The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform

Changzheng Yang - One of the best experts on this subject based on the ideXlab platform.

Walter M. Jarman - One of the best experts on this subject based on the ideXlab platform.

  • Contamination of Tris(4-Chlorophenyl) Methane and Tris(4-Chlorophenyl) Methanol in Marine Mammals from Russia and Japan: Body Distribution, Bioaccumulation and Contamination Status
    Marine Pollution Bulletin, 1999
    Co-Authors: Mafumi Watanabe, Shinsuke Tanabe, Nobuyuki Miyazaki, Evgeny A. Petrov, Walter M. Jarman
    Abstract:

    Four seal species (Phoca caspica, Phoca sibirica, Phoca hispida and Phoca largha) and one whale (Orcinus orca) from Russia and Japan were examined to determine the Body Distribution, bioaccumulation and contamination status of tris(4-chlorophenyl) methane (TCPMe) and tris(4-chlorophenyl) methanol (TCPMOH). Lipid normalized concentrations of TCPMe and TCPMOH were comparable in various organs and tissues, implying that their Body Distribution is followed to the lipid-dependent accumulation, similar to that for other organochlorines. The highest Body burden of these compounds was found in the blubber. Bioaccumulation potential of TCPMe and TCPMOH was high and comparable to PCBs and DDTs. Relatively higher concentrations of TCPMe and TCPMOH were observed in Caspian seal than in other seal species examined. TCPMOH concentration in killer whale was the highest of the marine mammals examined. Another peak detected had similar mass spectrum to TCPMOH, however, at a different retention time, suggesting the presence of an isomer of TCPMOH.

Jorg Kreuter - One of the best experts on this subject based on the ideXlab platform.

  • Body Distribution of polysorbate 80 and doxorubicin loaded 14c poly butyl cyanoacrylate nanoparticles after i v administration in rats
    Journal of Drug Targeting, 2005
    Co-Authors: Alessandra Ambruosi, Hiromitsu Yamamoto, Jorg Kreuter
    Abstract:

    Previously it was shown that poly(butyl cyanoacrylate) (PBCA) nanoparticles coated with polysorbate 80 are able to cross the blood-brain barrier (BBB) after i.v. administration. The objective of the present study was to investigate the influence of polysorbate 80 and doxorubicin-loading on the Body Distribution in rats. The bioDistribution profile and brain concentration of 14C-radiolabeled PBCA nanoparticles, polysorbate 80 coated 14C-PBCA nanoparticles, and doxorubicin-loaded 14C-PBCA nanoparticles were determined by radioactivity counting after i.v. administration in rats. The 14C-PBCA nanoparticles showed a significant accumulation in the organs of the reticuloendothelial system (RES). Polysorbate 80 coating of the 14C-PBCA nanoparticles decreased this accumulation to about 40% after 1 h post injection. The brain concentration was increased about 2-fold after polysorbate 80-coating at this time point. The presence of doxorubicin in this preparation, however, decreased the brain concentration to levels...

  • Influence of the surfactant concentration on the Body Distribution of nanoparticles
    Journal of drug targeting, 1999
    Co-Authors: L. Araujo, Raimar Löbenberg, Jorg Kreuter
    Abstract:

    The rapid reticuloendothelial system (RES) uptake of nanoparticles after i.v. injection, especially by the liver, can be reduced and the Body Distribution can be altered by coating them with non-ionic surfactants. In the present work 2-14C-poly(methyl methacrylate) nanoparticles were coated with poloxamine 908 and polysorbate 80, and the influence of different surfactant concentrations on the Body Distribution was investigated. These surfactants were chosen because earlier studies showed that poloxamine 908 was very effective in decreasing the liver uptake and keeping the nanoparticles in circulation, whereas polysorbate 80 was the most effective surfactant to direct the particles to organs that do not belong to the RES. Above nanoparticles were injected i.v. to rats and the animals were sacrificed after 30 min. Below a surfactant concentration of 0.1% the nanoparticle preparations behaved like uncoated particles. At a 0.1% concentration a very sudden and significant change in the Body Distribution occurred with poloxamine 908. The liver concentration decreased from about 75% of the dose to 13% and stayed at this level at higher surfactant concentrations. This decrease was combined with a similar sudden complementary increase in blood and other organ and tissue concentrations. With polysorbate 80 the decrease in liver concentration and increase in the blood and the other organ levels was gradual and became important only above 0.5% surfactant concentration. The results indicate that the type of interaction and the strength of the adsorptive binding to the nanoparticles are different with different surfactants. This in turn leads to different Body Distribution patterns after i.v. injection of surfactant coated nanoparticles.

  • Interaction of serum components with poly(methylmethacrylate) nanoparticles and the resulting Body Distribution after intravenous injection in rats.
    Journal of drug targeting, 1993
    Co-Authors: Gerrit Borchard, Jorg Kreuter
    Abstract:

    AbstractRadiolabelled poly(methylmethacrylate) (PMMA) nanoparticles were coated with rat serum albumin (RSA), serum and inactivated serum, to examine the influence of these blood components on the Body Distribution of a model colloidal drug carrier. The particles were incubated overnight at 37°C either in a 1% solution of RSA in phosphate buffered saline (PBS) or in serum obtained from the rats. A suspension of nanoparticles in PBS was used as a control. Serum complement inactivation was achieved by storage at 56°C for 30min. The suspensions were then injected intravenously via the tail vein of Wistar rats. The animals were sacrificed at five different time points (30min, 2h, 6h, 24 h, and 7 d after injection) and two samples of each organ and two blood samples were weighed into scintillation vials. The radioactivity of each sample was then measured in a Beckman scintillation counter. Coating with RSA led to no significant change in the Body Distribution of the particles, whereas incubation in serum, espe...

  • Influence of the surface properties of low contact angle surfactants on the Body Distribution of 14C-poly(methyl methacrylate) nanoparticles
    Journal of microencapsulation, 1992
    Co-Authors: S.d. Tröster, Jorg Kreuter
    Abstract:

    The Body Distribution of surfactant-coated and non-coated poly(methyl methacrylate) nanoparticles with a size of 131 +/- 30 nm after intravenous injection into rats was investigated. The coating materials were poloxamine 904, poloxamine 908, poloxamine 1508, poloxamer 338, and Brij 35. These materials were preselected by the method of contact angle measurement. No overall valid relation between contact angles and the modification of Body Distribution could be found. However, the classification of surfactants by determination of the contact angles of the surfactant solution on the polymer material seems to be a very helpful method for preselection of poloxamers and poloxamines. Another parameter for preselection could be molecular weights of the poloxamines. Poloxamine 1508 was the most efficient coating material in reducing the liver uptake and increasing the blood levels of poly(methyl methacrylate) nanoparticles.

  • Correlation of the surface hydrophobicity of 14C-poly(methyl methacrylate) nanoparticles to their Body Distribution
    Journal of Controlled Release, 1992
    Co-Authors: S.d. Tröster, Klaus H. Wallis, Rainer H. Müller, Jorg Kreuter
    Abstract:

    Abstract Poly (methyl methacrylate) nanoparticles for intravenous injection were surface-modified by the adsorption of poloxamine 908, Antarox DM 970 and Klucel EF. The coated particles were characterized in parameters relevant to their in vivo Distribution: adsorption layer thickness, particle charge, surface hydrophobicity, interaction with serum components. The Body Distribution of the 14C-labeled particles was determined after i.v. injection into rats over 7 days and correlated to the in vitro characterization data. The physicochemical characterization methods allowed to identify carriers which will be taken up by liver and spleen macrophages in vivo. Coating materials with potential protective effect against uptake could be placed in order of increasing efficiency.

Shinsuke Tanabe - One of the best experts on this subject based on the ideXlab platform.

  • accumulation features of trace elements in mass stranded harbor seals phoca vitulina in the north sea coast in 2002 the Body Distribution and association with growth and nutrition status
    Marine Pollution Bulletin, 2011
    Co-Authors: Shinsuke Tanabe, Tetsuro Agusa, Shinya Yasugi, Asami Iida, Tokutaka Ikemoto, Yasumi Anan, Thijs Kuiken, Albert D M E Osterhaus, Hisato Iwata
    Abstract:

    Body Distribution and growth- and nutritional status-dependent accumulation of 21 trace elements were investigated in harbor seals (Phoca vitulina) stranded in the North Sea coast in 2002. Higher concentrations and burdens of Mn, Se, Mo, Ag, Sn, Hg, and Bi in the liver, Cd in the kidney, As in the blubber, and Co, Sr, and Ba in the bone were observed. Significant positive correlations of hepatic Se, Mo, Ag, Cd, Sn, Hg, Tl, and Bi with standard Body length were found, while significant negative relationships were detected for Mn, As, Rb, Sr, and Sb in the liver. Concentrations of Co, Se, Sr, Sn, Hg, and Bi in the liver, V, Sr, Ag, Sn, and Hg in the kidney, V, Mn, Co, Rb, Sr, Sn, Ba, and Pb in the blubber increased with decreasing blubber thickness of harbor seals, indicating enrichment of these elements in the target tissue by emaciation.

  • Contamination of Tris(4-Chlorophenyl) Methane and Tris(4-Chlorophenyl) Methanol in Marine Mammals from Russia and Japan: Body Distribution, Bioaccumulation and Contamination Status
    Marine Pollution Bulletin, 1999
    Co-Authors: Mafumi Watanabe, Shinsuke Tanabe, Nobuyuki Miyazaki, Evgeny A. Petrov, Walter M. Jarman
    Abstract:

    Four seal species (Phoca caspica, Phoca sibirica, Phoca hispida and Phoca largha) and one whale (Orcinus orca) from Russia and Japan were examined to determine the Body Distribution, bioaccumulation and contamination status of tris(4-chlorophenyl) methane (TCPMe) and tris(4-chlorophenyl) methanol (TCPMOH). Lipid normalized concentrations of TCPMe and TCPMOH were comparable in various organs and tissues, implying that their Body Distribution is followed to the lipid-dependent accumulation, similar to that for other organochlorines. The highest Body burden of these compounds was found in the blubber. Bioaccumulation potential of TCPMe and TCPMOH was high and comparable to PCBs and DDTs. Relatively higher concentrations of TCPMe and TCPMOH were observed in Caspian seal than in other seal species examined. TCPMOH concentration in killer whale was the highest of the marine mammals examined. Another peak detected had similar mass spectrum to TCPMOH, however, at a different retention time, suggesting the presence of an isomer of TCPMOH.

Shicheng Yang - One of the best experts on this subject based on the ideXlab platform.