resistance for both formulations. At pH 6.8, the sodium alendronate release from the microparticles was delayed and was controlled by Fickian diffusion. In conclusion, the prepared microparticles showed high encapsulation efficiency of sodium alendronate presenting gastro-resistance and sustained release suitable for its oral administration.

  13. Alginate encapsulation parameters influence the differentiation of microencapsulated embryonic stem cell aggregates.

    Science.gov (United States)

    Wilson, Jenna L; Najia, Mohamad Ali; Saeed, Rabbia; McDevitt, Todd C

    2014-03-01

    Pluripotent embryonic stem cells (ESCs) have tremendous potential as tools for regenerative medicine and drug discovery, yet the lack of processes to manufacture viable and homogenous cell populations of sufficient numbers limits the clinical translation of current and future cell therapies. Microencapsulation of ESCs within microbeads can shield cells from hydrodynamic shear forces found in bioreactor environments while allowing for sufficient diffusion of nutrients and oxygen through the encapsulation material. Despite initial studies examining alginate microbeads as a platform for stem cell expansion and directed differentiation, the impact of alginate encapsulation parameters on stem cell phenotype has not been thoroughly investigated. Therefore, the objective of this study was to systematically examine the effects of varying alginate compositions on microencapsulated ESC expansion and phenotype. Pre-formed aggregates of murine ESCs were encapsulated in alginate microbeads composed of a high or low ratio of guluronic to mannuronic acid residues (High G and High M, respectively), with and without a poly-L-lysine (PLL) coating, thereby providing four distinct alginate bead compositions for analysis. Encapsulation in all alginate compositions was found to delay differentiation, with encapsulation within High G alginate yielding the least differentiated cell population. The addition of a PLL coating to the High G alginate prevented cell escape from beads for up to 14 days. Furthermore, encapsulation within High M alginate promoted differentiation toward a primitive endoderm phenotype. Taken together, the findings of this study suggest that distinct ESC expansion capacities and differentiation trajectories emerge depending on the alginate composition employed, indicating that encapsulation material physical properties can be used to control stem cell fate.

  14. Characterization and aerosol dispersion performance of advanced spray-dried chemotherapeutic PEGylated phospholipid particles for dry powder inhalation delivery in lung cancer.

    Science.gov (United States)

    Meenach, Samantha A; Anderson, Kimberly W; Zach Hilt, J; McGarry, Ronald C; Mansour, Heidi M

    2013-07-16

    Pulmonary inhalation chemotherapeutic drug delivery offers many advantages for lung cancer patients in comparison to conventional systemic chemotherapy. Inhalable particles are advantageous in their ability to deliver drug deep in the lung by utilizing optimally sized particles and higher local drug dose delivery. In this work, spray-dried and co-spray dried inhalable lung surfactant-mimic PEGylated lipopolymers as microparticulate/nanoparticulate dry powders containing paclitaxel were rationally designed via organic solution advanced spray drying (no water) in closed-mode from dilute concentration feed solution. Dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine poly(ethylene glycol) (DPPE-PEG) with varying PEG chain length were mixed with varying amounts of paclitaxel in methanol to produce co-spray dried microparticles and nanoparticles. Scanning electron microscopy showed the spherical particle morphology of the inhalable particles. Thermal analysis and X-ray powder diffraction confirmed the retention of the phospholipid bilayer structure in the solid-state following spray drying, the degree of solid-state molecular order, and solid-state phase transition behavior. The residual water content of the particles was very low as quantified analytically Karl Fisher titration. The amount of paclitaxel loaded into the particles was quantified which indicated high encapsulation efficiencies (43-99%). Dry powder aerosol dispersion performance was measured in vitro using the Next Generation Impactor (NGI) coupled with the Handihaler dry powder inhaler device and showed mass median aerodynamic diameters in the range of 3.4-7 μm. These results demonstrate that this novel microparticulate/nanoparticulate chemotherapeutic PEGylated phospholipid dry powder inhalation aerosol platform has great potential in lung cancer drug delivery.

  15. PHARMACEUTICAL AEROSOLS FOR THE TREATMENT AND PREVENTION OF TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    Shumaila N Muhammad Hanif

    2012-09-01

    Full Text Available Historically, pharmaceutical aerosols have been employed for the treatment of obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease, but in the past decades their use has been expanded to treat lung infections associated with cystic fibrosis and other respiratory diseases. Tuberculosis (TB is acquired after inhalation of aerosol droplets containing the bacilli from the cough of infected individuals. Even though TB affects other organs, the lungs are the primary site of infection, which makes the pulmonary route an ideal alternative route to administer vaccines or drug treatments. Optimization of formulations and delivery systems for anti-TB vaccines and drugs, as well as the proper selection of the animal model to evaluate those is of paramount importance if novel vaccines or drug treatments are to be successful. Pharmaceutical aerosols for patient use are generated from metered dose inhalers, nebulizers and dry powder inhalers. In addition to the advantages of providing more efficient delivery of the drug, low cost and portability, pharmaceutical dry powder aerosols are more stable than inhalable liquid dosage forms and do not require refrigeration. Methods to manufacture dry powders in respirable sizes include micronization, spray drying and other proprietary technologies. Inhalable dry powders are characterized in terms of their drug content, particle size and dispersibility to ensure deposition in the appropriate lung region and effective aerosolization from the device. These methods will be illustrated as they were applied for the manufacture and characterization of powders containing anti-tubercular agents and vaccines for pulmonary administration. The influence of formulation, selection of animal model, method of aerosol generation and administration on the efficacy demonstrated in a given study will be illustrated by the evaluation of pharmaceutical aerosols of anti-TB drugs and vaccines in guinea pigs by

  16. Encapsulation of naproxen in nanostructured system: structural characterization and in vitro release studies

    Directory of Open Access Journals (Sweden)

    Vanessa Azevedo de Mello

    2011-01-01

    Full Text Available Nanoparticles were produced by solvent emulsification evaporation method with the following characteristics: nanometric size (238 ± 3 nm, narrow polydispersity index (0.11, negative zeta potential (-15.1 mV, good yield of the process (73 ± 1.5%, excellent encapsulation efficiency (81.3 ± 4.2% and spherical shape. X-rays diffraction demonstrated the loss of drug crystallinity after encapsulation; however, the profile of the diffractograms of the poly-ε-caprolactone (PCL nanoparticles was kept. Differential scanning calorimetry thermograms, correspondingly, exhibited the loss of drug melting peak and the increasing of the melting point of the PCL nanoparticles, evidencing an interaction drug-polymer. Naproxen release was low and sustained obeying the Higuchi´s kinetic. The results show that nanoparticles are promising sustained release system to the naproxen.

  17. Cytokine production induced by non-encapsulated and encapsulated Porphyromonas gingivalis strains

    NARCIS (Netherlands)

    Kunnen, A.; Dekker, D.C.; van Pampus, M.G.; Harmsen, H.J.; Aarnoudse, J.G.; Abbas, F.; Faas, M.M.

    2012-01-01

    Objective: Although the exact reason is not known, encapsulated gram-negative Porphyromonas gingivalis strains are more virulent than non-encapsulated strains. Since difference in virulence properties may be due to difference in cytokine production following recognition of the bacteria or their prod

  18. Preparation of thermosensitive magnetic liposome encapsulated recombinant tissue plasminogen activator for targeted thrombolysis

    Science.gov (United States)

    Hsu, Hao-Lung; Chen, Jyh-Ping

    2017-04-01

    Recombinant tissue plasminogen activator (rtPA) was encapsulated in thermosensitive magnetic liposome (TML) prepared from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, distearolyphosphatidyl ethanolamine-N-poly(ethylene glycol) 2000, cholesterol and Fe3O4 magnetic nanoparticles by solvent evaporation/sonication and freeze-thaw cycles method. Response surface methodology was proved to be a powerful tool to predict the drug encapsulation efficiency and temperature-sensitive drug release. Validation experiments verified the accuracy of the model that provides a simple and effective method for fabricating TML with controllable encapsulation efficiency and predictable temperature-sensitive drug release behavior. The prepared samples were characterized for physico-chemical properties by dynamic light scattering, transmission electron microscopy, X-ray diffraction and differential scanning calorimetry. Temperature-sensitive release of rtPA could be confirmed from in vitro thrombolysis experiments. A thrombolytic drug delivery system using TML could be proposed for magnetic targeted delivery of rtPA to the site of thrombus followed by temperature-triggered controlled drug release in an alternating magnetic field.

  19. Encapsulation of 2-methoxyestradiol within multifunctional poly(amidoamine) dendrimers for targeted cancer therapy.

    Science.gov (United States)

    Wang, Yin; Guo, Rui; Cao, Xueyan; Shen, Mingwu; Shi, Xiangyang

    2011-04-01

    We report here a general approach to using multifunctional poly(amidoamine) (PAMAM) dendrimer-based platform to encapsulate a potential anticancer drug for targeted cancer therapy. In this approach, amine-terminated generation 5 (G5) PAMAM dendrimers were sequentially modified with fluorescein isothiocyanate (FI) and folic acid (FA) via covalent conjugation, followed by an acetylation reaction to neutralize the remaining amines of the dendrimer surfaces. The synthesized multifunctional dendrimers (G5.NHAc-FI-FA) were then used to complex a potential anticancer drug, 2-methoxyestradiol (2-ME) for targeted delivery of the drugs to cancer cells overexpressing high-affinity folic acid receptors (FAR). We show that the formed G5.NHAc-FI-FA/2-ME complexes with each dendrimer encapsulating approximately 3.7 2-ME molecules are water soluble and stable. In vitro release studies show that 2-ME complexed with the multifunctional dendrimers can be released in a sustained manner. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in conjunction with cell morphology observation demonstrates that the G5.NHAc-FI-FA/2-ME complexes can specifically target and display specific therapeutic efficacy to cancer cells overexpressing high-affinity FAR. Findings from this study suggest that multifunctional dendrimers may be used as a general drug carrier to encapsulate various cancer drugs for targeted therapy of different types of cancer.

  20. The encapsulation of an amphiphile into polystyrene microspheres of narrow size distribution

    Directory of Open Access Journals (Sweden)

    Pellach Michal

    2011-12-01

    Full Text Available Abstract Encapsulation of compounds into nano- or microsized organic particles of narrow size distribution is of increasing importance in fields of advanced imaging and diagnostic techniques and drug delivery systems. The main technology currently used for encapsulation of molecules within uniform template particles while retaining their size distribution is based on particle swelling methodology, involving penetration of emulsion droplets into the particles. The swelling method, however, is efficient for encapsulation only of hydrophobic compounds within hydrophobic template particles. In order to be encapsulated, the molecules must favor the hydrophobic phase of an organic/aqueous biphasic system, which is not easily achieved for molecules of amphiphilic character. The following work overcomes this difficulty by presenting a new method for encapsulation of amphiphilic molecules within uniform hydrophobic particles. We use hydrogen bonding of acid and base, combined with a pseudo salting out effect, for the entrapment of the amphiphile in the organic phase of a biphasic system. Following the entrapment in the organic phase, we demonstrated, using fluorescein and (antibiotic tetracycline as model molecules, that the swelling method usually used only for hydrophobes can be expanded and applied to amphiphilic molecules.

  1. The encapsulation of an amphiphile into polystyrene microspheres of narrow size distribution.

    Science.gov (United States)

    Pellach, Michal; Margel, Shlomo

    2011-12-06

    Encapsulation of compounds into nano- or microsized organic particles of narrow size distribution is of increasing importance in fields of advanced imaging and diagnostic techniques and drug delivery systems. The main technology currently used for encapsulation of molecules within uniform template particles while retaining their size distribution is based on particle swelling methodology, involving penetration of emulsion droplets into the particles. The swelling method, however, is efficient for encapsulation only of hydrophobic compounds within hydrophobic template particles. In order to be encapsulated, the molecules must favor the hydrophobic phase of an organic/aqueous biphasic system, which is not easily achieved for molecules of amphiphilic character.The following work overcomes this difficulty by presenting a new method for encapsulation of amphiphilic molecules within uniform hydrophobic particles. We use hydrogen bonding of acid and base, combined with a pseudo salting out effect, for the entrapment of the amphiphile in the organic phase of a biphasic system. Following the entrapment in the organic phase, we demonstrated, using fluorescein and (antibiotic) tetracycline as model molecules, that the swelling method usually used only for hydrophobes can be expanded and applied to amphiphilic molecules.

  2. Dynamic Mechanism of Single-Stranded DNA Encapsulated into Single-Wall Carbon Nanotubes: A Molecular Dynamics Simulation Study

    Science.gov (United States)

    Xing, Yan-Fei; Yang, Chuan-Lu; Mo, Yong-Fang; Wang, Mei-Shan; Ma, Xiao-Guang

    2014-02-01

    Hybrids of single-walled carbon nanotubes (SWCNTs) and biological molecules have been utilized for numerous applications in sensing, imaging, and drug delivery. By molecular dynamics simulation, we investigate the encapsulation of single-strand DNA (ssDNA) containing eight adenine bases with (17,17)-(12,12) SWCNTs. The effects of the diameter and length of SWCNTs on the encapsulation process are explored with the calculated curves of the center-of-mass distance, the van der Waals interaction between the ssDNA and SWCNT, the root-mean-square deviation of the ssDNA, and the radius of gyration of the ssDNA. The free energy of the encapsulated ssDNA for each SWCNT is also obtained via steered molecular dynamics simulation. The most suitable SWCNT for encapsulating the ssDNA is also suggested.

  3. DARE : Dedicated Aerosols Retrieval Experiment

    NARCIS (Netherlands)

    Smorenburg, K.; Courrèges-Lacoste, G.B.; Decae, R.; Court, A.J.; Leeuw, G. de; Visser, H.

    2004-01-01

    At present there is an increasing interest in remote sensing of aerosols from space because of the large impact of aerosols on climate, earth observation and health. TNO has performed a study aimed at improving aerosol characterisation using a space based instrument and state-of-the-art aerosol retr

  4. Sol-gel method for encapsulating molecules

    Science.gov (United States)

    Brinker, C. Jeffrey; Ashley, Carol S.; Bhatia, Rimple; Singh, Anup K.

    2002-01-01

    A method for encapsulating organic molecules, and in particular, biomolecules using sol-gel chemistry. A silica sol is prepared from an aqueous alkali metal silicate solution, such as a mixture of silicon dioxide and sodium or potassium oxide in water. The pH is adjusted to a suitably low value to stabilize the sol by minimizing the rate of siloxane condensation, thereby allowing storage stability of the sol prior to gelation. The organic molecules, generally in solution, is then added with the organic molecules being encapsulated in the sol matrix. After aging, either a thin film can be prepared or a gel can be formed with the encapsulated molecules. Depending upon the acid used, pH, and other processing conditions, the gelation time can be from one minute up to several days. In the method of the present invention, no alcohols are generated as by-products during the sol-gel and encapsulation steps. The organic molecules can be added at any desired pH value, where the pH value is generally chosen to achieve the desired reactivity of the organic molecules. The method of the present invention thereby presents a sufficiently mild encapsulation method to retain a significant portion of the activity of the biomolecules, compared with the activity of the biomolecules in free solution.

  5. Postdeposition dispersion of aerosol medications using surfactant carriers.

    Science.gov (United States)

    Marcinkowski, Amy L; Garoff, Stephen; Tilton, Robert D; Pilewski, Joseph M; Corcoran, Timothy E

    2008-12-01

    Inhaled aerosol drugs provide a means of directly treating the lungs; however, aerosol deposition and drug distribution can be nonuniform, especially in obstructive lung disease. We hypothesize that surfactant-based aerosol carriers will disperse medications over airway surfaces after deposition through surface tension driven flows, increasing dose uniformity and improving drug distribution into underventilated regions. We considered saline and surfactant aerosol delivery via cannula onto several model airway surfaces including porcine gastric mucus (PGM) and both cystic fibrosis (CF) and non-CF human bronchial epithelial cells (HBEs). Fluorescent dye and microspheres (d = 100 nm, 1 mum) were used to qualitatively and quantitatively assess postdeposition dispersion. Aerosol volume median diameters were in the 1-4 mum range. The tested surfactants included sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium bromide (CTAB), tyloxapol, and calfactant. All surfactants tested on PGM (tyloxapol, calfactant, SDS, and CTAB) significantly increased dispersion area versus saline with all markers (2-20-fold increases; all p surfactants tested on CF HBEs (tyloxapol and calfactant) significantly increased dispersion area versus saline with all markers (1.6-4.1-fold increases; all p Surfactant carriers enhanced dispersion after aerosol deposition onto model airway surfaces, and may improve the efficacy of inhaled preparations such as inhaled antibiotics for cystic fibrosis.

  6. MSA in Beijing aerosol

    Institute of Scientific and Technical Information of China (English)

    YUAN Hui; WANG Ying; ZHUANG Guoshun

    2004-01-01

    Methane sulphonate (MSA) and sulfate (SO42-), the main oxidation products of dimethyl sulfide (DMS), are the target of atmospheric chemistry study, as sulfate aerosol would have important impact on the global climate change. It is widely believed that DMS is mainly emitted from phytoplankton production in marine boundary layer (MBL), and MSA is usually used as the tracer of non-sea-salt sulfate (nss- SO42-) in marine and coastal areas (MSA/SO42- = 1/18). Many observations of MSA were in marine and coastal aerosols. To our surprise, MSA was frequently (>60%) detected in Beijing TSP, PM10, and PM2.5 aerosols, even in the samples collected during the dust storm period. The concentrations of MSA were higher than those measured in marine aerosols. Factor analysis, correlation analysis and meteorology analysis indicated that there was no obvious marine influence on Beijing aerosols. DMS from terrestrial emissions and dimethyl sulphoxide (DMSO) from industrial wastes could be the two possible precursors of MSA. Warm and low-pressure air masses and long time radiation were beneficial to the formation of MSA. Anthropogenic pollution from regional and local sources might be the dominant contributor to MSA in Beijing aerosol. This was the first report of MSA in aerosols collected in an inland site in China. This new finding would lead to the further study on the balance of sulfur in inland cities and its global biogeochemical cycle.

  7. Modal aerosol dynamics modeling

    Energy Technology Data Exchange (ETDEWEB)

    Whitby, E.R.; McMurry, P.H.; Shankar, U.; Binkowski, F.S.

    1991-02-01

    The report presents the governing equations for representing aerosol dynamics, based on several different representations of the aerosol size distribution. Analytical and numerical solution techniques for these governing equations are also reviewed. Described in detail is a computationally efficient numerical technique for simulating aerosol behavior in systems undergoing simultaneous heat transfer, fluid flow, and mass transfer in and between the gas and condensed phases. The technique belongs to a general class of models known as modal aerosol dynamics (MAD) models. These models solve for the temporal and spatial evolution of the particle size distribution function. Computational efficiency is achieved by representing the complete aerosol population as a sum of additive overlapping populations (modes), and solving for the time rate of change of integral moments of each mode. Applications of MAD models for simulating aerosol dynamics in continuous stirred tank aerosol reactors and flow aerosol reactors are provided. For the application to flow aerosol reactors, the discussion is developed in terms of considerations for merging a MAD model with the SIMPLER routine described by Patankar (1980). Considerations for incorporating a MAD model into the U.S. Environmental Protection Agency's Regional Particulate Model are also described. Numerical and analytical techniques for evaluating the size-space integrals of the modal dynamics equations (MDEs) are described. For multimodal logonormal distributions, an analytical expression for the coagulation integrals of the MDEs, applicable for all size regimes, is derived, and is within 20% of accurate numerical evaluation of the same moment coagulation integrals. A computationally efficient integration technique, based on Gauss-Hermite numerical integration, is also derived.

  8. The inhibitory effect of disulfiram encapsulated PLGA NPs on tumor growth: Different administration routes.

    Science.gov (United States)

    Fasehee, Hamidreza; Zarrinrad, Ghazaleh; Tavangar, Seyed Mohammad; Ghaffari, Seyed Hamidollah; Faghihi, Shahab

    2016-06-01

    The strong anticancer activity of disulfiram is hindered by its rapid degradation in blood system. A novel folate-receptor-targeted poly (lactide-co-glycolide) (PLGA)-polyethylene glycol (PEG) nanoparticle (NP) is developed for encapsulation and delivery of disulfiram into breast cancer tumor using passive (EPR effect) and active (folate receptor) targeting. The anticancer activity of disulfiram and its effect on caspase-3 activity and cell cycle are studied. The administration of encapsulated PLGA NPs using intra-peritoneal, intravenous and intra-tumor routes is investigated using animal model. Disulfiram shows strong cytotoxicity against MCF7 cell line. The activity of caspase-3 inhibited with disulfiram via dose dependent manner while the drug causes cell cycle arrest in G0/G1 and S phase time-dependently. The encapsulated disulfiram shows higher activity in apoptosis induction as compared to free drug. In nontoxic dose of encapsulated disulfiram, the highest and lowest efficacy of NPs in tumor growth inhibition is observed for intravenous injection and intraperitoneal injection. It is suggested that administration of disulfiram by targeted PLGA nanoparticles using intravenous injection would present an alternative therapeutic approach for solid tumor treatment.

  9. Preparation and anti-cancer activity of polymer-encapsulated curcumin nanoparticles

    Science.gov (United States)

    Thu Ha, Phuong; Huong Le, Mai; Nhung Hoang, Thi My; Thu Huong Le, Thi; Quang Duong, Tuan; Tran, Thi Hong Ha; Tran, Dai Lam; Phuc Nguyen, Xuan

    2012-09-01

    Curcumin (Cur) is a yellow compound isolated from rhizome of the herb curcuma longa. Curcumin possesses antioxidant, anti-inflammatory, anti-carcinogenic and antimicrobial properties, and suppresses proliferation of many tumor cells. However, the clinical application of curcumin in cancer treatment is considerably limited due to its serious poor delivery characteristics. In order to increase the hydrophilicity and drug delivery capability, we encapsulated curcumin into copolymer PLA-TPGS, 1,3-beta-glucan (Glu), O-carboxymethyl chitosan (OCMCs) and folate-conjugated OCMCs (OCMCs-Fol). These polymer-encapsulated curcumin nanoparticles (Cur-PLA-TPGS, Cur-Glu, Cur-OCMCs and Cur-OCMCs-Fol) were characterized by infrared (IR), fluorescence (FL), photoluminescence (PL) spectra, field emission scanning electron microscopy (FE-SEM), and found to be spherical particles with an average size of 50-100 nm, being suitable for drug delivery applications. They were much more soluble in water than not only free curcumin but also other biodegradable polymer-encapsulated curcumin nanoparticles. The anti-tumor promoting assay was carried out, showing the positive effects of Cur-Glu and Cur-PLA-TPGS on tumor promotion of Hep-G2 cell line in vitro. Confocal microscopy revealed that the nano-sized curcumin encapsulated by polymers OCMCs and OCMCs-Fol significantly enhanced the cellular uptake (cancer cell HT29 and HeLa).

  10. Degradation of Silicone Encapsulants in CPV Optics

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Can; Miller, David C.; Tappan, Ian A.; Dauskardt, Reinhold H.

    2016-11-21

    High efficiency multijunction solar cells in terrestrial concentrator photovoltaic (CPV) modules are becoming an increasingly cost effective and viable option in utility scale power generation. As with other utility scale photovoltaics, CPV modules need to guarantee operational lifetimes of at least 25 years. The reliability of optical elements in CPV modules poses a unique materials challenge due to the increased UV irradiance and enhanced temperature cycling associated with concentrated solar flux. The polymeric and thin film materials used in the optical elements are especially susceptible to UV damage, diurnal temperature cycling and active chemical species from the environment. We used fracture mechanics approaches to study the degradation modes including: the adhesion between the encapsulant and the cell or secondary optical element; and the cohesion of the encapsulant itself. Understanding the underlying mechanisms of materials degradation under elevated stress conditions is critical for commercialization of CPV technology and can offer unique insights into degradation modes in similar encapsulants used in other photovoltaic modules.

  11. Nondestructive Assay Options for Spent Fuel Encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, Stephen J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jansson, Peter [Uppsala Univ. (Sweden)

    2014-10-02

    This report describes the role that nondestructive assay (NDA) techniques and systems of NDA techniques may have in the context of an encapsulation and deep geological repository. The potential NDA needs of an encapsulation and repository facility include safeguards, heat content, and criticality. Some discussion of the facility needs is given, with the majority of the report concentrating on the capability and characteristics of individual NDA instruments and techniques currently available or under development. Particular emphasis is given to how the NDA techniques can be used to determine the heat production of an assembly, as well as meet the dual safeguards needs of 1) determining the declared parameters of initial enrichment, burn-up, and cooling time and 2) detecting defects (total, partial, and bias). The report concludes with the recommendation of three integrated systems that might meet the combined NDA needs of the encapsulation/repository facility.

  12. On-chip Magnetic Separation and Cell Encapsulation in Droplets

    Science.gov (United States)

    Chen, A.; Byvank, T.; Bharde, A.; Miller, B. L.; Chalmers, J. J.; Sooryakumar, R.; Chang, W.-J.; Bashir, R.

    2012-02-01

    The demand for high-throughput single cell assays is gaining importance because of the heterogeneity of many cell suspensions, even after significant initial sorting. These suspensions may display cell-to-cell variability at the gene expression level that could impact single cell functional genomics, cancer, stem-cell research and drug screening. The on-chip monitoring of individual cells in an isolated environment could prevent cross-contamination, provide high recovery yield and ability to study biological traits at a single cell level These advantages of on-chip biological experiments contrast to conventional methods, which require bulk samples that provide only averaged information on cell metabolism. We report on a device that integrates microfluidic technology with a magnetic tweezers array to combine the functionality of separation and encapsulation of objects such as immunomagnetically labeled cells or magnetic beads into pico-liter droplets on the same chip. The ability to control the separation throughput that is independent of the hydrodynamic droplet generation rate allows the encapsulation efficiency to be optimized. The device can potentially be integrated with on-chip labeling and/or bio-detection to become a powerful single-cell analysis device.

  13. Electrostatics in pharmaceutical aerosols for inhalation.

    Science.gov (United States)

    Wong, Jennifer; Chan, Hak-Kim; Kwok, Philip Chi Lip

    2013-08-01

    Electrostatics continues to play an important role in pharmaceutical aerosols for inhalation. Despite its ubiquitous nature, the charging process is complex and not well understood. Nonetheless, significant advances in the past few years continue to improve understanding and lead to better control of electrostatics. The purpose of this critical review is to present an overview of the literature, with an emphasis on how electrostatic charge can be useful in improving pulmonary drug delivery.

  14. Encapsulation of a proteasome inhibitor with gold-polysaccharide nanocarriers

    Science.gov (United States)

    Coelho, Sílvia Castro; Rocha, Sandra; Sampaio, Paula; Pereira, Maria Carmo; Coelho, Manuel A. N.

    2014-04-01

    Organic-inorganic hybrid nanoparticles are potential effective systems for drug delivery in cancer therapy and diagnosis. Chitosan-gum arabic with entrapped gold nanoparticles were developed as a carrier for an anticancer drug bortezomib. The nanosystem was designed to enhance the proteasome inhibitor activity in pancreatic cell lines, S2-013 and hTERT-HPNE. The hydrodynamic diameter of chitosan-gum arabic-gold nanoparticles loaded with bortezomib is around 330 nm. Laser scanning confocal microscopy images show the uptake of the gold nanoparticle/bortezomib encapsulated in chitosan-gum arabic matrix and the fast internalization of these nano combinations into pancreatic cells. Cytotoxic assays assessed that positively charged nanosystems reduce the cell growth and cell proliferation of S2-013s, but the same effect was not observed in cytotoxic response in hTERT-HPNE cells. The outcomes of this study demonstrate the capacity of chitosan-gum arabic nanocarriers to deliver gold nanoparticles/anticancer drug and to increase the permeation and retention effect in S2-013 cells and minimize drug side effects in HPNE cells.

  15. Encapsulation efficiency and controlled release characteristics of crosslinked polyacrylamide particles.

    Science.gov (United States)

    Sairam, Malladi; Babu, V Ramesh; Vijaya, Boya; Naidu, Kumar; Aminabhavi, Tejraj M

    2006-08-31

    Polyacrylamide (pAAm) particles crosslinked with N,N-methylenebis-acrylamide/ethylene glycol dimethacrylate (NNMBA/EGDMA) have been prepared in water-methanol medium by the dispersion polymerization using poly(vinyl pyrrolidone), PVP as a steric stabilizer. 5-fluorouracil an anticancer drug, has been loaded in situ into the crosslinked pAAm particles. Plain as well as drug loaded microparticles have been characterized by differential scanning calorimetry (DSC) and X-ray diffraction studies (XRD) and scanning electron microscopy (SEM). DSC and XRD studies have indicated a molecular level dispersion of the drug in pAAm particles during in situ loading and SEM pictures have shown the formation of spherical and oval-shaped particles. In vitro release of 5-fluorouracil from the crosslinked pAAm particles has been carried out in 7.4 pH buffer medium. Both encapsulation efficiency and release patterns are found to depend on the nature of the crosslinking agent, amount of crosslinking agent used and the amount of drug loaded. In vitro release studies indicated the controlled release of 5-fluorouracil up to 12 h.

  16. Encapsulation of Hydrocortisone and Mesalazine in Zein Microparticles

    Directory of Open Access Journals (Sweden)

    Peter J. Halley

    2013-05-01

    Full Text Available Zein was investigated for use as an oral-drug delivery system by loading prednisolone into zein microparticles using coacervation. To investigate the adaptability of this method to other drugs, zein microparticles were loaded with hydrocortisone, which is structurally related to prednisolone; or mesalazine, which is structurally different having a smaller LogP and ionizable functional groups. Investigations into the in vitro digestibility, and the electrophoretic profile of zein, and zein microparticles were conducted to shed further insight on using this protein as a drug delivery system. Hydrocortisone loading into zein microparticles was comparable with that reported for prednisolone, but mesalazine loading was highly variable. Depending on the starting quantities of hydrocortisone and zein, the average amount of microparticles equivalent to 4 mg hydrocortisone, (a clinically used dose, ranged from 60–115 mg, which is realistic and practical for oral dosing. Comparatively, an average of 2.5 g of microparticles was required to deliver 250 mg of mesalazine (a clinically used dose, so alternate encapsulation methods that can produce higher and more precise mesalazine loading are required. In vitro protein digestibility revealed that zein microparticles were more resistant to digestion compared to the zein raw material, and that individual zein peptides are not preferentially coacervated into the microparticles. In combination, these results suggest that there is potential to formulate a delivery system based on zein microparticles made using specific subunits of zein that is more resistant to digestion as starting material, to deliver drugs to the lower gastrointestinal tract.

  17. The brine shrimp ( Artemia parthenogenetica) as encapsulation organism for prophylactic chemotherapy of fish and prawn

    Science.gov (United States)

    Cao, Ji-Xiang; Bian, Bo-Zhong; Li, Ming-Ren

    1996-06-01

    Brine shrimp ( Artemia parthenogenetica) which had ingested three water-insoluble antibacterial drugs i.e. sulfadiazine(SD), oxytetracycline (OTC) and erythromycin estolate (ERY-Es) were fed to Tilapia and Mysis III of Penaeus orientalis K. The drug contents in the predators were then determined. After administration of drugs to Tilapia and Mysis III, through the bio-encapsulation of the brine shrimp, efficacious therapeutical concentration of OTC and ERY-Es (but not SD) in the predators could be reached and maintained for more than 8 hours.

  18. Assessment of bioburden encapsulated in bulk materials

    Science.gov (United States)

    Schubert, Wayne W.; Newlin, Laura; Chung, Shirley Y.; Ellyin, Raymond

    2016-05-01

    The National Aeronautics and Space Administration (NASA) imposes bioburden limitations on all spacecraft destined for solar system bodies that might harbor evidence of extant or extinct life. The subset of microorganisms trapped within solid materials during manufacture and assembly is referred to as encapsulated bioburden. In the absence of spacecraft-specific data, NASA relies on specification values to estimate total spacecraft encapsulated bioburden, typically 30 endospores/cm3 or 300 viable cells/cm3 in non-electronic materials. Specification values for endospores have been established conservatively, and represent no less than an order of magnitude greater abundance than that derived from empirical assessments of actual spacecraft materials. The goal of this study was to generate data germane to determining whether revised bulk encapsulated material values (lower than those estimated by historical specifications) tailored specifically to the materials designated in modern-day spacecraft design could be used, on a case-by-case basis, to comply with planetary protection requirements. Organic materials having distinctly different chemical properties and configurations were selected. This required more than one experimental and analytical approach. Filtration was employed for liquid electrolytes, lubricants were suspended in an aqueous solution and solids (wire and epoxy sealant) were cryogenically milled. The final data characteristic for all bioburden estimates was microbial colony formation in rich agar growth medium. To assess survival potential, three non-spore-forming bacterial cell lines were systematically encapsulated in an epoxy matrix, liberated via cryogenic grinding, and cultured. Results suggest that bulk solid materials harbor significantly fewer encapsulated microorganisms than are estimated by specification values. Lithium-ion battery electrolyte reagents housed fewer than 1 CFU/cm3. Results also demonstrated that non-spore-forming microorganisms

  19. Aerosol assisted depositions of polymers using an atomiser delivery system.

    Science.gov (United States)

    Crick, Colin R; Clausen-Thue, Victoria; Parkin, Ivan P

    2011-09-01

    The hydrophobicity, robustness and anti-microbial properties of Sylgard 184 polymer films deposited via AACVD were optimised by using aerosol droplets from an atomiser delivery system, polymer coating substrates and the swell encapsulation of methylene blue. By using an atomiser deposition system (average droplet size 0.35 microm) rather than a misting aerosol system (45 microm) lead to a surface with smaller surface features, which improved hydrophobicity (water contact angle 165 degrees) in addition to increasing the films transparency from ca 10 to 65%. Pre-treating the substrates with the same Sylgard 184 elastomer lead to a highly consistent surface hydrophobicity and an increase in average water contact angle measured (169 degrees). This paper shows the first example of dye incorporation in a CVD derived polymer film-these films have potential as antimicrobial surfaces.

  20. Temperature responsive hydroxypropyl cellulose for encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Heitfeld, Kevin A.; Guo, Tingtai; Yang, George; Schaefer, Dale W. (UCIN)

    2009-08-26

    This work focuses on the use of temperature responsive gels (TRGs) (polymeric hydrogels with a large temperature-dependent change in volume) for flavor retention at cooking temperatures. Specifically, we have studied a gel with a lower critical solution temperature (LCST) that swells at low temperatures and collapses at high temperatures. In the collapsed state, the polymer acts as a transport barrier, keeping the volatile flavors inside. We have successfully synthesized a cellulose gel that exhibits this volume change and have encapsulated an oil phase inside the gel. The flavor-loaded encapsulated oil exhibited an increased release time when compared to similar gelatin capsules.

  1. Performance evaluation soil samples utilizing encapsulation technology

    Energy Technology Data Exchange (ETDEWEB)

    Dahlgran, James R.

    1997-12-01

    Performance evaluation soil samples and method of their preparation are described using encapsulation technology to encapsulate analytes which are introduced into a soil matrix for analysis and evaluation by analytical laboratories. Target analytes are mixed in an appropriate solvent at predetermined concentrations. The mixture is emulsified in a solution of polymeric film forming material. The emulsified solution is polymerized to form microcapsules. The microcapsules are recovered, quantitated and introduced into a soil matrix in a predetermined ratio to form soil samples with the desired analyte concentration.

  2. Epoxy Foam Encapsulants: Processing and Dielectric Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Linda Domeier; Marion Hunter

    1999-01-01

    The dielectric performance of epoxy foams was investigated to determine if such materials might provide advantages over more standard polyurethane foams in the encapsulation of electronic assemblies. Comparisons of the dielectric characteristics of epoxy and urethane encapsulant foams found no significant differences between the two resin types and no significant difference between as-molded and machined foams. This study specifically evaluated the formulation and processing of epoxy foams using simple methylhydrosiloxanes as the flowing agent and compared the dielectric performance of those to urethane foams of similar density.

  3. The History of Therapeutic Aerosols: A Chronological Review

    Science.gov (United States)

    Thiel, Charles G.

    2017-01-01

    Abstract In 1956, Riker Laboratories, Inc., (now 3 M Drug Delivery Systems) introduced the first pressurized metered dose inhaler (MDI). In many respects, the introduction of the MDI marked the beginning of the modern pharmaceutical aerosol industry. The MDI was the first truly portable and convenient inhaler that effectively delivered drug to the lung and quickly gained widespread acceptance. Since 1956, the pharmaceutical aerosol industry has experienced dramatic growth. The signing of the Montreal Protocol in 1987 led to a surge in innovation that resulted in the diversification of inhaler technologies with significantly enhanced delivery efficiency, including modern MDIs, dry powder inhalers, and nebulizer systems. The innovative inhalers and drugs discovered by the pharmaceutical aerosol industry, particularly since 1956, have improved the quality of life of literally hundreds of millions of people. Yet, the delivery of therapeutic aerosols has a surprisingly rich history dating back more than 3500 years to ancient Egypt. The delivery of atropine and related compounds has been a crucial inhalation therapy throughout this period and the delivery of associated structural analogs remains an important therapy today. Over the centuries, discoveries from many cultures have advanced the delivery of therapeutic aerosols. For thousands of years, therapeutic aerosols were prepared by the patient or a physician with direct oversight of the patient using custom-made delivery systems. However, starting with the Industrial Revolution, advancements in manufacturing resulted in the bulk production of therapeutic aerosol delivery systems produced by people completely disconnected from contact with the patient. This trend continued and accelerated in the 20th century with the mass commercialization of modern pharmaceutical inhaler products. In this article, we will provide a summary of therapeutic aerosol delivery from ancient times to the present along with a look to the

  4. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T.

    2001-07-01

    This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

  5. The on-line analysis of aerosol-delivered pharmaceuticals via single particle aerosol mass spectrometry.

    Science.gov (United States)

    Morrical, Bradley D; Balaxi, Maria; Fergenson, David

    2015-07-15

    The use of single particle aerosol mass spectrometry (SPAMS) was evaluated for the analysis of inhaled pharmaceuticals to determine the mass distribution of the individual active pharmaceutical ingredients (API) in both single ingredient and combination drug products. SPAMS is an analytical technique where the individual aerodynamic diameters and chemical compositions of many aerosol particles are determined in real-time. The analysis was performed using a Livermore Instruments SPAMS 3.0, which allowed the efficient analysis of aerosol particles with broad size distributions and can acquire data even under a very large particle load. Data similar to what would normally require roughly three days of experimentation and analysis was collected in a five minute period and analyzed automatically. The results were computed to be comparable to those returned by a typical Next Generation Impactor (NGI) particle size distribution experiment.

  6. Emergency Protection from Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Cristy, G.A.

    2001-11-13

    Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) aerosols. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the aerosol cloud. Protection factors of 800 and above were achieved.

  7. RACORO aerosol data processing

    Energy Technology Data Exchange (ETDEWEB)

    Elisabeth Andrews

    2011-10-31

    The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.

  8. Controlled release of antibiotics encapsulated in the electrospinning polylactide nanofibrous scaffold and their antibacterial and biocompatible properties

    Science.gov (United States)

    Wang, Shu-Dong; Zhang, Sheng-Zhong; Liu, Hua; Zhang, You-Zhu

    2014-04-01

    In this research, the drug loaded polylactide nanofibers are fabricated by electrospinning. Morphology, microstructure and mechanical properties are characterized. Properties and mechanism of the controlled release of the nanofibers are investigated. The results show that the drug loaded polylactide nanofibers do not show dispersed phase, and there is a good compatibility between polylactide and drugs. FTIR spectra show that drugs are encapsulated inside the polylactide nanofibers, and drugs do not break the structure of polylcatide. Flexibility of drug loaded polylactide scaffolds is higher than that of the pure polylactide nanofibers. Release rate of the drug loaded nanofibers is significantly slower than that of the drug powder. Release rate increases with the increase of the drugs’ concentration. The research mechanism suggests a typical diffusion-controlled release of the three loaded drugs. Antibacterial and cell culture show that drug loaded nanofibers possess effective antibacterial activity and biocompatible properties.

  9. Antidiabetic Activity from Gallic Acid Encapsulated Nanochitosan

    Science.gov (United States)

    Purbowatiningrum; Ngadiwiyana; Ismiyarto; Fachriyah, E.; Eviana, I.; Eldiana, O.; Amaliyah, N.; Sektianingrum, A. N.

    2017-02-01

    Diabetes mellitus (DM) has become a health problem in the world because it causes death. One of the phenolic compounds that have antidiabetic activity is gallic acid. However, the use of this compound still provides unsatisfactory results due to its degradation during the absorption process. The solution offered to solve the problem is by encapsulated it within chitosan nanoparticles that serve to protect the bioactive compound from degradation, increases of solubility and delivery of a bioactive compound to the target site by using freeze-drying technique. The result of chitosan nanoparticle’s Scanning Electron Microscopy (SEM) showed that chitosan nanoparticle’s size is uniform and it is smaller than chitosan. The value of encapsulation efficiency (EE) of gallic acid which encapsulated within chitosan nanoparticles is about 50.76%. Inhibition test result showed that gallic acid-chitosan nanoparticles at 50 ppm could inhibite α-glucosidase activity in 28.87% with 54.94 in IC50. So it can be concluded that gallic acid can be encapsulated in nanoparticles of chitosan and proved that it could inhibit α-glucosidase.

  10. Liposome-Encapsulated Hemoglobin for Emergency Resuscitation.

    Science.gov (United States)

    1984-10-01

    have infused liposome -encapsulated amphotericin B to treat patients with systemic fungal infections. Their formulation includes 30% dimyristoyl...procedure, including exploring new industrial-scale methodologies for liposome manufacture. In addition we have focused on basic problems of biophysics...circulation persistance of this new formulation , as produced by the Microfluidizer, is obviously necessary. The influence of negatively-charged lipids on

  11. An Investigation of Membrane-Encapsulated Trypanocides.

    Science.gov (United States)

    1981-01-15

    M) SUV by soybean phosphtolipids MLV was negligible. This suggests that the encapsulation of a preformed * SUV by MIV may be related to the...lipid/g tissue was comparable to that of the same liposomes subjected to centrifugation at 10,000 g for 3 min (13) at an injected dose of 99 vig lipld/g

  12. Treatment of Diabetes with Encapsulated Islets

    NARCIS (Netherlands)

    de Vos, Paul; Spasojevic, Milica; Faas, Marijke M.; Pedraz, JL; Orive, G

    2010-01-01

    Cell encapsulation has been proposed for the treatment of a wide variety of diseases since it allows for transplantation of cells in the absence of undesired immunosuppression. The technology has been proposed to be a solution for the treatment of diabetes since it potentially allows a mandatory min

  13. Releasing dye encapsulated in proteinaceous microspheres on conductive fabrics by electric current.

    Science.gov (United States)

    Shimanovich, Ulyana; Perelshtein, Ilana; Cavaco-Paulo, Artur; Gedanken, Aharon

    2012-06-27

    The current paper reports on the relase properties of conductive fabrics coated with proteinaceous microspheres containing a dye. The release of the dye was achieved by passing an electric current through the fabric. The conductivity of the polyester fibers resulted from nanosilver (Ag NPs) coated on the surface of these fibers. Both types of coatings (nanosilver coating and the coating of the proteinaceous microspheres) were performed using high-intensity ultrasonic waves. Two different types of dyes, hydrophilic RBBR (Remazol Brilliant Blue R) and hydrophobic ORO (Oil Red O), were encapsulated inside the microspheres (attached to the surface of polyester) and then released by applying an electric current. The Proteinaceous Microsphere (PM)-coated conductive fabrics could be used in medicine for drug release. The encapsulated dye can be replaced with a drug that could be released from the surface of fabrics by applying a low voltage.

  14. Development of poly(glycerol adipate) nanoparticles loaded with non-steroidal anti-inflammatory drugs.

    NARCIS (Netherlands)

    Wahab, A.; Favretto, M.E.; Onyeagor, N.D.; Khan, G.M.; Douroumis, D.; Casely-Hayford, M.A.; Kallinteri, P.

    2012-01-01

    The aim of this study was to assess acylated and non-acylated poly(glycerol adipate) polymers (PGA) as suitable nanoparticulate systems for encapsulation and release of ibuprofen, ibuprofen sodium salt (IBU-Na) and ketoprofen as model drugs. Drug encapsulated nanoparticles were prepared using the in

  15. Encapsulation and retention of chelated-copper inside hydrophobic nanoparticles

    DEFF Research Database (Denmark)

    Hervella, Pablo; Ortiz, Elisa Parra; Needham, David

    2016-01-01

    ) Chelate copper into the octaethyl porphyrin; (3) Encapsulate OEP-Cu in nanoparticles: the encapsulation efficiency of copper into liquid nanoparticles (LNP), solid nanoparticles (SNP) and phospholipid liposomes (PL) was evaluated by UV-Vis and atomic absorption spectroscopy; (4) Retain the encapsulated...

  16. Mechanical Robustness and Hermeticity Monitoring for MEMS Thin Film Encapsulation

    NARCIS (Netherlands)

    Santagata, F.

    2011-01-01

    Many Micro-Electro-Mechanical-Systems (MEMS) require encapsulation, to prevent delicate sensor structures being exposed to external perturbations such as dust, humidity, touching, and gas pressure. An upcoming and cost-effective way of encapsulation is zero-level packaging or thin-film encapsulation

  17. Electrostatics of Pharmaceutical Aerosols for Pulmonary Delivery.

    Science.gov (United States)

    Lip Kwok, Philip Chi

    2015-01-01

    This paper provides a review on key research findings in the rapidly developing area of pharmaceutical aerosol electrostatics. Solids and liquids can become charged without electric fields, the former by contact or friction and the latter by flowing or spraying. Therefore, charged particles and droplets carrying net charges are produced from pharmaceutical inhalers (e.g. dry powder inhalers, metered dose inhalers, and nebulisers) due to the mechanical processes involved in aerosolisation. The charging depends on many physicochemical factors, such as formulation composition, solid state properties, inhaler material and design, and relative humidity. In silico, in vitro, and limited in vivo studies have shown that electrostatic charges may potentially influence particle deposition in the airways. However, the evidence is not yet conclusive. Furthermore, there are currently no regulatory requirements on the characterisation and control of the electrostatic properties of inhaled formulations. Besides the need for further investigations on the relationship between physicochemical factors and charging characteristics of the aerosols, controlled and detailed in vivo studies are also required to confirm whether charges can affect particle deposition in the airways. Since pharmaceutical aerosol electrostatics is a relatively new research area, much remains to be explored. Thus there is certainly potential for development. New findings in the future may contribute to the advancement of pharmaceutical aerosol formulations and respiratory drug delivery.

  18. The bipolar nature of charge resident on supposedly unipolar aerosols

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, M; Balachadran, W [School of Engineering and Design, Brunei University, Uxbridge, UB8 3PH (United Kingdom); Rogueda, P; Chambers, F [AstraZeneca R and D Charnwood, Bakewell Road, Loughborough, LE11 5RH (United Kingdom)], E-mail: mark.oleary@brunel.ac.uk

    2008-12-01

    Interest in aerosol electrostatic properties for optimisation of drug delivery within the lung has varied over time. The availability of the Dekati Electrostatic Low Pressure Impactor (ELPI) has facilitated several recent papers investigating distributions of aerosol size and charge. The ELPI operates in a similar fashion to conventional impactors fractionating the aerosol population by aerodynamic size. The impactor plates are electrically conducting and connected to electrometers allowing measurement of inherent aerosol charge transferred upon impaction. Results from pMDIs showing varying charge polarity with size have been cited as evidence of the bipolar nature of charge output. Sum charge over an aerosol measured by the ELPI is, however, simply net charge that may be seen to evolve with size. Electrostatic particle capture methods have been used to assess the nature of the charge resident on a pMDI aerosol population demonstrating unipolar output on the ELPI and have shown consistent bipolarity. Net charge output would have been measured as possessing single polarity but would consist of larger magnitude positive and negative components. Even moderate levels of bipolarity render as inherently flawed any attempt to characterise the level of charge on individual aerosol droplets or the entire population based solely on net charge data.

  19. Physical metrology of aerosols; Metrologie physique des aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Boulaud, D.; Vendel, J. [CEA Saclay, 91 - Gif-sur-Yvette (France). Inst. de Protection et de Surete Nucleaire

    1996-12-31

    The various detection and measuring methods for aerosols are presented, and their selection is related to aerosol characteristics (size range, concentration or mass range), thermo-hydraulic conditions (carrier fluid temperature, pressure and flow rate) and to the measuring system conditions (measuring frequency, data collection speed, cost...). Methods based on aerosol dynamic properties (inertial, diffusional and electrical methods) and aerosol optical properties (localized and integral methods) are described and their performances and applications are compared

  20. Use of a passive equilibration methodology to encapsulate cisplatin into preformed thermosensitive liposomes.

    Science.gov (United States)

    Woo, Janet; Chiu, Gigi N C; Karlsson, Göran; Wasan, Ellen; Ickenstein, Ludger; Edwards, Katarina; Bally, Marcel B

    2008-02-12

    A conventional, cholesterol-containing liposome formulation of cisplatin has demonstrated insignificant activity in clinical trials, due in part, to insufficient release of encapsulated content following localization within solid tumors. For this reason, the development of a triggered release liposome formulation is desirable. In this report, cisplatin was encapsulated into lysolipid-containing thermosensitive liposomes (LTSL) using a novel technique, which relies on the equilibration of cisplatin across the liposomal membrane at temperatures above the gel-to-liquid crystalline phase transition temperature (TC) of the bulk phospholipid. Mild heating and drug loading into LTSL did not induce morphological changes of the liposomes. In vitro data demonstrated that >95% of encapsulated cisplatin was released from LTSL within 5 min following mild heating at 42 degrees C, while liposomes exhibited 70% release of cisplatin at 42 degrees C, and cholesterol-containing liposomes exhibited negligible drug release at 42 degrees C. The pharmacokinetic profiles of LTSL- and TSL-cisplatin indicated that these formulations were rapidly eliminated from circulation (terminal t(1/2) of 1.09 and 2.83 h, respectively). The therapeutic utility of LTSL-cisplatin formulation will be based on strategies where hyperthermia is applied prior to the administration of the liposomal drug-a strategy similar to that used in the clinical assessment of LTSL-doxorubicin formulation.

  1. Encapsulation of indomethacin using coaxial ultrasonic atomization followed by solvent evaporation.

    Science.gov (United States)

    Graves, Richard A; Poole, Daniel; Moiseyev, Raisa; Bostanian, Levon A; Mandal, Tarun K

    2008-04-01

    We have encapsulated indomethacin into poly (lactide-co-glycolide) (PLGA) using coaxial ultrasonic atomization technique. The specific aims of this study were to evaluate the effect of drug loading and a change in relative concentration of polymer in the inner and outer layers of coflowing spray liquids on the physicochemical characteristics of the particles. Indomethacin, a non steroidal anti-inflammatory drug, was selected as a model compound. The micro/nanocapsules prepared using a drug free PLGA solution as an outer layer showed higher encapsulation efficiency. Thermal analysis of the formulations indicated that indomethacin was dissolved within the PLGA matrix. The formulations prepared with 25 mg indomethacin showed relatively smaller particle size compared with the formulations prepared with 50 mg indomethacin. The particles, in general, showed bi- and tri-modal distribution. Irrespective of the compositions of the liquids 1 and 2, all the particles were smooth and spherical. A cross-section view of the particles revealed the presence of three different internal morphologies. These formulations were a mixture of hollow or solid spheres, and single or multiple spheres encapsulated into a larger sphere. To the best of our knowledge, this is the first study revealing the cross-sectional view of particles prepared with coaxial ultrasonic atomization technique.

  2. Ex vivo encapsulation of dexamethasone sodium phosphate into human autologous erythrocytes using fully automated biomedical equipment.

    Science.gov (United States)

    Mambrini, Giovanni; Mandolini, Marco; Rossi, Luigia; Pierigè, Francesca; Capogrossi, Giovanni; Salvati, Patricia; Serafini, Sonja; Benatti, Luca; Magnani, Mauro

    2017-01-30

    Erythrocyte-based drug delivery systems are emerging as potential new solutions for the release of drugs into the bloodstream. The aim of the present work was to assess the performance of a fully automated process (EDS) for the ex-vivo encapsulation of the pro-drug dexamethasone sodium phosphate (DSP) into autologous erythrocytes in compliance with regulatory requirements. The loading method was based on reversible hypotonic hemolysis, which allows the opening of transient pores in the cell membrane to be crossed by DSP. The efficiency of encapsulation and the biochemical and physiological characteristics of the processed erythrocytes were investigated in blood samples from 34 healthy donors. It was found that the processed erythrocytes maintained their fundamental properties and the encapsulation process was reproducible. The EDS under study showed greater loading efficiency and reduced variability compared to previous EDS versions. Notably, these results were confirmed using blood samples from Ataxia Telangiectasia (AT) patients, 9.33±1.40 and 19.41±2.10mg of DSP (mean±SD, n=134) by using 62.5 and 125mg DSP loading quantities, respectively. These results support the use of the new EDS version 3.2.0 to investigate the effect of erythrocyte-delivered dexamethasone in regulatory trials in patients with AT.

  3. Protein encapsulated core-shell structured particles prepared by coaxial electrospraying: investigation on material and processing variables.

    Science.gov (United States)

    Zamani, Maedeh; Prabhakaran, Molamma P; Thian, Eng San; Ramakrishna, Seeram

    2014-10-01

    Biodegradable polymeric particles have been extensively investigated for controlled drug delivery of various therapeutic agents. 'Coaxial' electrospraying was successfully employed in this study, to fabricate core-shell PLGA particles containing bovine serum albumin (BSA) as the model protein, and the results were also compared to particles prepared by 'emulsion' electrospraying. Two different molecular weights of PLGA were employed to encapsulate the protein. Solution properties and processing parameters were found to influence the morphology of the core-shell particles. Depending on the type of solvent used to dissolve the polymer as well as the polymer concentration and molecular weight, the mean diameter of the particles varied between 3.0 to 5.5 μm. Fluorescence microscopic analysis of the electrosprayed particles using FITC-conjugated BSA demonstrated the core-shell structure of the developed particles. The encapsulation efficiency and release behavior of BSA was influenced by shell:core feeding ratio, protein concentration, and the electrospraying method. The encapsulation efficiency of BSA within the core-shell particles of high and low molecular weight PLGA was found 15.7% and 25.1% higher than the emulsion electrosprayed particles, respectively. Moreover, the total amount of BSA released from low molecular weight PLGA particles was significantly higher than high molecular weight PLGA particles within 43 days of release studies, with negligible effect on encapsulation efficiency. The technique of coaxial electrospraying has high potential for encapsulation of susceptible protein-based therapeutic agents such as growth factors for multiple drug delivery applications.

  4. Therapeutic efficacy of liposome-encapsulated gentamicin in rat Klebsiella pneumoniae pneumonia in relation to impaired host defense and low bacterial susceptibility to gentamicin.

    NARCIS (Netherlands)

    R.M. Schiffelers (Raymond); G. Storm (Gert); M.T. ten Kate (Marian); I.A.J.M. Bakker-Woudenberg (Irma)

    2001-01-01

    textabstractLong-circulating liposomes (LCL) may be used as targeted antimicrobial drug carriers as they localize at sites of infection. As a result, LCL-encapsulated gentamicin (LE-GEN) has demonstrated superior antibacterial activity over the free drug in a single-dos

  5. Characterisation of high dose dry powder aerosols by cascade impaction and laser diffraction analysis

    NARCIS (Netherlands)

    Grasmeijer, F.; Hagedoorn, P.; Frijlink, H.W.; De Boer, A.H.

    2011-01-01

    Background: Developments in high dose dry powder inhalationcontinue to challenge the viability of pharmacopoeialmethods for drug aerosol characterisation. Especiallythe occurrence of bounce effects can cause the amount offines (<1 lm) to be highly overestimated in particle sizedistributions (PSDs) o

  6. Thin film Encapsulations of Flexible Organic Light Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Tsai Fa-Ta

    2016-01-01

    Full Text Available Various encapsulated films for flexible organic light emitting diodes (OLEDs were studied in this work, where gas barrier layers including inorganic Al2O3 thin films prepared by atomic layer deposition, organic Parylene C thin films prepared by chemical vapor deposition, and their combination were considered. The transmittance and water vapor transmission rate of the various organic and inorgabic encapsulated films were tested. The effects of the encapsulated films on the luminance and current density of the OLEDs were discussed, and the life time experiments of the OLEDs with these encapsulated films were also conducted. The results showed that the transmittance are acceptable even the PET substrate were coated two Al2O3 and Parylene C layers. The results also indicated the WVTR of the PET substrate improved by coating the barrier layers. In the encapsulation performance, it indicates the OLED with Al2O3 /PET, 1 pair/PET, and 2 pairs/PET presents similarly higher luminance than the other two cases. Although the 1 pair/PET encapsulation behaves a litter better luminance than the 2 pairs/PET encapsulation, the 2 pairs/PET encapsulation has much better life time. The OLED with 2 pairs/PET encapsulation behaves near double life time to the 1 pair encapsulation, and four times to none encapsulation.

  7. Stabilization and encapsulation of photosensitive resveratrol within yeast cell.

    Science.gov (United States)

    Shi, Guorong; Rao, Liqun; Yu, Huazhong; Xiang, Hua; Yang, Hua; Ji, Runa

    2008-02-12

    The photosensitive resveratrol was successfully encapsulated in yeast cells for the first time, as characterized by FT-IR spectra, fluorescence and confocal micrographs of the yeast cells, resveratrol and microcapsules. The release characteristic of the obtained yeast-encapsulated resveratrol in simulated gastric fluid was evaluated, and its storage stability as a powder was investigated at 25 degrees C/75% relative humidity (RH), 25 degrees C/90% RH and 60 degrees C under the laboratory fluorescent lighting conditions (ca. 300 lx) or in the dark. Also, the scavenging capacity of yeast-encapsulated resveratrol on DPPH radical was compared with that of non-encapsulated resveratrol. It could be demonstrated clearly that no chemical changes occurred during the encapsulation. Besides, the DPPH radical-scavenging activity increased after the encapsulation. In addition, the yeast-encapsulated resveratrol exhibited good stability, and its bioavailability was enhanced as a result of increased solubility of resveratrol and sustained releasing.

  8. Chemical aerosol Raman detector

    Science.gov (United States)

    Aggarwal, R. L.; Farrar, L. W.; Di Cecca, S.; Amin, M.; Perkins, B. G.; Clark, M. L.; Jeys, T. H.; Sickenberger, D. W.; D'Amico, F. M.; Emmons, E. D.; Christesen, S. D.; Kreis, R. J.; Kilper, G. K.

    2017-03-01

    A sensitive chemical aerosol Raman detector (CARD) has been developed for the trace detection and identification of chemical particles in the ambient atmosphere. CARD includes an improved aerosol concentrator with a concentration factor of about 40 and a CCD camera for improved detection sensitivity. Aerosolized isovanillin, which is relatively safe, has been used to characterize the performance of the CARD. The limit of detection (SNR = 10) for isovanillin in 15 s has been determined to be 1.6 pg/cm3, which corresponds to 6.3 × 109 molecules/cm3 or 0.26 ppb. While less sensitive, CARD can also detect gases. This paper provides a more detailed description of the CARD hardware and detection algorithm than has previously been published.

  9. Recent advances in chitosan-based nanoparticulate pulmonary drug delivery

    Science.gov (United States)

    Islam, Nazrul; Ferro, Vito

    2016-07-01

    The advent of biodegradable polymer-encapsulated drug nanoparticles has made the pulmonary route of administration an exciting area of drug delivery research. Chitosan, a natural biodegradable and biocompatible polysaccharide has received enormous attention as a carrier for drug delivery. Recently, nanoparticles of chitosan (CS) and its synthetic derivatives have been investigated for the encapsulation and delivery of many drugs with improved targeting and controlled release. Herein, recent advances in the preparation and use of micro-/nanoparticles of chitosan and its derivatives for pulmonary delivery of various therapeutic agents (drugs, genes, vaccines) are reviewed. Although chitosan has wide applications in terms of formulations and routes of drug delivery, this review is focused on pulmonary delivery of drug-encapsulated nanoparticles of chitosan and its derivatives. In addition, the controversial toxicological effects of chitosan nanoparticles for lung delivery will also be discussed.

  10. Nano-encapsulated PCM via Pickering Emulsification

    Science.gov (United States)

    Wang, Xuezhen; Zhang, Lecheng; Yu, Yi-Hsien; Jia, Lisi; Sam Mannan, M.; Chen, Ying; Cheng, Zhengdong

    2015-08-01

    We designed a two-step Pickering emulsification procedure to create nano-encapsulated phase changing materials (NEPCMs) using a method whose simplicity and low energy consumption suggest promise for scale-up and mass production. Surface-modified amphiphilic zirconium phosphate (ZrP) platelets were fabricated as the Pickering emulsifiers, nonadecane was chosen as the core phase change material (PCM), and polystyrene, the shell material. The resultant capsules were submicron in size with remarkable uniformity in size distribution, which has rarely been reported. Differential scanning calorimetry (DSC) characterization showed that the capsulation efficiency of NEPCMs, and they were found to be thermal stable, as characterized by the DSC data for the sample after 200 thermal cycles. NEPCMs exhibit superior mechanical stability and mobility when compared with the well-developed micro-encapsulated phase change materials (MEPCMs). NEPCMs find useful applications in thermal management, including micro-channel coolants; solar energy storage media; building temperature regulators; and thermal transfer fabrics.

  11. Idiopathic sclerosing encapsulating peritonitis: Abdominal cocoon

    Institute of Scientific and Technical Information of China (English)

    Jenny N Tannoury; Bassam N Abboud

    2012-01-01

    Abdominal cocoon,the idiopathic form of sclerosing encapsulating peritonitis,is a rare condition of unknown etiology that results in an intestinal obstruction due to total or partial encapsulation of the small bowel by a fibrocollagenous membrane.Preoperative diagnosis re quires a high index of clinical suspicion.The early clinical features are nonspecific,are often not recognized and it is difficult to make a definite pre-operative diagnosis.Clinical suspicion may be generated by the recurrent episodes of small intestinal obstruction combined with relevant imaging findings and lack of other plausible etiologies.The radiological diagnosis of abdominal cocoon may now be confidently made on computed tomography scan.Surgery is important in the management of this disease.Careful dissection and excision of the thick sac with the release of the small intestine leads to complete recovery in the vast majority of cases.

  12. Design documentation: Krypton encapsulation preconceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, D.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1994-10-01

    US EPA regulations limit the release of Krypton-85 to the environment from commercial facilities after January 1, 1983. In order to comply with these regulations, Krypton-85, which would be released during reprocessing of commercial nuclear fuel, must be collected and stored. Technology currently exists for separation of krypton from other inert gases, and for its storage as a compressed gas in steel cylinders. The requirements, which would be imposed for 100-year storage of Krypton-85, have led to development of processes for encapsulation of krypton within a stable solid matrix. The objective of this effort was to provide preconceptual engineering designs, technical evaluations, and life cycle costing data for comparison of two alternate candidate processes for encapsulation of Krypton-85. This report has been prepared by The Ralph M. Parsons Company for the US Department of Energy.

  13. Stratospheric Aerosol Measurements

    Science.gov (United States)

    Pueschel, Rudolf, F.; Gore, Warren J. (Technical Monitor)

    1998-01-01

    Stratospheric aerosols affect the atmospheric energy balance by scattering and absorbing solar and terrestrial radiation. They also can alter stratospheric chemical cycles by catalyzing heterogeneous reactions which markedly perturb odd nitrogen, chlorine and ozone levels. Aerosol measurements by satellites began in NASA in 1975 with the Stratospheric Aerosol Measurement (SAM) program, to be followed by the Stratospheric Aerosol and Gas Experiment (SAGE) starting in 1979. Both programs employ the solar occultation, or Earth limb extinction, techniques. Major results of these activities include the discovery of polar stratospheric clouds (PSCs) in both hemispheres in winter, illustrations of the impacts of major (El Chichon 1982 and Pinatubo 1991) eruptions, and detection of a negative global trend in lower stratospheric/upper tropospheric aerosol extinction. This latter result can be considered a triumph of successful worldwide sulfur emission controls. The SAGE record will be continued and improved by SAGE III, currently scheduled for multiple launches beginning in 2000 as part of the Earth Observing System (EOS). The satellite program has been supplemented by in situ measurements aboard the ER-2 (20 km ceiling) since 1974, and from the DC-8 (13 km ceiling) aircraft beginning in 1989. Collection by wire impactors and subsequent electron microscopic and X-ray energy-dispersive analyses, and optical particle spectrometry have been the principle techniques. Major findings are: (1) The stratospheric background aerosol consists of dilute sulfuric acid droplets of around 0.1 micrometer modal diameter at concentration of tens to hundreds of monograms per cubic meter; (2) Soot from aircraft amounts to a fraction of one percent of the background total aerosol; (3) Volcanic eruptions perturb the sulfuric acid, but not the soot, aerosol abundance by several orders of magnitude; (4) PSCs contain nitric acid at temperatures below 195K, supporting chemical hypotheses

  14. Encapsulation of trans-dehydrocrotonin in liposomes: an enhancement of the antitumor activity.

    Science.gov (United States)

    Lapenda, T L S; Morais, W A; Almeida, F J F; Ferraz, M S; Lira, M C B; Santos, N P S; Maciel, M A M; Santos-Magalhães, N S

    2013-03-01

    The aim of this study was the encapsulation of trans-dehydrocrotonin (t-DCTN) and its inclusion complexes with hydropropyl-beta-cyclodextrin (HP-beta-CD) in liposomes to improve t-DCTN antitumor activity. The in vitro kinetic profiles of t-DCTN-loaded liposomes (LD) and t-DCTN:HP-beta-CD-loaded liposomes (LC) were evaluated using the dialysis technique. The antitumor activity of LD and LC were investigated against Sarcoma 180 in Swiss mice. Histopathological and hematological analyses were carried out. The amounts of t-DCTN and t-DCTN:HP-beta-CD inclusion complex encapsulated in liposomes were equivalent to 1 mg of t-DCTN. The encapsulation efficiencies of LD and LC were 95.0 +/- 3.8% and 91.1 +/- 5.6%, respectively. In relation to kinetics, the drug release profiles of t-DCTN are in substantial agreement with the Fickian model. The treatment of animals with LD and LC produced tumor inhibitions of 79.4 +/- 9.6% and 63.5 +/- 5.5%, respectively. The liposomal encapsulation of t-DCTN by entrapment in the phospholipid bilayer increased at twice the antitumor activity. Moreover, the liposomal formulations reduced the hepatotoxicity effect of the drug and no significant hematological toxicity was observed in the treated animals. However, the counting of platelets was slightly decreased. Thus, the results show that the development of liposomal formulations containing t-DCTN or t-DCTN:HP-beta-CD is an important advance for enabling this drug to be use in therapy.

  15. Encapsulating peritonitis: computed tomography and surgical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kadow, Juliana Santos; Fingerhut, Carla Jeronimo Peres; Fernandes, Vinicius de Barros; Coradazzi, Klaus Rizk Stuhr; Silva, Lucas Marciel Soares; Penachim, Thiago Jose, E-mail: vinicius.barros.fernandes@gmail.com [Pontificia Universidade Catolica de Campinas (PUC-Campinas), Campinas, SP (Brazil). Hospital e Maternidade Celso Pierro

    2014-07-15

    Sclerosing encapsulating peritonitis is a rare and frequently severe entity characterized by total or partial involvement of small bowel loops by a membrane of fibrous tissue. The disease presents with nonspecific clinical features of intestinal obstruction, requiring precise imaging diagnosis to guide the treatment. The present report emphasizes the importance of computed tomography in the diagnosis of this condition and its confirmation by surgical correlation. (author)

  16. Tracking Hypoxic Signaling within Encapsulated Cell Aggregates

    OpenAIRE

    Skiles, Matthew L.; Sahai, Suchit; Blanchette, James O.

    2011-01-01

    In Diabetes mellitus type 1, autoimmune destruction of the pancreatic β-cells results in loss of insulin production and potentially lethal hyperglycemia. As an alternative treatment option to exogenous insulin injection, transplantation of functional pancreatic tissue has been explored1,2. This approach offers the promise of a more natural, long-term restoration of normoglycemia. Protection of the donor tissue from the host's immune system is required to prevent rejection and encapsulation is...

  17. Ultrasonographic findings of sclerosing encapsulating peritonitis

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jong Kyu; Lee, Hae Kyung; Moon, Chul; Hong, Hyun Sook; Kwon, Kwi Hyang; Choi, Deuk Lin [Soonchunhyangi University College of Medicine, Seoul (Korea, Republic of)

    2001-03-15

    To evaluate the ultrasonographic findings of the patients with sclerosing encapsulating peritonitis (SEP). Thirteen patients with surgically confirmed sclerosing encapsulating peritonitis were involved in this study. Because of intestinal obstruction, all patients had received operations. Among 13 patients, 12 cases had continuous ambulatory peritoneal dialysis (CAPD) for 2 months-12 years and 4 months from (mean; 6 years and 10 months), owing to chronic renal failure and one patient had an operation due to variceal bleeding caused by liver cirrhosis. On ultrasonographic examination, all patients showed loculated ascites which were large (n=7) or small (n=6) in amount with multiple separations. The small bowel loops were tethered posteriorly perisaltic movement and covered with the thick membrane. The ultrasonographic of findings of sclerosing encapsulating peritonitis were posteriorly tethered small bowels covered with a thick membrane and loculated ascites with multiple septa. Ultrasonographic examination can detect the thin membrane covering the small bowel loops in the early phase of the disease, therefore ultrasonography would be a helpful modality to diagnose SEP early.

  18. Water encapsulation in a polyoxapolyaza macrobicyclic compound.

    Science.gov (United States)

    Mateus, Pedro; Delgado, Rita; Groves, Patrick; Campos, Sara R R; Baptista, António M; Brandão, Paula; Félix, Vítor

    2012-08-17

    A new heteroditopic macrobicyclic compound (t(2)pN(5)O(3)) containing two separate polyoxa and polyaza compartments was synthesized in good yield through a [1 + 1] "tripod-tripod coupling" strategy. The X-ray crystal structure of H(3)t(2)pN(5)O(3)(3+) revealed the presence of one encapsulated water molecule accepting two hydrogen bonds from two protonated secondary amines and donating a hydrogen bond to one amino group. The acid-base behavior of the compound was studied by potentiometry at 298.2 K in aqueous solution and at ionic strength 0.10 M in KCl. The results revealed unusual protonation behavior, namely a surprisingly low fourth protonation constant contrary to what was expected for the compound. (1)H NMR and DOSY experiments, as well as molecular modeling studies, showed that the water encapsulation and the conformation observed in the solid state are retained in solution. The strong binding of the encapsulated water molecule, reinforced by the cooperative occurrence of a trifurcated hydrogen bond at the polyether compartment of the macrobicycle, account for the very low log K(4)(H) value obtained.

  19. Encapsulating peritonitis and familial Mediterranean fever

    Institute of Scientific and Technical Information of China (English)

    Resat Dabak; Oya Uygur-Bayrami(c)li; Didem K1l1(c) Ayd1n; Can Dolap(c)1oglu; Cengiz Gemici; Turgay Erginel; Cem Turan; Nimet Karaday1

    2005-01-01

    AIM: To investigate the relationship between encapsulating peritonitis and familial Mediterranean fever (FMF). METHODS: The patient had a history of type 2 diabetes and laparoscopic cholecystectomy was performed one year ago for cholelithiasis. Eleven months after the operation she developed massive ascites. Biochemical evaluation revealed hyperglycemia, mild Fe deficiency anemia, hypoalbuminemia and a CA-125 level of 2 700 IU. Ascitic evaluation showed characteristics of exudation with a cell count of 580/mm3. Abdominal CT showed omental thickening and massive ascites. At exploratory laparotomy there was generalized thickening of the peritoneum and a laparoscopic clip encapsulated by fibrous tissue was found adherent to the uterus. Biopsies were negative for malignancy and a prophilactic total abdominal hysterectomy and bilateral salpingooophorectomy were performed. RESULTS: The histopathological evaluation was compatible with chronic nonspecific findings and mild mesothelial proliferation and chronic inflammation at the uterine serosa and liver biopsy showed inactive cirrhosis. CONCLUSION: The patient was evaluated as sclerosing encapsulating peritonitis induced by the laparoscopic clip acting as a foreign body. Due to the fact that the patient had FMF the immune response was probably exaggerated.

  20. Cell Membrane Capsules for Encapsulation of Chemotherapeutic and Cancer Cell Targeting in Vivo.

    Science.gov (United States)

    Peng, Li-Hua; Zhang, Yuan-Hong; Han, Li-Jie; Zhang, Chen-Zhen; Wu, Jia-He; Wang, Xia-Rong; Gao, Jian-Qing; Mao, Zheng-Wei

    2015-08-26

    Systemic administration of chemotherapeutic agents can cause indiscriminate drug distribution and severe toxicity. Until now, encapsulation and targeting of drugs have typically relied on synthetic vehicles, which cannot minimize the clearance by the renal system and may also increase the risk of chemical side effects. Cell membrane capsules (CMCs) provide a generic and far more natural approach to the challenges of drug encapsulation and delivery in vivo. Here aptamer AS1411, which can recognize and bind overexpressed nucleolin on a cancer cell membrane, was chemically conjugated onto CMCs. As a result, AS1411 modified CMCs showed enhanced ingestion in certain cancer cells in vitro and accumulation in mouse cancer xenografts in vivo. Chemotherapeutics and contrast agents with therapeutically significant concentrations can be packaged into CMCs by reversible permeating their plasma membranes. The systematic administration of cancer targeting CMCs loaded with doxorubicin hydrochloride can significantly inhibit tumor growth in mouse xenografts, with significantly reduced toxicity compared to free drug. These findings suggest that cancer targeting CMCs may have considerable benefits in drug delivery and cancer treatment.

  1. Experimental Study of Aerosol Deposition in a Realistic Lung Model

    Directory of Open Access Journals (Sweden)

    František LÍZAL

    2010-12-01

    Full Text Available The inhalation route for administration of medicaments is becoming more and more popular in recent years. The reason is non-invasiveness of the method and instantaneous absorption of drugs to the blood circulation. It is necessary to deliver exact amount of drug to the specific segment because of occurrence of diverse diseases in different segments of lungs. The aim of our work is to contribute to better understanding of transport and deposition of aerosolized drugs in lungs and hence to more effective treatment of respiratory diseases due to the targeted drug delivery. We provided measurements of aerosol deposition in segmented realistic model of lungs without a mouth cavity. Monodisperse particles marked with fluorescein were supplied to the model. The model was then disassembled to segments and each segment was rinsed with isopropanol, whereby fluorescent samples were created. Each sample was analysed by fluorometer and an amount of aerosol deposited in the segment was calculated. Experiences obtained by this study were used for creation of a new model with the mouth cavity. This model will be used for future studies with porous and fiber aerosols.

  2. UNIQUE ORAL DRUG DELIVERY SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Raphael M. Ottenbrite; ZHAO Ruifeng; Sam Milstein

    1995-01-01

    An oral drug delivery system using proteinoid microspheres is discussed with respect to its unique dependence on pH. It has been found that certain drugs such as insulin and heparin can be encapsulated in proteinoid spheres at stomach pH's (1-3). These spheres also dissemble at intestinal pH's (6-7) releasing the drug for absorption. Using this technique low molecular weight heparin and human growth hormone have been orally delivered successfully to several animal species. Future work has been proposed to study the interaction and binding of the specific drugs with synthesized oligopeptides.

  3. Encapsulation of antiviral nucleotide analogues azidothymidine-triphosphate and cidofovir in poly(iso-butylcyanoacrylate) nanocapsules.

    Science.gov (United States)

    Hillaireau, H; Le Doan, T; Besnard, M; Chacun, H; Janin, J; Couvreur, P

    2006-10-31

    Nucleoside analogues are widely used in the treatment of various viral infections. However, the poor in vivo conversion of the nucleoside analogues like azidothymidine (AZT) into their active triphosphate nucleotide counterpart limits their pharmacological efficacy. This could be overcome by the direct administration of azidothymidine triphosphate (AZT-TP), but it requires an appropriate drug delivery approach. Besides nucleoside analogues, nucleotide analogues like cidofovir (CDV) are also used in the treatment of viral infections. CDV has raised recent interest because of its promising activity against smallpox, but its use is limited by its poor bioavailability and nephrotoxicity. Here again, a proper drug delivery system should address these issues. In this study, we investigated the encapsulation of the nucleotide analogues AZT-TP and CDV into poly(iso-butylcyanoacrylate) aqueous core nanocapsules, known to efficiently entrap oligonucleotides. We show here that the encapsulation of these mono-nucleotides is less efficient than with oligonucleotides and that a rapid release of AZT-TP from the nanocapsules occurred in vitro. This highlights the importance of the molecular weight of the entrapped molecules which, if they are too small, are diffusing through the thin polymer membrane of the nanocapsules. On the other hand, a good protection of the encapsulated AZT-TP was observed.

  4. Microencapsulation of chemotherapeutics into monodisperse and tunable biodegradable polymers via electrified liquid jets: control of size, shape, and drug release.

    Science.gov (United States)

    Fattahi, Pouria; Borhan, Ali; Abidian, Mohammad Reza

    2013-09-06

    This paper describes microencapsulation of antitumor agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, Carmustine) into biodegradable polymer poly(lactic-co-glycolic) acid (PLGA) using an electrojetting technique. The resulting BCNU-loaded PLGA microcapsules have significantly higher drug encapsulation efficiency, more tunable drug loading capacity, and (3) narrower size distribution than those generated using other encapsulation methods.

  5. Composite block copolymer stabilized nanoparticles: simultaneous encapsulation of organic actives and inorganic nanostructures.

    Science.gov (United States)

    Gindy, Marian E; Panagiotopoulos, Athanassios Z; Prud'homme, Robert K

    2008-01-01

    We describe the preparation and characterization of hybrid block copolymer nanoparticles (NPs) for use as multimodal carriers for drugs and imaging agents. Stable, water-soluble, biocompatible poly(ethylene glycol)-block-poly(epsilon-caprolactone) NPs simultaneously co-encapsulating hydrophobic organic actives (beta-carotene) and inorganic imaging nanostructures (Au) are prepared using the flash nanoprecipitation process in a multi-inlet vortex mixer. These composite nanoparticles (CNPs) are produced with tunable sizes between 75 nm and 275 nm, narrow particle size distributions, high encapsulation efficiencies, specified component compositions, and long-term stability. The process is tunable and flexible because it relies on the control of mixing and aggregation timescales. It is anticipated that the technique can be applied to a variety of hydrophobic active compounds, fluorescent dyes, and inorganic nanostructures, yielding CNPs for combined therapy and multimodal imaging applications.

  6. Encapsulating contact allergens in liposomes, ethosomes, and polycaprolactone may affect their sensitizing properties

    DEFF Research Database (Denmark)

    Madsen, Jakob Torp; Vogel, Stefan; Johansen, Jeanne Duus

    2011-01-01

    dichromate compared with control solutions. However, encapsulating the lipophilic contact allergen dinitrochlorobenzene (DNCB) in polycaprolactone reduced the sensitizing capacity to 1211 ± 449 compared with liposomes (7602 ± 2658) and in acetone:olive oil (4:1) (5633 ± 666). The same trend was observed...... for encapsulating isoeugenol in polycaprolactone (1100 ± 406) compared with a formulation in acetone:olive oil (4491 ± 819) and in liposomes (3668 ± 950). Further, the size of DNCB-loaded liposomes did not affect the sensitizing properties. These results suggest that modern dermal drug-delivery systems may in some...

  7. The Adaptive Aerosol Delivery (AAD) technology: Past, present, and future.

    Science.gov (United States)

    Denyer, John; Dyche, Tony

    2010-04-01

    Conventional aerosol delivery systems and the availability of new technologies have led to the development of "intelligent" nebulizers such as the I-neb Adaptive Aerosol Delivery (AAD) System. Based on the AAD technology, the I-neb AAD System has been designed to continuously adapt to changes in the patient's breathing pattern, and to pulse aerosol only during the inspiratory part of the breathing cycle. This eliminates waste of aerosol during exhalation, and creates a foundation for precise aerosol (dose) delivery. To facilitate the delivery of precise metered doses of aerosol to the patient, a unique metering chamber design has been developed. Through the vibrating mesh technology, the metering chamber design, and the AAD Disc function, the aerosol output rate and metered (delivered) dose can be tailored to the demands of the specific drug to be delivered. In the I-neb AAD System, aerosol delivery is guided through two algorithms, one for the Tidal Breathing Mode (TBM), and one for slow and deep inhalations, the Target Inhalation Mode (TIM). The aim of TIM is to reduce the treatment time by increasing the total inhalation time per minute, and to increase lung deposition by reducing impaction in the upper airways through slow and deep inhalations. A key feature of the AAD technology is the patient feedback mechanisms that are provided to guide the patient on delivery performance. These feedback signals, which include visual, audible, and tactile forms, are configured in a feedback cascade that leads to a high level of compliance with the use of the I-neb AAD System. The I-neb Insight and the Patient Logging System facilitate a further degree of sophistication to the feedback mechanisms, by providing information on long term adherence and compliance data. These can be assessed by patients and clinicians via a Web-based delivery of information in the form of customized graphical analyses.

  8. Encapsulation of C60 fullerenes into single-walled carbon nanotubes: Fundamental mechanical principles and conventional applied mathematical modeling

    Science.gov (United States)

    Baowan, Duangkamon; Thamwattana, Ngamta; Hill, James M.

    2007-10-01

    A well-known self-assembled hybrid carbon nanostructure is a nanopeapod which may be regarded as the prototype nanocarrier for drug delivery. While the investigation of the packing of C60 molecules inside a carbon nanotube is usually achieved through either experimentation or large scale computation, this paper adopts elementary mechanical principles and classical applied mathematical modeling techniques to formulate explicit analytical criteria and ideal model behavior for such encapsulation. In particular, we employ the Lennard-Jones potential and the continuum approximation to determine three encapsulation mechanisms for a C60 fullerene entering a tube: (i) through the tube open end (head-on), (ii) around the edge of the tube open end, and (iii) through a defect opening on the tube wall. These three encapsulation mechanisms are undertaken for each of the three specific carbon nanotubes (10,10), (16,16), and (20,20). We assume that all configurations are in vacuum and the C60 fullerene is initially at rest. Double integrals are performed to determine the energy of the system and analytical expressions are obtained in terms of hypergeometric functions. Our results suggest that the C60 fullerene is most likely to be encapsulated by head-on through the open tube end and that encapsulation around the tube edge is least likely to occur because of the large van der Waals energy barriers which exist at the tube ends.

  9. The potential of liposome-encapsulated ciprofloxacin as a tularemia therapy.

    Science.gov (United States)

    Hamblin, Karleigh A; Wong, Jonathan P; Blanchard, James D; Atkins, Helen S

    2014-01-01

    Liposome-encapsulation has been suggested as method to improve the efficacy of ciprofloxacin against the intracellular pathogen, Francisella tularensis. Early work with a prototype formulation, evaluated for use against the F. tularensis live vaccine strain, showed that a single dose of liposomal ciprofloxacin given by the intranasal or inhalational route could provide protection in a mouse model of pneumonic tularemia. Liposomal ciprofloxacin offered better protection than ciprofloxacin given by the same routes. Liposomal ciprofloxacin has been further developed by Aradigm Corporation for Pseudomonas aeruginosa infections in patients with cystic fibrosis and non-cystic fibrosis bronchiectasis. This advanced development formulation is safe, effective and well tolerated in human clinical trials. Further evaluation of the advanced liposomal ciprofloxacin formulation against the highly virulent F. tularensis Schu S4 strain has shown that aerosolized CFI (Ciprofloxacin encapsulated in liposomes for inhalation) provides significantly better protection than oral ciprofloxacin. Thus, liposomal ciprofloxacin is a promising treatment for tularemia and further research with the aim of enabling licensure under the animal rule is warranted.

  10. Photovoltaic module encapsulation design and materials selection. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Cuddihy, E.

    1984-06-01

    This is Volume II of Photovoltaic Module Encapsulation Design and Materials Selection: a periodically updated handbook of encapsulation technology, developed with the support of the Flat-Plate Solar Array Project (FSA), managed for the Department of Energy (DOE) by the Jet Propulsion Laboratory. Volume II describes FSA encapsulation technology developed between June 1, 1982, and January 1, 1984. Emphasis during this period shifted from materials development to demonstration of reliability and durability in an outdoor environment; the updated information in this volume reflects the developing technology base related to both reliability and encapsulation process improvements.

  11. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2011-02-01

    Polymeric encapsulation materials are typically used in concentrating photovoltaic (CPV) modules to protect the cell from the field environment. Because it is physically located adjacent to the cell, the encapsulation is exposed to a high optical flux, often including light in the ultraviolet (UV) and infrared (IR) wavelengths. The durability of encapsulants used in CPV modules is critical to the technology, but is presently not well understood. This work seeks to identify the appropriate material types, field-induced failure mechanisms, and factors of influence (if possible) of polymeric encapsulation. These results will ultimately be weighed against those of future qualification and accelerated life test procedures.

  12. Computed tomography appearances of sclerosing encapsulating peritonitis

    Energy Technology Data Exchange (ETDEWEB)

    George, C. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)]. E-mail: cheriangeorge@hotmail.com; Al-Zwae, K. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Nair, S. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Cast, J.E.I. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)

    2007-08-15

    Sclerosing encapsulating peritonitis (SEP) is a serious complication of peritoneal dialysis (PD) characterized by thickened peritoneal membranes, which lead to decreased ultra-filtration and intestinal obstruction. Its early clinical features are nonspecific, and it is often diagnosed late following laparotomy and peritoneal biopsy, when the patient develops small bowel obstruction, which can be a life-threatening complication. However, this is changing with increasing awareness of computed tomography (CT) findings in SEP. CT can yield an early, non-invasive diagnosis that may improve patient outcome. We present a review of the CT appearances of SEP.

  13. Research on Rare Earth Encapsulated Luminescent Material

    Institute of Scientific and Technical Information of China (English)

    Yu Zhiwei; Liu Chengdong; Qi Xiaopeng

    2004-01-01

    A new method of preparation of irradiative material by using rare earth as luminophor and inorganic powder as base nucleus was presented.Rare earth was used to make colloid, which was mixed with base nucleus solution,where deposition/attachment reaction took place and rare earth was adhered onto the surface of base nucleus, hence yielding a new rare earth encapsulated irradiative material.Fluorescent spectrum analysis shows that this material possesses two emission peaks, one within 400 ~ 500 nm and the other within 580 ~ 700 nm, reflecting the luminous characteristics of original rare earth material.

  14. Optimizing indomethacin-loaded chitosan nanoparticle size, encapsulation, and release using Box-Behnken experimental design.

    Science.gov (United States)

    Abul Kalam, Mohd; Khan, Abdul Arif; Khan, Shahanavaj; Almalik, Abdulaziz; Alshamsan, Aws

    2016-06-01

    Indomethacin chitosan nanoparticles (NPs) were developed by ionotropic gelation and optimized by concentrations of chitosan and tripolyphosphate (TPP) and stirring time by 3-factor 3-level Box-Behnken experimental design. Optimal concentration of chitosan (A) and TPP (B) were found 0.6mg/mL and 0.4mg/mL with 120min stirring time (C), with applied constraints of minimizing particle size (R1) and maximizing encapsulation efficiency (R2) and drug release (R3). Based on obtained 3D response surface plots, factors A, B and C were found to give synergistic effect on R1, while factor A has a negative impact on R2 and R3. Interaction of AB was negative on R1 and R2 but positive on R3. The factor AC was having synergistic effect on R1 and on R3, while the same combination had a negative effect on R2. The interaction BC was positive on the all responses. NPs were found in the size range of 321-675nm with zeta potentials (+25 to +32mV) after 6 months storage. Encapsulation, drug release, and content were in the range of 56-79%, 48-73% and 98-99%, respectively. In vitro drug release data were fitted in different kinetic models and pattern of drug release followed Higuchi-matrix type.

  15. Encapsulation of diclofenac sodium within polymer beads by silica species via vapour-phase synthesis.

    Science.gov (United States)

    Kierys, Agnieszka; Kasperek, Regina; Krasucka, Patrycja; Goworek, Jacek

    2016-06-01

    The present study concerns the preparation of ternary composites via the in situ encapsulation of solid dispersion of diclofenac sodium within the acrylic polymer beads. The encapsulating species were produced through the hydrolysis and condensation of the silica precursors (tetraethoxysilane or ethyltriethoxysilane) introduced into the solid dispersion. The transformation of precursors occurred in the vapor phase of ammonia. A great advantage of the presented vapor-phase method is preventing the desorption of the highly soluble drug during gelation of silica precursors, which stands in contrast to the conventional sol-gel processes occurring in the solution. The conducted studies, involving the low temperature N2 sorption together with spectroscopic techniques, provide insight into the structural differences of drug loaded particles. They reveal that the formation of silica gel accompanies the conversion of the drug into its amorphous form. Finally, the desorption profiles of diclofenac sodium demonstrate that the deposition of silica gel successfully diminishes the degree of the initial drug desorption while significantly modifying its release rate.

  16. Dextran vesicular carriers for dual encapsulation of hydrophilic and hydrophobic molecules and delivery into cells.

    Science.gov (United States)

    Pramod, P S; Takamura, Kathryn; Chaphekar, Sonali; Balasubramanian, Nagaraj; Jayakannan, M

    2012-11-12

    Dextran vesicular nanoscaffolds were developed based on polysaccharide and renewable resource alkyl tail for dual encapsulation of hydrophilic and hydrophobic molecules (or drugs) and delivery into cells. The roles of the hydrophobic segments on the molecular self-organization of dextran backbone into vesicles or nanoparticles were investigated in detail. Dextran vesicles were found to be a unique dual carrier in which water-soluble molecules (like Rhodamine-B, Rh-B) and polyaromatic anticancer drug (camptothecin, CPT) were selectively encapsulated in the hydrophilic core and hydrophobic layer, respectively. The dextran vesicles were capable of protecting the plasma-sensitive CPT lactone pharmacophore against the hydrolysis by 10× better than the CPT alone in PBS. The aliphatic ester linkage connecting the hydrophobic tail with dextran was found to be cleaved by esterase under physiological conditions for fast releasing of CPT or Rh-B. Cytotoxicity of the dextran vesicle and its drug conjugate were tested on mouse embryonic fibroblast cells (MEFs) using MTT assay. The dextran vesicular scaffold was found to be nontoxic to living cells. CPT loaded vesicles were found to be 2.5-fold more effective in killing fibroblasts compared to that of CPT alone in PBS. Confocal microscopic images confirmed that both Rh-B and CPT loaded vesicles to be taken up by fibroblasts compared to CPT alone, showing a distinctly perinuclear localization in cells. The custom designed dextran vesicular provides new research opportunities for dual loading and delivering of hydrophilic and hydrophobic drug molecules.

  17. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    a relationship between plunging jet particle ux, oceanic particle ux, and energy dissipation rate in both systems. Previous sea spray aerosol studies dissipate an order of magnitude more energy for the same particle ux production as the open ocean. A scaling factor related to the energy expended in air...... emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use...... jet in high concentrations of surface active organics and brackish water salinities. The jet produces particles with less cloud condensation activity, implying an increase in organic material in aerosol particles produced by the plunging jet over the frit. In the second paper we determine...

  18. Aerosol Observing System (AOS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  19. Aerosol characterization during project POLINAT

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, D.E.; Hopkins, A.R.; Paladino, J.D.; Whitefield, P.D. [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H.V. [McDonnell Douglas Aerospace-East, St. Louis, MO (United States)

    1997-12-31

    The objectives of the aerosol/particulate characterization measurements of project POLINAT (POLlution from aircraft emissions In the North ATlantic flight corridor) are: to search for aerosol/particulate signatures of air traffic emissions in the region of the North Atlantic Flight Corridor; to search for the aerosol/particulate component of large scale enhancement (`corridor effects`) of air traffic related species in the North Atlantic region; to determine the effective emission indices for the aerosol/particulate component of engine exhaust in both the near and far field of aircraft exhaust plumes; to measure the dispersion and transformation of the aerosol/particulate component of aircraft emissions as a function of ambient condition; to characterize background levels of aerosol/particulate concentrations in the North Atlantic Region; and to determine effective emission indices for engine exhaust particulates for regimes beyond the jet phase of plume expansion. (author) 10 refs.

  20. Acidic aerosol in urban air

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, M.; Yamaoka, S.; Miyazaki, T.; Oka, M.

    1982-01-01

    The distribution and chemical composition of acidic aerosol in Osaka City were investigated. Samples were collected at five sites in the city from June to September, 1979. Acidic aerosol was determined by the acid-base titration method, sulfate ion by barium chloride turbidimetry, nitrate ion by the xylenol method, and chloride ion by the mercury thiocyanate method. The concentration of acidic aerosol at five sites ranged from 7.7 micrograms per cubic meter to 10.0 micrograms per cubic meter, but mean concentrations in the residential area were slightly higher than those in the industrial area. When acidic aerosol concentrations were compared with concentrations of sulfate, nitrate, and chloride ions, a significant correlation was found between acidic aerosol and sulfate ion. The sum of the ion equivalents of the three types showed good correlation with the acidic aerosol equivalent during the whole period.

  1. 21 CFR 700.14 - Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Use of vinyl chloride as an ingredient, including... Products § 700.14 Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products. (a) Vinyl chloride has been used as an ingredient in cosmetic aerosol products including hair...

  2. Idiopathic sclerosing encapsulating peritonitis (or abdominal cocoon

    Directory of Open Access Journals (Sweden)

    Legakis Nikolaos

    2006-02-01

    Full Text Available Abstract Background Idiopathic sclerosing encapsulating peritonitis (or abdominal cocoon is a rare cause of small bowel obstruction, especially in adult population. Diagnosis is usually incidental at laparotomy. We discuss one such rare case, outlining the fact that an intra-operative surprise diagnosis could have been facilitated by previous investigations. Case presentation A 56 year-old man presented in A&E department with small bowel ileus. He had a history of 6 similar episodes of small bowel obstruction in the past 4 years, which resolved with conservative treatment. Pre-operative work-up did not reveal any specific etiology. At laparotomy, a fibrous capsule was revealed, in which small bowel loops were encased, with the presence of interloop adhesions. A diagnosis of abdominal cocoon was established and extensive adhesiolysis was performed. The patient had an uneventful recovery and follow-up. Conclusion Idiopathic sclerosing encapsulating peritonitis, although rare, may be the cause of a common surgical emergency such as small bowel ileus, especially in cases with attacks of non-strangulating obstruction in the same individual. A high index of clinical suspicion may be generated by the recurrent character of small bowel ileus combined with relevant imaging findings and lack of other plausible etiologies. Clinicians must rigorously pursue a preoperative diagnosis, as it may prevent a "surprise" upon laparotomy and result in proper management.

  3. Method of producing zeolite encapsulated nanoparticles

    DEFF Research Database (Denmark)

    2015-01-01

    The invention therefore relates to a method for producing zeolite, zeolite-like or zeotype encapsulated metal nanoparticles, the method comprises the steps of: 1) Adding one or more metal precursors to a silica or alumina source; 2) Reducing the one or more metal precursors to form metal nanopart......The invention therefore relates to a method for producing zeolite, zeolite-like or zeotype encapsulated metal nanoparticles, the method comprises the steps of: 1) Adding one or more metal precursors to a silica or alumina source; 2) Reducing the one or more metal precursors to form metal...... nanoparticles on the surface of the silica or alumina source; 3) Passing a gaseous hydrocarbon, alkyl alcohol or alkyl ether over the silica or alumina supported metal nanoparticles to form a carbon template coated zeolite, zeolite-like or zeotype precursor composition; 4a) Adding a structure directing agent...... to the carbon template coated zeolite, zeolite-like or zeotype precursor composition thereby creating a zeolite, zeolite-like or zeotype gel composition; 4b) Crystallising the zeolite, zeolite-like or zeotype gel composition by subjecting said composition to a hydrothermal treatment; 5) Removing the carbon...

  4. FBG sensor of breathing encapsulated into polydimethylsiloxane

    Science.gov (United States)

    Fajkus, Marcel; Nedoma, Jan; Siska, Petr; Vasinek, Vladimir

    2016-10-01

    The technology of Fiber Bragg grating (FBG) belongs to the most widespread fiber-optic sensors. They are used for measuring a large number of physical and chemical quantities. Small size, immunity to electromagnetic interference, high sensitivity and a principle of information encoding about the measurement value into spectral characteristics causes usability of FBG sensors in medicine for monitoring vital signs such as temperature, blood pressure, pulse, and respiration. An important factor is the use of an inert material for the encapsulation of Bragg gratings in this area. A suitable choice is a polydimethylsiloxane (PDMS) elastomer having excellent thermal and elastic properties. Experimental results describe the creation of FBG sensory prototype for monitoring breathing in this paper. The sensor is realized by encapsulation of Bragg grating into PDMS. The FBG sensor is mounted on the elastic contact strap which encircles the chest of the patient. This tension leads to a spectral shift of the reflected light from the FBG. For measurement, we used a broadband light source Light-Emitting Diode (LED) with central wavelength 1550 nm and optical spectrum analyzer.

  5. Accelerated degradation studies of encapsulation polymers

    Science.gov (United States)

    Weiss, Karl-Anders; Huelsmann, Jan Philip; Kaltenbach, Thomas; Philipp, Daniel; Schuhmacher, Tanja; Wirth, Jochen; Koehl, Michael

    2008-08-01

    The estimation of PV-modules lifetime facilitates the further development and helps to lower risks for producers and investors. One base for this extensive testing and simulation work is the knowledge of the chemical degradation processes and their kinetics, as well as of the permeation of water and oxygen into the module, especially of the encapsulant. Besides ethylen-vinylacetate copolymer (EVA), which is the dominant material for encapsulation, new materials become available and need the assessment of their properties and the durability impact. Accelerated durability tests were performed on different EVA materials. The paper reports on several measurement methods for analysis of the polymers that were used, FT-IR with attenuated total reflection (ATR), and Raman microscopy, e.g. It is very important to identify degradation products and intermediates in order to identify the leading degradation processes and their kinetics as well as potential interactions between different processes. Another important factor for the degradation of the PV-modules and the concerned polymers in particular is the permeation of reactive substances, especially of water vapor, into and inside the modules. The paper shows results of permeation measurements of the new materials, as well as FEM-based numerical simulations of the humidity diffusion within a PV-module what is an important step towards the calculation of the chemical degradation using numerical simulation tools in the future.

  6. Stabilization of reactive species by supramolecular encapsulation.

    Science.gov (United States)

    Galan, Albano; Ballester, Pablo

    2016-03-21

    Molecular containers have attracted the interest of supramolecular chemists since the early beginnings of the field. Cavitands' inner cavities were quickly exploited by Cram and Warmuth to construct covalent containers able to stabilize and assist the characterization of short-lived reactive species such as cyclobutadiene or o-benzyne. Since then, more complex molecular architectures have been prepared able to store and isolate a myriad of fleeting species (i.e. organometallic compounds, cationic species, radical initiators…). In this review we cover selected examples of the stabilization of reactive species by encapsulation in molecular containers from the first reports of covalent containers described by Cram et al. to the most recent examples of containers with self-assembled structure (metal coordination cages and hydrogen bonded capsules). Finally, we briefly review examples reported by Rebek et al. in which elusive reaction intermediates could be detected in the inner cavities of self-folding resorcin[4]arene cavitands by the formation of covalent host-guest complexes. The utilization of encapsulated reactive species in catalysis or synthesis is not covered.

  7. Clinical Controversies in Aerosol Therapy for Infants and Children.

    Science.gov (United States)

    DiBlasi, Robert M

    2015-06-01

    Pediatric patients are different from adult patients with respect to airway anatomy and breathing patterns. They are also incapable of following commands and often reject breathing treatments. For these reasons, aerosol drug delivery is one of the most technically challenging aspects for clinicians providing respiratory care to young children. Improvements in nebulizer technology have provided better delivery options for pediatric patients. This review highlights research related to pediatric nebulizer and interface devices and how they can be used to provide the safest and most efficient treatments with the array of treatment delivery options. Also addressed are clinical controversies and debates in pediatric aerosol science, including drug delivery in crying versus resting infants, pressurized metered-dose inhalers and small-volume nebulizers for bronchodilator administration, continuous nebulization, noninvasive drug delivery options, and optimization of nebulizer performance during infant and large pediatric conventional and high-frequency ventilation.

  8. Presence of multiple lesion types with vastly different microenvironments in C3HeB/FeJ mice following aerosol infection with Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Scott M. Irwin

    2015-06-01

    Full Text Available Cost-effective animal models that accurately reflect the pathological progression of pulmonary tuberculosis are needed to screen and evaluate novel tuberculosis drugs and drug regimens. Pulmonary disease in humans is characterized by a number of heterogeneous lesion types that reflect differences in cellular composition and organization, extent of encapsulation, and degree of caseous necrosis. C3HeB/FeJ mice have been increasingly used to model tuberculosis infection because they produce hypoxic, well-defined granulomas exhibiting caseous necrosis following aerosol infection with Mycobacterium tuberculosis. A comprehensive histopathological analysis revealed that C3HeB/FeJ mice develop three morphologically distinct lesion types in the lung that differ with respect to cellular composition, degree of immunopathology and control of bacterial replication. Mice displaying predominantly the fulminant necrotizing alveolitis lesion type had significantly higher pulmonary bacterial loads and displayed rapid and severe immunopathology characterized by increased mortality, highlighting the pathological role of an uncontrolled granulocytic response in the lung. Using a highly sensitive novel fluorescent acid-fast stain, we were able to visualize the spatial distribution and location of bacteria within each lesion type. Animal models that better reflect the heterogeneity of lesion types found in humans will permit more realistic modeling of drug penetration into solid caseous necrotic lesions and drug efficacy testing against metabolically distinct bacterial subpopulations. A more thorough understanding of the pathological progression of disease in C3HeB/FeJ mice could facilitate modulation of the immune response to produce the desired pathology, increasing the utility of this animal model.

  9. Topics in current aerosol research

    CERN Document Server

    Hidy, G M

    1971-01-01

    Topics in Current Aerosol Research deals with the fundamental aspects of aerosol science, with emphasis on experiment and theory describing highly dispersed aerosols (HDAs) as well as the dynamics of charged suspensions. Topics covered range from the basic properties of HDAs to their formation and methods of generation; sources of electric charges; interactions between fluid and aerosol particles; and one-dimensional motion of charged cloud of particles. This volume is comprised of 13 chapters and begins with an introduction to the basic properties of HDAs, followed by a discussion on the form

  10. Photovoltaic-module encapsulation design and materials selection: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Cuddihy, E.; Carroll, W.; Coulbert, C.; Gupta, A.; Liang, R.

    1982-06-01

    Encapsulation-material system requirements, material-selection criteria, and the status and properties of encapsulation materials and processes available to the module manufacturer are presented in detail. Technical and economic goals established for photovoltaic modules and encapsulation systems and their status are described for material suppliers to assist them in assessing the suitability of materials in their product lines and the potential of new-material products. A comprehensive discussion of available encapsulation technology and data is presented to facilitate design and material selection for silicon flat-plate photovoltaic modules, using the best materials available and processes optimized for specific power applications and geographic sites. A basis is provided for specifying the operational and environmental loads that encapsulation material systems must resist. Potential deployment sites for which cost effectiveness may be achieved at a module price much greater than $0.70/W/sub p/, are also considered; data on higher-cost encapsulant materials and processes that may be in use and other material candidates that may be justified for special application are discussed. Described are encapsulation-system functional requirements and candidate design concepts and materials that have been identified and analyzed as having the best potential to meet the cost and performance goals for the Flat-Plate Solar Array Project. The available data on encapsulant material properties, fabrication processing, and module life and durability characteristics are presented.

  11. The interpretation of encapsulating anaphors in Spanish and their functions

    DEFF Research Database (Denmark)

    Dam, Lotte

    2014-01-01

    Encapsulating anaphors differ from other types of anaphor by having one or more situations - not an entity - as its referent. The main aim of the article is to propose a hypothesis for how anaphoric encapsulation is resolved. The hypothesis builds on the cognitive linguistic theory of instruction...

  12. Screening Plastic-Encapsulated Solid-State Devices

    Science.gov (United States)

    Buldhaupt, L.

    1984-01-01

    Suitability of plastic-encapsulated solid-state electronic devices for use in spacecraft discussed. Conclusion of preliminary study was plasticencapsulated parts sufficiently reliable to be considered for use in lowcost equipment used at moderate temperature and low humidity. Useful to engineers as guides to testing or use of plastic encapsulated semiconductors in severe terrestrial environments.

  13. Encapsulation of essential oils in zein nanosperical particles

    Science.gov (United States)

    Essential oils, oregano, red thyme, and cassia (100% pure oil), were encapsulated by phase separation into zein particles. Typical yields were between 65% and 75% of product. Encapsulation efficiency of all oils was 87% except for cassia oil which was 49%. Loading efficiency of all oils was 22% exce...

  14. Characterization studies of lower and non-TDI polyurethane encapsulants

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.H.

    1993-09-01

    Polyurethane prepolymers containing toluene diisocyanate (TDI) are used within the Nuclear Weapons complex for many adhesive and encapsulation applications. As part of a program for minimizing hazards to workers and the environment, TDI will be eliminated. This report presents evaluation of alternative encapsulants.

  15. Biocompatible Hydrogels for Microarray Cell Printing and Encapsulation

    Directory of Open Access Journals (Sweden)

    Akshata Datar

    2015-10-01

    Full Text Available Conventional drug screening processes are a time-consuming and expensive endeavor, but highly rewarding when they are successful. To identify promising lead compounds, millions of compounds are traditionally screened against therapeutic targets on human cells grown on the surface of 96-wells. These two-dimensional (2D cell monolayers are physiologically irrelevant, thus, often providing false-positive or false-negative results, when compared to cells grown in three-dimensional (3D structures such as hydrogel droplets. However, 3D cell culture systems are not easily amenable to high-throughput screening (HTS, thus inherently low throughput, and requiring relatively large volume for cell-based assays. In addition, it is difficult to control cellular microenvironments and hard to obtain reliable cell images due to focus position and transparency issues. To overcome these problems, miniaturized 3D cell cultures in hydrogels were developed via cell printing techniques where cell spots in hydrogels can be arrayed on the surface of glass slides or plastic chips by microarray spotters and cultured in growth media to form cells encapsulated 3D droplets for various cell-based assays. These approaches can dramatically reduce assay volume, provide accurate control over cellular microenvironments, and allow us to obtain clear 3D cell images for high-content imaging (HCI. In this review, several hydrogels that are compatible to microarray printing robots are discussed for miniaturized 3D cell cultures.

  16. Aerosol absorption and radiative forcing

    Directory of Open Access Journals (Sweden)

    P. Stier

    2007-05-01

    Full Text Available We present a comprehensive examination of aerosol absorption with a focus on evaluating the sensitivity of the global distribution of aerosol absorption to key uncertainties in the process representation. For this purpose we extended the comprehensive aerosol-climate model ECHAM5-HAM by effective medium approximations for the calculation of aerosol effective refractive indices, updated black carbon refractive indices, new cloud radiative properties considering the effect of aerosol inclusions, as well as by modules for the calculation of long-wave aerosol radiative properties and instantaneous aerosol forcing. The evaluation of the simulated aerosol absorption optical depth with the AERONET sun-photometer network shows a good agreement in the large scale global patterns. On a regional basis it becomes evident that the update of the BC refractive indices to Bond and Bergstrom (2006 significantly improves the previous underestimation of the aerosol absorption optical depth. In the global annual-mean, absorption acts to reduce the short-wave anthropogenic aerosol top-of-atmosphere (TOA radiative forcing clear-sky from –0.79 to –0.53 W m−2 (33% and all-sky from –0.47 to –0.13 W m−2 (72%. Our results confirm that basic assumptions about the BC refractive index play a key role for aerosol absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations is comparably small. We demonstrate that the diversity in the AeroCom land-surface albedo fields contributes to the uncertainty in the simulated anthropogenic aerosol radiative forcings: the usage of an upper versus lower bound of the AeroCom land albedos introduces a global annual-mean TOA forcing range of 0.19 W m−2 (36% clear-sky and of 0.12 W m−2 (92% all-sky. The consideration of black carbon inclusions on cloud radiative properties results in a small global annual-mean all-sky absorption of 0.05 W

  17. Solubility, photostability and antifungal activity of phenylpropanoids encapsulated in cyclodextrins.

    Science.gov (United States)

    Kfoury, Miriana; Lounès-Hadj Sahraoui, Anissa; Bourdon, Natacha; Laruelle, Frédéric; Fontaine, Joël; Auezova, Lizette; Greige-Gerges, Hélène; Fourmentin, Sophie

    2016-04-01

    Effects of the encapsulation in cyclodextrins (CDs) on the solubility, photostability and antifungal activities of some phenylpropanoids (PPs) were investigated. Solubility experiments were carried out to evaluate the effect of CDs on PPs aqueous solubility. Loading capacities and encapsulation efficiencies of freeze-dried inclusion complexes were determined. Moreover, photostability assays for both inclusion complexes in solution and solid state were performed. Finally, two of the most widespread phytopathogenic fungi, Fusarium oxysporum and Botrytis cinerea, were chosen to examine the antifungal activity of free and encapsulated PPs. Results showed that encapsulation in CDs significantly increased the solubility and photostability of studied PPs (by 2 to 17-fold and 2 to 44-fold, respectively). Free PPs revealed remarkable antifungal properties with isoeugenol showing the lowest half-maximal inhibitory concentration (IC50) values of mycelium growth and spore germination inhibition. Encapsulated PPs, despite their reduced antifungal activity, could be helpful to solve drawbacks such as solubility and stability.

  18. High-Performance CCSDS Encapsulation Service Implementation in FPGA

    Science.gov (United States)

    Clare, Loren P.; Torgerson, Jordan L.; Pang, Jackson

    2010-01-01

    The Consultative Committee for Space Data Systems (CCSDS) Encapsulation Service is a convergence layer between lower-layer space data link framing protocols, such as CCSDS Advanced Orbiting System (AOS), and higher-layer networking protocols, such as CFDP (CCSDS File Delivery Protocol) and Internet Protocol Extension (IPE). CCSDS Encapsulation Service is considered part of the data link layer. The CCSDS AOS implementation is described in the preceding article. Recent advancement in RF modem technology has allowed multi-megabit transmission over space links. With this increase in data rate, the CCSDS Encapsulation Service needs to be optimized to both reduce energy consumption and operate at a high rate. CCSDS Encapsulation Service has been implemented as an intellectual property core so that the aforementioned problems are solved by way of operating the CCSDS Encapsulation Service inside an FPGA. The CCSDS En capsula tion Service in FPGA implementation consists of both packetizing and de-packetizing features

  19. Primary Amyloidosis Presenting as Small Bowel Encapsulation

    Directory of Open Access Journals (Sweden)

    Jennifer Jones

    2004-01-01

    Full Text Available Amyloidosis is a pathological process which encompasses a spectrum of diseases that result from extracellular deposition of pathological fibrillar proteins. Clinical presentations vary depending on the organs involved. There is no documented case of amyloidosis presenting as small bowel encapsulation. A previously healthy 62-year-old man developed a small bowel obstruction in 1997. At surgery, a peculiar membrane encasing his entire small bowel was discovered. This appeared to have no vascularity and was removed without difficulty, exposing a grossly normal bowel. Histopathology revealed thick bands of collagen overlying the peritoneal surface, which was congo red positive and showed apple green birefringence. The findings were consistent with encapsulating peritonitis due to amyloidosis. There was no history or symptoms of any chronic inflammatory condition and he became symptom-free postoperatively. An abdominal fat pad biopsy failed to demonstrate amyloidosis. Endoscopic duodenal biopsies revealed classical primary amyloidosis. Quantitative immunoglobulins, lactate dehydrogenase, C3, C4 and beta-2 microglobulin were normal. Protein electrophoresis identified monoclonal paraprotein, immunoglobulin G lambda 3.7 g/L. Bone marrow biopsy and aspirate revealed only a mild plasmacytosis (5% to 10%. Echocardiogram and skeletal survey were normal. He had mild proteinuria. Complete blood count, C-reactive protein, calcium, albumin and total protein were normal. No specific therapy was instituted. In January of 1998 the patient remained asymptomatic with no gastrointestinal, cardiovascular or constitutional symptoms. He had developed nephrotic range proteinuria (3.95 g/24 h, microalbuminuria, hypoalbuminemia and a renal biopsy consistent with renal amyloidosis. In 1999 there was an increase in the monoclonal paraprotein (6.2 g/L. The remaining investigations were normal except for an echocardiogram which showed left ventricular hypertrophy but a normal

  20. Tracking Hypoxic Signaling in Encapsulated Stem Cells

    Science.gov (United States)

    Sahai, Suchit; McFarland, Rachel; Skiles, Mathew L.; Sullivan, Denise; Williams, Amanda

    2012-01-01

    Oxygen is not only a nutrient but also an important signaling molecule whose concentration can influence the fate of stem cells. This study details the development of a marker of hypoxic signaling for use with encapsulated cells. Testing of the marker was performed with adipose-derived stem cells (ADSCs) in two-dimensional (2D) and 3D culture conditions in varied oxygen environments. The cells were genetically modified with our hypoxia marker, which produces a red fluorescent protein (DsRed-DR), under the control of a hypoxia-responsive element (HRE) trimer. For 3D culture, ADSCs were encapsulated in poly(ethylene glycol)–based hydrogels. The hypoxia marker (termed HRE DsRed-DR) is built on a recombinant adenovirus and ADSCs infected with the marker will display red fluorescence when hypoxic signaling is active. This marker was not designed to measure local oxygen concentration but rather to show how a cell perceives its local oxygen concentration. ADSCs cultured in both 2D and 3D were exposed to 20% or 1% oxygen environments for 96 h. In 2D at 20% O2, the marker signal was not observed during the study period. In 1% O2, the fluorescent signal was first observed at 24 h, with maximum prevalence observed at 96 h as 59%±3% cells expressed the marker. In 3D, the signal was observed in both 1% and 20% O2. The onset of signal in 1% O2 was observed at 4 h, reaching maximum prevalence at 96 h with 76%±4% cells expressing the marker. Interestingly, hypoxic signal was also observed in 20% O2, with 13%±3% cells showing positive marker signal after 96 h. The transcription factor subunit hypoxia inducible factor-1α was tracked in these cells over the same time period by immunostaining and western blot analysis. Immunostaining results in 2D correlated well with our marker at 72 h and 96 h, but 3D results did not correlate well. The western blotting results in 2D and 3D correlated well with the fluorescent marker. The HRE DsRed-DR virus can be used to track

  1. Acetalated dextran encapsulated AR-12 as a host-directed therapy to control Salmonella infection.

    Science.gov (United States)

    Hoang, Ky V; Borteh, Hassan M; Rajaram, Murugesan V S; Peine, Kevin J; Curry, Heather; Collier, Michael A; Homsy, Michael L; Bachelder, Eric M; Gunn, John S; Schlesinger, Larry S; Ainslie, Kristy M

    2014-12-30

    AR-12 has been evaluated in clinical trials as an anti-cancer agent but also has demonstrated host-directed, broad-spectrum clearance of bacteria. We have previously shown that AR-12 has activity in vitro against Salmonella enterica serovar Typhimurium and Francisella species by inducing autophagy and other host immune pathways. AR-12 treatment of S. Typhimurium-infected mice resulted in a 10-fold reduction in bacterial load in the liver and spleen and an increased survival time. However, AR-12 treatment did not protect mice from death, likely due poor formulation. In the current study, AR-12 was encapsulated in a microparticulate carrier formulated from the novel degradable biopolymer acetalated dextran (Ace-DEX) and subsequently evaluated for its activity in human monocyte-derived macrophages (hMDMs). Our results show that hMDMs efficiently internalized Ace-DEX microparticles (MPs), and that encapsulation significantly reduced host cell cytotoxicity compared to unencapsulated AR-12. Efficient macrophage internalization of AR-12 loaded MPs (AR-12/MPs) was further demonstrated by autophagosome formation that was comparable to free AR-12 and resulted in enhanced clearance of intracellular Salmonella. Taken together, these studies provide support that Ace-DEX encapsulated AR-12 may be a promising new therapeutic agent to control intracellular bacterial pathogens of macrophages by targeting delivery and reducing drug toxicity.

  2. Preparation and efficacy of Newcastle disease virus DNA vaccine encapsulated in chitosan nanoparticles.

    Science.gov (United States)

    Zhao, Kai; Zhang, Yang; Zhang, Xiaoyan; Li, Wei; Shi, Ci; Guo, Chen; Dai, Chunxiao; Chen, Qian; Jin, Zheng; Zhao, Yan; Cui, Hongyu; Wang, Yunfeng

    2014-01-01

    Optimal preparation conditions of Newcastle disease virus (NDV) F gene deoxyribonucleic acid (DNA) vaccine encapsulated in chitosan nanoparticles (pFNDV-CS-NPs) were determined. The pFNDV-CS-NPs were prepared according to a complex coacervation method. The pFNDV-CS-NPs were produced with good morphology, high stability, a mean diameter of 199.5 nm, encapsulation efficiency of 98.37% ± 0.87%, loading capacity of 36.12% ± 0.19%, and a zeta potential of +12.11 mV. The in vitro release assay showed that the plasmid DNA was sustainably released from the pFNDV-CS-NPs, up to 82.9% ± 2.9% of the total amount. Cell transfection test indicated that the vaccine expressed the F gene in cells and maintained good bioactivity. Additionally, the safety of mucosal immunity delivery system of the pFNDV-CS-NPs was also tested in vitro by cell cytotoxicity and in vivo by safety test in chickens. In vivo immunization showed that better immune responses of specific pathogen-free chickens immunized with the pFNDV-CS-NPs were induced, and prolonged release of the plasmid DNA was achieved compared to the chickens immunized with the control plasmid. This study lays the foundation for the further development of mucosal vaccines and drugs encapsulated in chitosan nanoparticles.

  3. Erythrocytes encapsulated with phenylalanine hydroxylase exhibit improved pharmacokinetics and lowered plasma phenylalanine levels in normal mice.

    Science.gov (United States)

    Yew, Nelson S; Dufour, Emmanuelle; Przybylska, Malgorzata; Putelat, Julie; Crawley, Cristin; Foster, Meta; Gentry, Sarah; Reczek, David; Kloss, Alla; Meyzaud, Aurélien; Horand, Françoise; Cheng, Seng H; Godfrin, Yann

    2013-08-01

    Enzyme replacement therapy is often hampered by the rapid clearance and degradation of the administered enzyme, limiting its efficacy and requiring frequent dosing. Encapsulation of therapeutic molecules into red blood cells (RBCs) is a clinically proven approach to improve the pharmacokinetics and efficacy of biologics and small molecule drugs. Here we evaluated the ability of RBCs encapsulated with phenylalanine hydroxylase (PAH) to metabolize phenylalanine (Phe) from the blood and confer sustained enzymatic activity in the circulation. Significant quantities of PAH were successfully encapsulated within murine RBCs (PAH-RBCs) with minimal loss of endogenous hemoglobin. While intravenously administered free PAH enzyme was rapidly eliminated from the blood within a few hours, PAH-RBCs persisted in the circulation for at least 10days. A single injection of PAH-RBCs was able to decrease Phe levels by nearly 80% in normal mice. These results demonstrate the ability of enzyme-loaded RBCs to metabolize circulating amino acids and highlight the potential to treat disorders of amino acid metabolism.

  4. Encapsulation of catechin and epicatechin on BSA NPS improved their stability and antioxidant potential.

    Science.gov (United States)

    Yadav, Ramdhan; Kumar, Dharmesh; Kumari, Avnesh; Yadav, Sudesh Kumar

    2014-01-01

    Nanoencapsulation of antioxidant molecules on protein nanoparticles (NPs) could be an advanced approach for providing stable, better food nutraceuticals and anticancer drugs. The bioavailability and stability of catechin (CAT) and epicatechin (ECAT) were very poor. In the present study, the CAT and ECAT were loaded on bovine serum albumin (BSA) NPs following desolvation method. The transmission electron microscope (TEM) and atomic force microscope (AFM) recorded size of CAT-BSA NPs and ECAT-BSA NPs were 45 ± 5 nm and 48 ± 5 nm respectively. The encapsulation efficiency of CAT and ECAT on BSA NPs was found to be 60.5 and 54.5 % respectively. CAT-BSA NPs and ECAT-BSA NPs show slow and sustained in vitro release. The CAT-BSA NPs and ECAT-BSA NPs were stable in solution at various temperatures 37 °C, 47 °C and 57 °C. DPPH assay revealed that CAT and ECAT maintained their functional activity even after encapsulation on BSA NPs. Furthermore, the efficacy of CAT-BSA NPs and ECAT-BSA NPs determined against A549 cell lines was found to be improved. CAT and ECAT aptly encapsulated in BSA NPs, showed satisfactory sustained release, maintained antioxidant potential and found improved efficacy. This has thus suggested their more effective use in food and nutraceuticals as well as in medical field.

  5. Electroporation of micro-droplet encapsulated HeLa cells in oil phase

    KAUST Repository

    Xiao, Kang

    2010-08-27

    Electroporation (EP) is a method widely used to introduce foreign genes, drugs or dyes into cells by permeabilizing the plasma membrane with an external electric field. A variety of microfluidic EP devices have been reported so far. However, further integration of prior and posterior EP processes turns out to be very complicated, mainly due to the difficulty of developing an efficient method for precise manipulation of cells in microfluidics. In this study, by means of a T-junction structure within a delicate microfluidic device, we encapsulated HeLa cells in micro-droplet of poration medium in oil phase before EP, which has two advantages: (i) precise control of cell-encapsulating droplets in oil phase is much easier than the control of cell populations or individuals in aqueous buffers; (ii) this can minimize the electrochemical reactions on the electrodes. Finally, we successfully introduced fluorescent dyes into the micro-droplet encapsulated HeLa cells in oil phase. Our results reflected a novel way to realize the integrated biomicrofluidic system for EP. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

  6. Patterned three-dimensional encapsulation of embryonic stem cells using dielectrophoresis and stereolithography.

    Science.gov (United States)

    Bajaj, Piyush; Marchwiany, Daniel; Duarte, Carlos; Bashir, Rashid

    2013-03-01

    Controlling the assembly of cells in three dimensions is very important for engineering functional tissues, drug screening, probing cell-cell/cell-matrix interactions, and studying the emergent behavior of cellular systems. Although the current methods of cell encapsulation in hydrogels can distribute them in three dimensions, these methods typically lack spatial control of multi-cellular organization and do not allow for the possibility of cell-cell contacts as seen for the native tissue. Here, we report the integration of dielectrophoresis (DEP) with stereolithography (SL) apparatus for the spatial patterning of cells on custom made gold micro-electrodes. Afterwards, they are encapsulated in poly (ethylene glycol) diacrylate (PEGDA) hydrogels of different stiffnesses. This technique can mimic the in vivo microscale tissue architecture, where the cells have a high degree of three dimensional (3D) spatial control. As a proof of concept, we show the patterning and encapsulation of mouse embryonic stem cells (mESCs) and C2C12 skeletal muscle myoblasts. mESCs show high viability in both the DEP (91.79% ± 1.4%) and the no DEP (94.27% ± 0.5%) hydrogel samples. Furthermore, we also show the patterning of mouse embryoid bodies (mEBs) and C2C12 spheroids in the hydrogels, and verify their viability. This robust and flexible in vitro platform can enable various applications in stem cell differentiation and tissue engineering by mimicking elements of the native 3D in vivo cellular micro-environment.

  7. Preparation and Characterization of SN-38-Encapsulated Phytantriol Cubosomes Containing α-Monoglyceride Additives.

    Science.gov (United States)

    Ali, Md Ashraf; Noguchi, Shuji; Iwao, Yasunori; Oka, Toshihiko; Itai, Shigeru

    2016-01-01

    SN-38 is a potent active metabolite of irinotecan that has been considered as an anticancer candidate. However, the clinical development of this compound has been hampered by its poor aqueous solubility and chemical instability. In this study, we developed SN-38-encapsulated cubosomes to resolve these problems. Six α-monoglyceride additives, comprising monocaprylin, monocaprin, monolaurin, monomyristin, monopalmitin, and monostearin, were used to prepare phytantriol (PHYT) cubosomes by probe sonication. The mean particle size, polydispersity index, and zeta potential values of these systems were around 190-230 nm, 0.19-0.25 and -17 to -22 mV, respectively. Small-angle X-ray scattering analyses confirmed that the SN-38-encapsulated cubosomes existed in the Pn̄3m space group both with and without the additives. The monoglyceride additives led to around a two-fold increase in the solubility of SN-38 compared with the PHYT cubosome. The drug entrapment efficiency of PHYT cubosomes with additives was greater than 97%. The results of a stability study at 25°C showed no dramatic changes in the particle size or polydispersity index characteristics, with at least 85% of the SN-38 existing in its active lactone form after 10 d, demonstrating the high stability of the cubosome nanoparticles. Furthermore, approximately 55% of SN-38 was slowly released from the cubosomes with additives over 96 h in vitro under physiological conditions. Taken together, these results show that the SN-38-encapsulated PHYT cubosome particles are promising drug carriers that should be considered for further in vivo experiments, including drug delivery to tumor cells using the enhanced permeability and retention effect.

  8. Drug: D03789 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D03789 Drug Dichlorodifluoromethane (NF) CCl2F2 119.9345 120.9135 D03789.gif Pharmaceutic aid [aerosol prope...llant] CAS: 75-71-8 PubChem: 17397877 LigandBox: D03789 NIKKAJI: J1.462A ATOM 5 1 X

  9. Drug: D06220 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D06220 Drug Trichloromonofluoromethane (NF); Freon 11 (TN) CCl3F 135.905 137.3681 D06220....gif Pharmaceutic aid [aerosol propellant] CAS: 75-69-4 PubChem: 47207878 LigandBox: D06220 NIKKAJI: J1

  10. Influence of the Encapsulation Efficiency and Size of Liposome on the Oral Bioavailability of Griseofulvin-Loaded Liposomes

    Science.gov (United States)

    Ong, Sandy Gim Ming; Ming, Long Chiau; Lee, Kah Seng; Yuen, Kah Hay

    2016-01-01

    The objective of the present study was to investigate the influence of the encapsulation efficiency and size of liposome on the oral bioavailability of griseofulvin-loaded liposomes. Griseofulvin-loaded liposomes with desired characteristics were prepared from pro-liposome using various techniques. To study the effect of encapsulation efficiency, three preparations of griseofulvin, namely, griseofulvin aqueous suspension and two griseofulvin-loaded liposomes with different amounts of griseofulvin encapsulated [i.e., F1 (32%) and F2(98%)], were administered to rats. On the other hand, to study the effect of liposome size, the rats were given three different griseofulvin-loaded liposomes of various sizes, generated via different mechanical dispersion techniques [i.e., FTS (142 nm), MS (357 nm) and NS (813 nm)], but with essentially similar encapsulation efficiencies (about 93%). Results indicated that the extent of bioavailability of griseofulvin was improved 1.7–2.0 times when given in the form of liposomes (F1) compared to griseofulvin suspension. Besides that, there was an approximately two-fold enhancement of the extent of bioavailability following administration of griseofulvin-loaded liposomes with higher encapsulation efficiency (F2), compared to those of F1. Also, the results showed that the extent of bioavailability of liposomal formulations with smaller sizes were higher by approximately three times compared to liposomal formulation of a larger size. Nevertheless, a further size reduction of griseofulvin-loaded liposome (≤400 nm) did not promote the uptake or bioavailability of griseofulvin. In conclusion, high drug encapsulation efficiency and small liposome size could enhance the oral bioavailability of griseofulvin-loaded liposomes and therefore these two parameters deserve careful consideration during formulation. PMID:27571096

  11. Influence of the Encapsulation Efficiency and Size of Liposome on the Oral Bioavailability of Griseofulvin-Loaded Liposomes

    Directory of Open Access Journals (Sweden)

    Sandy Gim Ming Ong

    2016-08-01

    Full Text Available The objective of the present study was to investigate the influence of the encapsulation efficiency and size of liposome on the oral bioavailability of griseofulvin-loaded liposomes. Griseofulvin-loaded liposomes with desired characteristics were prepared from pro-liposome using various techniques. To study the effect of encapsulation efficiency, three preparations of griseofulvin, namely, griseofulvin aqueous suspension and two griseofulvin-loaded liposomes with different amounts of griseofulvin encapsulated [i.e., F1 (32% and F2(98%], were administered to rats. On the other hand, to study the effect of liposome size, the rats were given three different griseofulvin-loaded liposomes of various sizes, generated via different mechanical dispersion techniques [i.e., FTS (142 nm, MS (357 nm and NS (813 nm], but with essentially similar encapsulation efficiencies (about 93%. Results indicated that the extent of bioavailability of griseofulvin was improved 1.7–2.0 times when given in the form of liposomes (F1 compared to griseofulvin suspension. Besides that, there was an approximately two-fold enhancement of the extent of bioavailability following administration of griseofulvin-loaded liposomes with higher encapsulation efficiency (F2, compared to those of F1. Also, the results showed that the extent of bioavailability of liposomal formulations with smaller sizes were higher by approximately three times compared to liposomal formulation of a larger size. Nevertheless, a further size reduction of griseofulvin-loaded liposome (≤400 nm did not promote the uptake or bioavailability of griseofulvin. In conclusion, high drug encapsulation efficiency and small liposome size could enhance the oral bioavailability of griseofulvin-loaded liposomes and therefore these two parameters deserve careful consideration during formulation.

  12. One-Step Generation of Cell-Encapsulating Compartments via Polyelectrolyte Complexation in an Aqueous Two Phase System.

    Science.gov (United States)

    Hann, Sarah D; Niepa, Tagbo H R; Stebe, Kathleen J; Lee, Daeyeon

    2016-09-28

    Diverse fields including drug and gene delivery and live cell encapsulation require biologically compatible encapsulation systems. One widely adopted means of forming capsules exploits cargo-filled microdroplets in an external, immiscible liquid phase that are encapsulated by a membrane that forms by trapping of molecules or particles at the drop surface, facilitated by the interfacial tension. To eliminate the potentially deleterious oil phase often present in such processes, we exploit the aqueous two phase system of poly(ethylene glycol) (PEG) and dextran. We form capsules by placing dextran-rich microdroplets in an external PEG-rich phase. Strong polyelectrolytes present in either phase form complexes at the drop interface, thereby forming a membrane encapsulating the fluid interior. This process requires considerable finesse as both polyelectrolytes are soluble in either the drop or external phase, and the extremely low interfacial tension is too weak to provide a strong adsorption site for these molecules. The key to obtaining microcapsules is to tune the relative fluxes of the two polyelectrolytes so that they meet and complex at the interface. We identify conditions for which complexation can occur inside or outside of the drop phase, resulting in microparticles or poor encapsulation, respectively, or when properly balanced, at the interface, resulting in microcapsules. The resulting microcapsules respond to the stimuli of added salts or changes in osmotic pressure, allowing perturbation of capsule permeability or triggered release of capsule contents. We demonstrate that living cells can be sequestered and interrogated by encapsulating Pseudomonas aeruginosa PAO1 and using a Live/Dead assay to assess their viability. This method paves the way to the formation of a broad variety of versatile functional membranes around all aqueous capsules; by tuning the fluxes of complexing species to interact at the interface, membranes comprising other complexing

  13. Co-encapsulating nanostructured lipid carriers for transdermal application: from experimental design to the molecular detail.

    Science.gov (United States)

    Vitorino, C; Almeida, J; Gonçalves, L M; Almeida, A J; Sousa, J J; Pais, A A C C

    2013-05-10

    Co-encapsulation of drugs directed at commonly associated diseases provides a convenient means for administration, especially if transdermally delivered. In this work, a comprehensive study for the co-encapsulation of drugs with a differential lipophilicity, olanzapine and simvastatin, and their transdermal delivery in a formulation containing nanostructured lipid carriers (NLC) is presented. Focus is given to the evaluation of a strategy in which NLC and chemical permeation enhancers are combined. It comprises in vitro, in silico and cellular viability approaches. The optimization and rationalization of the systems are carried out using a two-step factorial design. It is shown that the external medium in the NLC dispersion strongly influences permeation. It is also seen that the use of NLC determines a synergistic effect with selected permeation enhancers, thus promoting marked flux enhancement ratios (48 and 21, respectively for olanzapine and simvastatin) relative to the drugs in solution. The developed formulations can be considered non-irritant. A correlation between enhancer positioning in a lipid bilayer, partially governed by a H-bonding phenomenon, and enhancement effect is suggested from molecular dynamics studies and experimental observations.

  14. Aerosol dynamics in porous media

    NARCIS (Netherlands)

    Ghazaryan, Lilya

    2014-01-01

    In this thesis, a computational model was developed for the simulation of aerosol formation through nucleation, followed by condensation and evaporation and filtration by porous material. Understanding aerosol dynamics in porous media can help improving engineering models that are used in various in

  15. Encapsulating Urban Traffic Rhythms into Road Networks

    Science.gov (United States)

    Wang, Junjie; Wei, Dong; He, Kun; Gong, Hang; Wang, Pu

    2014-02-01

    Using road GIS (geographical information systems) data and travel demand data for two U.S. urban areas, the dynamical driver sources of each road segment were located. A method to target road clusters closely related to urban traffic congestion was then developed to improve road network efficiency. The targeted road clusters show different spatial distributions at different times of a day, indicating that our method can encapsulate dynamical travel demand information into the road networks. As a proof of concept, when we lowered the speed limit or increased the capacity of road segments in the targeted road clusters, we found that both the number of congested roads and extra travel time were effectively reduced. In addition, the proposed modeling framework provided new insights on the optimization of transport efficiency in any infrastructure network with a specific supply and demand distribution.

  16. Encapsulated liquid sorbents for carbon dioxide capture.

    Science.gov (United States)

    Vericella, John J; Baker, Sarah E; Stolaroff, Joshuah K; Duoss, Eric B; Hardin, James O; Lewicki, James; Glogowski, Elizabeth; Floyd, William C; Valdez, Carlos A; Smith, William L; Satcher, Joe H; Bourcier, William L; Spadaccini, Christopher M; Lewis, Jennifer A; Aines, Roger D

    2015-02-05

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

  17. Encapsulated magnetite particles for biomedical application

    CERN Document Server

    Landfester, K

    2003-01-01

    The process of miniemulsification allows the generation of small, homogeneous, and stable droplets containing monomer or polymer precursors and magnetite which are then transferred by polymer reactions to the final polymer latexes, keeping their particular identity without serious exchange kinetics involved. It is shown that the miniemulsion process can excellently be used for the formulation of polymer-coated magnetic nanoparticles which can further be used for biomedical applications. The use of high shear, appropriate surfactants, and the addition of a hydrophobe in order to suppress the influence of Ostwald ripening are key factors for the formation of the small and stable droplets in miniemulsion and will be discussed. Two different approaches based on miniemulsion processes for the encapsulation of magnetite into polymer particles will be presented in detail.

  18. Preparation and Characterization of Biodegradable Polylactide(PLA) Microspheres Encapsulating Ginsenoside Rg3

    Institute of Scientific and Technical Information of China (English)

    LIU Cheng-bai; ZHANG Di; LI De-guan; JIANG Dan; CHEN Xia

    2008-01-01

    In this study,the process of a biodegradable polylactide(PLA) microsphere encapsulating ginsenoside Rg3 was first studied by the emulsion solvent evaporation method,for enhancing solubility and stability of ginsenoside Rg3.Alabum was also first used as a modifier in this method.The mean diameter of the prepared PLA microspheres containing Rg3 was 40 μm.Ginsenoside Rg3 released from the microspheres was studied by HPLC and detected by UV.It was found that the drug release curve fitted the Model Heller-Baker best.

  19. Cellular trafficking and anticancer activity of Garcinia mangostana extract-encapsulated polymeric nanoparticles

    Directory of Open Access Journals (Sweden)

    Pan-In P

    2014-08-01

    Full Text Available Porntip Pan-In,1,2 Supason Wanichwecharungruang,3,4 Justin Hanes,2,5 Anthony J Kim2,6,7 1Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand; 2Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; 3Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand; 4Nanotec-CU Center of Excellence on Food and Agriculture, Bangkok, Thailand; 5Department of Ophthalmology, Biomedical Engineering, Chemical and Biomolecular Engineering, Neurosurgery, and Oncology, Johns Hopkins University School of Medicine, 6Department of Neurosurgery, University of Maryland School of Medicine, 7Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, USA Abstract: Garcinia mangostana Linn extract (GME is a natural product that has received considerable attention in cancer therapy, and has the potential to reduce side effects of chemotherapeutics and improve efficacy. We formulated GME-encapsulated ethyl cellulose (GME-EC and a polymer blend of ethyl cellulose and methyl cellulose (GME-EC/MC nanoparticles. We achieved high drug-loading and encapsulation efficiency using a solvent-displacement method with particle sizes around 250 nm. Cellular uptake and accumulation of GME was higher for GME-encapsulated nanoparticles compared to free GME. In vitro cytotoxicity analysis showed effective anticancer activity of GME-EC and GME-EC/MC nanoparticles in HeLa cells in a dose-dependent manner. GME-EC/MC nanoparticles showed approximately twofold-higher anticancer activity compared to GME-EC nanoparticles, likely due to their enhanced bioavailability. GME-encapsulated nanoparticles primarily entered HeLa cells by clathrin-mediated endocytosis and trafficked through the endolysosomal pathway. As far as we know, this is the first report on the cellular uptake and intracellular trafficking mechanism of drug-loaded cellulose-based nanoparticles

  20. Charge effect of a liposomal delivery system encapsulating simvastatin to treat experimental ischemic stroke in rats

    Directory of Open Access Journals (Sweden)

    Campos-Martorell M

    2016-06-01

    were able to reach the brain and accumulate specifically in the infarcted area. Moreover, neutral liposomes exhibited higher bioavailability in plasma 4 hours after being administered. The detection of simvastatin by ultra-high-protein liquid chromatography confirmed its ability to cross the blood–brain barrier, when administered either as a free drug or encapsulated into liposomes. Conclusion: This study confirms that liposome charge is critical to promote its accumulation in the brain infarct after MCAOt. Furthermore, simvastatin can be delivered after being encapsulated. Thus, simvastatin encapsulation might be a promising strategy to ensure that the drug reaches the brain, while increasing its bioavailability and reducing possible side effects. Keywords: simvastatin, liposomes, delivery, brain, stroke, rat

  1. Nanoparticles containing ketoprofen and acrylic polymers prepared by an aerosol flow reactor method.

    Science.gov (United States)

    Eerikäinen, Hannele; Peltonen, Leena; Raula, Janne; Hirvonen, Jouni; Kauppinen, Esko I

    2004-09-23

    The purpose of this study was to outline the effects of interactions between a model drug and various acrylic polymers on the physical properties of nanoparticles prepared by an aerosol flow reactor method. The amount of model drug, ketoprofen, in the nanoparticles was varied, and the nanoparticles were analyzed for particle size distribution, particle morphology, thermal properties, IR spectroscopy, and drug release. The nanoparticles produced were spherical, amorphous, and had a matrix-type structure. Ketoprofen crystallization was observed when the amount of drug in Eudragit L nanoparticles was more than 33% (wt/wt). For Eudragit E and Eudragit RS nanoparticles, the drug acted as an effective plasticizer resulting in lowering of the glass transition of the polymer. Two factors affected the preparation of nanoparticles by the aerosol flow reactor method, namely, the solubility of the drug in the polymer matrix and the thermal properties of the resulting drug-polymer matrix.

  2. Improved Hepatoprotective Effect of Liposome-Encapsulated Astaxanthin in Lipopolysaccharide-Induced Acute Hepatotoxicity.

    Science.gov (United States)

    Chiu, Chun-Hung; Chang, Chun-Chao; Lin, Shiang-Ting; Chyau, Charng-Cherng; Peng, Robert Y

    2016-07-14

    Lipopolysaccharide (LPS)-induced acute hepatotoxicity is significantly associated with oxidative stress. Astaxanthin (AST), a xanthophyll carotenoid, is well known for its potent antioxidant capacity. However, its drawbacks of poor aqueous solubility and low bioavailability have limited its utility. Liposome encapsulation is considered as an effective alternative use for the improvement of bioavailability of the hydrophobic compound. We hypothesized that AST encapsulated within liposomes (LA) apparently shows improved stability and transportability compared to that of free AST. To investigate whether LA administration can efficiently prevent the LPS-induced acute hepatotoxicity, male Sprague-Dawley rats (n = six per group) were orally administered liposome-encapsulated AST at 2, 5 or 10 mg/kg-day (LA-2, LA-5, and LA-10) for seven days and then were LPS-challenged (i.p., 5 mg/kg). The LA-10 administered group, but not the other groups, exhibited a significant amelioration of serum glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), blood urea nitrogen (BUN), creatinine (CRE), hepatic malondialdehyde (MDA) and glutathione peroxidase (GSH-Px), IL-6, and hepatic nuclear NF-κB and inducible nitric oxide synthase (iNOS), suggesting that LA at a 10 mg/kg-day dosage renders hepatoprotective effects. Moreover, the protective effects were even superior to that of positive control N-acetylcysteine (NAC, 200 mg/kg-day). Histopathologically, NAC, free AST, LA-2 and LA-5 partially, but LA-10 completely, alleviated the acute inflammatory status. These results indicate that hydrophobic AST after being properly encapsulated by liposomes improves bioavailability and can also function as potential drug delivery system in treating hepatotoxicity.

  3. Improved Hepatoprotective Effect of Liposome-Encapsulated Astaxanthin in Lipopolysaccharide-Induced Acute Hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Chun-Hung Chiu

    2016-07-01

    Full Text Available Lipopolysaccharide (LPS-induced acute hepatotoxicity is significantly associated with oxidative stress. Astaxanthin (AST, a xanthophyll carotenoid, is well known for its potent antioxidant capacity. However, its drawbacks of poor aqueous solubility and low bioavailability have limited its utility. Liposome encapsulation is considered as an effective alternative use for the improvement of bioavailability of the hydrophobic compound. We hypothesized that AST encapsulated within liposomes (LA apparently shows improved stability and transportability compared to that of free AST. To investigate whether LA administration can efficiently prevent the LPS-induced acute hepatotoxicity, male Sprague-Dawley rats (n = six per group were orally administered liposome-encapsulated AST at 2, 5 or 10 mg/kg-day (LA-2, LA-5, and LA-10 for seven days and then were LPS-challenged (i.p., 5 mg/kg. The LA-10 administered group, but not the other groups, exhibited a significant amelioration of serum glutamic pyruvic transaminase (GPT, glutamic oxaloacetic transaminase (GOT, blood urea nitrogen (BUN, creatinine (CRE, hepatic malondialdehyde (MDA and glutathione peroxidase (GSH-Px, IL-6, and hepatic nuclear NF-κB and inducible nitric oxide synthase (iNOS, suggesting that LA at a 10 mg/kg-day dosage renders hepatoprotective effects. Moreover, the protective effects were even superior to that of positive control N-acetylcysteine (NAC, 200 mg/kg-day. Histopathologically, NAC, free AST, LA-2 and LA-5 partially, but LA-10 completely, alleviated the acute inflammatory status. These results indicate that hydrophobic AST after being properly encapsulated by liposomes improves bioavailability and can also function as potential drug delivery system in treating hepatotoxicity.

  4. Drug delivery goes supercritical

    Directory of Open Access Journals (Sweden)

    Patrick J. Ginty

    2005-08-01

    Full Text Available In the field of drug delivery, the ability to control the size, morphology, and release of drug particles is fundamental to good targeting, but is often hampered by harsh processing conditions or inadequate methods; likewise for the processing of polymeric controlled-release systems. However, the use of supercritical fluids such as supercritical CO2 (scCO2 has provided a ‘clean’ and effective alternative to traditional methods of drug and polymer processing. In particular, scCO2 has a number of unique properties that make it possible to process both bioactive molecules and amorphous polymers without using toxic organic solvents or elevated temperatures. Here, we review the positive impact that supercritical fluids have had on the micronization, encapsulation, and impregnation of molecules of interest to both the pharmaceutical and biotechnology industries.

  5. Aerosols indirectly warm the Arctic

    Directory of Open Access Journals (Sweden)

    T. Mauritsen

    2010-07-01

    Full Text Available On average, airborne aerosol particles cool the Earth's surface directly by absorbing and scattering sunlight and indirectly by influencing cloud reflectivity, life time, thickness or extent. Here we show that over the central Arctic Ocean, where there is frequently a lack of aerosol particles upon which clouds may form, a small increase in aerosol loading may enhance cloudiness thereby likely causing a climatologically significant warming at the ice-covered Arctic surface. Under these low concentration conditions cloud droplets grow to drizzle sizes and fall, even in the absence of collisions and coalescence, thereby diminishing cloud water. Evidence from a case study suggests that interactions between aerosol, clouds and precipitation could be responsible for attaining the observed low aerosol concentrations.

  6. An Indigenously Developed Insecticidal Aerosol

    Directory of Open Access Journals (Sweden)

    R. N. Varma

    1969-10-01

    Full Text Available A total of 6 "Test" insecticidal aerosols (TA-I to VI indigenously produced were tested during the years 1966-67 as suitable replacements for imported aerosols.TA-I produced deep yellow staining and a yellowish spray mist. Its capacity was only 120 ml fluid. TA-III types II and III containing modified aerosol formulation with "Esso solvent 3245" and mineral turpentine oil (Burmah Shelland Freon 12 11 (all indigenouswere comparable to he "SRA" in insecticidial efficacy. The container was also manufactured in the country and it compared well with the "SRA" in construction, resistance against rough usage and mechanical function. They were both finally approved for introduction in the services as replacement for imported aerosols. TA-IV performed well in inscticidial assessment, but the aerosols formulation. TA-V and VI were similar to TA-III types II and III respectively.

  7. Magnetic targeted drug delivery

    Directory of Open Access Journals (Sweden)

    Timothy Wiedmann

    2009-10-01

    Full Text Available Lung cancer is the most common cause of death from cancer in both men and women. Treatment by intravenous or oral administration of chemotherapy agents results in serious and often treatment-limiting side effects. Delivery of drugs directly to the lung by inhalation of an aerosol holds the promise of achieving a higher concentration in the lung with lower blood levels. To further enhance the selective lung deposition, it may be possible to target deposition by using external magnetic fields to direct the delivery of drug coupled to magnetic particles. Moreover, alternating magnetic fields can be used to induce particle heating, which in turn controls the drug release rate with the appropriate thermal sensitive material.With this goal, superparamagetic nanoparticles (SPNP were prepared and characterized, and enhanced magnetic deposition was demonstrated in vitro and in vivo. SPNPs were also incorporated into a lipid-based/SPNP aerosol formulation, and drug release was shown to be controlled by thermal activation. Because of the inherent imaging potential of SPNPs, this use of nanotechnology offers the possibility of coupling the diagnosis of lung cancer to drug release, which perhaps will ultimately provide the “magic bullet” that Paul Ehrlich originally sought.

  8. Combined treatment of tyrosine kinase inhibitor labeled gold nanorod encapsulated albumin with laser thermal ablation in a renal cell carcinoma model

    Science.gov (United States)

    This manuscript served to characterize and evaluate Human Serum Albumin-encapsulated Nanoparticles (NPs) for drug delivery of a tyrosine kinase inhibitor combined with induction of photothermal ablation (PTA) combination therapy of Renal Cell Carcinoma (RCC). RCC is the most common type of kidney c...

  9. Encapsulation of Liquids Via Extrusion--A Review.

    Science.gov (United States)

    Tackenberg, Markus W; Kleinebudde, Peter

    2015-01-01

    Various encapsulation techniques are known for pharmaceutical applications. Extrusion is of minor importance. However, extrusion is used to obtain granules with encapsulate liquid active ingredients (AI) like essential oils and flavours for food applications since decades. Many of these AIs can be used for agrochemical, home care, and pharmaceutical products, too. Thus, the focus of this review is on the interdisciplinary presentation and evaluation of the available knowledge about the encapsulation process via extrusion. The desired microcapsule structure is discussed at the outset. The microcapsule is compared to the alternative glassy solid solution system, before an overview of suitable excipients is given. In the next section the development of the extrusion technique, used for encapsulation processes, is presented. Thereby, the focus is on encapsulation using twin-screw extruders. Additionally, the influence of the downstream processes on the products is discussed, too. The understanding of the physical processes during extrusion is essential for specifically adjustment of the desired product properties and thus, highlighted in this paper. Unfortunately not all processes, especially the mixing process, are well studied. Suggestions for further studies, to improve process understanding and product quality, are given, too. The last part of this review focuses on the characterization of the obtained granules, especially AI content, encapsulation efficiency, and storage stability. In conclusion, extrusion is a standard technique for flavour encapsulation, but future studies, may lead to more (pharmaceutical) applications and new products.

  10. Mechanical modeling of stress generation during cure of encapsulating resins

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, R.R.; Chambers, R.S.; Guess, T.R. (Sandia National Labs., Albuquerque, NM (USA)); Plazek, D.J.; Bero, C. (Pittsburgh Univ., PA (USA). Dept. of Materials Science and Engineering)

    1991-01-01

    We have developed a numerical model for calculating stresses generated during cure of shrinking encapsulating resins. Mechanical modeling of polymer encapsulated electronic devices usually focuses on stress generated during cooling after cure. The stress developed during cure, due to shrinkage of the encapsulant, is normally neglected. That assumption is valid if both the shear and bulk moduli of the encapsulant at the cure temperature are negligible with respect to the moduli at lower temperatures. Our measurements on a model epoxy encapsulant show that the shear modulus during cure, varying from 0 to 6 MPa, is at least 100 times smaller than that at ambient temperature. In contrast, the bulk modulus at the cure temperature is only 2.5 times smaller. Since the bulk modulus during cure cannot be neglected, significant stress can be produced if volume shrinkage is constrained by a stiff mold or embedded elements. In fact, mechanical failure of encapsulating materials during cure has been evident in some of our experiments. Using measurements of shear and bulk moduli plus volume shrinkage as inputs to a finite element model, we have successfully predicted the shrinkage strains and stresses developed during cure of a model epoxy resin inside a cylindrical tube. Consideration of cure shrinkage stress has led to a process modification that appears to reduce mechanical failures in a real encapsulated device. 6 refs., 6 figs.

  11. Atmospheric and aerosol chemistry

    Energy Technology Data Exchange (ETDEWEB)

    McNeill, V. Faye [Columbia Univ., New York, NY (United States). Dept. of Chemical Engineering; Ariya, Parisa A. (ed.) [McGill Univ. Montreal, QC (Canada). Dept. of Chemistry; McGill Univ. Montreal, QC (Canada). Dept. of Atmospheric and Oceanic Sciences

    2014-09-01

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  12. International Cooperative for Aerosol Prediction Workshop on Aerosol Forecast Verification

    Science.gov (United States)

    Benedetti, Angela; Reid, Jeffrey S.; Colarco, Peter R.

    2011-01-01

    The purpose of this workshop was to reinforce the working partnership between centers who are actively involved in global aerosol forecasting, and to discuss issues related to forecast verification. Participants included representatives from operational centers with global aerosol forecasting requirements, a panel of experts on Numerical Weather Prediction and Air Quality forecast verification, data providers, and several observers from the research community. The presentations centered on a review of current NWP and AQ practices with subsequent discussion focused on the challenges in defining appropriate verification measures for the next generation of aerosol forecast systems.

  13. Tracking Hypoxic Signaling within Encapsulated Cell Aggregates

    Science.gov (United States)

    Skiles, Matthew L.; Sahai, Suchit; Blanchette, James O.

    2011-01-01

    In Diabetes mellitus type 1, autoimmune destruction of the pancreatic β-cells results in loss of insulin production and potentially lethal hyperglycemia. As an alternative treatment option to exogenous insulin injection, transplantation of functional pancreatic tissue has been explored1,2. This approach offers the promise of a more natural, long-term restoration of normoglycemia. Protection of the donor tissue from the host's immune system is required to prevent rejection and encapsulation is a method used to help achieve this aim. Biologically-derived materials, such as alginate3 and agarose4, have been the traditional choice for capsule construction but may induce inflammation or fibrotic overgrowth5 which can impede nutrient and oxygen transport. Alternatively, synthetic poly(ethylene glycol) (PEG)-based hydrogels are non-degrading, easily functionalized, available at high purity, have controllable pore size, and are extremely biocompatible,6,7,8. As an additional benefit, PEG hydrogels may be formed rapidly in a simple photo-crosslinking reaction that does not require application of non-physiological temperatures6,7. Such a procedure is described here. In the crosslinking reaction, UV degradation of the photoinitiator, 1-[4-(2-Hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (Irgacure 2959), produces free radicals which attack the vinyl carbon-carbon double bonds of dimethacrylated PEG (PEGDM) inducing crosslinking at the chain ends. Crosslinking can be achieved within 10 minutes. PEG hydrogels constructed in such a manner have been shown to favorably support cells7,9, and the low photoinitiator concentration and brief exposure to UV irradiation is not detrimental to viability and function of the encapsulated tissue10. While we methacrylate our PEG with the method described below, PEGDM can also be directly purchased from vendors such as Sigma. An inherent consequence of encapsulation is isolation of the cells from a vascular network. Supply of

  14. Tracking hypoxic signaling within encapsulated cell aggregates.

    Science.gov (United States)

    Skiles, Matthew L; Sahai, Suchit; Blanchette, James O

    2011-12-16

    In Diabetes mellitus type 1, autoimmune destruction of the pancreatic β-cells results in loss of insulin production and potentially lethal hyperglycemia. As an alternative treatment option to exogenous insulin injection, transplantation of functional pancreatic tissue has been explored. This approach offers the promise of a more natural, long-term restoration of normoglycemia. Protection of the donor tissue from the host's immune system is required to prevent rejection and encapsulation is a method used to help achieve this aim. Biologically-derived materials, such as alginate and agarose, have been the traditional choice for capsule construction but may induce inflammation or fibrotic overgrowth which can impede nutrient and oxygen transport. Alternatively, synthetic poly(ethylene glycol) (PEG)-based hydrogels are non-degrading, easily functionalized, available at high purity, have controllable pore size, and are extremely biocompatible. As an additional benefit, PEG hydrogels may be formed rapidly in a simple photo-crosslinking reaction that does not require application of non-physiological temperatures. Such a procedure is described here. In the crosslinking reaction, UV degradation of the photoinitiator, 1-[4-(2-Hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (Irgacure 2959), produces free radicals which attack the vinyl carbon-carbon double bonds of dimethacrylated PEG (PEGDM) inducing crosslinking at the chain ends. Crosslinking can be achieved within 10 minutes. PEG hydrogels constructed in such a manner have been shown to favorably support cells, and the low photoinitiator concentration and brief exposure to UV irradiation is not detrimental to viability and function of the encapsulated tissue. While we methacrylate our PEG with the method described below, PEGDM can also be directly purchased from vendors such as Sigma. An inherent consequence of encapsulation is isolation of the cells from a vascular network. Supply of nutrients, notably oxygen

  15. Microbubbles for Molecular Imaging and Drug Delivery

    NARCIS (Netherlands)

    I. Skachkov (Ilya)

    2016-01-01

    markdownabstractIn my thesis, microbubbles (MBs) for ultrasound (US) imaging, ultrasound molecular imaging, and drug delivery were studied. Microbubbles are gas-encapsulated lipid or polymer shell coated micro-particles, widely used as ultrasound contrast agents (UCA). MBs oscillate in response to t

  16. Probiotic Encapsulation Technology: From Microencapsulation to Release into the Gut

    Directory of Open Access Journals (Sweden)

    Gildas K. Gbassi

    2012-02-01

    Full Text Available Probiotic encapsulation technology (PET has the potential to protect microorgansisms and to deliver them into the gut. Because of the promising preclinical and clinical results, probiotics have been incorporated into a range of products. However, there are still many challenges to overcome with respect to the microencapsulation process and the conditions prevailing in the gut. This paper reviews the methodological approach of probiotics encapsulation including biomaterials selection, choice of appropriate technology, in vitro release studies of encapsulated probiotics, and highlights the challenges to be overcome in this area.

  17. Characterization of encapsulant materials for photovoltaic solar energy conversion

    Science.gov (United States)

    Agroui, K.; Koll, B.; Collins, G.; Salama, M.; Hadj Arab, A.; Belghachi, A.; Doulache, N.; Khemici, M. W.

    2008-08-01

    The polyvinyl butyral (PVB) encapsulant material is being evaluated as a candidate for use in photovoltaic solar cells encapsulation process due to high stability against UV radiation and the high adhesive force to glass. This material is used for a long time in automotive technology, building integrated vitrification and security glazing. The long experience in this sector can direct be carried over to the photovoltaic industry. The purpose of this experimental investigation is to better understand the electrical properties and thermal stability of PVB based encapsulant material and their dependence on temperature will be presented. An overview of some main electrical and thermal properties of PVB is compared to EVA.

  18. The GRAPE aerosol retrieval algorithm

    Directory of Open Access Journals (Sweden)

    G. E. Thomas

    2009-11-01

    Full Text Available The aerosol component of the Oxford-Rutherford Aerosol and Cloud (ORAC combined cloud and aerosol retrieval scheme is described and the theoretical performance of the algorithm is analysed. ORAC is an optimal estimation retrieval scheme for deriving cloud and aerosol properties from measurements made by imaging satellite radiometers and, when applied to cloud free radiances, provides estimates of aerosol optical depth at a wavelength of 550 nm, aerosol effective radius and surface reflectance at 550 nm. The aerosol retrieval component of ORAC has several incarnations – this paper addresses the version which operates in conjunction with the cloud retrieval component of ORAC (described by Watts et al., 1998, as applied in producing the Global Retrieval of ATSR Cloud Parameters and Evaluation (GRAPE data-set.

    The algorithm is described in detail and its performance examined. This includes a discussion of errors resulting from the formulation of the forward model, sensitivity of the retrieval to the measurements and a priori constraints, and errors resulting from assumptions made about the atmospheric/surface state.

  19. Inhalation delivery of asthma drugs.

    Science.gov (United States)

    Matthys, H

    1990-01-01

    In the immediate future, metered-dose inhalers (MDIs) with spacers remain the aerosol application of choice for topical steroids, mainly to reduce side effects. For beta 2-agonist, anticholinergics and prophylactic drugs, MDI (with or without demand valve), dry powder inhalers (multidose inhalers), ultrasonic or jet aerosol generators (with or without mechanical breathing assistance [IPPB]) are chosen according to the preference or the ability of the patients to perform the necessary breathing maneuvers as well as the availability of different products in different countries.

  20. Development of polyherbal antidiabetic formulation encapsulated in the phospholipids vesicle system

    Directory of Open Access Journals (Sweden)

    Vinod Kumar Gauttam

    2013-01-01

    Full Text Available Multifactorial metabolic diseases, for instance diabetes develop several complications like hyperlipidemia, hepatic toxicity, immunodeficiency etc., Hence, instead of mono-drug therapy the management of the disease requires the combination of herbs. Marketed herbal drugs comprise of irrational combinations, which makes their quality control more difficult. Phytoconstituents, despite having excellent bioactivity in vitro demonstrate less or no in vivo actions due to their poor lipid solubility, resulting in high therapeutic dose regimen; phospholipids encapsulation can overcome this problem. Hence, present study was designed to develop a phospholipids encapsulated polyherbal anti-diabetic formulation. In the present study, polyherbal formulation comprises of lyophilized hydro-alcoholic (50% v/v extracts of Momordica charantia, Trigonella foenum-graecum and Withania somnifera 2:2:1, respectively, named HA, optimized based on oral glucose tolerance test model in normal Wistar rats. The optimized formulation (HA entrapped in the phosphatidylcholine and cholesterol (8:2 vesicle system is named HA lipids (HAL. The vesicles were characterized for shape, morphology, entrapment efficiency, polar-dispersity index and release profile in the gastric pH. The antidiabetic potential of HA, marketed polyherbal formulation (D-fit and HAL was compared in streptozotocin-induced diabetic rat model of 21 days study. The parameters evaluated were behavioral changes, body weight, serum glucose level, lipid profile and oxidative stress. The antidiabetic potential of HA (1000 mg/kg was at par with the D-fit (1000 mg/kg. However, the potential was enhanced by phospholipids encapsulation; as HAL (500 mg/kg has shown more significant (P < 0.05 potential in comparison to HA (1000 mg/kg and at par with metformin (500 mg/kg.

  1. Pre-clinical evaluation of rHDL encapsulated retinoids for the treatment of Neuroblastoma

    Directory of Open Access Journals (Sweden)

    Nirupama eSabnis

    2013-03-01

    Full Text Available Despite major advances in pediatric cancer research, there has been only modest progress in the survival of children with high risk neuroblastoma (HRNB. The long term survival rates of HRNB in the United States are still only 30-50%. Due to resistance that often develops during therapy, development of new effective strategies is essential to improve the survival and overcome the tendency of HRNB patients to relapse subsequent to initial treatment. Current chemotherapy regimens also have a serious limitation due to off target toxicity. In the present work, we evaluated the potential application of reconstituted high density lipoprotein (rHDL containing fenretinide (FR nanoparticles as a novel approach to current neuroblastoma therapeutics. The characterization and stability studies of rHDL-FR nanoparticles showed small size (<40nm and high encapsulation efficiency. The cytotoxicity studies of free FR vs. rHDL/ FR towards the neuroblastoma cell lines SK-N-SH and SMS-KCNR showed 2.8 and 2 fold lower IC50 values for the rHDL encapsulated FR vs. free FR. More importantly, the IC50 value for retinal pigment epithelial cells (ARPE-19, a recipient of off target toxicity during FR therapy, was over 40 times higher for the rHDL/ FR as compared to that of free FR. The overall improvement in in vitro selective therapeutic efficiency was thus about 100 fold upon encapsulation of the drug into the rHDL nanoparticles. These studies support the potential value of this novel drug delivery platform for treating pediatric cancers in general, and neuroblastoma in particular

  2. eDPS Aerosol Collection

    Energy Technology Data Exchange (ETDEWEB)

    Venzie, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-13

    The eDPS Aerosol Collection project studies the fundamental physics of electrostatic aerosol collection for national security applications. The interpretation of aerosol data requires understanding and correcting for biases introduced from particle genesis through collection and analysis. The research and development undertaken in this project provides the basis for both the statistical correction of existing equipment and techniques; as well as, the development of new collectors and analytical techniques designed to minimize unwanted biases while improving the efficiency of locating and measuring individual particles of interest.

  3. Instrumentation for tropospheric aerosol characterization

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Z.; Young, S.E.; Becker, C.H.; Coggiola, M.J. [SRI International, Menlo Park, CA (United States); Wollnik, H. [Giessen Univ. (Germany)

    1997-12-31

    A new instrument has been developed that determines the abundance, size distribution, and chemical composition of tropospheric and lower stratospheric aerosols with diameters down to 0.2 {mu}m. In addition to aerosol characterization, the instrument also monitors the chemical composition of the ambient gas. More than 25.000 aerosol particle mass spectra were recorded during the NASA-sponsored Subsonic Aircraft: Contrail and Cloud Effects Special Study (SUCCESS) field program using NASA`s DC-8 research aircraft. (author) 7 refs.

  4. Encapsulation de la vitamine E dans des vecteurs pharmaceutiques inhalables préparés par des contacteurs à membrane

    OpenAIRE

    Laouini, Abdallah

    2013-01-01

    The present study investigated the preparation of pharmaceutical drug carriers encapsulating the vitamin E and intended for pulmonary administration after nebulisation. Vitamin E, a physiological antioxidant, could be used to prevent cigarette smoke toxicity since several pulmonary disorders are mainly caused by oxidative stress phenomena. The methods used for the drug carriers’ preparation were based on the membrane emulsification principle. In these methods, the to-be-dispersed phase was in...

  5. Aerosol measurement program strategy for global aerosol backscatter model development

    Science.gov (United States)

    Bowdle, David A.

    1985-01-01

    The purpose was to propose a balanced program of aerosol backscatter research leading to the development of a global model of aerosol backscatter. Such a model is needed for feasibility studies and systems simulation studies for NASA's prospective satellite-based Doppler lidar wind measurement system. Systems of this kind measure the Doppler shift in the backscatter return from small atmospheric aerosol wind tracers (of order 1 micrometer diameter). The accuracy of the derived local wind estimates and the degree of global wind coverage for such a system are limited by the local availability and by the global scale distribution of natural aerosol particles. The discussions here refer primarily to backscatter model requirements at CO2 wavelengths, which have been selected for most of the Doppler lidar systems studies to date. Model requirements for other potential wavelengths would be similar.

  6. Stability studies on piroxicam encapsulated niosomes.

    Science.gov (United States)

    Ertekin, Zehra Ceren; Bayindir, Zerrin Sezgin; Yuksel, Nilufer

    2015-01-01

    Drug delivery systems which yield ideal treatments are currently the center of interest for researchers. Niosomes have numerous advantages over other drug delivery systems. However, stability issue is not clear yet and is a serious drawback for niosomes. In this study, the stability of niosomes was the center of interest. Piroxicam which was chosen as the model drug was loaded to niosomes. Niosomes were prepared by thin-film method and different forms (aqueous dispersion, lyophilized powder and lyophilized powder with cryoprotectant) of the original niosome formulation were prepared. The samples were stored either at 5°C±3°C or 25°C±2°C/60% RH±5% RH for 3 months. The drug leakage percent, particle size and distribution, zeta potential, drug release profiles were determined and niosomes were visualized under optic microscope. Niosome formulation provided sustained release of piroxicam. The drug leakage from stored niosomes was observed at the level of 1.56-6.63 %. Individual vesicle images were obtained for all samples by optical microscope. However, particle size of niosomes was increased upon storage. The zeta potential values were neither related to time nor physical form. Drug release profiles and amounts were quite similar for all forms of niosomes and the original formulation but a slight decrease was noticed on drug release amounts by time. This indicates that niosomes become more rigid by time. Although the ideal storage was obtained with lyophilized niosomes at 5±3°C in this study, the usage of suitable cryoprotectant and optimized lyophilization process should be further evaluated.

  7. Stratospheric aerosol geoengineering

    Science.gov (United States)

    Robock, Alan

    2015-03-01

    The Geoengineering Model Intercomparison Project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, has found that insolation reduction could keep the global average temperature constant, but global average precipitation would reduce, particularly in summer monsoon regions around the world. Temperature changes would also not be uniform; the tropics would cool, but high latitudes would warm, with continuing, but reduced sea ice and ice sheet melting. Temperature extremes would still increase, but not as much as without geoengineering. If geoengineering were halted all at once, there would be rapid temperature and precipitation increases at 5-10 times the rates from gradual global warming. The prospect of geoengineering working may reduce the current drive toward reducing greenhouse gas emissions, and there are concerns about commercial or military control. Because geoengineering cannot safely address climate change, global efforts to reduce greenhouse gas emissions and to adapt are crucial to address anthropogenic global warming.

  8. Aerosol Transmission of Filoviruses

    Directory of Open Access Journals (Sweden)

    Berhanu Mekibib

    2016-05-01

    Full Text Available Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire and Sudan, the 2013–2015 western African Ebola virus disease (EVD outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses.

  9. Stratospheric aerosol geoengineering

    Energy Technology Data Exchange (ETDEWEB)

    Robock, Alan [Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901 (United States)

    2015-03-30

    The Geoengineering Model Intercomparison Project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, has found that insolation reduction could keep the global average temperature constant, but global average precipitation would reduce, particularly in summer monsoon regions around the world. Temperature changes would also not be uniform; the tropics would cool, but high latitudes would warm, with continuing, but reduced sea ice and ice sheet melting. Temperature extremes would still increase, but not as much as without geoengineering. If geoengineering were halted all at once, there would be rapid temperature and precipitation increases at 5–10 times the rates from gradual global warming. The prospect of geoengineering working may reduce the current drive toward reducing greenhouse gas emissions, and there are concerns about commercial or military control. Because geoengineering cannot safely address climate change, global efforts to reduce greenhouse gas emissions and to adapt are crucial to address anthropogenic global warming.

  10. Net Shape Rapid Manufacturing Using Nano Encapsulated Powders Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase II program is developing NET Shape components from Encapsulated Powders. Significant advances in Phase I for various materials and in net shape processing...

  11. Encapsulating peritoneal sclerosis: experience of a tertiary referral center.

    LENUS (Irish Health Repository)

    Phelan, P J

    2010-05-01

    Encapsulating peritoneal sclerosis (EPS) is arguably the most serious complication of chronic peritoneal dialysis (PD) therapy with extremely high mortality rates. We aimed to establish the rates of EPS and factors associated with its development in a single center.

  12. A quantitative method for photovoltaic encapsulation system optimization

    Science.gov (United States)

    Garcia, A., III; Minning, C. P.; Cuddihy, E. F.

    1981-01-01

    It is pointed out that the design of encapsulation systems for flat plate photovoltaic modules requires the fulfillment of conflicting design requirements. An investigation was conducted with the objective to find an approach which will make it possible to determine a system with optimum characteristics. The results of the thermal, optical, structural, and electrical isolation analyses performed in the investigation indicate the major factors in the design of terrestrial photovoltaic modules. For defect-free materials, minimum encapsulation thicknesses are determined primarily by structural considerations. Cell temperature is not strongly affected by encapsulant thickness or thermal conductivity. The emissivity of module surfaces exerts a significant influence on cell temperature. Encapsulants should be elastomeric, and ribs are required on substrate modules. Aluminum is unsuitable as a substrate material. Antireflection coating is required on cell surfaces.

  13. The improved stability of enzyme encapsulated in biomimetic titania particles

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Yanjun; Sun Qianyun [Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Jiang Zhongyi [Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)], E-mail: zhyjiang@tju.edu.cn; Zhang Lei; Li Jian; Li Lin; Sun Xiaohui [Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)

    2009-01-01

    This study demonstrates a novel biomimetic approach for the entrapment of yeast alcohol dehydrogenase (YADH) within titania nanoparticles to improve its stability. Protamine was as the template and catalyst for the condensation of titanium (IV) bis(ammonium lactato) dihydroxide (Ti-BALDH) into titania nanoparticles in which YADH was trapped. The as-prepared titania/protamine/YADH composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The mechanism of YADH encapsulation was tentatively proposed from a series of experimental results. The preliminary investigation showed that encapsulated YADH could retain most of its initial activity. Compared to free YADH, encapsulated YADH exhibited significantly improved thermal, pH and recycling stability. After 5 weeks storage, no substantial loss of catalytic activity for encapsulated YADH was observed.

  14. Formation and microstructure of carbon encapsulated superparamagnetic Co nanoparticles

    Science.gov (United States)

    Sun, Xiang-Cheng; Reyes-Gasga, J.; Dong, X. L.

    Carbon encapsulated magnetic cobalt nanoparticles have been synthesized by the modified arc-discharge method. Both high resolution transmission electron microscopy (HREM) and powder X-ray diffraction (XRD) profiles reveal the presence of 8-15nm diameter crystallites coated with 1-3 carbon layers. In particular, HREM images indicate that the intimate and contiguous carbon fringe around those Co nanoparticles is good evidence for complete encapsulation by carbon shell layers. The encapsulated phases are identified as hcp α-Co, fcc β-Co and cobalt carbide (Co 3 C) nanocrystals using X-ray diffraction (XRD), nano-area electron diffraction (SAED) and energy dispersive X-ray analysis (EDX). However, some fcc β-Co particles with a significant fraction of stacking faults are observed by HREM and confirmed by means of numerical fast Fourier transform (FFT) of HREM lattice images. The carbon encapsulation formation and growth mechanism are also reviewed.

  15. Study on preparation of β-cyclodextrin encapsulation tea extract.

    Science.gov (United States)

    Haidong, Liang; Fang, Yu; Zhihong, Tong; Changle, Ren

    2011-11-01

    Microencapsulation of ethanol extract of tea was performed in this study. In order to microencapsulate, β-cyclodextrin was used as wall material. Ethanol extract of tea was used as the core material. Microcapsules in the solid form were obtained by drying the emulsions. RSM showed that optimal processing parameters were as followings: core material/wall material 1/4, β-cyclodextrin content 16%, stirring time 30 min and stirring temperature 200°C. Pharmacological activities of β-cyclodextrin encapsulation tea extract were determined. It was found that β-cyclodextrin encapsulation tea extract could enhance BMD, BMC and bone Ca, Zn and Cu contents. In addition, β-cyclodextrin encapsulation tea extract could still reduce blood Ca contents. These results indicated that β-cyclodextrin encapsulation tea extract was useful for improving bone quality in aged animals.

  16. Accelerated UV Test Methods for Encapsulants of Photovoltaic Modules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Kempe, M. D.

    2008-05-01

    This paper asserts that materials used for PV encapsulation must be evaluated for their ability to transmit light and to maintain mechanical integrity for extended periods of time under long term UV exposure.

  17. Peptide encapsulation regulated by the geometry of carbon nanotubes.

    Science.gov (United States)

    Zhang, Zhi-Sen; Kang, Yu; Liang, Li-Jun; Liu, Ying-Chun; Wu, Tao; Wang, Qi

    2014-02-01

    In this work the encapsulation of an α-helical peptide in single carbon nanotubes (CNTs) with similar diameter and length but different geometry (armchair and zigzag) was investigated through molecular dynamics simulations and free energy calculations. Our simulation results showed that in vacuo it makes no evident difference whether the investigated peptide is encapsulated in armchair or zigzag CNTs; however, in aqueous solution the armchair CNT encapsulates the peptide remarkably easier than the zigzag CNT does. A detailed analysis revealed that the equilibrium conformation of the water molecules inside the CNTs with varying geometry mediates the peptide encapsulation. It suggests that the water molecules play an important role in regulating behaviors of biomolecules in bio-systems. Then the impact of the CNT geometry on the conformational changes of the confined peptide was studied. Analyses of secondary structures showed the α-helix of the peptide could be better maintained in the zigzag CNT.

  18. The combined effect of encapsulating curcumin and C6 ceramide in liposomal nanoparticles against osteosarcoma.

    Science.gov (United States)

    Dhule, Santosh S; Penfornis, Patrice; He, Jibao; Harris, Michael R; Terry, Treniece; John, Vijay; Pochampally, Radhika

    2014-02-01

    This study examines the antitumor potential of curcumin and C6 ceramide (C6) against osteosarcoma (OS) cell lines when both are encapsulated in the bilayer of liposomal nanoparticles. Three liposomal formulations were prepared: curcumin liposomes, C6 liposomes and C6-curcumin liposomes. Curcumin in combination with C6 showed 1.5 times enhanced cytotoxic effect in the case of MG-63 and KHOS OS cell lines, in comparison with curcumin liposomes alone. Importantly, C6-curcumin liposomes were found to be less toxic on untransformed primary human cells (human mesenchymal stem cells) in comparison to OS cell lines. In addition, cell cycle assays on a KHOS cell line after treatment revealed that curcumin only liposomes induced G2/M arrest by upregulation of cyclin B1, while C6 only liposomes induced G1 arrest by downregulation of cyclin D1. C6-curcumin liposomes induced G2/M arrest and showed a combined effect in the expression levels of cyclin D1 and cyclin B1. The efficiency of the preparations was tested in vivo using a human osteosarcoma xenograft assay. Using pegylated liposomes to increase the plasma half-life and tagging with folate (FA) for targeted delivery in vivo, a significant reduction in tumor size was observed with C6-curcumin-FA liposomes. The encapsulation of two water insoluble drugs, curcumin and C6, in the lipid bilayer of liposomes enhances the cytotoxic effect and validates the potential of combined drug therapy.

  19. Overview of the main methods used to combine proteins with nanosystems: absorption, bioconjugation, and encapsulation

    Directory of Open Access Journals (Sweden)

    Mariagrazia Di Marco

    2009-12-01

    Full Text Available Mariagrazia Di Marco1, Shaharum Shamsuddin2, Khairunisak Abdul Razak3, Azlan Abdul Aziz4, Corinne Devaux1, Elsa Borghi1, Laurent Levy1, Claudia Sadun51Nanobiotix, Paris, France; 2School of Health Sciences, Health Campus Universiti Sains Malaysia, Kelantan, Malaysia; 3School of Materials and Mineral Resources Engineering, Engineering Campus, 4School of Physics, Universiti Sains Malaysia, Penang, Malaysia; 5Department of Chemistry, Sapienza, University of Rome, Rome, ItalyAbstract: The latest development of protein engineering allows the production of proteins having desired properties and large potential markets, but the clinical advances of therapeutical proteins are still limited by their fragility. Nanotechnology could provide optimal vectors able to protect from degradation therapeutical biomolecules such as proteins, enzymes or specific polypeptides. On the other hand, some proteins can be also used as active ligands to help nanoparticles loaded with chemotherapeutic or other drugs to reach particular sites in the body. The aim of this review is to provide an overall picture of the general aspects of the most successful approaches used to combine proteins with nanosystems. This combination is mainly achieved by absorption, bioconjugation and encapsulation. Interactions of nanoparticles with biomolecules and caveats related to protein denaturation are also pointed out. A clear understanding of nanoparticle-protein interactions could make possible the design of precise and versatile hybrid nanosystems. This could further allow control of their pharmacokinetics as well as activity, and safety.Keywords: nanoparticles, drug delivery, proteins, polypeptides, absorption, bioconjugation, encapsulation

  20. Betamethasone-in-cyclodextrin-in-liposome: the effect of cyclodextrins on encapsulation efficiency and release kinetics.

    Science.gov (United States)

    Piel, Géraldine; Piette, Marie; Barillaro, Valery; Castagne, Delphine; Evrard, Brigitte; Delattre, Luc

    2006-04-07

    Lipophilic drugs have limited solubility in phospholipid systems, hence maximum entrapment levels in liposomes are known to be low. "Drugs-in-cyclodextrin-in-liposome" systems were previously proposed to overcome this drawback but studies were limited to betaCD and HPbetaCD. In some cases, other cyclodextrins may be more interesting than betaCD or HPbetaCD, such as methylated cyclodextrins. However, these cyclodextrins are known to extract lipid components from the lipid membrane, which may destabilize liposomes. We tested the influence of several cyclodextrins (betaCD, gammaCD, Dimeb, Trimeb, Crysmeb, Rameb, HPbetaCD and HPgammaCD) on the aqueous solubility of betamethasone by phase solubility diagrams and on the encapsulation efficiency in liposomes. The release kinetics of betamethasone was studied using Franz diffusion cells. We showed that release kinetics are directly correlated with encapsulation efficiency, which is closely related to betamethasone concentration in cyclodextrin complex solution. No liposome destruction was observed, even with the testing of methylated cyclodextrins at the highest concentration (40 mM). This can be explained by the fact that these cyclodextrins have a higher affinity for betamethasone than for cholesterol. This was proved by the comparison of phase solubility diagrams of both betamethasone and cholesterol.

  1. Reduced in vivo toxicity of doxorubicin by encapsulation in cholesterol-containing self-assembled nanoparticles.

    Science.gov (United States)

    Gonzalez-Fajardo, Laura; Mahajan, Lalit H; Ndaya, Dennis; Hargrove, Derek; Manautou, José E; Liang, Bruce T; Chen, Ming-Hui; Kasi, Rajeswari M; Lu, Xiuling

    2016-05-01

    We previously reported the development of an amphiphilic brush-like block copolymer composed of polynorbornene-cholesterol/polyethylene glycol (P(NBCh9-b-NBPEG)) that self-assembles in aqueous media to form long circulating nanostructures capable of encapsulating doxorubicin (DOX-NPs). Biodistribution studies showed that this formulation preferentially accumulates in tumor tissue with markedly reduced accumulation in the heart and other major organs. The aim of the current study was to evaluate the in vivo efficacy and toxicity of DOX containing self-assembled polymer nanoparticles in a mouse xenograft tumor model and compare its effects with the hydrochloride non-encapsulated form (free DOX). DOX-NPs significantly reduced the growth of tumors without inducing any apparent toxicity. Conversely, mice treated with free DOX exhibited significant weight loss, early toxic cardiomyopathy, acute toxic hepatopathy, reduced hematopoiesis and fatal toxicity. The improved safety profile of the polymeric DOX-NPs can be explained by the low circulating concentration of non-nanoparticle-associated drug as well as the reduced accumulation of DOX in non-target organs. These findings support the use of P(NBCh9-b-NBPEG) nanoparticles as delivery platforms for hydrophobic anticancer drugs intended to reduce the toxicity of conventional treatments.

  2. Hydrogels of sodium alginate in cationic surfactants: Surfactant dependent modulation of encapsulation/release toward Ibuprofen.

    Science.gov (United States)

    Jabeen, Suraya; Chat, Oyais Ahmad; Maswal, Masrat; Ashraf, Uzma; Rather, Ghulam Mohammad; Dar, Aijaz Ahmad

    2015-11-20

    The interaction of cetyltrimethylammoium bromide (CTAB) and its gemini homologue (butanediyl-1,4-bis (dimethylcetylammonium bromide), 16-4-16 with biocompatible polymer sodium alginate (SA) has been investigated in aqueous medium. Addition of K2CO3 influences viscoelastic properties of surfactant impregnated SA via competition between electrostatic and hydrophobic interactions. Viscosity of these polymer-surfactant systems increases with increase in concentration of K2CO3, and a cryogel is formed at about 0.5M K2CO3 concentration. The thermal stability of gel (5% SA+0.5M K2CO3) decreases with increase in surfactant concentration, a minimum is observed with increase in 16-4-16 concentration. The impact of surfactant addition on the alginate structure vis-à-vis its drug loading capability and release thereof was studied using Ibuprofen (IBU) as the model drug. The hydrogel with 16-4-16 exhibits higher IBU encapsulation and faster release in comparison to the one containing CTAB. This higher encapsulation-cum-faster release capability has been related to micelle mediated solubilization and greater porosity of the hydrogel with gemini surfactant.

  3. Plastic encapsulated, dye sensitised photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Potter, R.J.; Otley, L.C.; Durrant, J.R.; Haque, S.; Xu, C. [Imperial College of Science, Technology and Medicine, London (United Kingdom); Holmes, A.B.; Park, T.; Schulte, N. [Cambridge Univ. (United Kingdom)

    2004-07-01

    The report presents the results of a collaborative project that aimed to demonstrate the technical feasibility of a plastic-encapsulated, solid state, dye-sensitised solar cell (DSSC) with an energy conversion efficiency (ECE) of at least 3%. DSSCs offer a possible 'step change' in photovoltaic technology resulting in lower costs compared with existing technologies. The project involved a series of eight main tasks: the development of first and second generation HTM electrolytes; the development of polymer-supported electrolytes; the development of low temperature electrode coating procedures; dye development; cell assembly and testing; component integration; and overall process development. A wide range of innovative HTMs have been synthesised, including materials incorporating both hole-transporting and ion-chelating functional groups. The ruthenium-based dye, N3, remained the preferred sensitising component. The project has produced a system that can routinely achieve over 5% ECE at 0.1 Sun illumination on 1 cm{sup 2} cells using polymer-supported electrolytes.

  4. Safe epoxy encapsulant for high voltage magnetics

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, R.O.; Archer, W.E.

    1998-01-01

    This paper describes the use of Formula 456, an aliphatic amine cured epoxy for impregnating coils and high voltage transformers. Sandia has evaluated a number of MDA-free epoxy encapsulants which relied on either anhydride or other aromatic amine curing agents. The use of aliphatic amine curing agents was more recently evaluated and has resulted in the definition of Formula 456 resin. Methylene dianiline (MDA) has been used for more than 20 years as the curing agent for various epoxy formulations throughout the Department of Energy and much of industry. Sandia National Laboratories began the process of replacing MDA with other formulations because of regulations imposed by OSHA on the use of MDA. OSHA has regulated MDA because it is a suspect carcinogen. Typically the elimination of OSHA-regulated materials provides a rare opportunity to qualify new formulations in a range of demanding applications. It was important to take full advantage of that opportunity, although the associated materials qualification effort was costly. Small high voltage transformers are one of those demanding applications. The successful implementation of the new formulation for high reliability transformers will be described. The test results that demonstrate the parts are qualified for use in DOE weapon systems will be presented.

  5. Comparative properties of optically clear epoxy encapsulants

    Science.gov (United States)

    Edwards, Maury; Zhou, Yan

    2001-12-01

    Three epoxy systems were evaluated for physical dn optical properties. The three systems chosen for the study were selected on the basis of their optical clarity, color and chemistry. Three distinctly different chemistries were chosen, aromatic epoxy-amine cured. Aromatic epoxy- anhydride cured and cycloaliphatic epoxy-anhydride cured. All three systems remained optically clear and water-white after full cure. The three selected systems were tested for physical properties, adhesion and light transmission properties. Light transmission was measured after thermal and humidity exposure. Adhesion was measured after humidity exposure only. Both of the epoxy-anhydride systems performed well in optical properties but poorer in adhesion as compared to the epoxy-amine system. The aromatic epoxy- amine system discolored badly during thermal exposure at 100 C. Data generated from this work will be used in selecting clear encapsulating materials for photonics applications. No single system offers optimal performance in all areas. The best compromise material is the aromatic epoxy-anhydride system.

  6. Biological studies of matrix metalloproteinase sensitive drug delivery systems

    DEFF Research Database (Denmark)

    Johansen, Pia Thermann

    due to severe side effects as a result of drug distribution to healthy tissues. To enhance ecacy of treatment and improve life quality of patients, tumor specific drug delivery strategies, such as liposome encapsulated drugs, which accumulate in tumor tissue, has gained increased attention. Several...... for delivery of drugs to specific tissues or cells utilizing biological knowledge of cancer tissue is getting increased attention. In this thesis a novel matrix metalloproteinase-2 (MMP-2) sensitive poly-ethylene glycol (PEG) coated liposomal drug delivery system for treatment of cancer was developed...... the use of MMP- 2 as a trigger for liposomal activation in tumor tissue. Thus, this new strategy provides a promising system for specific delivery of encapsulated drugs and controlled release in tumor tissues, resulting in enhanced drug bioavailability and decreased systemic side effects. In addition, we...

  7. Remote loading of preencapsulated drugs into stealth liposomes.

    Science.gov (United States)

    Sur, Surojit; Fries, Anja C; Kinzler, Kenneth W; Zhou, Shibin; Vogelstein, Bert

    2014-02-11

    Loading drugs into carriers such as liposomes can increase the therapeutic ratio by reducing drug concentrations in normal tissues and raising their concentrations in tumors. Although this strategy has proven advantageous in certain circumstances, many drugs are highly hydrophobic and nonionizable and cannot be loaded into liposomes through conventional means. We hypothesized that such drugs could be actively loaded into liposomes by encapsulating them into specially designed cyclodextrins. To test this hypothesis, two hydrophobic drugs that had failed phase II clinical trials because of excess toxicity at deliverable doses were evaluated. In both cases, the drugs could be remotely loaded into liposomes after their encapsulation (preloading) into cyclodextrins and administered to mice at higher doses and with greater efficacy than possible with the free drugs.

  8. Probiotic Encapsulation Technology: From Microencapsulation to Release into the Gut

    OpenAIRE

    Gbassi, Gildas K.; Thierry Vandamme

    2012-01-01

    Probiotic encapsulation technology (PET) has the potential to protect microorgansisms and to deliver them into the gut. Because of the promising preclinical and clinical results, probiotics have been incorporated into a range of products. However, there are still many challenges to overcome with respect to the microencapsulation process and the conditions prevailing in the gut. This paper reviews the methodological approach of probiotics encapsulation including biomaterials selection, choice ...

  9. Dysprosium Acetylacetonato Single-Molecule Magnet Encapsulated in Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Ryo Nakanishi

    2016-12-01

    Full Text Available Dy single-molecule magnets (SMMs, which have several potential uses in a variety of applications, such as quantum computing, were encapsulated in multi-walled carbon nanotubes (MWCNTs by using a capillary method. Encapsulation was confirmed by using transmission electron microscopy (TEM. In alternating current magnetic measurements, the magnetic susceptibilities of the Dy acetylacetonato complexes showed clear frequency dependence even inside the MWCNTs, meaning that this hybrid can be used as magnetic materials in devices.

  10. Encapsulation of Alcohol Dehydrogenase in Mannitol by Spray Drying

    OpenAIRE

    Hirokazu Shiga; Hiromi Joreau; Tze Loon Neoh; Takeshi Furuta; Hidefumi Yoshii

    2014-01-01

    The retention of the enzyme activity of alcohol dehydrogenase (ADH) has been studied in various drying processes such as spray drying. The aim of this study is to encapsulate ADH in mannitol, either with or without additive in order to limit the thermal denaturation of the enzyme during the drying process. The retention of ADH activity was investigated at different drying temperatures. When mannitol was used, the encapsulated ADH was found inactive in all the dried powders. This is presumably...

  11. Electrodeposited polymer encapsulated nickel sulphide thin films: frequency switching material

    Energy Technology Data Exchange (ETDEWEB)

    Jana, Sumanta, E-mail: sumantajana85@gmail.com [Department of Chemistry, Bengal Engineering and Science University, Botanic Garden, Howrah 711103, WB (India); Mukherjee, Nillohit [Centre of Excellence for Green Energy and Sensor Systems, Bengal Engineering and Science University, Howrah 711103, WB (India); Chakraborty, Biswajit [Department of Chemistry, Vivekananda Mahavidyalay, Burdwan 713103, WB (India); Mitra, Bibhas Chandra [Department of Physics, Bengal Engineering and Science University, Botanic Garden, Howrah 711103, WB (India); Mondal, Anup, E-mail: anupmondal2000@yahoo.co.in [Department of Chemistry, Bengal Engineering and Science University, Botanic Garden, Howrah 711103, WB (India)

    2014-05-01

    Graphical abstract: Polyvinylpyrrolidone encapsulated NiS thin films were synthesized electrochemically. The light induced frequency switching study of the synthesized material was carried out and it was observed that the films performed well as a switching device under 1 Sun illumination. This pulse generation within an insulating polymer encapsulated semicondctor matrix (PVP NiS) might be due to surface covering which leads to reduction of recombination process. Highlights: • PVP-NiS thin films were electrochemically synthesized. • Encapsulation of PVP causes surface modification of NiS by reducing surface states. • The synthesized thin films were used as frequency switching material which generates ~ 50 Hz frequency under 1 Sun irradiation. Abstract: Polyvinylpyrrolidone (PVP) encapsulated nickel sulfide (NiS) thin films have been synthesized electrochemically from aqueous solution of hydrated nickel chloride (NiCl₂, 6H₂O), thioacetamide (CH₃C(S) NH₂) (TAA) and polyvinylpyrrolidone (PVP). Surface modification of nickel sulfide (NiS) thin films was achieved by this polymer encapsulation. X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), field emission scanning electron microscopy (FESEM) and Energy dispersive X-radiation (EDAX) techniques were used for the characterization of thin films. Infrared spectroscopy (IR) confirmed the formation of polymer encapsulated semiconductor. Frequency switching generation study shows that the encapsulated material could be used as a frequency switching device that generates a frequency ~ 50 Hz under 1 Sun illumination. Encapsulation with PVP causes surface modification that reduces the surface states and barrier height. As a result, the width of the depletion region decreases. So the number of electron-hole pairs increases. Consequently, the number of excitons and exciton related emission increases and this leads to reduction of recombination process and shows photo induced

  12. Distribution of liposome-encapsulated antimony in dogs

    Directory of Open Access Journals (Sweden)

    D.A. Schettini

    2003-02-01

    Full Text Available The achievement of complete cure in dogs with visceral leishmaniasis is currently a great challenge, since dogs are the main reservoir for the transmission of visceral leishmaniasis to humans and they respond poorly to conventional treatment with pentavalent antimonials. In order to improve the efficacy of treatment, we developed a novel formulation for meglumine antimoniate based on the encapsulation of this drug in freeze-dried liposomes (LMA. The aim of the present study was to evaluate the biodistribution of antimony (Sb in dogs following a single intravenous bolus injection of LMA. Four healthy male mongrel dogs received LMA at 3.8 mg Sb/kg body weight and were sacrificed 3, 48 and 96 h and 7 days later. Antimony was determined in the blood, liver, spleen and bone marrow. In the bone marrow, the highest Sb concentration was observed at 3 h (2.8 µg/g wet weight whereas in the liver and spleen it was demonstrated at 48 h (43.6 and 102.4 µg/g, respectively. In these organs, Sb concentrations decreased gradually and reached levels of 19.1 µg/g (liver, 28.1 µg/g (spleen and 0.2 µg/g (bone marrow after 7 days. Our data suggest that the critical organ for the treatment with LMA could be the bone marrow, since it has low Sb levels and, presumably, high rates of Sb elimination. A multiple dose treatment with LMA seems to be necessary for complete elimination of parasites from bone marrow in dogs with visceral leishmaniasis.

  13. Designing deoxidation inhibiting encapsulation of metal oxide nanostructures for fluidic and biological applications

    Science.gov (United States)

    Ghosh, Moumita; Ghosh, Siddharth; Seibt, Michael; Schaap, Iwan A. T.; Schmidt, Christoph F.; Mohan Rao, G.

    2016-12-01

    Due to their photoluminescence, metal oxide nanostructures such as ZnO nanostructures are promising candidates in biomedical imaging, drug delivery and bio-sensing. To apply them as label for bio-imaging, it is important to study their structural stability in a bio-fluidic environment. We have explored the effect of water, the main constituent of biological solutions, on ZnO nanostructures with scanning electron microscopy (SEM) and photoluminescence (PL) studies which show ZnO nanorod degeneration in water. In addition, we propose and investigate a robust and inexpensive method to encapsulate these nanostructures (without structural degradation) using bio-compatible non-ionic surfactant in non-aqueous medium, which was not reported earlier. This new finding is an immediate interest to the broad audience of researchers working in biophysics, sensing and actuation, drug delivery, food and cosmetics technology, etc.

  14. Encapsulation of liquids using a counter rotating twin screw extruder.

    Science.gov (United States)

    Tackenberg, Markus W; Krauss, Ralph; Marmann, Andreas; Thommes, Markus; Schuchmann, Heike P; Kleinebudde, Peter

    2015-01-01

    Until now extrusion is not applied for pharmaceutical encapsulation processes, whereas extrusion is widely used for encapsulation of flavours within food applications. Based on previous mixing studies, a hot melt counter-rotating extrusion process for encapsulation of liquid active pharmaceutical ingredients (APIs) was investigated. The mixing ratio of maltodextrin to sucrose as matrix material was adapted in first extrusion trials. Then the number of die holes was investigated to decrease expansion and agglutination of extrudates to a minimum. At a screw speed of 180 min(-1) the product temperature was decreased below 142 °C, resulting in extrudates of cylindrical shape with a crystalline content of 9-16%. Volatile orange terpenes and the nonvolatile α-tocopherol were chosen as model APIs. Design of experiments were performed to investigate the influences of barrel temperature, powder feed rate, and API content on the API retentions. A maximum of 9.2% α-tocopherol was encapsulated, while the orange terpene encapsulation rate decreased to 6.0% due to evaporation after leaving the die. During 12 weeks of storage re-crystallization of sucrose occurred; however, the encapsulated orange terpene amount remained unchanged.

  15. Enzyme-encapsulated silica nanoparticle for cancer chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Yi-Rong; Ho, Wei-Jen; Chao, Jiun-Shuan; Yuan, Chiun-Jye, E-mail: cjyuan@mail.nctu.edu.tw [National Chiao Tung University, Department of Biological Science and Technology, Taiwan (China)

    2012-03-15

    A novel horseradish peroxidase-encapsulated silica nanoparticle (SNP) was generated in this study under relatively mild conditions. The generated enzyme-encapsulated SNP were relatively uniform in size (average 70 {+-} 14.3 nm), monodispersed, and spherical, as characterized by transmission electron microscopy and scanning electron microscopy. The horseradish peroxidase encapsulated in silica nanoparticle exhibits biological properties, such as a pH-dependent activity profile and k{sub m} value, similar to that of free enzymes. Furthermore, enzyme-encapsulated SNP exhibited good operational stability for the repetitive usage with a relative standard deviation of 5.1 % (n = 10) and a high stability for long term storage (>60 days) at 4 Degree-Sign C. The feasibility of using enzyme-encapsulated SNP in prodrug cancer therapy was also demonstrated by its capability to convert the prodrug indole-3-acetic acid into cytotoxic peroxyl radicals and trigger the death of tumor cells. These results indicate that the developed enzyme-encapsulated SNP has potential in the applications of prodrug cancer therapy.

  16. Stability analysis of an encapsulated microbubble against gas diffusion.

    Science.gov (United States)

    Katiyar, Amit; Sarkar, Kausik

    2010-03-01

    Linear stability analysis is performed for a mathematical model of diffusion of gases from an encapsulated microbubble. It is an Epstein-Plesset model modified to account for encapsulation elasticity and finite gas permeability. Although bubbles, containing gases other than air, are considered, the final stable bubble, if any, contains only air, and stability is achieved only when the surrounding medium is saturated or oversaturated with air. In absence of encapsulation elasticity, only a neutral stability is achieved for zero surface tension, the other solution being unstable. For an elastic encapsulation, different equilibrium solutions are obtained depending on the saturation level and whether the surface tension is smaller or higher than the elasticity. For an elastic encapsulation, elasticity can stabilize the bubble. However, imposing a non-negativity condition on the effective surface tension (consisting of reference surface tension and the elastic stress) leads to an equilibrium radius which is only neutrally stable. If the encapsulation can support a net compressive stress, it achieves actual stability. The linear stability results are consistent with our recent numerical findings. Physical mechanisms for the stability or instability of various equilibriums are provided.

  17. Do atmospheric aerosols form glasses?

    OpenAIRE

    Zobrist, B.; Marcolli, C.; Pedernera, D. A.; Koop, T.

    2008-01-01

    A new process is presented by which water soluble organics might influence ice nucleation, ice growth, chemical reactions and water uptake of aerosols in the upper troposphere: the formation of glassy aerosol particles. Glasses are disordered amorphous (non-crystalline) solids that form when a liquid is cooled without crystallization until the viscosity increases exponentially and molecular diffusion practically ceases. The glass transition temperatures, Tg

  18. CALIPSO Observations of Aerosol Properties Near Clouds

    Science.gov (United States)

    Marshak, Alexander; Varnai, Tamas; Yang, Weidong

    2010-01-01

    Clouds are surrounded by a transition zone of rapidly changing aerosol properties. Characterizing this zone is important for better understanding aerosol-cloud interactions and aerosol radiative effects as well as for improving satellite measurements of aerosol properties. We present a statistical analysis of a global dataset of CALIPSO (Cloud-Aerosol Lidar and infrared Pathfinder Satellite Observation) Lidar observations over oceans. The results show that the transition zone extends as far as 15 km away from clouds and it is ubiquitous over all oceans. The use of only high confidence level cloud-aerosol discrimination (CAD) data confirms the findings. However, the results underline the need for caution to avoid biases in studies of satellite aerosol products, aerosol-cloud interactions, and aerosol direct radiative effects.

  19. Devices and methods for generating an aerosol

    KAUST Repository

    Bisetti, Fabrizio

    2016-03-03

    Aerosol generators and methods of generating aerosols are provided. The aerosol can be generated at a stagnation interface between a hot, wet stream and a cold, dry stream. The aerosol has the benefit that the properties of the aerosol can be precisely controlled. The stagnation interface can be generated, for example, by the opposed flow of the hot stream and the cold stream. The aerosol generator and the aerosol generation methods are capable of producing aerosols with precise particle sizes and a narrow size distribution. The properties of the aerosol can be controlled by controlling one or more of the stream temperatures, the saturation level of the hot stream, and the flow times of the streams.

  20. New liquid aerosol generation devices: systems that force pressurized liquids through nozzles.

    Science.gov (United States)

    Geller, David E

    2002-12-01

    Over the past few decades, aerosol delivery devices have been relatively inefficient, wasteful, and difficult for patients to use. These drawbacks have been tolerated because the drugs available for inhalation have wide therapeutic margins and steep dose-response curves at low doses. Recently several forces have converged to drive innovation in the aerosol device industry: the ban on chlorofluorocarbon propellants in metered-dose inhalers, the need for more user-friendly devices, and the invention of expensive inhalable therapies for topical and systemic lung delivery. Numerous devices are in development to improve the efficiency, ease of use, and reproducibility of aerosol delivery to the lung, including systems that force liquid through a nozzle to form the aerosol cloud. The Respimat is a novel, compact, propellant-free, multi-dose inhaler that employs a spring to push drug solution through a nozzle, which generates a slow-moving aerosol. Deposition studies show that the Respimat can deliver 39-44% of a dose to the lungs. Clinical asthma and chronic obstructive pulmonary disease trials with bronchodilators show that the Respimat is 2-8 times as effective as a metered-dose inhaler. Respimat has been tested with bronchodilators and inhaled corticosteroids. The AERx device uses sophisticated electronics to deliver aerosol from a single-dose blister, using an integral, disposable nozzle array. The electronics control dose expression and titration, timing of aerosol generation with the breath, and provide feedback for proper inhalation technique. Lung deposition ranges from 50 to 80% of the loaded dose, with remarkable reproducibility. AERx has been tested with a variety of drugs, for both topical and systemic delivery, including rhDNase (dornase alfa), insulin, and opioids. These novel devices face competition from other technologies as well as financial and regulatory hurdles, but they both offer a marked improvement in the efficiency of pulmonary drug delivery.

  1. Tuneable & degradable polymeric micelles for drug delivery: from synthesis to feasibility in vivo

    NARCIS (Netherlands)

    Rijcken, C.J.F.

    2007-01-01

    In recent years, colloidal systems (e.g. liposomes, nanoparticles and micelles) are increasingly applied as vehicles for controlled drug delivery purposes. Ideally, the encapsulation of hydrophobic drugs in a micellar core prolongs the systemic circulation and drug-loaded micelles selectively accumu

  2. Study of Aerosol Chemical Composition Based on Aerosol Optical Properties

    Science.gov (United States)

    Berry, Austin; Aryal, Rudra

    2015-03-01

    We investigated the variation of aerosol absorption optical properties obtained from the CIMEL Sun-Photometer measurements over three years (2012-2014) at three AERONET sites GSFC; MD Science_Center and Tudor Hill, Bermuda. These sites were chosen based on the availability of data and locations that can receive different types of aerosols from land and ocean. These absorption properties, mainly the aerosol absorption angstrom exponent, were analyzed to examine the corresponding aerosol chemical composition. We observed that the retrieved absorption angstrom exponents over the two sites, GSFC and MD Science Center, are near 1 (the theoretical value for black carbon) and with low single scattering albedo values during summer seasons indicating presence of black carbon. Strong variability of aerosol absorption properties were observed over Tudor Hill and will be analyzed based on the air mass embedded from ocean side and land side. We will also present the seasonal variability of these properties based on long-range air mass sources at these three sites. Brent Holben, NASA GSFC, AERONET, Jon Rodriguez.

  3. Cell encapsulation : technical and clinical advances

    NARCIS (Netherlands)

    Orive, Gorka; Santos, Edorta; Poncelet, Denis; Maria Hernandez, Rosa; Luis Pedraz, Jose; Wahlberg, Lars U.; De Vos, Paul; Emerich, Dwaine

    2015-01-01

    Treating many chronic diseases will require a tight, minute-to-minute regulation of therapeutic molecules that is currently not achievable with most pharmaceutical therapies. For these diseases, implantable living cellular systems may be able to provide unlimited drug delivery, enabling seamless mat

  4. Encapsulation of ionic electroactive polymers: reducing the interaction with environment

    Science.gov (United States)

    Jaakson, P.; Aabloo, A.; Tamm, T.

    2016-04-01

    Ionic electro-active polymer (iEAP) actuators are composite materials that change their mechanical properties in response to external electrical stimulus. The interest in these devices is mainly driven by their capability to generate biomimetic movements, and their potential use in soft robotics. The driving voltage of an iEAP-actuator (0.5… 3 V) is at least an order of magnitude lower than that needed for other types of electroactive polymers. To apply iEAP-actuators in potential real-world applications, the capability of operating in different environments (open air, different solvents) must be available. In their natural form, the iEAP-actuators are capable of interacting with the surrounding environment (evaporation of solvent from the electrolyte solution, ion or solvent exchange, humidity effects), therefore, for prevention of unpredictable behavior of the actuator and the contamination of the environment, encapsulation of the actuator is needed. The environmental contamination aspect of the encapsulation material is substantial when selecting an applicable encapsulant. The suitable encapsulant should form thin films, be light in weight, elastic, fit tightly, low cost, and easily reproducible. The main goal of the present study is to identify and evaluate the best potential encapsulation techniques for iEAPactuators. Various techniques like thin film on liquid coating, dip coating, hot pressing, hot rolling; and several materials like polydimethylsiloxane, polyurethane, nitrocellulose, paraffin-composite-films were investigated. The advantages and disadvantages of the combinations of the above mentioned techniques and materials are discussed. Successfully encapsulated iEAP-actuators gained durability and were stably operable for long periods of time under ambient conditions. The encapsulation process also increased the stability of the iEAP-actuator by minimizing the environment effects. This makes controlling iEAP-actuators more straight-forward and

  5. A formulation to encapsulate nootkatone for tick control.

    Science.gov (United States)

    Behle, Robert W; Flor-Weiler, Lina B; Bharadwaj, Anuja; Stafford, Kirby C

    2011-11-01

    Nootkatone is a component of grapefruit oil that is toxic to the disease-vectoring tick, Ixodes scapularis Say, but unfortunately causes phytotoxicity to treated plants and has a short residual activity due to volatility. We prepared a lignin-encapsulated nootkatone formulation to compare with a previously used emulsifiable formulation for volatility, plant phytotoxicity, and toxicity to unfed nymphs of I. scapularis. Volatility of nootkatone was measured directly by trapping nootkatone vapor in a closed system and indirectly by measuring nootkatone residue on treated filter paper after exposure to simulated sunlight (Xenon). After 24 h in the closed system, traps collected only 15% of the nootkatone applied as the encapsulated formulation compared with 40% applied as the emulsifiable formulation. After a 1-h light exposure, the encapsulated formulation retained 92% of the nootkatone concentration compared with only 26% retained by the emulsifiable formulation. For plant phytotoxicity, cabbage, Brassica oleracea L., leaves treated with the encapsulated formulation expressed less necrosis, retaining greater leaf weight compared with leaves treated with the emusifiable formulation. The nootkatone in the emulsifiable formulation was absorbed by cabbage and oat, Avena sativa L., plants (41 and 60% recovered 2 h after application, respectively), as opposed to 100% recovery from the plants treated with encapsulated nootkatone. Using a treated vial technique, encapsulated nootkatone was significantly more toxic to I. scapularis nymphs (LC50 = 20 ng/cm2) compared with toxicity of the emulsifiable formulation (LC50 = 35 ng/cm2). Thus, the encapsulation of nootkatone improved toxicity for tick control, reduced nootkatone volatility, and reduced plant phytotoxicity.

  6. History of aerosol therapy: liquid nebulization to MDIs to DPIs.

    Science.gov (United States)

    Anderson, Paula J

    2005-09-01

    Inhaled therapies have been used since ancient times and may have had their origins with the smoking of datura preparations in India 4,000 years ago. In the late 18th and in the 19th century, earthenware inhalers were popular for the inhalation of air drawn through infusions of plants and other ingredients. Atomizers and nebulizers were developed in the mid-1800s in France and were thought to be an outgrowth of the perfume industry as well as a response to the fashion of inhaling thermal waters at spas. Around the turn of the 20th century, combustible powders and cigarettes containing stramonium were popular for asthma and other lung complaints. Following the discovery of the utility of epinephrine for treating asthma, hand-bulb nebulizers were developed, as well as early compressor nebulizers. The marketing of the first pressurized metered-dose inhaler for epinephrine and isoproterenol, by Riker Laboratories in 1956, was a milestone in the development of inhaled drugs. There have been remarkable advances in the technology of devices and formulations for inhaled drugs in the past 50 years. These have been influenced greatly by scientific developments in several areas: theoretical modeling and indirect measures of lung deposition, particle sizing techniques and in vitro deposition studies, scintigraphic deposition studies, pharmacokinetics and pharmacodynamics, and the 1987 Montreal Protocol, which banned chlorofluorocarbon propellants. We are now in an era of rapid technologic progress in inhaled drug delivery and applications of aerosol science, with the use of the aerosolized route for drugs for systemic therapy and for gene replacement therapy, use of aerosolized antimicrobials and immunosuppressants, and interest in specific targeting of inhaled drugs.

  7. Global simulations of aerosol processing in clouds

    Directory of Open Access Journals (Sweden)

    C. Hoose

    2008-12-01

    Full Text Available An explicit and detailed representation of in-droplet and in-crystal aerosol particles in stratiform clouds has been introduced in the global aerosol-climate model ECHAM5-HAM. The new scheme allows an evaluation of the cloud cycling of aerosols and an estimation of the relative contributions of nucleation and collision scavenging, as opposed to evaporation of hydrometeors in the global aerosol processing by clouds. On average an aerosol particle is cycled through stratiform clouds 0.5 times. The new scheme leads to important changes in the simulated fraction of aerosol scavenged in clouds, and consequently in the aerosol wet deposition. In general, less aerosol is scavenged into clouds with the new prognostic treatment than what is prescribed in standard ECHAM5-HAM. Aerosol concentrations, size distributions, scavenged fractions and cloud droplet concentrations are evaluated and compared to different observations. While the scavenged fraction and the aerosol number concentrations in the marine boundary layer are well represented in the new model, aerosol optical thickness, cloud droplet number concentrations in the marine boundary layer and the aerosol volume in the accumulation and coarse modes over the oceans are overestimated. Sensitivity studies suggest that a better representation of below-cloud scavenging, higher in-cloud collision coefficients, or a reduced water uptake by seasalt aerosols could reduce these biases.

  8. Global simulations of aerosol processing in clouds

    Directory of Open Access Journals (Sweden)

    C. Hoose

    2008-07-01

    Full Text Available An explicit and detailed representation of in-droplet and in-crystal aerosol particles in stratiform clouds has been introduced in the global aerosol-climate model ECHAM5-HAM. The new scheme allows an evaluation of the cloud cycling of aerosols and an estimation of the relative contributions of nucleation and collision scavenging, as opposed to evaporation of hydrometeors in the global aerosol processing by clouds. On average an aerosol particle is cycled through stratiform clouds 0.5 times. The new scheme leads to important changes in the simulated fraction of aerosol scavenged in clouds, and consequently in the aerosol wet deposition. In general, less aerosol is scavenged into clouds with the new prognostic treatment than what is prescribed in standard ECHAM5-HAM. Aerosol concentrations, size distributions, scavenged fractions and cloud droplet concentrations are evaluated and compared to different observations. While the scavenged fraction and the aerosol number concentrations in the marine boundary layer are well represented in the new model, aerosol optical thickness, cloud droplet number concentrations in the marine boundary layer and the aerosol volume in the accumulation and coarse modes over the oceans are overestimated. Sensitivity studies suggest that a better representation of below-cloud scavenging, higher in-cloud collision coefficients, or a reduced water uptake by seasalt aerosols could reduce these biases.

  9. Enhancement of anti-inflammatory activity of glycyrrhizic acid by encapsulation in chitosan-katira gum nanoparticles.

    Science.gov (United States)

    Bernela, Manju; Ahuja, Munish; Thakur, Rajesh

    2016-08-01

    Efforts were made to improve the bioavailability and efficacy of Glycyrrhizic acid, a triterpentine saponin obtained from Glycyrrhiza glabra, having several pharmacological properties, by its encapsulation in biocompatible biopolymeric nanoparticles. Polycationic chitosan and polyanionic gum katira were used to prepare nanoparticles by ionic complexation method. Glycyrrhizic acid was loaded into the nanoparticles and was then examined for change in its in vivo anti-inflammatory activity against carrageenan-induced rat hind paw inflammation. The effects of concentrations of glycyrrhizic acid, chitosan and katira gum, upon particle size and encapsulation efficiency of glycyrrhizic acid were studied with the help of response surface methodology employing 3-factor, 3-level central composite experimental design. Particle size and encapsulation efficiency of optimized nanoparticulate formulation were 175.8nm and 84.77%, respectively. Particles were observed in transmission electron microscopy to be spherical in shape and 80nm in size. FTIR analysis indicated electrostatic interactions between carboxyl groups of ammonium glycyrrhizinate and amino groups of chitosan. In vitro drug release studies indicated that glycyrrhizic acid was released from the nanoparticles following zero-order kinetics and that there was a sustained release of the drug with 90.71% of it being released over a 12h period, and that the mechanism of release of glycyrrhizic acid from the nanoparticles was a combination of diffusion and erosion of the polymer matrix. In-vivo anti inflammatory efficacy of glycyrrhizic acid clearly improved upon encapsulation in chitosan-katira gum nanoparticles, by overcoming the limited bioavailability of its other forms.

  10. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the UK

    Science.gov (United States)

    McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

    2011-05-01

    Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the UK. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA observed in

  11. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

    Science.gov (United States)

    McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

    2011-09-01

    Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA

  12. Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

    Directory of Open Access Journals (Sweden)

    G. R. McMeeking

    2011-09-01

    Full Text Available Black carbon (BC aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2 measurements of refractory BC (rBC mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA operated by the Facility for Airborne Atmospheric Measurements (FAAM. We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS and used positive matrix factorization to separate hydrocarbon-like (HOA and oxygenated organic aerosols (OOA. We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA did change for

  13. Enhanced encapsulation and bioavailability of breviscapine in PLGA microparticles by nanocrystal and water-soluble polymer template techniques.

    Science.gov (United States)

    Wang, Hong; Zhang, Guangxing; Ma, Xueqin; Liu, Yanhua; Feng, Jun; Park, Kinam; Wang, Wenping

    2017-03-02

    Poly (lactide-co-glycolide) (PLGA) microparticles are widely used for controlled drug delivery. Emulsion methods have been commonly used for preparation of PLGA microparticles, but they usually result in low loading capacity, especially for drugs with poor solubility in organic solvents. In the present study, the nanocrystal technology and a water-soluble polymer template method were used to fabricate nanocrystal-loaded microparticles with improved drug loading and encapsulation efficiency for prolonged delivery of breviscapine. Breviscapine nanocrystals were prepared using a precipitation-ultrasonication method and further loaded into PLGA microparticles by casting in a mold from a water-soluble polymer. The obtained disc-like particles were then characterized and compared with the spherical particles prepared by an emulsion-solvent evaporation method. X-ray powder diffraction (XRPD) and confocal laser scanning microscopy (CLSM) analysis confirmed a highly-dispersed state of breviscapine inside the microparticles. The drug form, loading percentage and fabrication techniques significantly affected the loading capacity and efficiency of breviscapine in PLGA microparticles, and their release performance as well. Drug loading was increased from 2.4 % up to 15.3 % when both nanocrystal and template methods were applied, and encapsulation efficiency increased from 48.5 % to 91.9 %. But loading efficiency was reduced as the drug loading was increased. All microparticles showed an initial burst release, and then a slow release period of 28 days followed by an erosion-accelerated release phase, which provides a sustained delivery of breviscapine over a month. A relatively stable serum drug level for more than 30 days was observed after intramuscular injection of microparticles in rats. Therefore, PLGA microparticles loaded with nanocrystals of poorly soluble drugs provided a promising approach for long-term therapeutic products characterized with preferable in vitro and in

  14. Electrostatic extrusion as a dispersion technique for encapsulation of cells and bioactive compounds

    Directory of Open Access Journals (Sweden)

    Kostić Ivana T.

    2012-01-01

    Full Text Available Significant development of cells and bioactive compound encapsulation technologies is taking place due to an exceptional possibility of their application in various scientific disciplines, including biomedicine, pharmacy, cosmetology, food and agricultural sciences, beverage production, industrial waste treatment. Despite the broad application of microencapsulation, the literature reviews on dispersion techniques for microcapsule/microbead production, their advantages, restrictions and drawbacks are scarce. The purpose of this paper is to assess the possibilities of electrostatic extrusion for encapsulation of biological material, including living cells in hydrogel microbeads. The paper presents an overview of the mechanisms of droplet formation and controlling experimental parameters for producing microbeads by means of electrostatic extrusion. Electrostatic droplet formation utilizes a special type of physical process taking advantage of electrostatic effects occurring in flowing conductive liquids after introduction of an electric field.When an electrostatic field is applied to the metal needle and an electric charge is induced in the liquid flowing out of the needle, the size of droplet detaching from the needle tip decreases as a funcion of applied electrostatic field. It has been shown that few parameters affect microbead size: applied voltage, electrode geometry, needle size, polarity arrangement and polymer concentration. The electrostatic droplet formation is one of the most precise methods, which enables one to produce spherical and uniform particles ranging from 100 μm up to 1000 μm. Most of the authors report that the encapsulated compounds (drugs, enzymes and living cells remain unaltered after electrostatic extrusion. This technique seems to be particularly promising in biotechnology, pharmaceutical and cosmetics industries, where a low-temperature process, preserving heat-sensitive material is a prerequisite. Future efforts in

  15. Trojan Microparticles for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Thierry F. Vandamme

    2012-01-01

    Full Text Available During the last decade, the US Food and Drug Administration (FDA have regulated a wide range of products, (foods, cosmetics, drugs, devices, veterinary, and tobacco which may utilize micro and nanotechnology or contain nanomaterials. Nanotechnology allows scientists to create, explore, and manipulate materials in nano-regime. Such materials have chemical, physical, and biological properties that are quite different from their bulk counterparts. For pharmaceutical applications and in order to improve their administration (oral, pulmonary and dermal, the nanocarriers can be spread into microparticles. These supramolecular associations can also modulate the kinetic releases of drugs entrapped in the nanoparticles. Different strategies to produce these hybrid particles and to optimize the release kinetics of encapsulated drugs are discussed in this review.

  16. Factors Affecting Aerosol Radiative Forcing

    Science.gov (United States)

    Wang, Jingxu; Lin, Jintai; Ni, Ruijing

    2016-04-01

    Rapid industrial and economic growth has meant a large amount of aerosols in the atmosphere with strong radiative forcing (RF) upon the climate system. Over parts of the globe, the negative forcing of aerosols has overcompensated for the positive forcing of greenhouse gases. Aerosol RF is determined by emissions and various chemical-transport-radiative processes in the atmosphere, a multi-factor problem whose individual contributors have not been well quantified. In this study, we analyze the major factors affecting RF of secondary inorganic aerosols (SIOAs, including sulfate, nitrate and ammonium), primary organic aerosol (POA), and black carbon (BC). We analyze the RF of aerosols produced by 11 major regions across the globe, including but not limited to East Asia, Southeast Asia, South Asia, North America, and Western Europe. Factors analyzed include population size, per capita gross domestic production (GDP), emission intensity (i.e., emissions per unit GDP), chemical efficiency (i.e., mass per unit emissions) and radiative efficiency (i.e., RF per unit mass). We find that among the 11 regions, East Asia produces the largest emissions and aerosol RF, due to relatively high emission intensity and a tremendous population size. South Asia produce the second largest RF of SIOA and BC and the highest RF of POA, in part due to its highest chemical efficiency among all regions. Although Southeast Asia also has large emissions, its aerosol RF is alleviated by its lowest chemical efficiency. The chemical efficiency and radiative efficiency of BC produced by the Middle East-North Africa are the highest across the regions, whereas its RF is lowered by a small per capita GDP. Both North America and Western Europe have low emission intensity, compensating for the effects on RF of large population sizes and per capita GDP. There has been a momentum to transfer industries to Southeast Asia and South Asia, and such transition is expected to continue in the coming years. The

  17. MISR Aerosol Climatology Product V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This product is 1)the microphysical and scattering characteristics of pure aerosol upon which routine retrievals are based;2)mixtures of pure aerosol to be compared...

  18. CATS Aerosol Typing and Future Directions

    Science.gov (United States)

    McGill, Matt; Yorks, John; Scott, Stan; Palm, Stephen; Hlavka, Dennis; Hart, William; Nowottnick, Ed; Selmer, Patrick; Kupchock, Andrew; Midzak, Natalie; Trepte, Chip; Vaughan, Mark; Colarco, Peter; da Silva, Arlindo

    2016-01-01

    The Cloud Aerosol Transport System (CATS), launched in January of 2015, is a lidar remote sensing instrument that will provide range-resolved profile measurements of atmospheric aerosols and clouds from the International Space Station (ISS). CATS is intended to operate on-orbit for at least six months, and up to three years. Status of CATS Level 2 and Plans for the Future:Version. 1. Aerosol Typing (ongoing): Mode 1: L1B data released later this summer; L2 data released shortly after; Identify algorithm biases (ex. striping, FOV (field of view) biases). Mode 2: Processed Released Currently working on correcting algorithm issues. Version 2 Aerosol Typing (Fall, 2016): Implementation of version 1 modifications Integrate GEOS-5 aerosols for typing guidance for non spherical aerosols. Version 3 Aerosol Typing (2017): Implementation of 1-D Var Assimilation into GEOS-5 Dynamic lidar ratio that will evolve in conjunction with simulated aerosol mixtures.

  19. Miniature Sensor for Aerosol Mass Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project seeks to develop a miniature sensor for mass measurement of size-classified aerosols. A cascade impactor will be used to classify aerosol sample...

  20. Aerosol Emission during Human Speech

    Science.gov (United States)

    Asadi, Sima; Ristenpart, William

    2016-11-01

    The traditional emphasis for airborne disease transmission has been on coughing and sneezing, which are dramatic expiratory events that yield easily visible droplets. Recent research suggests that normal speech can release even larger quantities of aerosols that are too small to see with the naked eye, but are nonetheless large enough to carry a variety of pathogens (e.g., influenza A). This observation raises an important question: what types of speech emit the most aerosols? Here we show that the concentration of aerosols emitted during healthy human speech is positively correlated with both the amplitude (loudness) and fundamental frequency (pitch) of the vocalization. Experimental measurements with an aerodynamic particle sizer (APS) indicate that speaking in a loud voice (95 decibels) yields up to fifty times more aerosols than in a quiet voice (75 decibels), and that sounds associated with certain phonemes (e.g., [a] or [o]) release more aerosols than others. We interpret these results in terms of the egressive airflow rate associated with each phoneme and the corresponding fundamental frequency, which is known to vary significantly with gender and age. The results suggest that individual speech patterns could affect the probability of airborne disease transmission.

  1. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Muller, M.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2012-03-01

    Many concentrating photovoltaic (CPV) systems use a polymeric encapsulant to couple and optical component and/or coverglass to the cell. In that location, the encapsulation improves the transmission of concentrated optical flux through interface(s), while protecting the cell from the environment. The durability of encapsulation materials, however, is not well established relative to the desired service life of 30 years. Therefore, we have initiated a screen test to identify the field-induced failure modes for a variety of popular PV encapsulation materials. An existing CPV module (with no PV cells present) was modified to accommodate encapsulation specimens. The module (where nominal concentration of solar flux is 500x for the domed-Fresnel design) has been mounted on a tracker in Golden, CO (elevation 1.79 km). Initial results are reported here for 18 months cumulative exposure, including the hottest and coldest months of the past year. Characteristics observed at intervals during that time include: visual appearance, direct and hemispherical transmittance, and mass. Degradation may be assessed from subsequent analysis (including yellowness index and cut-on frequency) relative to the ambient conditions present during field exposure. The fluorescence signature observed of all the silicone specimens is examined here, including possible factors of causation -- the platinum catalyst used in the addition cured materials as well as the primer used to promote adhesion to the quartz substrate and superstrate.

  2. Antioxidant Effects of Quercetin and Catechin Encapsulated into PLGA Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hector Pool

    2012-01-01

    Full Text Available Polymeric nanoparticles (PLGA have been developed for the encapsulation and controlled release of quercetin and catechin. Nanoparticles were fabricated using a solvent displacement method. Physicochemical properties were measured by light scattering, scanning electron microscopy and ζ-potential, X-ray diffraction, infrared spectroscopy and differential scanning calorimetry. Encapsulation efficiency and in vitro release profiles were obtained from differential pulse voltammetry experiments. Antioxidant properties of free and encapsulated flavonoids were determined by TBARS, fluorescence spectroscopy and standard chelating activity methods. Relatively small (d≈ 400 nm polymeric nanoparticles were obtained containing quercetin or catechin in a non-crystalline form (EE ≈ 79% and the main interactions between the polymer and each flavonoid were found to consist of hydrogen bonds. In vitro release profiles were pH-dependant, the more acidic pH, the faster release of each flavonoid from the polymeric nanoparticles. The inhibition of the action of free radicals and chelating properties, were also enhanced when quercetin and catechin were encapsulated within PLGA nanoparticles. The information obtained from this study will facilitate the design and fabrication of polymeric nanoparticles as possible oral delivery systems for encapsulation, protection and controlled release of flavonoids aimed to prevent oxidative stress in human body or food products.

  3. Recent trends and applications of encapsulating materials for probiotic stability.

    Science.gov (United States)

    Riaz, Qurat Ul Ain; Masud, Tariq

    2013-01-01

    The importance of probiotics and their live delivery in the gastrointestinal tract has gained much importance in the recent past. Many reports have indicated that there is poor viability of probiotic bacteria in dairy based products, both fermented and non-fermented, and also in the human gastro-intestinal system is questionable. In this case, microencapsulation is the most significant emerging and efficient technology that is being used for the preservation of probiotics against adverse environmental conditions. Apart from different techniques of microencapsulation, various types of encapsulating materials are also used for the process, namely, alginate, chitosan, carrageenan, gums (locust bean, gellan gum, xanthan gum, etc.), gelatin, whey protein, starch, and compression coating. Each one of the encapsulating materials has its own unique characteristics of capsule formation and provision of shape, appearance, and strength to microbeads. The type of encapsulating material also influences the viability of probiotics during storage, processing, and in the gastrointestinal tract. The effectiveness of any material depends not upon its capsule forming capability, strength, and enhancing viability but also on its cheapness, availability, and biocompatibility. So, added convenience and reduced packaging costs may also be used to offset the cost of encapsulating one or more ingredients. Encapsulated forms of ingredients provide a longer shelf life for the product.

  4. Antigenic heterogeneity of immunoglobulin A1 proteases from encapsulated and non-encapsulated Haemophilus influenzae.

    Science.gov (United States)

    Kilian, M; Thomsen, B

    1983-10-01

    Indirect evidence suggests that immunoglobulin A1 (IgA1) proteases may be factors in the pathogenesis of certain infectious diseases, including meningitis, gonorrhoea, and destructive periodontitis. Bacterial IgA1 proteases are therefore potential candidates as vaccines. In this study, IgA1 proteases from 166 clinical isolates and reference strains of Haemophilus influenzae and Haemophilus aegyptius were compared with regard to specific activity and pattern of enzyme inhibition by antisera raised against IgA1 protease from nine selected strains of H. influenzae. A total of 93% of H. influenzae strains and all H. aegyptius strains had detectable IgA1 protease activity. The majority of strains cleaved a prolyl-seryl or a prolyl-threonyl peptide bond in the alpha 1 hinge region, whereas occasional H. influenzae strains possessed two separate IgA1 proteases with these two specific activities. Of the 155 IgA1 protease-producing strains, all except 12 could be assigned to one of 14 IgA1 protease "inhibition types," each defined by a characteristic pattern of inhibition by the nine antisera. There was no correlation between IgA1 protease type and biotype of the strains. However, among 92 encapsulated H. influenzae strains, a close correlation between capsular serotype and IgA1 protease type was observed. With the exception of serotype f, strains of all capsular serotypes produced an exclusive antigenic type of IgA1 protease. All 38 strains of serotype b produced IgA1 protease of inhibition type 1, which was never demonstrated in non-encapsulated H. influenzae strains. These results facilitate the detection of an antibody response against specific IgA1 proteases and are of practical value for a possible future vaccine against H. influenzae serotype b infections.

  5. Drug Facts

    Medline Plus

    Full Text Available ... The Link Between Drug Use and HIV/AIDS Recovery & Treatment Drug Treatment Facts Does Drug Treatment Work? ... and Family Can Help Find Treatment/Rehab Resources Prevent Drug Use Help Children and Teens Stay Drug- ...

  6. Drug Facts

    Medline Plus

    Full Text Available ... Addiction? Addiction Risk Factors Does Addiction Run in Families? Why Is It So Hard to Quit Drugs? ... Drug Use Hurts Other People Drug Use Hurts Families Drug Use Hurts Kids Drug Use Hurts Unborn ...

  7. Drug Allergy

    Science.gov (United States)

    ... Loss of consciousness Other conditions resulting from drug allergy Less common drug allergy reactions occur days or ... you take the drug. Drugs commonly linked to allergies Although any drug can cause an allergic reaction, ...

  8. Drug Facts

    Medline Plus

    Full Text Available ... Use Hurts Unborn Children Drug Use Hurts Your Health Drug Use Hurts Bodies Drug Use Hurts Brains Drug Use and Mental Health Problems Often Happen Together The Link Between Drug ...

  9. Drug-loaded erythrocytes: on the road toward marketing approval

    OpenAIRE

    Bourgeaux V; Lanao JM; Bax BE; Godfrin Y

    2016-01-01

    Vanessa Bourgeaux,1 José M Lanao,2 Bridget E Bax,3 Yann Godfrin11ERYTECH Pharma, Lyon, France; 2Department of Pharmacy and Pharmaceutical Technology, University of Salamanca, Salamanca, Spain; 3Cardiovascular and Cell Sciences Research Institute, St George’s University of London, London, UKAbstract: Erythrocyte drug encapsulation is one of the most promising therapeutic alternative approaches for the administration of toxic or rapidly cleared drugs. Drug-loaded erythrocyt...

  10. Origins of atmospheric aerosols. Basic concepts on aerosol main physical properties; L`aerosol atmospherique: ses origines quelques notions sur les principales proprietes physiques des aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Renoux, A. [Paris-12 Univ., 94 - Creteil (France). Laboratoire de Physique des aerosols et de transferts des contaminations

    1996-12-31

    Natural and anthropogenic sources of atmospheric aerosols are reviewed and indications of their concentrations and granulometry are given. Calculation of the lifetime of an atmospheric aerosol of a certain size is presented and the various modes of aerosol granulometry and their relations with photochemical and physico-chemical processes in the atmosphere are discussed. The main physical, electrical and optical properties of aerosols are also presented: diffusion coefficient, dynamic mobility and relaxation time, Stokes number, limit rate of fall, electrical mobility, optical diffraction

  11. The detection of encapsulated and non-encapsulated species of Trichinella suggests the existence of two evolutive lines in the genus

    Directory of Open Access Journals (Sweden)

    Pozio E.

    2001-06-01

    Full Text Available In recent years, the discovery of many non-encapsulated isolates of Trichinella, designated Trichinella pseudospiralis and the identification of a new non-encapsulated species, Trichinella papuae, has revealed that the biomass of the genus Trichinella does not only include the well known encapsulated species (T. spiralis, T. nativa, T. britovi, T. murrelli, and T. nelsoni but also includes geographically disseminated, non-encapsulated species that represent important biological entities in the genus. Larvae of the first stage (L1 of both non-encapsulated and encapsulated species are able to penetrate the muscle cell and induce a dedifferentiation of this cell. But following this point in the parenteral cycle, non-encapsulated and encapsulated species diverge with respect to their developmental strategies where L1 of encapsulated species are able to induce the nurse cell to synthesize collagen, unlike non-encapsulated larvae which do not induce collagen production. The presence or absence of a collagen capsule is of great importance in the natural cycle of these parasites in that it allows the encapsulated larva to survive to substantially longer periods of time and therefore remain infective even within putrefied muscle tissue.

  12. New hybrid encapsulation for flexible organic light-emitting devices on plastic substrates

    Institute of Scientific and Technical Information of China (English)

    LIU Song; ZHANG DeQiang; LI Yang; DUAN Lian; DONG GuiFang; WANG LiDuo; QIU Yong

    2008-01-01

    The hybrid encapsulation for flexible organic light-emitting devices on plastic substrate was investi-gated. The hybrid encapsulation consisted of four periods of Alq3/LiF layers as the pre-encapsulation layer and a flexible aluminum foil coated with getter as the encapsulation cap. We measured the device lifetime at a continuous constant current of 20 mA/cm2, which corresponded to an initial luminance of 2000 cd/m2, The half-luminance decay time of the encapsulated device was about 458 h. More over, the hybrid encapsulation is ultrathin and flexible, ensuring device bendability.

  13. ATI TDA 5A aerosol generator evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, D.A.

    1998-07-27

    Oil based aerosol ``Smoke`` commonly used for testing the efficiency and penetration of High Efficiency Particulate Air filters (HEPA) and HEPA systems can produce flammability hazards that may not have been previously considered. A combustion incident involving an aerosol generator has caused an investigation into the hazards of the aerosol used to test HEPA systems at Hanford.

  14. DARE: a dedicated aerosols retrieval instrument

    NARCIS (Netherlands)

    Court, A.J.; Smorenburg, K.; Courrèges-Lacoste, G.B.; Visser, H.; Leeuw, G. de; Decae, R.

    2004-01-01

    Satellite remote sensing of aerosols is a largely unresolved problem. A dedicated instrument aimed at aerosols would be able to reduce the large uncertainties connected to this kind of remote sensing. TNO is performing a study of a space based instrument for aerosol measurements, together with the s

  15. Highly Resolved Paleoclimatic Aerosol Records

    DEFF Research Database (Denmark)

    Kettner, Ernesto

    In ice cores a plethora of proxies for paleoclimatic conditions is archived. Air trapped in the ice during firnification allows for direct measurements of the concentrations and isotope ratios of paleoatmospheric gases while, the isotopic composition of the ice matrix itself is related...... to paleotemperatures. Impurities in the matrix are comprised of particulate and soluble aerosols, each carrying information on its source’s activitiy and|or proximity. Opposed to gases and water isotopes, the seasonality of many aerosols is not smoothed out in the firn column so that large concentration gradients...... with frequently changing signs are preserved. Therefore, these aerosol records can be used for dating by annual layer counting. However, with increasing depth the annual layer thicknesses decreases due to pressure and ice flow and accurate dating is possible only as long as the rapid variations can be resolved...

  16. Wind reduction by aerosol particles

    Science.gov (United States)

    Jacobson, Mark Z.; Kaufman, Yoram J.

    2006-12-01

    Aerosol particles are known to affect radiation, temperatures, stability, clouds, and precipitation, but their effects on spatially-distributed wind speed have not been examined to date. Here, it is found that aerosol particles, directly and through their enhancement of clouds, may reduce near-surface wind speeds below them by up to 8% locally. This reduction may explain a portion of observed ``disappearing winds'' in China, and it decreases the energy available for wind-turbine electricity. In California, slower winds reduce emissions of wind-driven soil dust and sea spray. Slower winds and cooler surface temperatures also reduce moisture advection and evaporation. These factors, along with the second indirect aerosol effect, may reduce California precipitation by 2-5%, contributing to a strain on water supply.

  17. Aerosol retrieval experiments in the ESA Aerosol_cci project

    Directory of Open Access Journals (Sweden)

    T. Holzer-Popp

    2013-08-01

    Full Text Available Within the ESA Climate Change Initiative (CCI project Aerosol_cci (2010–2013, algorithms for the production of long-term total column aerosol optical depth (AOD datasets from European Earth Observation sensors are developed. Starting with eight existing pre-cursor algorithms three analysis steps are conducted to improve and qualify the algorithms: (1 a series of experiments applied to one month of global data to understand several major sensitivities to assumptions needed due to the ill-posed nature of the underlying inversion problem, (2 a round robin exercise of "best" versions of each of these algorithms (defined using the step 1 outcome applied to four months of global data to identify mature algorithms, and (3 a comprehensive validation exercise applied to one complete year of global data produced by the algorithms selected as mature based on the round robin exercise. The algorithms tested included four using AATSR, three using MERIS and one using PARASOL. This paper summarizes the first step. Three experiments were conducted to assess the potential impact of major assumptions in the various aerosol retrieval algorithms. In the first experiment a common set of four aerosol components was used to provide all algorithms with the same assumptions. The second experiment introduced an aerosol property climatology, derived from a combination of model and sun photometer observations, as a priori information in the retrievals on the occurrence of the common aerosol components. The third experiment assessed the impact of using a common nadir cloud mask for AATSR and MERIS algorithms in order to characterize the sensitivity to remaining cloud contamination in the retrievals against the baseline dataset versions. The impact of the algorithm changes was assessed for one month (September 2008 of data: qualitatively by inspection of monthly mean AOD maps and quantitatively by comparing daily gridded satellite data against daily averaged AERONET sun

  18. Aerosol retrieval experiments in the ESA Aerosol_cci project

    Science.gov (United States)

    Holzer-Popp, T.; de Leeuw, G.; Griesfeller, J.; Martynenko, D.; Klüser, L.; Bevan, S.; Davies, W.; Ducos, F.; Deuzé, J. L.; Graigner, R. G.; Heckel, A.; von Hoyningen-Hüne, W.; Kolmonen, P.; Litvinov, P.; North, P.; Poulsen, C. A.; Ramon, D.; Siddans, R.; Sogacheva, L.; Tanre, D.; Thomas, G. E.; Vountas, M.; Descloitres, J.; Griesfeller, J.; Kinne, S.; Schulz, M.; Pinnock, S.

    2013-08-01

    Within the ESA Climate Change Initiative (CCI) project Aerosol_cci (2010-2013), algorithms for the production of long-term total column aerosol optical depth (AOD) datasets from European Earth Observation sensors are developed. Starting with eight existing pre-cursor algorithms three analysis steps are conducted to improve and qualify the algorithms: (1) a series of experiments applied to one month of global data to understand several major sensitivities to assumptions needed due to the ill-posed nature of the underlying inversion problem, (2) a round robin exercise of "best" versions of each of these algorithms (defined using the step 1 outcome) applied to four months of global data to identify mature algorithms, and (3) a comprehensive validation exercise applied to one complete year of global data produced by the algorithms selected as mature based on the round robin exercise. The algorithms tested included four using AATSR, three using MERIS and one using PARASOL. This paper summarizes the first step. Three experiments were conducted to assess the potential impact of major assumptions in the various aerosol retrieval algorithms. In the first experiment a common set of four aerosol components was used to provide all algorithms with the same assumptions. The second experiment introduced an aerosol property climatology, derived from a combination of model and sun photometer observations, as a priori information in the retrievals on the occurrence of the common aerosol components. The third experiment assessed the impact of using a common nadir cloud mask for AATSR and MERIS algorithms in order to characterize the sensitivity to remaining cloud contamination in the retrievals against the baseline dataset versions. The impact of the algorithm changes was assessed for one month (September 2008) of data: qualitatively by inspection of monthly mean AOD maps and quantitatively by comparing daily gridded satellite data against daily averaged AERONET sun photometer

  19. Drug-Loaded Perfluorocarbon Nanodroplets for Ultrasound-Mediated Drug Delivery.

    Science.gov (United States)

    Rapoport, Natalya

    2016-01-01

    The interaction of nanoparticles with directed energy is a novel application in targeted drug delivery. This chapter focuses on perfluorocarbon nanoemulsions, whose action in drug delivery depends on the ultrasound-triggered phase shift from liquid to gaseous state. These nanoemulsions have great potential for unloading encapsulated drugs at a desired time and location in the body in response to directed ultrasound. In addition, they actively alter their nano-environment for enhancing drug transport through various biological barriers to sites of action, which significantly enhances therapeutic outcome.

  20. Properties of probiotics and encapsulated probiotics in food

    Directory of Open Access Journals (Sweden)

    V. Hazal Ozyurt

    2014-12-01

    Full Text Available Probiotics are microorganisms which confer health benefi ts upon application in suffi ciently-high viable cell amounts. Probiotics are typically members of Lactobacillus and Bifidobacterium species commonly associated with human gastrointestinal tracts. In the recent past, there has been a rising interest in producing functional foods containing encapsulated probiotic bacteria. Recent studies have been reported using dairy products like cheese, yogurt and ice cream as food carrier, and non-dairy products like meat, fruits, cereals, chocolate, etc. However, the industrial sector contains only few encapsulated probiotic products. Probiotics have been developed by several companies in a capsule or a tablet form. The review compiles probiotics, encapsulation technology and cell life in the food matrices.

  1. Hydrogels for in situ encapsulation of biomimetic membrane arrays

    DEFF Research Database (Denmark)

    Ibragimova, Sania; Jensen, Karin Bagger Stibius; Szewczykowski, Piotr Przemyslaw

    2012-01-01

    . We investigated gels for in situ encapsulation of multiple BLMs formed across apertures in a hydrophobic ethylene tetrafluoroethylene (ETFE) support. The encapsulation gels consisted of networks of poly(ethylene glycol)-dimethacrylate or poly(ethylene glycol)-diacrylate polymerized using either...... to chemically initiated hydrogels; however, for all hydrogels the permeability was several-fold higher than the water permeability of conventional reverse osmosis (RO) membranes. Lifetimes of freestanding BLM arrays in gel precursor solutions were short compared to arrays formed in buffer. However, polymerizing......Hydrogels are hydrophilic, porous polymer networks that can absorb up to thousands of times their own weight in water. They have many potential applications, one of which is the encapsulation of freestanding black lipid membranes (BLMs) for novel separation technologies or biosensor applications...

  2. Degradation of Silicone Encapsulants in CPV Optics: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David C.; Tappan, Ian A.; Cai, Can; Dauskardt, Reinhold H.

    2016-07-01

    High efficiency multijunction solar cells in terrestrial concentrator photovoltaic (CPV) modules are becoming an increasingly cost effective and viable option in utility scale power generation. As with other utility scale photovoltaics, CPV modules need to guarantee operational lifetimes of at least 25 years. The reliability of optical elements in CPV modules poses a unique materials challenge due to the increased UV irradiance and enhanced temperature cycling associated with concentrated solar flux. The polymeric and thin film materials used in the optical elements are especially susceptible to UV damage, diurnal temperature cycling and active chemical species from the environment. We used fracture mechanics approaches to study the degradation modes including: the adhesion between the encapsulant and the cell or secondary optical element; and the cohesion of the encapsulant itself. Understanding the underlying mechanisms of materials degradation under elevated stress conditions is critical for commercialization of CPV technology and can offer unique insights into degradation modes in similar encapsulants used in other photovoltaic modules.

  3. Charge transfer in conjugated oligomers encapsulated into carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Almadori, Y.; Alvarez, L.; Michel, T.; Le Parc, R.; Bantignies, J.L.; Hermet, P.; Sauvajol, J.L. [Laboratoire Charles Coulomb UMR 5521, Universite Montpellier 2, 34095 Montpellier (France); Laboratoire Charles Coulomb UMR 5521, CNRS, 34095 Montpellier (France); Arenal, R. [Laboratoire d' Etude des Microstructures, CNRS-ONERA, 92322 Chatillon (France); Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, U. Zaragoza, 50018 Zaragoza (Spain); Babaa, R. [Laboratoire de Chimie des Surfaces et Interfaces, CEA, IRAMIS, SPCSI, 91191 Gif-sur-Yvette Cedex (France); Chemical Engineering Department, University of Technology PETRONAS, UTP, Ipoh-Perak (Malaysia); Jouselme, B.; Palacin, S. [Laboratoire de Chimie des Surfaces et Interfaces, CEA, IRAMIS, SPCSI, 91191 Gif-sur-Yvette Cedex (France)

    2011-11-15

    This study deals with a hybrid system consisting in quaterthiophene derivative encapsulated inside single-walled and multi-walled carbon nanotubes. Investigations of the encapsulation step are performed by transmission electron microscopy. Raman spectroscopy data point out different behaviors depending on the laser excitation energy with respect to the optical absorption of quaterthiophene. At low excitation energy (far from the oligomer resonance window) there is no significant modification of the Raman spectra before and after encapsulation. By contrast, at high excitation energy (close to the oligomer resonance window), Raman spectra exhibit a G-band shift together with an important RBM intensity loss, suggesting a significant charge transfer between the inserted molecule and the host nanotubes. Those results suggest a photo induced process leading to a significant charge transfer. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Encapsulation of black carrot juice using spray and freeze drying.

    Science.gov (United States)

    Murali, S; Kar, Abhijit; Mohapatra, Debabandya; Kalia, Pritam

    2015-12-01

    Black carrot juice extracted using pectinase enzyme was encapsulated in three different carrier materials (maltodextrin 20DE, gum arabic and tapioca starch) using spray drying at four inlet temperatures (150, 175, 200 and 225 ℃) and freeze drying at a constant temperature of - 53 ℃ and vacuum of 0.22-0.11 mbar with the constant feed mixture. The products were analyzed for total anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and total colour change. For both the drying methods followed in this study, maltodextrin 20DE as the carrier material has proven to be better in retaining maximum anthocyanin and antioxidant activity compared to gum arabic and tapioca starch. The best spray dried product, was obtained at 150 ℃. The most acceptable was the freeze dried product with maximum anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and colour change.

  5. Properties of probiotics and encapsulated probiotics in food.

    Science.gov (United States)

    Ozyurt, V Hazal; Ötles, Semih

    2014-01-01

    Probiotics are microorganisms which confer health benefits upon application in sufficiently-high viable cell amounts. Probiotics are typically members of Lactobacillus and Bifidobacterium species commonly associated with human gastrointestinal tracts. In the recent past, there has been a rising interest in producing functional foods containing encapsulated probiotic bacteria. Recent studies have been reported using dairy products like cheese, yogurt and ice cream as food carrier, and non-dairy products like meat, fruits, cereals, chocolate, etc. However, the industrial sector contains only few encapsulated probiotic products. Probiotics have been developed by several companies in a capsule or a tablet form. The review compiles probiotics, encapsulation technology and cell life in the food matrices.

  6. Conformally encapsulated multi-electrode arrays with seamless insulation

    Energy Technology Data Exchange (ETDEWEB)

    Tabada, Phillipe J.; Shah, Kedar G.; Tolosa, Vanessa; Pannu, Satinderall S.; Tooker, Angela; Delima, Terri; Sheth, Heeral; Felix, Sarah

    2016-11-22

    Thin-film multi-electrode arrays (MEA) having one or more electrically conductive beams conformally encapsulated in a seamless block of electrically insulating material, and methods of fabricating such MEAs using reproducible, microfabrication processes. One or more electrically conductive traces are formed on scaffold material that is subsequently removed to suspend the traces over a substrate by support portions of the trace beam in contact with the substrate. By encapsulating the suspended traces, either individually or together, with a single continuous layer of an electrically insulating material, a seamless block of electrically insulating material is formed that conforms to the shape of the trace beam structure, including any trace backings which provide suspension support. Electrical contacts, electrodes, or leads of the traces are exposed from the encapsulated trace beam structure by removing the substrate.

  7. Encapsulation of bacteria and viruses in electrospun nanofibres

    Science.gov (United States)

    Salalha, W.; Kuhn, J.; Dror, Y.; Zussman, E.

    2006-09-01

    Bacteria and viruses were encapsulated in electrospun polymer nanofibres. The bacteria and viruses were suspended in a solution of poly(vinyl alcohol) (PVA) in water and subjected to an electrostatic field of the order of 1 kV cm-1. Encapsulated bacteria in this work, (Escherichia coli, Staphylococcus albus) and bacterial viruses (T7, T4, λ) managed to survive the electrospinning process while maintaining their viability at fairly high levels. Subsequently the bacteria and viruses remain viable during three months at -20 and -55 °C without a further decrease in number. The present results demonstrate the potential of the electrospinning process for the encapsulation and immobilization of living biological material.

  8. Encapsulation of bacteria and viruses in electrospun nanofibres

    Energy Technology Data Exchange (ETDEWEB)

    Salalha, W [Faculty of Mechanical Engineering, Technion, Israel Institute of Technology, Haifa 32000 (Israel); Kuhn, J [Faculty of Biology, Technion, Israel Institute of Technology, Haifa 32000 (Israel); Dror, Y [Faculty of Mechanical Engineering, Technion, Israel Institute of Technology, Haifa 32000 (Israel); Zussman, E [Faculty of Mechanical Engineering, Technion, Israel Institute of Technology, Haifa 32000 (Israel)

    2006-09-28

    Bacteria and viruses were encapsulated in electrospun polymer nanofibres. The bacteria and viruses were suspended in a solution of poly(vinyl alcohol) (PVA) in water and subjected to an electrostatic field of the order of 1 kV cm{sup -1}. Encapsulated bacteria in this work (Escherichia coli, Staphylococcus albus) and bacterial viruses (T7, T4, {lambda}) managed to survive the electrospinning process while maintaining their viability at fairly high levels. Subsequently the bacteria and viruses remain viable during three months at -20 and -55 deg. C without a further decrease in number. The present results demonstrate the potential of the electrospinning process for the encapsulation and immobilization of living biological material.

  9. Encapsulation method for atom probe tomography analysis of nanoparticles.

    Science.gov (United States)

    Larson, D J; Giddings, A D; Wu, Y; Verheijen, M A; Prosa, T J; Roozeboom, F; Rice, K P; Kessels, W M M; Geiser, B P; Kelly, T F

    2015-12-01

    Open-space nanomaterials are a widespread class of technologically important materials that are generally incompatible with analysis by atom probe tomography (APT) due to issues with specimen preparation, field evaporation and data reconstruction. The feasibility of encapsulating such non-compact matter in a matrix to enable APT measurements is investigated using nanoparticles as an example. Simulations of field evaporation of a void, and the resulting artifacts in ion trajectory, underpin the requirement that no voids remain after encapsulation. The approach is demonstrated by encapsulating Pt nanoparticles in an ZnO:Al matrix created by atomic layer deposition, a growth technique which offers very high surface coverage and conformality. APT measurements of the Pt nanoparticles are correlated with transmission electron microscopy images and numerical simulations in order to evaluate the accuracy of the APT reconstruction.

  10. Modeling powder encapsulation in dosator-based machines: I. Theory.

    Science.gov (United States)

    Khawam, Ammar

    2011-12-15

    Automatic encapsulation machines have two dosing principles: dosing disc and dosator. Dosator-based machines compress the powder to plugs that are transferred into capsules. The encapsulation process in dosator-based capsule machines was modeled in this work. A model was proposed to predict the weight and length of produced plugs. According to the model, the plug weight is a function of piston dimensions, powder-bed height, bulk powder density and precompression densification inside dosator while plug length is a function of piston height, set piston displacement, spring stiffness and powder compressibility. Powder densification within the dosator can be achieved by precompression, compression or both. Precompression densification depends on the powder to piston height ratio while compression densification depends on piston displacement against powder. This article provides the theoretical basis of the encapsulation model, including applications and limitations. The model will be applied to experimental data separately.

  11. Encapsulation of shiitake (Lenthinus edodes) flavors by spray drying.

    Science.gov (United States)

    Shiga, Hirokazu; Yoshii, Hidefumi; Ohe, Hisashi; Yasuda, Masahumi; Furuta, Takeshi; Kuwahara, Hiroshige; Ohkawara, Masaaki; Linko, Pekka

    2004-01-01

    Powdery encapsulation of shiitake flavors, extracted from dried shiitake, was investigated by spray drying. Flavor retention increased with an increase in drying air temperature and solid content, and decreased with an increase in dextrose equivalents of maltodextrin. A heat-treatment of the extract liquid made the lenthionine concentration increase, but did not influence the concentrations of the other flavors. The formation of lenthionine with heat-treatment could be described by the consecutive unimolecular-type first order reaction. Lenthionine content in a spray-dried powder prepared with the heated extracted liquid significantly increased. alpha-Cyclodextrin was the most suitable encapsulant of alpha-, beta-, and gamma-cyclodextrins to prepare the spray-dried powder, including lenthionine. The flavor retentions were markedly increased by using of alpha-cyclodextrin and maltodextrin in combination as an encapsulant.

  12. Evaluation of Encapsulated Inhibitor for Autonomous Corrosion Protection

    Science.gov (United States)

    Johnsey, M. N.; Li, W.; Buhrow, J. W.; Calle, L. M.; Pearman, B. P.; Zhang, X.

    2015-01-01

    This work concerns the development of smart coating technologies based on microencapsulation for the autonomous control of corrosion. Microencapsulation allows the incorporation of corrosion inhibitors into coating which provides protection through corrosion-controlled release of these inhibitors.One critical aspect of a corrosion protective smart coating is the selection of corrosion inhibitor for encapsulation and comparison of the inhibitor function before and after encapsulation. For this purpose, a systematic approach is being used to evaluate free and encapsulated corrosion inhibitors by salt immersion. Visual, optical microscope, and Scanning Electron Microscope (with low-angle backscatter electron detector) are used to evaluate these inhibitors. It has been found that the combination of different characterization tools provide an effective method for evaluation of early stage localized corrosion and the effectiveness of corrosion inhibitors.

  13. Enhanced structural stability of DNA origami nanostructures by graphene encapsulation

    Science.gov (United States)

    Matković, Aleksandar; Vasić, Borislav; Pešić, Jelena; Prinz, Julia; Bald, Ilko; Milosavljević, Aleksandar R.; Gajić, Radoš

    2016-02-01

    We demonstrate that a single-layer graphene replicates the shape of DNA origami nanostructures very well. It can be employed as a protective layer for the enhancement of structural stability of DNA origami nanostructures. Using the AFM based manipulation, we show that the normal force required to damage graphene encapsulated DNA origami nanostructures is over an order of magnitude greater than for the unprotected ones. In addition, we show that graphene encapsulation offers protection to the DNA origami nanostructures against prolonged exposure to deionized water, and multiple immersions. Through these results we demonstrate that graphene encapsulated DNA origami nanostructures are strong enough to sustain various solution phase processing, lithography and transfer steps, thus extending the limits of DNA-mediated bottom-up fabrication.

  14. Adhesion and debonding kinetics of photovoltaic encapsulation in moist environments: Adhesion and debonding kinetics of photovoltaic encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Novoa, Fernando D. [Department of Materials Science and Engineering, Stanford University, Stanford CA 94305-2205 USA; Miller, David C. [National Center for Photovoltaics, NREL, Golden CO USA; Dauskardt, Reinhold H. [Department of Materials Science and Engineering, Stanford University, Stanford CA 94305-2205 USA

    2015-07-27

    Debonding of photovoltaic (PV) encapsulation in moist environments is frequently reported but presently not well understood or quantified. Temperature cycling, moisture, and mechanical loads often cause loss of encapsulation adhesion and interfacial debonding, initially facilitating back-reflectance and reduced electrical current, but ultimately leading to internal corrosion and loss of module functionality. To investigate the effects of temperature (T) and relative humidity (RH) on the kinetics of encapsulation debonding, we developed a mechanics-based technique to measure encapsulation debond energy and debond growth rates in a chamber of controlled environment. The debond energy decreased from 2.15 to 1.75 kJ m-2 in poly(ethylene-co-vinyl acetate) (EVA) and from 0.67 to 0.52 kJ m-2 in polyvinyl butyral when T increased from 25 to 50 degrees C and 20 to 40 degrees C, respectively. The debond growth rates of EVA increased up to 1000-fold with small increases of T (10 degrees C) and RH (15%). To elucidate the mechanisms of environmental debonding, we developed a fracture-kinetics model, where the viscoelastic relaxation processes at the debonding-tip are used to predict debond growth. The model and techniques constitute the fundamental basis for developing accelerated aging tests and long-term reliability predictions for PV encapsulation.

  15. Aerosol Transport Over Equatorial Africa

    Science.gov (United States)

    Gatebe, C. K.; Tyson, P. D.; Annegarn, H. J.; Kinyua, A. M.; Piketh, S.; King, M.; Helas, G.

    1999-01-01

    Long-range and inter-hemispheric transport of atmospheric aerosols over equatorial Africa has received little attention so far. Most aerosol studies in the region have focussed on emissions from rain forest and savanna (both natural and biomass burning) and were carried out in the framework of programs such as DECAFE (Dynamique et Chimie Atmospherique en Foret Equatoriale) and FOS (Fires of Savanna). Considering the importance of this topic, aerosols samples were measured in different seasons at 4420 meters on Mt Kenya and on the equator. The study is based on continuous aerosol sampling on a two stage (fine and coarse) streaker sampler and elemental analysis by Particle Induced X-ray Emission. Continuous samples were collected for two seasons coinciding with late austral winter and early austral spring of 1997 and austral summer of 1998. Source area identification is by trajectory analysis and sources types by statistical techniques. Major meridional transports of material are observed with fine-fraction silicon (31 to 68 %) in aeolian dust and anthropogenic sulfur (9 to 18 %) being the major constituents of the total aerosol loading for the two seasons. Marine aerosol chlorine (4 to 6 %), potassium (3 to 5 %) and iron (1 to 2 %) make up the important components of the total material transport over Kenya. Minimum sulfur fluxes are associated with recirculation of sulfur-free air over equatorial Africa, while maximum sulfur concentrations are observed following passage over the industrial heartland of South Africa or transport over the Zambian/Congo Copperbelt. Chlorine is advected from the ocean and is accompanied by aeolian dust recirculating back to land from mid-oceanic regions. Biomass burning products are transported from the horn of Africa. Mineral dust from the Sahara is transported towards the Far East and then transported back within equatorial easterlies to Mt Kenya. This was observed during austral summer and coincided with the dying phase of 1997/98 El

  16. Synthesis and characterization of chitosan tripolyphosphate nanoparticles and its encapsulation efficiency containing Russell's viper snake venom.

    Science.gov (United States)

    Venkatesan, C; Vimal, S; Hameed, A S Sahul

    2013-08-01

    Chitosan Tripolyphosphate (CS/TPP) nanoparticle is a biodegradable and nontoxic polysaccharide, used as a carrier for drug delivery. The morphology and particle-size measurements of the nanoparticles were studied by field emission scanning electron microscopy and Fourier Transform Infrared Spectroscopy (FTIR). This study aims to evaluate the impact of Russell's viper venom encapsulation on various factors and loading capacity, in addition to explore the physicochemical structure of nanoparticles. FTIR confirmed that tripolyphosphoric groups of TPP linked with ammonium groups of CS in the nanoparticles. Our results showed that CS can react with TPP to form stable cationic nanoparticles. The results also showed that encapsulation efficiency of venom at different concentrations of 20, 40, 60, 500, and 1000 µg/mL were achieved for CS/TPP nanoparticles at different concentrations of 1.5, 2, and 3 mg/mL. The cytotoxicity of CS/TPP nanoparticles was evaluated by MTT (-3 (4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a tetrazole) assay.

  17. Polymeric micelles encapsulating fisetin improve the therapeutic effect in colon cancer.

    Science.gov (United States)

    Chen, Yishan; Wu, Qinjie; Song, Linjiang; He, Tao; Li, Yuchen; Li, Ling; Su, Weijun; Liu, Lei; Qian, Zhiyong; Gong, Changyang

    2015-01-14

    The natural flavonoid fisetin (3,3',4',7-tetrahydroxyflavone) was discovered to possess antitumor activity, revealing its potential value in future chemotherapy. However, its poor water solubility makes it difficult for intravenous administration. In this study, the monomethyl poly(ethylene glycol)-poly(ε-caprolactone) (MPEG-PCL) copolymer was applied to prepare nanoassemblies of fisetin by a self-assembly procedure. The prepared fisetin micelles gained a mean particle size of 22 ± 3 nm, polydisperse index of 0.163 ± 0.032, drug loading of 9.88 ± 0.14%, and encapsulation efficiency of 98.53 ± 0.02%. Compared with free fisetin, fisetin micelles demonstrated a sustained and prolonged in vitro release behavior, as well as enhanced cytotoxicity, cellular uptake, and fisetin-induced apoptosis in CT26 cells. As for in vivo studies, fisetin micelles were more competent for suppressing tumor growth and prolonging survival time than free fisetin in the subcutaneous CT26 tumor model. Furthermore, histological analysis, terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, immunohistochemical detection of Ki-67, and microvessel density detection were conducted, demonstrating that fisetin micelles gained increased tumor apoptosis induction, proliferation suppression, and antiangiogenesis activities. In conclusion, we have successfully produced a MPEG-PCL-based nanocarrier encapsulating fisetin with enhanced antitumor activity.

  18. ICAM-1 targeted catalase encapsulated PLGA-b-PEG nanoparticles against vascular oxidative stress.

    Science.gov (United States)

    Sari, Ece; Tunc-Sarisozen, Yeliz; Mutlu, Hulya; Shahbazi, Reza; Ucar, Gulberk; Ulubayram, Kezban

    2015-01-01

    Targeted delivery of therapeutics is the favourable idea, whereas it is possible to distribute the therapeutically active drug molecule only to the site of action. For this purpose, in this study, catalase encapsulated poly(D,L-lactide-co-glycolide)-block-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles were developed and an endothelial target molecule (anti-ICAM-1) was conjugated to this carrier system in order to decrease the oxidative stress level in the target site. According to the enzymatic activity results, initial catalase activity of nanoparticles was increased from 27.39 U/mg to up to 45.66 U/mg by adding 5 mg/mL bovine serum albumin (BSA). After 4 h, initial catalase activity was preserved up to 46.98% while free catalase retained less than 4% of its activity in proteolytic environment. Furthermore, FITC labelled anti-ICAM-1 targeted catalase encapsulated nanoparticles (anti-ICAM-1/CatNPs) were rapidly taken up by cultured endothelial cells and concomitantly endothelial cells were resistant to H2O2 induced oxidative impairment.

  19. Aerosol effects on deep convective clouds: impact of changes in aerosol size distribution and aerosol activation parameterization

    Science.gov (United States)

    Ekman, A. M. L.; Engström, A.; Söderberg, A.

    2010-03-01

    A cloud-resolving model including explicit aerosol physics and chemistry is used to study the impact of aerosols on deep convective strength. More specifically, by conducting six sensitivity series we examine how the complexity of the aerosol model, the size of the aerosols and the aerosol activation parameterization influence the aerosol-induced deep convective cloud sensitivity. Only aerosol effects on liquid droplet formation are considered. We find that an increased aerosol concentration generally results in stronger convection, which for the simulated case is in agreement with the conceptual model presented by Rosenfeld et al. (2008). However, there are two sensitivity series that do not display a monotonic increase in updraft velocity with increasing aerosol concentration. These exceptions illustrate the need to: 1) account for changes in evaporation processes and subsequent cooling when assessing aerosol effects on deep convective strength, 2) better understand graupel impaction scavenging of aerosols which may limit the number of CCN at a critical stage of cloud development and thereby dampen the convection, 3) increase our knowledge of aerosol recycling due to evaporation of cloud droplets. Furthermore, we find a significant difference in the aerosol-induced deep convective cloud sensitivity when using different complexities of the aerosol model and different aerosol activation parameterizations. For the simulated case, a 100% increase in aerosol concentration results in a difference in average updraft between the various sensitivity series which is as large as the average updraft increase itself. The model simulations also show that the change in graupel and rain formation is not necessarily directly proportional to the change in updraft velocity. For example, several of the sensitivity series display a decrease of the rain amount at the lowest model level with increasing updraft velocity. Finally, an increased number of aerosols in the Aitken mode (here

  20. Aerosol effects on deep convective clouds: impact of changes in aerosol size distribution and aerosol activation parameterization

    Directory of Open Access Journals (Sweden)

    A. M. L. Ekman

    2010-03-01

    Full Text Available A cloud-resolving model including explicit aerosol physics and chemistry is used to study the impact of aerosols on deep convective strength. More specifically, by conducting six sensitivity series we examine how the complexity of the aerosol model, the size of the aerosols and the aerosol activation parameterization influence the aerosol-induced deep convective cloud sensitivity. Only aerosol effects on liquid droplet formation are considered. We find that an increased aerosol concentration generally results in stronger convection, which for the simulated case is in agreement with the conceptual model presented by Rosenfeld et al. (2008. However, there are two sensitivity series that do not display a monotonic increase in updraft velocity with increasing aerosol concentration. These exceptions illustrate the need to: 1 account for changes in evaporation processes and subsequent cooling when assessing aerosol effects on deep convective strength, 2 better understand graupel impaction scavenging of aerosols which may limit the number of CCN at a critical stage of cloud development and thereby dampen the convection, 3 increase our knowledge of aerosol recycling due to evaporation of cloud droplets. Furthermore, we find a significant difference in the aerosol-induced deep convective cloud sensitivity when using different complexities of the aerosol model and different aerosol activation parameterizations. For the simulated case, a 100% increase in aerosol concentration results in a difference in average updraft between the various sensitivity series which is as large as the average updraft increase itself. The model simulations also show that the change in graupel and rain formation is not necessarily directly proportional to the change in updraft velocity. For example, several of the sensitivity series display a decrease of the rain amount at the lowest model level with increasing updraft velocity. Finally, an increased number of aerosols in the

  1. Stepwise encapsulation and controlled two-stage release system for cis-Diamminediiodoplatinum

    Directory of Open Access Journals (Sweden)

    Chen Y

    2014-06-01

    Full Text Available Yun Chen,1,* Qian Li,1,2,* Qingsheng Wu1 1Department of Chemistry, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai; 2Shanghai Institute of Quality Inspection and Technical Research, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: cis-Diamminediiodoplatinum (cis-DIDP is a cisplatin-like anticancer drug with higher anticancer activity, but lower stability and price than cisplatin. In this study, a cis-DIDP carrier system based on micro-sized stearic acid was prepared by an emulsion solvent evaporation method. The maximum drug loading capacity of cis-DIDP-loaded solid lipid nanoparticles was 22.03%, and their encapsulation efficiency was 97.24%. In vitro drug release in phosphate-buffered saline (pH =7.4 at 37.5°C exhibited a unique two-stage process, which could prove beneficial for patients with tumors and malignancies. MTT (3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay results showed that cis-DIDP released from cis-DIDP-loaded solid lipid nanoparticles had better inhibition activity than cis-DIDP that had not been loaded. Keywords: stearic acid, emulsion solvent evaporation method, drug delivery, cis-DIDP, in vitro

  2. Strategy to use the Terra Aerosol Information to Derive the Global Aerosol Radiative Forcing of Climate

    Science.gov (United States)

    Kaufman, Yoram J.; Tanre, Didier; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Terra will derive the aerosol optical thickness and properties. The aerosol properties can be used to distinguish between natural and human-made aerosol. In the polar orbit Terra will measure aerosol only once a day, around 10:30 am. How will we use this information to study the global radiative impacts of aerosol on climate? We shall present a strategy to address this problem. It includes the following steps: - From the Terra aerosol optical thickness and size distribution model we derive the effect of aerosol on reflection of solar radiation at the top of the atmosphere. In a sensitivity study we show that the effect of aerosol on solar fluxes can be derived 10 times more accurately from the MODIS data than derivation of the optical thickness itself. Applications to data over several regions will be given. - Using 1/2 million AERONET global data of aerosol spectral optical thickness we show that the aerosol optical thickness and properties during the Terra 10:30 pass are equivalent to the daily average. Due to the aerosol lifetime of several days measurements at this time of the day are enough to assess the daily impact of aerosol on radiation. - Aerosol impact on the top of the atmosphere is only part of the climate question. The INDOEX experiment showed that addressing the impact of aerosol on climate, requires also measurements of the aerosol forcing at the surface. This can be done by a combination of measurements of MODIS and AERONET data.

  3. Systematic aerosol characterization by combining GOME-2 UV Aerosol Indices with trace gas concentrations

    Science.gov (United States)

    Penning de Vries, M.; Stammes, P.; Wagner, T.

    2012-04-01

    The task of determining aerosol type using passive remote sensing instruments is a daunting one. First, because the variety in aerosol (optical) properties is very large; and second, because the effect of aerosols on the detected top-of-atmosphere reflectance spectrum is smooth and mostly featureless. In addition, spectrometers like GOME-2 have a coarse spatial resolution, which makes aerosol characterization even more difficult due to interferences with clouds. On account of these problems, we do not attempt to derive aerosol properties from single measurements: instead, we combine time series of UV Aerosol Index and trace gas concentrations to derive the dominating aerosol type for each season. Aside from the Index values and trace gas concentrations themselves, the correlation between UV Aerosol Indices (which are indicative of aerosol absorption) with NO2, HCHO, and CHOCHO columns - or absence of it - provides clues to the (main) source of the aerosols in the investigated region and time range. For example: a high correlation of HCHO and Absorbing Aerosol Index points to aerosols from biomass burning, highly correlated CHOCHO, HCHO, and SCattering Index indicate biogenic secondary organic aerosols, and coinciding high NO2 concentrations with high SCattering Index values are associated with industrial and urban aerosols. We here present case studies for several regions to demonstrate the suitability of our approach. Then, we introduce a method to systematically derive the dominating aerosol type on a global scale on time scales varying from monthly to yearly.

  4. Stability of lactobacilli encapsulated in various microbial polymers.

    Science.gov (United States)

    Jiménez-Pranteda, María Luján; Poncelet, Denis; Náder-Macías, María Elena; Arcos, Antonio; Aguilera, Margarita; Monteoliva-Sánchez, Mercedes; Ramos-Cormenzana, Alberto

    2012-02-01

    Various microbial polymers, namely xanthan gum, gellan gum, pullulan gum and jamilan, were tested as a suitable encapsulating material for Lactobacillus plantarum CRL 1815 and Lactobacillus rhamnosus ATCC 53103. Resulting capsules were also studied for their pH and simulated gastrointestinal conditions tolerance. The morphology of the microcapsules was studied using scanning electron microscopy. pH tolerance was tested at pH 2.0, 3.5, 5.0 and 6.5 over a 6h incubation period. Simulated gastrointestinal conditions were assayed with simulated gastric and pancreatic juices and simulated bile over a 24h incubation period. Suspensions of probiotic organisms were used as a control. The results from encapsulation with microbial polymers indicate that mixtures of 1% xanthan gum with 0.75% gellan gum and 1% jamilan with 1% gellan gum were the most suitable for microencapsulation. Results for the pH tolerance tests showed no improvement in the viability of cells in relation to the control, except for pH 2.0 where lactobacilli encapsulated in xanthan:gellan gum (1%:0.75%) prolonged their viability by 6h exposure. Xanthan:gellan gum (1%:0.75%) was the most effective of the encapsulating materials tested in protecting L. plantarum and L. rhamnosus against simulated bile, improving its viability in 1-2 logCFU when compared with control. The results of this study suggest that microbial polymers are an interesting source of encapsulating material that should be taken into account for prospective studies of probiotic encapsulation for oral delivery applications.

  5. Factors Influencing the Quality of Encapsulation in Rock Bolting

    Science.gov (United States)

    Aziz, Naj; Craig, Peter; Mirzaghorbanali, Ali; Nemcik, Jan

    2016-08-01

    Bolt installation quality is influenced by various factors, some are well known and others are less recognised. A programme of field and laboratory studies was undertaken to examine various factors of relevance to the load transfer mechanism between the bolt, resin and rock to ensure test methods truly represent field performance. Short encapsulation tests were undertaken as part of the Australian Coal Association Research Program (ACARP) funded project (C21011) with the ultimate aim of developing standard test methods for assessing bolt encapsulation with chemical resin anchor installations. The field study consisted of a series of Short Encapsulation Pull Tests (SEPT) carried out in three mines with different geological conditions to determine the most representative and practical method of SEPT. Additional field work included installation of bolts into threaded steel tubes for subsequent removal and laboratory evaluation. A series of pull tests was carried out by installing bolts in overhead rig mounted sandstone block, cast in concrete with controlled encapsulation length. Factors of importance considered included; borehole diameter, resin annulus thickness, installation time (including bolt spin to the back and "spin at back"), the effect of gloving and hole over drill. It was found that the borehole diameter had a detrimental effect on the encapsulation bonding strength. Bolt installation time of approximately 10 s constituted an acceptable time for effective bolt installation and within the resin manufacturers recommended time of 14 s. Maintaining constant length of encapsulation was paramount for obtaining consistency and repeatability of the test results. Finally, a numerical simulation study was carried out to assess the capabilities of FLAC 2D software in simulating the pull testing of rock bolts.

  6. Encapsulation of Menthol in Beeswax by a Supercritical Fluid Technique

    OpenAIRE

    Linjing Zhu; Hongqiao Lan; Bingjing He; Wei Hong; Jun Li

    2010-01-01

    Encapsulation of menthol in beeswax was prepared by a modified particles from gas-saturated solutions (PGSS) process with controlling the gas-saturated solution flow rate. Menthol/beeswax particles with size in the range of 2–50 μm were produced. The effects of the process conditions, namely, the pre-expansion pressure, pre-expansion temperature, gas-saturated solution flow rate, and menthol composition, on the particle size, particle size distribution, and menthol encapsulation rate were inv...

  7. Oxidation of Bioethanol using Zeolite-Encapsulated Gold Nanoparticles

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen; Abildstrøm, Jacob Oskar; Wang, Feng

    2014-01-01

    With the ongoing developments in biomass conversion, the oxidation of bioethanol to acetaldehyde may become a favorable and green alternative to the preparation from ethylene. Here, a simple and effective method to encapsulate gold nanoparticles in zeolite silicalite‐1 is reported and their high...... zeolite crystals comprise a broad range of mesopores and contain up to several hundred gold nanoparticles with a diameter of 2–3 nm that are distributed inside the zeolites rather than on the outer surface. The encapsulated nanoparticles have good stability and result in 50 % conversion of ethanol with 98...

  8. Oxidation of Bioethanol using Zeolite-Encapsulated Gold Nanoparticles

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen; Abildstrøm, Jacob Oskar; Wang, Feng

    2014-01-01

    With the ongoing developments in biomass conversion, the oxidation of bioethanol to acetaldehyde may become a favorable and green alternative to the preparation from ethylene. Here, a simple and effective method to encapsulate gold nanoparticles in zeolite silicalite-1 is reported and their high...... zeolite crystals comprise a broad range of mesopores and contain up to several hundred gold nanoparticles with a diameter of 2-3nm that are distributed inside the zeolites rather than on the outer surface. The encapsulated nanoparticles have good stability and result in 50% conversion of ethanol with 98...

  9. Cyclodextrins as encapsulation agents for plant bioactive compounds.

    Science.gov (United States)

    Pinho, Eva; Grootveld, Martin; Soares, Graça; Henriques, Mariana

    2014-01-30

    Plants possess a wide range of molecules capable of improve healing: fibre, vitamins, phytosterols, and further sulphur-containing compounds, carotenoids, organic acid anions and polyphenolics. However, they require an adequate level of protection from the environmental conditions to prevent losing their structural integrity and bioactivity. Cyclodextrins are cyclic oligosaccharides arising from the degradation of starch, which can be a viable option as encapsulation technique. Cyclodextrins are inexpensive, friendly to humans, and also capable of improving the biological, chemical and physical properties of bioactive molecules. Therefore, the aim of this review is to highlight the use of cyclodextrins as encapsulating agents for bioactive plant molecules in the pharmaceutical field.

  10. Preliminary toxicological study of Sylgard 184 encapsulating resin

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.M.; Drake, G.A.; London, J.E.; Thomas, R.G.

    1978-06-01

    The acute oral LD/sub 50//sup 30/ values for Sylgard 184 encapsulating resin in mice and rats were greater than 5 g/kg. According to classical guidelines, the compound would be considered slightly toxic or practically nontoxic in both species. Skin application studies in the rabbit demonstrated this material to be mildly irritating. Eye irritation studies, also in the rabbit, showed that Sylgard 184 encapsulating resin was a mild but transitory irritant. The sensitization study in guinea pigs did not show the resin to be deleterious in this regard.

  11. Photothermal characterization of encapsulant materials for photovoltaic modules

    Science.gov (United States)

    Liang, R. H.; Gupta, A.; Distefano, S.

    1982-01-01

    A photothermal test matrix and a low cost testing apparatus for encapsulant materials of photovoltaic modules were defined. Photothermal studies were conducted to screen and rank existing as well as future encapsulant candidate materials and/or material formulations in terms of their long term physiochemical stability under accelerated photothermal aging conditions. Photothermal characterization of six candidate pottant materials and six candidate outer cover materials were carried out. Principal products of photothermal degradation are identified. Certain critical properties are also monitored as a function of photothermal aging.

  12. Surface Encapsulation for Low-Loss Silicon Photonics

    CERN Document Server

    Borselli, M; Michael, C P; Henry, M D; Painter, Oskar

    2007-01-01

    Encapsulation layers are explored for passivating the surfaces of silicon to reduce optical absorption in the 1500-nm wavelength band. Surface-sensitive test structures consisting of microdisk resonators are fabricated for this purpose. Based on previous work in silicon photovoltaics, coatings of SiNx and SiO2 are applied under varying deposition and annealing conditions. A short dry thermal oxidation followed by a long high-temperature N2 anneal is found to be most effective at long-term encapsulation and reduction of interface absorption. Minimization of the optical loss is attributed to simultaneous reduction in sub-bandgap silicon surface states and hydrogen in the capping material.

  13. Multiple encapsulation of LANL waste using polymers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, R.L.

    1994-08-12

    Polymer encapsulation of lead shielding/blasting grit (surrogate) mixed waste was optimized at bench scale using melamine formaldehyde, polyurethane, and butadiene thermosetting polymers. Three pellet-based intermediate waste forms, and a final waste form, were prepared, each providing an additional level of integrity. Encapsulated waste integrity was measured by chemical and physical techniques. Compliance was established using the Toxicity Characteristic Leaching Procedure. Equipment appropriate to pilot-scale demonstration of program techniques was investigated. A preliminary equipment list and layout, and process block flow diagram were prepared.

  14. Tetrahedron DNA dendrimers and their encapsulation of gold nanoparticles.

    Science.gov (United States)

    Zhou, Tao; Wang, Yijie; Dong, Yuanchen; Chen, Chun; Liu, Dongsheng; Yang, Zhongqiang

    2014-08-15

    DNA dendrimers have achieved increasing attention recently. Previously reported DNA dendrimers used Y-DNA as monomers. Tetrahedron DNA is a rigid tetrahedral cage made of DNA. Herein, we use tetrahedron DNA as monomers to prepare tetrahedron DNA dendrimers. The prepared tetrahedron DNA dendrimers have larger size compared with those made of Y-DNA. In addition, thanks to the central cavity of tetrahedron DNA monomers, some nanoscale structures (e.g., gold nanoparticles) can be encapsulated within tetrahedron DNA monomers. Tetrahedron DNA encapsulated with gold nanoparticles can be further assembled into dendrimers, guiding gold nanoparticles into clusters.

  15. Encapsulated mesalamine granules (Apriso) for ulcerative colitis.

    Science.gov (United States)

    2009-05-18

    Apriso (Salix) is a new formulation of mesalamine (5-aminosalicylic acid; 5-ASA) approved by the FDA for maintenance of remission in mild to moderate ulcerative colitis (UC). Mesalamine is a locally acting antiinflammatory agent that is widely used both to maintain and induce remission in inflammatory bowel disease. Various mesalamine formulations have been developed to target drug delivery to areas of the small intestine and colon. Most of these agents require frequent dosing and have a high pill burden. The newest products--Lialda, introduced in 2007, and now Apriso--can be dosed once daily.

  16. Aerosols of Mongolian arid area

    Science.gov (United States)

    Golobokova, L.; Marinayte, I.; Zhamsueva, G.

    2012-04-01

    Sampling was performed in July-August 2005-2010 at Station Sain Shand (44°54'N, 110°07'E) in the Gobi desert (1000 m a.s.l.), West Mongolia. Aerosol samples were collected with a high volume sampler PM 10 (Andersen Instruments Inc., USA) onto Whatman-41 filters. The substance was extracted from the filters by de-ionized water. The solution was screened through an acetate-cellulose filter with 0.2 micron pore size. Ions of ammonium, sodium, potassium, magnesium, and calcium, as well as sulphate ions, nitrate ions, hydrocarbonate, chloride ions were determined in the filtrate by means of an atomic adsorption spectrometer Carl Zeiss Jena (Germany), a high performance liquid chromatographer «Milichrome A-02» (Russia), and an ionic chromatographer ICS-3000 (Dionex, USA). The PAH fraction was separated from aerosol samples using hexane extraction at room temperature under UV environment. The extract was concentrated to 0.1-0.2 ml and analysed by a mass-spectrometer "Agilent, GC 6890, MSD 5973 Network". Analysis of concentrations of aerosols components, their correlation ratios, and meteorological modeling show that the main factor affecting chemical composition of aerosols is a flow of contaminants transferred by air masses to the sampling area mainly from the south and south-east, as well as wind conditions of the area, dust storms in particular. Sulphate, nitrate, and ammonium are major ions in aerosol particles at Station Sain Shand. Dust-borne aerosol is known to be a sorbent for both mineral and organic admixtures. Polycyclic aromatic hydrocarbons (PAH) being among superecotoxicants play an important role among resistant organic substances. PAH concentrations were determined in the samples collected in 2010. All aerosol samples contained dominant PAHs with 5-6 benzene rings ( (benze(k)fluoranthen, benze(b)flouranthen, benze(a)pyren, benze(?)pyren, perylene, benze(g,h,i)perylene, and indene(1,2,3-c,d)pyrene). Their total quantity varied between 42 and 90

  17. Diffusive confinement of free radical intermediates in the OH radical oxidation of semisolid aerosols.

    Science.gov (United States)

    Wiegel, Aaron A; Liu, Matthew J; Hinsberg, William D; Wilson, Kevin R; Houle, Frances A

    2017-03-01

    Multiphase chemical reactions (gas + solid/liquid) involve a complex interplay between bulk and interface chemistry, diffusion, evaporation, and condensation. Reactions of atmospheric aerosols are an important example of this type of chemistry: the rich array of particle phase states and multiphase transformation pathways produce diverse but poorly understood interactions between chemistry and transport. Their chemistry is of intrinsic interest because of their role in controlling climate. Their characteristics also make them useful models for the study of principles of reactivity of condensed materials under confined conditions. In previous work, we have reported a computational study of the oxidation chemistry of a liquid aliphatic aerosol. In this study, we extend the calculations to investigate nearly the same reactions at a semisolid gas-aerosol interface. A reaction-diffusion model for heterogeneous oxidation of triacontane by hydroxyl radicals (OH) is described, and its predictions are compared to measurements of aerosol size and composition, which evolve continuously during oxidation. These results are also explicitly compared to those obtained for the corresponding liquid system, squalane, to pinpoint salient elements controlling reactivity. The diffusive confinement of the free radical intermediates at the interface results in enhanced importance of a few specific chemical processes such as the involvement of aldehydes in fragmentation and evaporation, and a significant role of radical-radical reactions in product formation. The simulations show that under typical laboratory conditions semisolid aerosols have highly oxidized nanometer-scale interfaces that encapsulate an unreacted core and may confer distinct optical properties and enhanced hygroscopicity. This highly oxidized layer dynamically evolves with reaction, which we propose to result in plasticization. The validated model is used to predict chemistry under atmospheric conditions, where the OH

  18. Identifying Drugs

    Science.gov (United States)

    ... Oxycodone PCP (Phencyclidine) Peyote and Mescaline Psilocybin Rohypnol Salvia Divinorum Spice/ K2, Synthetic Marijuana Steroids U-47700 Flakka ( ... Oxycodone PCP (Phencyclidine) Peyote and Mescaline Psilocybin Rohypnol Salvia Divinorum Spice/ K2, Synthetic Marijuana Steroids U-47700 Aerosol ...

  19. Drug allergies

    Science.gov (United States)

    Allergic reaction - drug (medication); Drug hypersensitivity; Medication hypersensitivity ... A drug allergy involves an immune response in the body that produces an allergic reaction to a medicine. The ...

  20. Drugs and Drug Abuse.

    Science.gov (United States)

    Anastas, Robert, Comp.; And Others.

    GRADES OR AGES: Secondary grades. SUBJECT MATTER: Drugs and drug abuse. ORGANIZATION AND PHYSICAL APPEARANCE: The guide is divided into several sections, each of which is in outline or list form. It is xeroxed and spiral-bound with a paper cover. OBJECTIVES AND ACTIVITIES: No objectives are mentioned. The major portion of the guide contains a…