References of "Castagne, Delphine"
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See detailComparison of chitosan/siRNA and trimethylchitosan/siRNA complexes behaviour in vitro
Dehousse, Vincent ULg; Garbacki, Nancy ULg; Jaspart, Séverine ULg et al

in International Journal of Biological Macromolecules (2010), 46

Chitosan and trimethylchitosan (TMC)-siRNA nanoparticles were produced by simple complexation technique or by ionic gelation using tripolyphosphate (TPP). The obtained complexes were characterized in ... [more ▼]

Chitosan and trimethylchitosan (TMC)-siRNA nanoparticles were produced by simple complexation technique or by ionic gelation using tripolyphosphate (TPP). The obtained complexes were characterized in terms of physicochemical properties such as size, zeta potential, complexation efficiency and stability. Furthermore, cytotoxicity, cell uptake and transfection efficiency of polyplexes were evaluated in vitro. Under pH condition of cell culture medium, a strong decrease in siRNA condensation efficiency was observed with chitosan nanoparticles. This characteristic resulted in low transfection efficiencies in HEK293 cell line. Formulation of chitosan polyplexes with TPP led to improvement of polyplexes stability but no significant increase in transfection efficiency was observed compared to simple chitosan complexes. By contrast, TMC complexes did not have pH dependency on siRNA complexation. TMCsiRNA nanoparticles were stable in physiological condition. Accordingly, cellular uptake was increased compared to chitosan polyplexes. However, improvement of transfection efficiency was low regarding to cellular uptake of these complexes. Chitosan and TMC complexes present some characteristics favourable for siRNA delivery, such as ability to integrate siRNA into small discrete particles or low toxicity of the complexes. This study also highlights the importance of complexes stability in physiological environment for siRNA transfection purposes. [less ▲]

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See detailEffect of β-cyclodextrin and its derivatives on caveolae disruption, relationships with their cholesterol extraction capacities
Castagne, Delphine ULg; Evrard, Brigitte ULg; Nusgens, Betty ULg et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2010), 67

Endothelial cells (HUVEC) were treated with b-cyclodextrin (b-CD) and hydroxypropylated or methylated derivatives solutions to confirm their lack of affinity with phospholipids and their specificity ... [more ▼]

Endothelial cells (HUVEC) were treated with b-cyclodextrin (b-CD) and hydroxypropylated or methylated derivatives solutions to confirm their lack of affinity with phospholipids and their specificity towards cholesterol. Further studies were performed on bovine aortic endothelial cells to assess the effect of b-CDs (mainly methylated derivatives) on membrane microdomains (lipid rafts or caveolae), by detecting the caveolae marker caveolin-1 in fractions of sucrose gradients. A displacement from the lighter to the heavier fractions, characteristic of caveolae disruption, was observed using CDs. The strongest effect was obtained with dimethyl-b-CD, for which an accumulation of caveolin-1 was observed in the bottom of the gradient. Crysmeb and trimethyl-b-CD seemed to have the weaker effects as a significative amount of caveolin-1 was still detected in the light fraction corresponding to caveolae. b-CD and CDs having a degree of methylation a bit lower than 2 showed intermediate effects. The results of the present study on microdomains seem in good correlation with the cell cholesterol extraction capacities of CDs previously determined. [less ▲]

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See detailSpectroscopic studies and molecular modeling for understanding the interactions between cholesterol and cyclodextrins
Castagne, Delphine ULg; Dive, Georges ULg; Evrard, Brigitte ULg et al

in Journal of Pharmacy & Pharmaceutical Sciences : A Publication of the Canadian Society for Pharmaceutical Sciences (2010), 13(2), 362-377

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See detailStudy of the cholesterol extraction capacity of β-cyclodextrin and its derivatives, relationships with their effects on endothelial cell viability and on membrane models
Castagne, Delphine ULg; Fillet, Marianne ULg; Delattre, Luc ULg et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2009), 63(3-4), 225-231

Endothelial cells (HUVEC) were treated with β-cyclodextrin and hydroxypropylated or methylated derivatives solutions in order to quantify their cholesterol extraction capacity. Non-toxic concentrations of ... [more ▼]

Endothelial cells (HUVEC) were treated with β-cyclodextrin and hydroxypropylated or methylated derivatives solutions in order to quantify their cholesterol extraction capacity. Non-toxic concentrations of cyclodextrins (CDs) were determined following methyl thiazol tetrazolium (MTT) assays, total protein measurements, morphological observations and trypan blue assays. The residual cholesterol content of cells was measured and the extraction power of CDs compared to results obtained by phase solubility diagrams. Cholesterol was extracted with a dose-response relationship, the lowest residual cholesterol content being obtained with β-CD at 10 mM. Low substituted derivatives (Crysmeb® and hydroxypropyl-β-CD) maintained liposomes integrity (as shown before), were the less cytotoxic and presented the lowest affinity for cholesterol contrary to methylated derivatives with degrees of substitution around 2. [less ▲]

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See detailStudy of the relationship between lipid binding properties of cyclodextrins and their effect on the integrity of liposomes
Piel, Géraldine ULg; Piette, Marie ULg; Barillaro, Valery et al

in International Journal of Pharmaceutics (2007), 338(1-2), 35-42

It is well known that cyclodextrins are able to extract lipids constituting membranes, increasing their fluidity and permeability. This behaviour towards biological membranes is directly linked to the ... [more ▼]

It is well known that cyclodextrins are able to extract lipids constituting membranes, increasing their fluidity and permeability. This behaviour towards biological membranes is directly linked to the toxicological effects of methylated cyclodextrins. However, confusion is currently made in the literature between the different methylated cyclodextrin derivatives. Moreover, a new methylated cyclodextrin derivative recently occurred in the market. the Crysmeb (R). We wanted to compare and understand the effect of the most currently used cyclodextrins on a model membrane. We studied the influence of natural cyclodextrins (beta CD and gamma CD), methylated derivatives (2,6-dimethyl-beta CD (Dimeb), 2,3,6-trimethyl-beta CD (Trimeb) and randomly methylated-beta CD (Rameb), as well as the new derivative Crysmeb), hydroxypropylated derivatives (HP beta CD of different substitution degrees and HP gamma CD) and the sulfobutylated derivative (SBE beta CD) on the release of a fluorescent marker encapsulated in the inner cavity of liposomes. It was shown that the observed effect on calcein release can be directly related to the affinity of cyclodextrins for both lipid components of liposomes, cholesterol and phosphatidylcholine. From this relationship, we were able to determine, for each cyclodextrin, a theoretical concentration giving rise to 50% or 100% calcein release. This theoretical concentration was confirmed experimentally. We have also showed that cyclodextrins which provoke calcein release also induce large structure modifications of liposomes. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailStudy of the interaction between cyclodextrins and liposome membranes: effect on the permeability of liposomes
Piel, Géraldine ULg; Piette, Marie ULg; Barillaro, Valery et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2007, April), 57(1-4), 309-311

We wanted to compare and understand the effect of the most currently used cyclodextrins on a model membrane. We studied the influence of most currently used cyclodextrins on the release of a fluorescent ... [more ▼]

We wanted to compare and understand the effect of the most currently used cyclodextrins on a model membrane. We studied the influence of most currently used cyclodextrins on the release of a fluorescent marker encapsulated in the inner cavity of SUV liposomes. It was shown that the observed effect on calcein release can be directly related to the affinity of cyclodextrins for both lipid components of liposomes, cholesterol and phosphatidylcholine. From this relationship, we were able to determine, for each cyclodextrin, a theoretical concentration giving rise to 50% or 100% calcein release. This theoretical concentration was confirmed experimentally. [less ▲]

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See detailEvaluation of the cytotoxicity of cyclodextrins on endothelial cells using MTT assay
Castagne, Delphine ULg; Belhadj Salem, Leila; Delattre, Luc ULg et al

Poster (2007, April)

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See detailPreparation and evaluation of liposomes encapsulating synthetic MMP inhibitor (Ro 28-2653) - cyclodextrin complexes
Piette, Marie ULg; Castagne, Delphine ULg; Delattre, Luc ULg et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2007, April), 57(1-4), 101-103

In this study, preparation and evaluation of liposomes, intended for intravenous administration, encapsulating synthetic MMP inhibitor (Ro 28-2653) - cyclodextrin complexes were realized. An increase in ... [more ▼]

In this study, preparation and evaluation of liposomes, intended for intravenous administration, encapsulating synthetic MMP inhibitor (Ro 28-2653) - cyclodextrin complexes were realized. An increase in Ro solubility, via formation of binary (Ro/HP beta CD) or ternary (Ro/HP beta CD/L-lysine) complexes, permitted a similar increase in encapsulation efficiency of liposomes (Table 1). Moreover, Ro release kinetics depend on the encapsulation efficiency. [less ▲]

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See detailEffect of cyclodextrins on the viability of endothelial cells
Castagne, Delphine ULg; Belhadj Salem, Leila; Delattre, Luc ULg et al

in Journal of Inclusion Phenomena and Macrocyclic Chemistry (2007), 57(1-4), 105-107

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See detailPharmacokinetic study of a new synthetic MMP inhibitor (Ro 28-2653) after IV and oral administration of cyclodextrin solutions
Piette, Marie ULg; Evrard, Brigitte ULg; Frankenne, Francis et al

in European Journal of Pharmaceutical Sciences (2006), 28(3), 189-195

Ro 28-2653 (5-biphenyl-4-yl-5-[4-(4-nitro-phenyl)-piperazin-1-yl]-pyrimidine-2,4,6-trione) is a new synthetic inhibitor of matrix metalloproteinases (MMPs) with a high selectivity towards MMP2, MMP9 and ... [more ▼]

Ro 28-2653 (5-biphenyl-4-yl-5-[4-(4-nitro-phenyl)-piperazin-1-yl]-pyrimidine-2,4,6-trione) is a new synthetic inhibitor of matrix metalloproteinases (MMPs) with a high selectivity towards MMP2, MMP9 and membrane type 1-MMP. It has been shown that cyclodextrins (CDs) are able to form inclusion complexes with Ro 28-2653 and to increase its aqueous solubility. The aim of this study is to demonstrate that an increase in Ro 28-2653 solubility, via ternary complex formation, can lead to an increase in the oral bioavailability of this drug. This study shows that a synergistic effect exists between hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and L-lysine. The use of this multicomponent system enabled the preparation of oral and intravenous solutions of Ro 28-2653. In vivo evaluation of the oral solution of the inclusion complex of Ro 28-2653 in comparison with a suspension of the same uncomplexed drug showed a significant (p < 0.05) increase in absolute bioavailability. The area under curve (AUC) and the peak serum concentration (C-max) were approximately 10 times higher than those obtained with the suspension, while the time (T-max) to reach C-max was reduced. Moreover, in vivo administration of Ro 28-2653 solutions highlighted some information about the pharmacokinetic behavior of Ro 28-2653: a long biologic half-life (about 15.5 h) and a small overall volume of distribution (81). (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailBetamethasone-in-cyclodextrin-in-liposome: The effect of cyclodextrins on encapsulation efficiency and release kinetics
Piel, Géraldine ULg; Piette, Marie ULg; Barillaro, Valery et al

in International Journal of Pharmaceutics (2006), 312(1-2), 75-82

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 ... [more ▼]

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 beta CD and HP beta CD. In some cases, other cyclodextrins may be more interesting than beta CD or HPPCD, 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 (beta CD, gamma CD, Dimeb, Trimeb, Crysmeb, Rameb, HP beta CD and HP gamma CD) 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. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailEffect of cyclodextrins on the membrane permeability of liposomes
Piel, Géraldine ULg; Piette, Marie ULg; Barillaro, Valery et al

Poster (2005, November)

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