18 results on '"Dembele F"'
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2. Fire and water: the role of grass competition on juvenile tree growth and survival rates in a mesic savanna
- Author
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Laris, P., Yang, L., Dembele, F., and Rodrigue, C. M.
- Published
- 2021
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3. The AMMA-CATCH Gourma observatory site in Mali: Relating climatic variations to changes in vegetation, surface hydrology, fluxes and natural resources
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Mougin, E., Hiernaux, P., Kergoat, L., Grippa, M., de Rosnay, P., Timouk, F., Le Dantec, V., Demarez, V., Lavenu, F., Arjounin, M., Lebel, T., Soumaguel, N., Ceschia, E., Mougenot, B., Baup, F., Frappart, F., Frison, P.L., Gardelle, J., Gruhier, C., Jarlan, L., Mangiarotti, S., Sanou, B., Tracol, Y., Guichard, F., Trichon, V., Diarra, L., Soumaré, A., Koité, M., Dembélé, F., Lloyd, C., Hanan, N.P., Damesin, C., Delon, C., Serça, D., Galy-Lacaux, C., Seghieri, J., Becerra, S., Dia, H., Gangneron, F., and Mazzega, P.
- Published
- 2009
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4. Tree vegetation patterns along a gradient of human disturbance in the Sahelian area of Mali
- Author
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Dembélé, F., Picard, N., Karembé, M., and Birnbaum, P.
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- 2006
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5. Variation de quelques parametres floristiques suivant les zones de conservation de la reserve de biosphere du Baoule (Mali)
- Author
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Sanogo, M, Timbely, D, Ballo, A, Toko Imorou, I, Djego, J, Karembe, M, Dembele, F, Berthe, A, Houinato, M, Oumorou, M, and Sinsin, B
- Subjects
Indice de similarité, distances de Hamming, origine phytogéographique, zones de conservation, Réserve de Biosphère de la boucle de Baoulé (RBBB), index of similarity, distance the Hamming, phytogeographical origin, zones of conservation, Biosphere Reserve - Abstract
L’une des fonctions principales de l’aménagement de la Réserve de Biosphère de la Boucle du Baoulé (RBBB) au Mali est de conserver la végétation dans son état originel dans l’aire centrale. L'étude des paramètres floristiques est indispensable si l'on veut mettre en place des aménagements durables dans la RBBB.La présente étude vise à étudier les variations des paramètres floristiques suivant les zones de conservation afin de réussir une conservation durable de la phytodiversité dans la RBBB. Le traitement à l’aide des logiciels EXCEL et CAP « Community Analysis Package 3.0 » des données de 35 relevés phytosociologiques réalisés sur un sol sableux d’origine éolienne dans l’aire centrale et les zones (tampon et transition) a mis en évidence une homogénéité dans la composition floristique de la végétation quelles que soient les zones de conservation comparées deux à deux.Les différences de biomasses ont été faibles (D = 0,24) entre les zones de transition et tampon et très faibles (D = 0,18-0,19) entre la zone de transition et l’aire centrale d’une part et entre cette dernière et la zone tampon d’autre part. Les espèces soudano-zambéziennes et de l’Elément base soudanien ont été les plus prépondérantes dans la zone de transition et moins dominantes dans l’aire centrale tandis que ce sont les espèces à large distribution et plurirégionales qui ont été prédominantes dans la zone tampon. Pour répondre aux objectifs de conservation de la phytodiversité dans la RBBB et assurer une conservation durable de la phytodiversité, il convient d’intensifier la protection et de procéder à des interventions sylvicoles visant à préserver la flore dans son état originel voir l’enrichir dans l’aire centrale et dans la zone tampon.Mots clés: Indice de similarité, distances de Hamming, origine phytogéographique, zones de conservation, Réserve de Biosphère de la boucle de Baoulé (RBBB)English Title: Variation of some floristic parameters according to the zones of conservation of the biosphere reserve of Baoule (in Mali)English AbstractThe Reserve of Biosphere of the Loop of Baoulé (RBBB) in Mali, is a protected area of arranged according to the model of reserve of biosphere of UNESCO in central surface, buffer zones and of transition separated by corridors from passage from the animals.The goal of this managment is to especially preserve the vegetation in its original state in the central surface. The present study aims at studying the variations of the floristic parameters according to the zones of conservation in order to make a success of a sustainable conservation of the phytodiversity in the RBBB. The treatment using the software EXCEL and CAP “Community Analysis Package 3.0” of the data of 35 phytosociological releves carried out on a sandy ground of wind origin in the central surface and the zones (buffer and transition) highlighted homogeneity in the floristic composition of the vegetation whatever the zones of conservation compared two to two.The differences of biomasses were weak (D = 0.24) between the zones of very weak transition and buffer and (D = 0,18 - 0,19) between the zone of transition and the central surface on the one hand and between the latter and the buffer zone on the other hand. The species soudanozambéziennes and of the Element bases soudanien were most dominating in the zone of transition and less dominant in the central surface while in fact the species with broad distribution and pluri-regional were prevalent in the buffer zone. To answer the objectives of conservation of the phytodiversity in the RBBB and to ensure a conservation of the phytodiversity. If is advisable to intensify protection and to proceed to forestry interventions aiming at preserving the flora in its original state to see enriching it in the central surface and the buffer zone.Keywords: index of similarity, distance the Hamming, phytogeographical origin, zones of conservation, Biosphere Reserve of the Bend of Baoulé
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- 2016
6. Etude comparative de la flore aux abords des cours d’eau dans les zones hypo et hyper endémiques d’ulcère de Buruli en Côte d’Ivoire
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Boni, C. Cisse, primary, Ehouman, E., additional, Soro, D., additional, Kone, M.W., additional, Bakayoko, A., additional, Dembele, F., additional, Bauthire, K., additional, and Dosso, M, additional
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- 2017
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7. Sample preparation of complex biological samples in the analysis of trace-level contaminants
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Lee, H.K., Tang, S., Dembele, F., Basheer, C., Alhooshani, K., Nuhu, A.A., and Kanimozhi, S.
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- 2013
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8. Choice-making in facilitation of agricultural innovation platforms in different contexts in West Africa: experiences from Benin, Ghana and Mali
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van Paassen, A., Klerkx, L.W.A., Adjei-Nsiah, S., Adu-Acheampong, R., Ouologuem, B., Zannou, E., Vissoh, P., Soumano, L., Dembele, F., and Traore, M.
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Knowledge Technology and Innovation ,Life Science ,WASS ,Kennis, Technologie and Innovatie - Abstract
Platforms provide an increased capacity for learning and coordinated innovation. The value of platforms for innovation is widely recognized, but more understanding is needed of the choices made in facilitation, to enable platforms to perform effectively within varying value chain contexts. This paper applies a comparative case study analysis of four innovation platforms in West Africa that aim to create institutional change for the benefit of smallholders. Each institutional context (emerging or developing value chain, a well-established value chain with more or less distortion by politics and rent-seeking behaviour) constituted a specific type of constraint and required different facilitation choices. Comparison showed that it is imperative for facilitators to have a clear platform purpose and design criteria, and good situation and actor analyses, and to interactively design small platforms, fit to create institutional change in a given context. Platforms need actors with capacities relating to the issue at stake, but also communicative qualities. Then there are situational facilitation choices: local level platforms need more structuring of deliberation, data-gathering, networking, and advocacy than higher level platforms. However, what emerged as essential for all was delicate mediation and dynamic agenda-setting. This created trust, relationships, and momentum for mutually supportive team action and institutional change.
- Published
- 2013
9. African monsoon multidisciplinary analyses : extended abstracts
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Mougin, Eric, Herniaux, P., Kergoat, L., Seghieri, Josiane, Lavenu, François, Tracol, Y., Jarlan, L., Diarra, L., Dembele, F., Karembe, M., Mougenot, Bernard, Timouk, Franck, Rosnay, P. de, Le Dantec, V., Baup, F., Mangiarotti, S., Genau, I. (ed.), Marsh, S. (ed.), McQuaid, J. (ed.), Redelsperger, J.L. (ed.), Thorncroft, C. (ed.), and Van Den Akker, E. (ed.)
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VARIATION TEMPORELLE ,INTERFACE SOL ATMOSPHERE ,PLUVIOMETRIE ,VEGETATION ,ANALYSE DE DONNEES ,IMPACT SUR L'ENVIRONNEMENT - Published
- 2006
10. Compounding of cellulose fibers with polypropylene: Effect of fiber treatment on dispersion in the polymer matirx.
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Raj, R. G., Kokta, B. V., Dembele, F., and Sanschagrain, B.
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- 1989
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11. One Finger Cannot Lift a Rock: Facilitating Innovation Platforms to Trigger Institutional Change in West Africa
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Nederlof, S., Pyburn, R., Sustainable Agriculture and Natural Resource Management (SANREM) Knowledgebase, Debrah, K.A., Adjei-Nsiah, S., Adu-Acheampong, R.K., Dembele, F., Kossou, D., Lassine, S., Mundy, P., Nederlof, S., Ouologuem, S., Pyburn, R., Saïdou, A., Sakyi-Dawson, O., Traore, M., Vissoh, P.V., and Zannou, E.T.
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Institutional change ,Enterprise development ,Social learning ,Community participation ,Small holder enterprise ,Leadership development ,Stakeholders ,Social capital ,Value chains ,Community management ,Community development ,Institutional capacity building ,Empowerment ,Innovation platforms ,Governance Watershed ,Community institutions - Abstract
Metadata only record Smallholder African farmers, who produce most of the produce, tea, coffee, and other agricultural goods exported to Europe, are constrained by the institutional arrangements under which they operate. Institutional changes must take place that facilitate smallholder farmers’ ability to take advantage of opportunities. To this end, Wageningen University developed a research program labeled Convergence of Sciences-Strengthening Agricultural Innovation Systems (CoS-SIS). Through this effort, doctoral candidates and research associates facilitated innovation platforms called Concertation and Innovation Groups (CIGs), with the objectives of removing institutional constraints and investigating pathways that lead to innovation. This book describes the experiences of these facilitators, mapping out the development of each CIG: Their formation, the constraints they encountered, and the development of solutions. It provides a practical reference for the formation of innovation platforms which seek to create institutional change in a value chain.
- Published
- 2012
12. Metastable water at several compression rates and its freezing kinetics into ice VII.
- Author
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Pépin CM, André R, Occelli F, Dembele F, Mozzanica A, Hinger V, Levantino M, and Loubeyre P
- Abstract
Water can be dynamically over-compressed well into the stability field of ice VII. Whether water then transforms into ice VII, vitreous ice or a metastable novel crystalline phase remained uncertain. We report here the freezing of over-compressed water to ice VII by time-resolved X-ray diffraction. Quasi-isothermal dynamic compression paths are achieved using a dynamic-piezo-Diamond-Anvil-Cell, with programmable pressure rise time from 0.1 ms to 100 ms. By combining the present data set with those obtained on various ns-dynamical platforms, a complete evolution of the solidification pressure of metastable water versus the compression rate is rationalized within the classical nucleation theory framework. Also, when crystallization into ice VII occurs in between 1.6 GPa and 2.0 GPa, that is in the stability field of ice VI, a structural evolution over few ms is then observed into a mixture of ice VI and ice VII that seems to resolve apparent contradictions between previous results., (© 2024. The Author(s).)
- Published
- 2024
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13. Efficacy and safety of three antiretroviral therapy regimens for treatment-naive African adults living with HIV-2 (FIT-2): a pilot, phase 2, non-comparative, open-label, randomised controlled trial.
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Eholie SP, Ekouevi DK, Chazallon C, Charpentier C, Messou E, Diallo Z, Zoungrana J, Minga A, Ngom Gueye NF, Hawerlander D, Dembele F, Colin G, Tchounga B, Karcher S, Le Carrou J, Tchabert-Guié A, Toni TD, Ouédraogo AS, Bado G, Toure Kane C, Seydi M, Poda A, Mensah E, Diallo I, Drabo YJ, Anglaret X, and Brun-Vezinet F
- Subjects
- Humans, Adult, Male, Female, Pilot Projects, CD4 Lymphocyte Count, Treatment Outcome, Lopinavir therapeutic use, Lopinavir adverse effects, Lopinavir administration & dosage, Raltegravir Potassium therapeutic use, Raltegravir Potassium adverse effects, Raltegravir Potassium administration & dosage, Lamivudine therapeutic use, Lamivudine administration & dosage, Lamivudine adverse effects, Viral Load drug effects, Antiretroviral Therapy, Highly Active, Middle Aged, Zidovudine therapeutic use, Zidovudine adverse effects, Zidovudine administration & dosage, Drug Therapy, Combination, HIV-1 drug effects, HIV Infections drug therapy, HIV-2 drug effects, Tenofovir therapeutic use, Tenofovir adverse effects, Emtricitabine therapeutic use, Emtricitabine administration & dosage, Emtricitabine adverse effects, Anti-HIV Agents therapeutic use, Anti-HIV Agents adverse effects, Anti-HIV Agents administration & dosage, Ritonavir therapeutic use, Ritonavir administration & dosage, Ritonavir adverse effects
- Abstract
Background: Due to the low number of individuals with HIV-2, no randomised trials of HIV-2 treatment have ever been done. We hypothesised that a non-comparative study describing the outcomes of several antiretroviral therapy (ART) regimens in parallel groups would improve understanding of how differences between HIV-1 and HIV-2 might lead to different therapeutic approaches., Methods: This pilot, phase 2, non-comparative, open-label, randomised controlled trial was done in Burkina Faso, Côte d'Ivoire, Senegal, and Togo. Adults with HIV-2 who were ART naive with CD4 counts of 200 cells per μL or greater were randomly assigned 1:1:1 to one of three treatment groups. A computer-generated sequentially numbered block randomisation list stratified by country was used for online allocation to the next available treatment group. In all groups, tenofovir disoproxil fumarate (henceforth tenofovir) was dosed at 245 mg once daily with either emtricitabine at 200 mg once daily or lamivudine at 300 mg once daily. The triple nucleoside reverse transcriptase inhibitor (NRTI) group received zidovudine at 250 mg twice daily. The ritonavir-boosted lopinavir group received lopinavir at 400 mg twice daily boosted with ritonavir at 100 mg twice daily. The raltegravir group received raltegravir at 400 mg twice daily. The primary outcome was the rate of treatment success at week 96, defined as an absence of serious morbidity event during follow-up, plasma HIV-2 RNA less than 50 copies per mL at week 96, and a substantial increase in CD4 cells between baseline and week 96. This trial is registered at ClinicalTrials.gov, NCT02150993, and is closed to new participants., Findings: Between Jan 26, 2016, and June 29, 2017, 210 participants were randomly assigned to treatment groups. Five participants died during the 96 weeks of follow-up (triple NRTI group, n=2; ritonavir-boosted lopinavir group, n=2; and raltegravir group, n=1), eight had a serious morbidity event (triple NRTI group, n=4; ritonavir-boosted lopinavir group, n=3; and raltegravir group, n=1), 17 had plasma HIV-2 RNA of 50 copies per mL or greater at least once (triple NRTI group, n=11; ritonavir-boosted lopinavir group, n=4; and raltegravir group, n=2), 32 (all in the triple NRTI group) switched to another ART regimen, and 18 permanently discontinued ART (triple NRTI group, n=5; ritonavir-boosted lopinavir group, n=7; and raltegravir group, n=6). The Data Safety Monitoring Board recommended premature termination of the triple NRTI regimen for safety reasons. The overall treatment success rate was 57% (95% CI 47-66) in the ritonavir-boosted lopinavir group and 59% (49-68) in the raltegravir group., Interpretation: The raltegravir and ritonavir-boosted lopinavir regimens were efficient and safe in adults with HIV-2. Both regimens could be compared in future phase 3 trials. The results of this pilot study suggest a trend towards better virological and immunological efficacy in the raltegravir-based regimen., Funding: ANRS MIE., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2024
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14. Fragrance Encapsulates: Effect of Polymeric Shell Purification Method on the Accuracy of Biodegradability Testing.
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Karagianni K, Kuntzmann-Dembele F, Bocokic V, Charbonnier A, Harrison I, Kreutzer G, Mendoza A, and Jenner K
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- Perfume, Biodegradation, Environmental, Polymers
- Abstract
Fragrance encapsulates are widely used in consumer care applications such as fabric softeners or other liquid laundry products; they provide multiple benefits, from fragrance protection in the commercial product to a controlled release and improved sensorial experience for the consumers. Polymeric fragrance encapsulates are in the scope of the EU regulation restricting the use of intentionally added microplastic particles, and industry is actively working on innovation programs to find biodegradable alternatives. However, particular attention needs to be paid to claims that a fragrance encapsulation system is biodegradable, because biodegradation test results can vary considerably depending on how a test material is prepared, which can even lead to false-positive biodegradation test results, as shown in our study. We demonstrate the importance of the sample preparation phase of the process. We show how the biodegradation level can fluctuate from 0% to 91%, depending on how the test material is isolated from a given microcapsule slurry system, and we present a method that can be used to obtain trustworthy biodegradation results. Environ Toxicol Chem 2024;43:1242-1249. © 2024 Givaudan France SAS. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC., (© 2024 Givaudan France SAS. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.)
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- 2024
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15. Zwitterionic polymer ligands: an ideal surface coating to totally suppress protein-nanoparticle corona formation?
- Author
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Debayle M, Balloul E, Dembele F, Xu X, Hanafi M, Ribot F, Monzel C, Coppey M, Fragola A, Dahan M, Pons T, and Lequeux N
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- Betaine analogs & derivatives, Betaine chemistry, Biotin chemistry, Hydrodynamics, Ligands, Phosphorylcholine chemistry, Quantum Dots chemistry, Coated Materials, Biocompatible chemistry, Nanoparticles chemistry, Polymers chemistry, Protein Corona chemistry
- Abstract
In the last few years, zwitterionic polymers have been developed as antifouling surface coatings. However, their ability to completely suppress protein adsorption at the surface of nanoparticles in complex biological media remains undemonstrated. Here we investigate the formation of hard (irreversible) and soft (reversible) protein corona around model nanoparticles (NPs) coated with sulfobetaine (SB), phosphorylcholine (PC) and carboxybetaine (CB) polymer ligands in model albumin solutions and in whole serum. We show for the first time a complete absence of protein corona around SB-coated NPs, while PC- and CB-coated NPs undergo reversible adsorption or partial aggregation. These dramatic differences cannot be described by naïve hard/soft acid/base electrostatic interactions. Single NP tracking in the cytoplasm of live cells corroborate these in vitro observations. Finally, while modification of SB polymers with additional charged groups lead to consequent protein adsorption, addition of small neutral targeting moieties preserves antifouling and enable efficient intracellular targeting., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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16. Zwitterionic Silane Copolymer for Ultra-Stable and Bright Biomolecular Probes Based on Fluorescent Quantum Dot Nanoclusters.
- Author
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Dembele F, Tasso M, Trapiella-Alfonso L, Xu X, Hanafi M, Lequeux N, and Pons T
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- Polymers, Quantum Dots, Semiconductors, Silicon Dioxide, Silanes chemistry
- Abstract
Fluorescent semiconductor quantum dots (QDs) exhibit several unique properties that make them suitable candidates for biomolecular sensing, including high brightness, photostability, broad excitation, and narrow emission spectra. Assembling these QDs into robust and functionalizable nanosized clusters (QD-NSCs) can provide fluorescent probes that are several orders of magnitude brighter than individual QDs, thus allowing an even greater sensitivity of detection with simplified instrumentation. However, the formation of compact, antifouling, functionalizable, and stable QD-NSCs remains a challenging task, especially for a use at ultralow concentrations for single-molecule detection. Here, we describe the development of fluorescent QD-NSCs envisioned as a tool for fast and sensitive biomolecular recognition. First, QDs were assembled into very compact 100-150 nm diameter spherical aggregates; the final QD-NSCs were obtained by growing a cross-linked silica shell around these aggregates. Hydrolytic stability in several concentration and pH conditions is a key requirement for a potential and efficient single-molecule detection tool. However, the hydrolysis of Si-O-Si bonds leads to desorption of monosilane-based surface groups at very low silica concentrations or in a slightly basic medium. Thus, we designed a novel multidentate copolymer composed of multiple silane as well as zwitterionic monomers. Coating silica beads with this multidentate copolymer provided a robust surface chemistry that was demonstrated to be stable against hydrolysis, even at low concentrations. Copolymer-coated silica beads also showed low fouling properties and high colloidal stability in saline solutions. Furthermore, incorporation of additional azido-monomers enabled easy functionalization of QD-NSCs using copper-free bio-orthogonal cyclooctyne-azide click chemistry, as demonstrated by a biotin-streptavidin affinity test.
- Published
- 2017
- Full Text
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17. Nanobody-functionalized PEG-b-PCL polymersomes and their targeting study.
- Author
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Zou T, Dembele F, Beugnet A, Sengmanivong L, Trepout S, Marco S, de Marco A, and Li MH
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- Cell Line, Tumor, Cryoelectron Microscopy, Humans, Particle Size, Receptor, ErbB-2 metabolism, Drug Carriers chemistry, Drug Carriers pharmacokinetics, Lactones chemistry, Polyethylene Glycols chemistry, Single-Domain Antibodies chemistry, Single-Domain Antibodies metabolism
- Abstract
We prepared and characterized polymersomes functionalized with nanobodies (VHHs) on the basis of biocompatible, biodegradable and FDA-approved poly(ethylene glycol)-block-poly(ϵ-caprolactone) (PEG-b-PCL). Fluorescein isothiocyanate (FITC) and N-beta-maleimidopropyl-oxysuccinimide ester were allowed reacting with H2N-PEG-b-PCL to produce FITC and maleimide (Mal) functionalized copolymers, Mal-PEG-b-PCL and FITC-PEG-b-PCL. A mixture of MeO-PEG-b-PCL, Mal-PEG-b-PCL and FITC-PEG-b-PCL was used to prepare polymersomes by thin film hydration and nanoprecipitation methods. Morphological studies by cryogenic transmission electron microscopy (Cryo-TEM) showed that the nanoparticles exhibited predominantly vesicular structures (polymersomes). Their mean diameters measured by dynamic light scattering were around 150 nm and the zeta-potentials around -1 mV at pH 7.4. The nanoparticles were functionalized with either anti-HER2 (VHH1) or anti-GFP (VHH2) nanobodies using maleimide-cysteine chemistry. Their particle size and zeta-potential increased slightly after nanobody-functionalization. The specific binding of VHH-functionalized polymersomes and control nanoparticles towards HER2 positive breast cancer cells was analyzed by flow cytometry and confocal microscopy. The collected results represent the first report which experimentally demonstrates that VHH1-functionalized PEO-b-PCL polymersomes can target specifically breast cancer cells expressing HER2 receptors. The detailed morphological and cell-binding studies described herein pave the way for future in vivo studies to evaluate the feasibility to use such nanoparticles for targeted drug delivery., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
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18. Nanobody-functionalized polymersomes.
- Author
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Zou T, Dembele F, Beugnet A, Sengmanivong L, de Marco A, and Li MH
- Published
- 2015
- Full Text
- View/download PDF
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