References of "Piel, Géraldine"
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See detailIntéret des liposomes dans le développement des compléments alimentaires
Piel, Géraldine ULiege

Conference given outside the academic context (2021)

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See detailAmphiphilic N-vinyl pyrrolidone-based polymers as PEG alternatives to avoid blood proteins adsorption around liposomes
Berger, Manon ULiege; Toussaint, François ULiege; Pairoux, Charlotte ULiege et al

Conference (2021, April 06)

Introduction: After a systemic administration, liposomes are quickly covered by proteins leading to the formation of a protein corona. This corona is responsible for a change of physicochemical properties ... [more ▼]

Introduction: After a systemic administration, liposomes are quickly covered by proteins leading to the formation of a protein corona. This corona is responsible for a change of physicochemical properties (as an increase of the size), pharmacokinetics, biodistribution, targeting ability, … [1]. Polyethylene glycol (PEG) is generally grafted onto the liposomes surface to reduce these non-specific interactions with blood components [2]. Since PEG faces some issues [3], alternatives are searched which should optimally prevent the formation of this corona. The goal of this study is to evaluate the protein corona formation around cationic liposomes (DOTAP/Chol/DOPE 1/0.75/0.5 molar ratio) encapsulating a model siRNA. Method: Different formulations were tested: naked liposomes, PEGylated liposomes (15% molar ratio of total lipids) and liposomes grafted with the new synthetic amphiphilic N-vinyl pyrrolidone-based polymers. Liposomes were incubated in FBS for two hours and their sizes were compared before and after incubation. Measurements were performed by DLS and NTA. An increase in liposomes size is related to the adsorption of proteins around the particles. Results: Results show that 15% PEG allows to prevent a significant size increase. However, 15% amphiphilic N-vinyl pyrrolidone-based polymers are not able to prevent corona formation since both analyses revealed a huge increase of particles sizes. A higher concentration (40%) was necessary to hinder a significant size increase meaning probably that their insertion/coating into/onto lipoplexes is different compared to PEG. Conclusions: To conclude, we showed that new synthetic amphiphilic N-vinyl pyrrolidone-based polymers were able to prevent protein corona formation around lipoplexes. Further studies are ongoing in order to evaluate the transfection capacity of these coated-vectors carrying siRNA. [less ▲]

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See detailImpact of amphiphilic copolymer used as PEG alternative on the formation of a protein corona around coated-liposomes encapsulating siRNA
Berger, Manon ULiege; Toussaint, François ULiege; Pairoux, Charlotte ULiege et al

Conference (2021, March 04)

After a systemic administration, liposomes are quickly covered by blood proteins leading to the formation of a protein corona. This corona is responsible for liposomes with a change of physicochemical ... [more ▼]

After a systemic administration, liposomes are quickly covered by blood proteins leading to the formation of a protein corona. This corona is responsible for liposomes with a change of physicochemical properties (as an increase of the size), pharmacokinetics, biodistribution, targeting ability and cellular uptake, complement activation and liposomes rapid clearance. To decrease this phenomenon, polyethylene glycol (PEG) is generally grafted onto liposomes surface to reduce non-specific interactions with blood components. Since PEG faces some issues, alternatives are searched which should optimally protect the liposomes surface from proteins adsorption. The goal of this study was to evaluate the protein corona formation around cationic liposomes (DOTAP/Chol/DOPE 1/0.75/0.5 molar ratio) encapsulating siRNA (N/P ratio of 2.5). Different formulations were tested: naked liposomes, PEGylated liposomes (15% molar ratio of total lipids) and liposomes grafted with new synthetic amphiphilic N-vinyl pyrrolidone-based copolymers used as PEG alternatives (B15b and B19a differing by the number of monomer units). Liposomes were incubated in Fetal Bovine Serum for two hours and their sizes were compared before and after incubation. An increase in liposomes size was related to the adsorption of proteins around the particles. Measurements were performed with Malvern Zetasizer® and Malvern NanoSight®. Results showed that PEG was already effective at 15% to prevent a significant increase of the size. However, both alternatives used at this concentration were not able to prevent corona formation since both analyses revealed a huge increasing of particles sizes. Higher concentration (40%) was necessary to hinder a significant increase of the size meaning probably that their insertion/coating into lipoplexes are different compared to PEG. These polymers may therefore be a great alternative able to face PEG limitations. To conclude, through this project, we have proven that our new amphiphilic copolymers were able to prevent protein corona formation around lipoplexes. Further studies are ongoing in order to evaluate the transfection capacity of these coated-vectors carrying siRNA. [less ▲]

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See detailDevelopment of a highly persistent silicone-based sprayable emulsion containing essential oils for treatment of skin infections
Sounouvou, Axel Gérald Hope Tognidé ULiege; Defourny, Charline ULiege; Gbaguidi, Fernand et al

in International Journal of Pharmaceutics (2021), 596

Essential oils have known a renewed interest, particularly for their antimicrobial properties. In the field of skin delivery of essential oils, fluid oil-in-water (O/W) emulsions have been studied for ... [more ▼]

Essential oils have known a renewed interest, particularly for their antimicrobial properties. In the field of skin delivery of essential oils, fluid oil-in-water (O/W) emulsions have been studied for several years in order to improve their stability. When dealing with infections of the upper skin layers, these vehicles, in spite of their low viscosity, must have a good skin persistence and also concentrate the essential oil components in the target skin layers. Given the well-known ability of alkylsiloxysilicate resins to induce a very substantive and non-occlusive film after cutaneous application in an appropriate preparation, it has been undertaken to use them to prepare a highly persistent O/W fluid emulsion of essential oil. Hence, after the successful development of a fluid silicone-in-water (Si/W) emulsion integrating a 100% trimethylsiloxysilicate resin, the essential oil was incorporated in this emulsion. The physical and chemical stabilities of the prepared emulsion were then studied in the final packaging under different storage conditions. In addition, the skin penetration profile of essential oil from this vehicle was investigated, ex vivo, on pig ear skin, using Franz diffusion cells and analytical techniques such as confocal Raman microscopy. As the developed vehicle was found to meet our delivery expectations, its skin tolerance has been proven by an in vivo chromametric evaluation of its irritant potential. The skin persistence of this emulsion containing an antimicrobial essential oil was then studied. Considering its properties, the developed emulsion is expected to represent a real asset in the treatment of skin infections, particularly infections of upper layers of human skin such as dermatophytosis. [less ▲]

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See detailSterilization methods of liposomes: drawbacks of conventional methods and perspectives
Delma, Kouka Luc ULiege; Lechanteur, Anna ULiege; Semde, Rasmané et al

in International Journal of Pharmaceutics (2021)

Liposomes are targeted drug delivery systems that are of great pharmaceutical and therapeutic interest. Parenteral route is the main way used for liposome administration. In this case, their sterility is ... [more ▼]

Liposomes are targeted drug delivery systems that are of great pharmaceutical and therapeutic interest. Parenteral route is the main way used for liposome administration. In this case, their sterility is a requirement. However, due to the particular sensitivity of liposomes and their tendency to physicochemical alterations, their sterilization remains a real challenge. Conventional sterilization methods such as heat, ethylene oxide, ultraviolet and gamma irradiations are considered as unsuitable for liposome sterilization and the recommended methods for obtaining sterility of liposomes are filtration and aseptic manufacturing. Unfortunately, these recommended methods are not without limitations. This review outlines the difficulties associated with the use of these different classical methods for obtaining liposome sterility. The effects on liposome physicochemical and biopharmaceutical characteristics as well as efficacy, toxicity and practical problems of these sterilization techniques have been discussed. The search for an alternative method being therefore necessary, the applicability of supercritical carbon dioxide (ScCO2) technology, which is nowadays a promising strategy for the sterilization of sensitive products such as liposomes, is also examined. It appears from this analysis that ScCO2 could effectively be an interesting alternative to achieve sterility of liposomes, but for this, sterilization assays including challenge tests and optimization studies are needed. [less ▲]

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See detailSystematic study of liposomes composition towards efficient delivery of plasmid DNA as potential application of dermal fibroblasts targeting
Bellefroid, Coralie ULiege; Reusch, Céline ULiege; Lechanteur, Anna ULiege et al

in International Journal of Pharmaceutics (2021), 592

The use of non-viral DNA vectors to topically treat skin diseases has demonstrated a high potential. However, vectors applied on the skin face extracellular barriers including the stratum corneum and ... [more ▼]

The use of non-viral DNA vectors to topically treat skin diseases has demonstrated a high potential. However, vectors applied on the skin face extracellular barriers including the stratum corneum and intracellular barriers such as the endosomal escape and the nuclear targeting of the plasmid DNA. The aim of this study was to develop a formulation suitable for dermal application and effective for delivering plasmid DNA into cells. Different formulations were prepared using different cationic lipids (DOTAP, DC-Chol, DOTMA) and co-lipids (DOPE, DSPE). Lipoplexes were produced by complexing liposomes with plasmid DNA at different pDNA/CL (w/w) ratios. Our results showed that appropriate pDNA/CL ratios allowing total complexation of plasmid DNA differed depending on the structure of the lipid used. The transfection rates showed that (i) higher rates were obtained with DOTMA lipoplexes, (ii) DC-Chol lipoplexes provided a transfection twice as important as DOTAP lipoplexes and (iii) when DSPE was added, the cytotoxicity decreased while transfection rates were similar. We found that formulations composed of DC-Chol:DOPE:DSPE or DOTMA:DOPE were appropriate to complex plasmid DNA and to transfect human primary dermal fibroblasts with efficacy and limited cytotoxicity. Therefore, these formulations are highly promising in the context of gene therapy to treat skin diseases. [less ▲]

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See detailA supercritical fluid technology for liposome production and comparison with the film hydration method
Penoy, Noémie ULiege; Grignard, Bruno ULiege; Evrard, Brigitte ULiege et al

in International Journal of Pharmaceutics (2021), 592

Liposomes were produced by an innovative method using supercritical carbon dioxide as a dispersing agent. A quality by design strategy was used to find optimal production conditions with specific ... [more ▼]

Liposomes were produced by an innovative method using supercritical carbon dioxide as a dispersing agent. A quality by design strategy was used to find optimal production conditions with specific parameters (lipid concentration, dispersion volume, agitation rate, temperature and pressure) allowing the production of liposomes with predicted physicochemical characteristics (particles size and PdI). Two conditions were determined with specific production parameters. It was shown that these two conditions allowed the production of liposomes of different compositions and that most of the liposome formulations had size and dispersity in accordance with the prediction values. The condition involving the higher lipid concentration showed a higher variability in terms of size and dispersity. However, this variability remained acceptable. This innovative supercritical method allowed the production of liposomes with physicochemical characteristics similar to those obtained by the conventional thin film hydration method. This new supercritical carbon dioxide method easily scalable in GMP conditions is a one-step production method contrarily to conventional methods which generally need an additional step as extrusion to homogenize the size of liposomes. [less ▲]

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See detailHeparin-Coated Liposomes Improve Antiplasmodial Activity and Reduce the Toxicity of Poupartone B
Ledoux, Allison ULiege; Mamede, Lucia; Palazzo, Claudio et al

in Planta Medica International Open (2020), 7(e), 7380

Poupartone B is an alkyl cyclohexenone derivative isolated from Poupartia borbonica. This compound demonstrated promising antimalarial activity (IC50 < 1 μg/mL), however, it was not de- void of toxicity ... [more ▼]

Poupartone B is an alkyl cyclohexenone derivative isolated from Poupartia borbonica. This compound demonstrated promising antimalarial activity (IC50 < 1 μg/mL), however, it was not de- void of toxicity. Thus, to reduce the adverse side effects of this natural bioactive molecule, a delivery strategy involving a na- nostructure was formulated. Additionally, poupartone B-load- ed liposomes were coated with heparin, a glycosaminoglycan that is known to target proteins on the surface of Plasmodium falciparum-infected red blood cells. The quantification of the compound in the formulation was performed by HPLC-DAD, while heparin was quantitated by 1H NMR spectroscopy. The liposomes’ antiplasmodial activity was tested on artemisinin- resistant P. falciparum isolate, and toxicity was evaluated on human HeLa cells and zebrafish embryos. Throughout this re- search, the formulation demonstrated higher antiplasmodial activities against both P. falciparum strains and a significant decrease of in vitro toxicity. The formulation improved the se- lectivity index 2 times in vitro and proved to be 3 times less toxic than the compound alone in the zebrafish embryo acute toxicity test. Hence, the use of this strategy to deliver natural products in Plasmodium-infected cells, particularly those with a narrow therapeutic margin, is proposed. [less ▲]

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See detailLiposomes and drug-in-cyclodextrin-in-liposomes formulations encapsulating 17β-estradiol: an innovative drug delivery system that prevents the activation of the membrane-initiated steroid signaling (MISS) of estrogen receptor α
Gallez, Anne ULiege; Palazzo, Claudio ULiege; Blacher, Silvia ULiege et al

in International Journal of Pharmaceutics (2020), 573

The encapsulation into liposomes of several types of molecules presents the advantages to protect the activity of these molecules and to target specific tissues. Nevertheless, a major obstacle remains the ... [more ▼]

The encapsulation into liposomes of several types of molecules presents the advantages to protect the activity of these molecules and to target specific tissues. Nevertheless, a major obstacle remains the incomplete understanding of nano-bio interactions. Specifically, the impact that inclusion of drug into liposomes or of drug-in-cyclodextrin-in liposomes (DCL) could have on the molecular and cellular mechanism of drug action is largely unknown. As a proof of concept, we evaluated the impact of 17β-estradiol (E2) included into liposomes or DCL on estrogen receptor (ER)α signaling pathways. Indeed, ERα relays the pleiotropic actions of E2 in physiology and pathophysiology through two major pathways: (1) the genomic/nuclear effects associated to the transcriptional activity of the ERα and (2) the rapid/nongenomic/membrane-initiated steroid signaling (MISS) effects related to the induction of fast signaling pathways occurring when ERα is anchored to the plasma membrane. We evidenced that the inclusion of E2 into liposomes (Lipo-E2) or into DCL (DCL-E2) prevented the activation of the rapid/nongenomic/extranuclear/MISS pathway of ERα, while the activation of the genomic/nuclear pathway was maintained. These results support that Lipo-E2 and DCL-E2 could be a useful tool to delineate the complex molecular mechanisms associated to ERα. In conclusion, this study supports the notion that inclusion of drugs into liposomes or DCL could modify some specific pathways of their molecular and cellular mechanisms of action. These results emphasized that attention should be paid to nano-bio interactions induced by the use of nanovectors in medicine. [less ▲]

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See detailLiposomal Encapsulated Curcumin Effectively Attenuates Neuroinflammatory and Reactive Astrogliosis Reactions in Glia Cells and Organotypic Brain Slices
Schmitt, Christina; Lechanteur, Anna ULiege; Cossais, François et al

in International Journal of Nanomedicine (2020), 15

Introduction: The polyphenolic spice and food coloring ingredient curcumin has beneficial effects in a broad variety of inflammatory diseases. Amongst them, curcumin has been shown to attenuate microglia ... [more ▼]

Introduction: The polyphenolic spice and food coloring ingredient curcumin has beneficial effects in a broad variety of inflammatory diseases. Amongst them, curcumin has been shown to attenuate microglia reaction and prevent from glial scar formation in spinal cord and brain injuries. Methods: We developed a protocol for the efficient encapsulation of curcumin as a model for anti-inflammatory drugs yielding long-term stable, non-toxic liposomes with favorable physicochemical properties. Subsequently, we evaluate the effects of liposomal curcumin in experimental models for neuroinflammation and reactive astrogliosis. Results: We could show that liposomal curcumin can efficiently reduce the reactivity of human microglia and astrocytes and preserve tissue integrity of murine organotypic cortex slices. Discussion and Perspective: In perspective, we want to administer this curcumin formulation in brain implant coatings to prevent neuroinflammation and glial scar formation as foreign body responses of the brain towards implanted materials. [less ▲]

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See detailIn vitro skin penetration enchancement techniques: a combined approach of ethosomes and microneedles
Bellefroid, Coralie ULiege; Lechanteur, Anna ULiege; Evrard, Brigitte ULiege et al

in International Journal of Pharmaceutics (2019), 572

Detailed reference viewed: 59 (19 ULiège)
See detailEffects of supercritical carbon dioxide sterilization conditions on physicochemical characteristics of liposomes
Delma, Kouka Luc ULiege; Semdé, Rasmané; Evrard, Brigitte ULiege et al

Poster (2019, December 11)

Sterility is a requirement for parenteral administration of liposomes. However, conventional sterilization methods of liposomes have limitations. Supercritical Carbon Dioxide (ScCO2) is a promising ... [more ▼]

Sterility is a requirement for parenteral administration of liposomes. However, conventional sterilization methods of liposomes have limitations. Supercritical Carbon Dioxide (ScCO2) is a promising strategy for the sterilization of sensitive products. In this work, the effects of ScCO2 sterilization conditions on physicochemical characteristics of liposomes were investigated using a liposome formulation previously validated in the LPTB. This model formulation contains cholesterol, dimethylaminoethane-carbamoyl hydrochloride (DC-cholesterol), egg phosphatidylcholine (EPC) and distearoylphosphatidylethanolamine (DSPE) PEG2000, and as active drug, apigenin. Liposomes were prepared by thin-film hydration method and the physicochemical characteristics such as pH, particle size, polydispersity index (PDI), zeta potential, amount of encapsulated apigenin and phospholipids concentration were determined before and after submission to the selected ScCO2 sterilization conditions: 70 ° C, 150 bar for 4h (Karajanagi and al, 2011). The results showed a decrease of the pH of the dispersion, the size, the zeta potential of the vesicles and of the amount of encapsulated apigenin. On the contrary, an increase in PDI after treatment with ScCO2 was observed. In spite of changes observed with this liposome formulation under sterilization conditions used in this work, others conditions should be tested in order to maintain the characteristics of the formulations before and after the sterilization process. [less ▲]

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See detailA quality by design approach for liposomes production by innovative method using supercritical fluids: which parameters use to obtain good physicochemical characteristics?
Penoy, Noémie ULiege; Avohou, Tonakpon Hermane ULiege; Lebrun, Pierre ULiege et al

Scientific conference (2019, December 11)

Liposomes are nanoparticles made of phospholipids, able to encapsulate many active molecules, protecting and transporting them in a targeted way. Liposomes are thus widely studied as vectors of numerous ... [more ▼]

Liposomes are nanoparticles made of phospholipids, able to encapsulate many active molecules, protecting and transporting them in a targeted way. Liposomes are thus widely studied as vectors of numerous active molecules, improving their therapeutic window. However, the usual production methods at the laboratory scale have many disadvantages and are generally difficult to transfer to the industrial scale under GMP conditions [1], [2]. Supercritical fluids are increasingly used in the pharmaceutical industry. One of the pharmaceutical applications of supercritical fluids is the production of particles. For the liposomes production, the use of supercritical CO2 as a dispersing agent has been preferred because of the total absence of organic solvent. Since this process involves many parameters such as pressure, temperature, stirring speed, lipid concentration, volume and contact time, a quality by design approach was used in order to determine the influence of each parameters on the physicochemical properties of liposomes such as the size and the polydispersity. These experimental analyses helped us to find two production areas. These conditions were validated with five different liposome formulations regarding the size and polydispersity expectations. We will now focus on the impact of each parameter on the physicochemical properties of liposomes but also their impact on the integrity of the phospholipids used. [less ▲]

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See detailLC-UV as tool for nanovectorized anticancer peptide quality control: evaluation of encapsulation efficiency
Ilangala Booka, Ange ULiege; COBRAIVILLE, Gaël ULiege; EVRARD, Aude ULiege et al

Poster (2019, December 11)

Many peptides have today a recognized and growing therapeutic interest. However, their administration is not an easy task, since systemically administrated peptides may suffer from several issues such as ... [more ▼]

Many peptides have today a recognized and growing therapeutic interest. However, their administration is not an easy task, since systemically administrated peptides may suffer from several issues such as rapid elimination or unspecific biodistribution. Moreover, many compounds of this emerging class of therapeutics have their targets at the intracellular level, adding another challenge to their therapeutic success. LB19 is a peptidic selective inhibitors of LDHB that catalyzes the conversion of lactate + NAD to pyruvate + NADH + H+, a new therapeutic approach for cancer therapy. The necessity of intravenous administration of LB19 lead to the development of liposomes as drug carriers, combining the protective properties of PEG (stealth liposomes) with the transfection properties of pH-sensitive lipids. This general concept raises the need to develop analytical tools enabling the determination of the encapsulation efficiency of LB19 into these nanocarriers and quantitatively demonstrate their ability to achieve intracellular delivery of their payload. In this project, a LC-UV method was developed to selectively quantify this new anticancer peptide in liposomes. More particularly, we generated stability data of LB19 to support its formulation development. The LC-UV method was employed to study the adsorption of the peptide and demonstrate the impact of the adsorption behaviour on quantitative analysis during the evaluation of the encapsulation efficiency of liposomes. Altogether, this analytical part of our project has the potential to control the quality of the formulated LB19 loaded liposomes, and has also a goal to provide a LC-MS/MS method for the intracellular assay of the peptide on long run. [less ▲]

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See detailA quality by design approach for liposomes production by innovative method using supercritical fluids: which parameters use to obtain good physicochemical characteristics?
Penoy, Noémie ULiege; Avohou, Tonakpon Hermane ULiege; Lebrun, Pierre ULiege et al

Scientific conference (2019, December 11)

Liposomes are nanoparticles made of phospholipids, able to encapsulate many active molecules, protecting and transporting them in a targeted way. Liposomes are thus widely studied as vectors of numerous ... [more ▼]

Liposomes are nanoparticles made of phospholipids, able to encapsulate many active molecules, protecting and transporting them in a targeted way. Liposomes are thus widely studied as vectors of numerous active molecules, improving their therapeutic window. However, the usual production methods at the laboratory scale have many disadvantages and are generally difficult to transfer to the industrial scale under GMP conditions [1], [2]. Supercritical fluids are increasingly used in the pharmaceutical industry. One of the pharmaceutical applications of supercritical fluids is the production of particles. For the liposomes production, the use of supercritical CO2 as a dispersing agent has been preferred because of the total absence of organic solvent. Since this process involves many parameters such as pressure, temperature, stirring speed, lipid concentration, volume and contact time, a quality by design approach was used in order to determine the influence of each parameters on the physicochemical properties of liposomes such as the size and the polydispersity. These experimental analyses helped us to find two production areas. These conditions were validated with five different liposome formulations regarding the size and polydispersity expectations. We will now focus on the impact of each parameter on the physicochemical properties of liposomes but also their impact on the integrity of the phospholipids used. References [1] C. Tikshdeep, A. Sonia, P. Bharat, and C. Abhishek, “Liposome Drug Delivery,” Int. J. Pharm. Chem. Sci., vol. 1, no. 3, pp. 1103–1113, 2012. [2] L. A. Meure, N. R. Foster, and F. Dehghani, “Conventional and Dense Gas Techniques for the Production of Liposomes: A Review,” AAPS PharmSciTech, vol. 9, no. 3, pp. 798–809, 2008. [3] B. S. Sekhon, “Supercritical fluid technology: An overview of pharmaceutical applications,” Int. J. PharmTech Res., vol. 2, no. 1, pp. 810–826, 2010 [less ▲]

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See detailAssessment of the feasibility to develop a fast and easy reproducible 3D bronchial model growing at the air-liquid interface: Which critical culture parameters must be controlled?
Lechanteur, Anna ULiege; Evrard, Brigitte ULiege; Piel, Géraldine ULiege

Poster (2019, December 11)

The discovery and evaluation of new active drugs will be easier thanks to the development of 3D-epithelial model mimicking biological barriers (1). These models closer to in vivo conditions should help to ... [more ▼]

The discovery and evaluation of new active drugs will be easier thanks to the development of 3D-epithelial model mimicking biological barriers (1). These models closer to in vivo conditions should help to speed up the drug development process. Regarding lung administration, despite many studies exploring the development of 2D-model using Calu-3 cells, there are still multiple disparities about experimental methods and a standardization is needed. We investigated the impact of different culture parameters (time, cell densities,…) on the integrity and the morphology of a 2D model (2). Using permeability studies, electron microscopy and immunohistochemistry, we propose an easy and reproducible 2D-model with Calu-3 cells fully differentiated after 14 days of growing at the air-liquid interface. Moreover, based on these results, we went further with a 3D-bronchial model which consists of a collagen matrix, fibroblasts laid under the epithelial layer. We aim to assess the feasibility to develop a 3D cell-based model of the human airway growing at the air-liquid interface. Many parameters which have to be tightly controlled to develop an extracellular matrix equivalent without any shrinking of the gel encompassing alive fibroblasts as well as over epithelial cells have been identified. Overall, this in vitro model is a differentiated pseudo-stratified bronchial mucosa with mucus expression which is the basis for further optimization allowing the screening of pulmonary drugs in terms of permeability, cytotoxicity or particle-mucus interactions. (1) A. Lechanteur, et al. ADDR. 124 (2018) 50–63. (2) A. Lechanteur, et al. EJPB. 144 (2019) 2–10. [less ▲]

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See detailChromametric assessment of drug skin tolerance: A comparative study between Africans and Caucasians skins
Sounouvou, Axel Gérald Hope Tognidé ULiege; Lechanteur, Anna ULiege; Quetin-Leclercq, Joëlle et al

in Skin Research and Technology (2019)

Background/Aims: During dermatological forms development, one of the simplest non-invasive techniques used to evaluate cutaneous tolerance of formulations is to monitor the color changes using a ... [more ▼]

Background/Aims: During dermatological forms development, one of the simplest non-invasive techniques used to evaluate cutaneous tolerance of formulations is to monitor the color changes using a tristimulus chromameter. Most published tolerance studies involving chromametric measurements are performed on Caucasian subjects. However, in the context of drug formulation for African-type populations, it is not always relevant to transpose tolerance results obtained on Caucasians populations to African-type ones due to histological ethnic differences of the skin. The goal of this work was to assess whether tristimulus chromameter can be used to highlight color variations following the application of dermatological topics on black skin in order to validate skin tolerance studies made on African-type subjects. Materials and Methods: After application of two commercial creams with opposite side effects (skin irritation and skin blanching) in both Africans and Caucasians populations, color variations were evaluated using a tristimulus chromameter in L*a*b* color system and compared between both populations. L* indicating color brightness, a* represents green and red directions and b* represents blue and yellow directions. Results: While skin irritation resulted in a significant increase of a* parameter in both studied populations, the skin blanching resulted in a decrease of a* associated with an increase of L*. Conclusion: We established that tristimulus chromameter can be used to achieve in vivo skin tolerance study of dermatologic formulations in Africans despite their dark skin even though it appeared less sensitive. This study can speed up the development of dermatological forms dedicated to Africans and/or Caucasians subjects. [less ▲]

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See detailEtude de l’influence des conditions de stérilisation par le dioxyde de carbone en phase supercritique (CO2Sc) sur les caractéristiques physicochimiques de liposomes
Delma, Kouka Luc ULiege; Semdé, Rasmané; Evrard, Brigitte ULiege et al

Conference (2019, November 27)

Sterility is a requirement for parenteral administration of liposomes. However, conventional sterilization methods of liposomes have limitations. Supercritical Carbon Dioxide (ScCO2) is a promising ... [more ▼]

Sterility is a requirement for parenteral administration of liposomes. However, conventional sterilization methods of liposomes have limitations. Supercritical Carbon Dioxide (ScCO2) is a promising strategy for the sterilization of sensitive products. In this work, the effects of ScCO2 sterilization conditions on physicochemical characteristics of liposomes were investigated using a liposome formulation previously validated in the LPTB. This model formulation contains cholesterol, dimethylaminoethane-carbamoyl hydrochloride (DC-cholesterol), egg phosphatidylcholine (EPC) and distearoylphosphatidylethanolamine (DSPE) PEG2000, and as active drug, apigenin. Liposomes were prepared by thin-film hydration method and the physicochemical characteristics such as pH, particle size, polydispersity index (PDI), zeta potential, amount of encapsulated apigenin and phospholipids concentration were determined before and after submission to the selected ScCO2 sterilization conditions: 70 ° C, 150 bar for 4h (Karajanagi and al, 2011). The results showed a decrease of the pH of the dispersion, the size, the zeta potential of the vesicles and of the amount of encapsulated apigenin. On the contrary, an increase in PDI after treatment with ScCO2 was observed. In spite of changes observed with this liposome formulation under sterilization conditions used in this work, others conditions should be tested in order to maintain the characteristics of the formulations before and after the sterilization process. [less ▲]

Detailed reference viewed: 44 (1 ULiège)