The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform

Sheldon S. Miller - One of the best experts on this subject based on the ideXlab platform.

Soli F. Contractor - One of the best experts on this subject based on the ideXlab platform.

  • Effect of the size of liposomes on the transfer and uptake of Carboxyfluorescein by the perfused human term placenta.
    The Journal of pharmacy and pharmacology, 1997
    Co-Authors: Rekha Bajoria, Soli F. Contractor
    Abstract:

    The effect of the size of liposomes on the uptake and transfer of the low molecular-weight, hydrophilic and polar molecule Carboxyfluorescein has been determined across the perfused human term placenta. Carboxyfluorescein-encapsulated neutral liposomes of three different sizes were prepared from equimolar concentrations of lecithin and cholesterol. Size distribution, encapsulation efficiency and stability of liposomes in blood-based media were determined. The concentration of Carboxyfluorescein was measured spectro-photometrically. The transplacental transfer and placental uptake of free Carboxyfluorescein (control data) were respectively 1.9 ±0.2 and 5.0 ± 0.7% of initial dose. The placental uptake and foetal concentration of Carboxyfluorescein were significantly increased by small liposomes (P < 0.05), and reduced by large (0.82 ± 0.13%; P < 0.05) and multilamellar liposomes (0.32 ± 0.11%). There was a negative correlation between liposome size and transplacental transfer (y = −0.53 + 0.9x; r = 0.96; P < 0.001; n = 24) and placental uptake of Carboxyfluorescein (y = −5.9 + 6.5x; r = 0.84; P < 0.001; n = 24). The study indicates that placental uptake and transfer rate of liposomal Carboxyfluorescein were dependant upon the size of liposomes.

  • Effect of surface charge of small unilamellar liposomes on uptake and transfer of Carboxyfluorescein across the perfused human term placenta
    Pediatric research, 1997
    Co-Authors: Rekha Bajoria, Soli F. Contractor
    Abstract:

    We aim to investigate the effect of surface charge of small unilamellar liposomes on transfer and uptake of a low molecular weight, hydrophilic and polar molecule Carboxyfluorescein in an in vitro model of perfused human term placenta. Carboxyfluorescein-encapsulated neutral liposomes were prepared by using an equimolar concentration of lecithin and cholesterol. Anionic and cationic liposomes were prepared by adding dicetylcholine and stearylamine, respectively. Size distribution, encapsulation efficiency, and stability of liposomes in blood-based medium were determined. The transfer kinetics of free Carboxyfluorescein and liposomally encapsulated Carboxyfluorescein were studied in a dually perfused isolated lobule of human term placenta. The concentration of Carboxyfluorescein was measured fluorometrically. The maternal to fetal transfer and placental uptake of free Carboxyfluorescein was 1.6 +/- 0.1% and 4.2 +/- 0.1% of the initial dose, respectively. This constitutes the control data. The placental transfer of Carboxyfluorescein was significantly increased by neutral (2.5 +/- 0.1%; p < 0.01) and anionic liposomes (3.1 +/- 0.2%; p < 0.001), whereas cationic liposomes prevented its transfer (0.4 +/- 0.1%; p < 0.001). The placental uptake of neutral (14.9 +/- 2.3%; p < 0.001) and anionic liposomes (21.1 +/- 1.2%; p < 0.001) were significantly higher than the cationic liposomes (2.3 +/- 0.6%) and control group (p < 0.001). The placental uptake of cationic liposomes was comparable with the control data. These results indicate that placental uptake of small unilamellar liposomes depends upon their surface charge, and transfer of Carboxyfluorescein is enhanced by anionic and impeded by cationic liposomes.

Rekha Bajoria - One of the best experts on this subject based on the ideXlab platform.

  • Effect of the size of liposomes on the transfer and uptake of Carboxyfluorescein by the perfused human term placenta.
    The Journal of pharmacy and pharmacology, 1997
    Co-Authors: Rekha Bajoria, Soli F. Contractor
    Abstract:

    The effect of the size of liposomes on the uptake and transfer of the low molecular-weight, hydrophilic and polar molecule Carboxyfluorescein has been determined across the perfused human term placenta. Carboxyfluorescein-encapsulated neutral liposomes of three different sizes were prepared from equimolar concentrations of lecithin and cholesterol. Size distribution, encapsulation efficiency and stability of liposomes in blood-based media were determined. The concentration of Carboxyfluorescein was measured spectro-photometrically. The transplacental transfer and placental uptake of free Carboxyfluorescein (control data) were respectively 1.9 ±0.2 and 5.0 ± 0.7% of initial dose. The placental uptake and foetal concentration of Carboxyfluorescein were significantly increased by small liposomes (P < 0.05), and reduced by large (0.82 ± 0.13%; P < 0.05) and multilamellar liposomes (0.32 ± 0.11%). There was a negative correlation between liposome size and transplacental transfer (y = −0.53 + 0.9x; r = 0.96; P < 0.001; n = 24) and placental uptake of Carboxyfluorescein (y = −5.9 + 6.5x; r = 0.84; P < 0.001; n = 24). The study indicates that placental uptake and transfer rate of liposomal Carboxyfluorescein were dependant upon the size of liposomes.

  • Effect of surface charge of small unilamellar liposomes on uptake and transfer of Carboxyfluorescein across the perfused human term placenta
    Pediatric research, 1997
    Co-Authors: Rekha Bajoria, Soli F. Contractor
    Abstract:

    We aim to investigate the effect of surface charge of small unilamellar liposomes on transfer and uptake of a low molecular weight, hydrophilic and polar molecule Carboxyfluorescein in an in vitro model of perfused human term placenta. Carboxyfluorescein-encapsulated neutral liposomes were prepared by using an equimolar concentration of lecithin and cholesterol. Anionic and cationic liposomes were prepared by adding dicetylcholine and stearylamine, respectively. Size distribution, encapsulation efficiency, and stability of liposomes in blood-based medium were determined. The transfer kinetics of free Carboxyfluorescein and liposomally encapsulated Carboxyfluorescein were studied in a dually perfused isolated lobule of human term placenta. The concentration of Carboxyfluorescein was measured fluorometrically. The maternal to fetal transfer and placental uptake of free Carboxyfluorescein was 1.6 +/- 0.1% and 4.2 +/- 0.1% of the initial dose, respectively. This constitutes the control data. The placental transfer of Carboxyfluorescein was significantly increased by neutral (2.5 +/- 0.1%; p < 0.01) and anionic liposomes (3.1 +/- 0.2%; p < 0.001), whereas cationic liposomes prevented its transfer (0.4 +/- 0.1%; p < 0.001). The placental uptake of neutral (14.9 +/- 2.3%; p < 0.001) and anionic liposomes (21.1 +/- 1.2%; p < 0.001) were significantly higher than the cationic liposomes (2.3 +/- 0.6%) and control group (p < 0.001). The placental uptake of cationic liposomes was comparable with the control data. These results indicate that placental uptake of small unilamellar liposomes depends upon their surface charge, and transfer of Carboxyfluorescein is enhanced by anionic and impeded by cationic liposomes.

Sandrine Alfenore - One of the best experts on this subject based on the ideXlab platform.

  • Assessment of Candida shehatae viability by flow cytometry and fluorescent probes.
    Journal of microbiological methods, 2012
    Co-Authors: Julie Montheard, Sandy Garcier, Eric Lombard, Xavier Cameleyre, Stéphane E. Guillouet, Carole Molina-jouve, Sandrine Alfenore
    Abstract:

    Quantification of different physiological states of Candida shehatae cells was performed by flow cytometry associated with two fluorescent probes. Propidium iodide and Carboxyfluorescein diacetate acetoxymethyl ester fluorescent dyes were chosen based on data from the literature. A staining procedure, developed from the previous works was applied to the yeast. Then, the protocol was improved to fit with fermentation constraints such as no physiological interference between the staining procedure and the cells, shortest preparation time and small amounts of dyes. From this optimisation, propidium iodide was included in the sample at 8 mg/L whereas Carboxyfluorescein was first diluted in Pluronic® agent and used at 3mg/L, samples were incubated for 10 min at 40°C. Repeatability and accuracy were evaluated to validate this flow cytometry procedure for viability determination.

  • Assessment of Candida shehatae viability by flow cytometry and fluorescent probes
    Journal of Microbiological Methods, 2012
    Co-Authors: Julie Montheard, Sandy Garcier, Eric Lombard, Xavier Cameleyre, Stéphane E. Guillouet, Carole Molina-jouve, Sandrine Alfenore
    Abstract:

    Quantification of different physiological states of Candida shehatae cells was performed by flow cytometry associated with two fluorescent probes. Propidium iodide and Carboxyfluorescein diacetate acetoxymethyl ester fluorescent dyes were chosen based on data from the literature. A staining procedure, developed from the previous works was applied to the yeast. Then, the protocol was improved to fit with fermentation constraints such as no physiological interference between the staining procedure and the cells, shortest preparation time and small amounts of dyes. From this optimisation, propidium iodide was included in the sample at 8 mg/L whereas Carboxyfluorescein was first diluted in Pluronic (R) agent and used at 3 mg/L, samples were incubated for 10 min at 40 degrees C. Repeatability and accuracy were evaluated to validate this flow cytometry procedure for viability determination. (C) 2012 Elsevier B.V. All rights reserved.

Andrew P Halestrap - One of the best experts on this subject based on the ideXlab platform.