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LEROY Adrien
Thème de Recherche: Biopolymères Artificiels
leroy.adrien
ymail.com
0467548562
Bureau: 217, Etg: 2, Bât: I - Site : Faculté de Pharmacie
Domaines de Recherche: - Chimie
- chim/chim.mate
- Sciences du Vivant/Microbiologie et Parasitologie/Virologie
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Productions scientifiques :
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FTIR microscopy contribution for comprehension of degradation mechanisms in PLA-based implantable medical devices
Auteur(s): Leroy A., Ribeiro Sofia, Grossiord Carole, Alves Antoine, Vestberg Robert H., Salles Vincent, Brunon Céline, Gritsch Kerstin, Grosgogeat Brigitte, Bayon Yves
(Article) Publié:
Journal Of Materials Science: Materials In Medicine, vol. 28 p. (2017)
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PLA-poloxamer/poloxamine copolymers for ligament tissue engineering: sound macromolecular design for degradable scaffolds and MSC differentiation
Auteur(s): Leroy A., Nottelet B., Bony Claire, Pinese C., Charlot Benoît, Garric X., Noël Danièle, Coudane J.
(Article) Publié:
Biomaterials Science, vol. 3 p.617-626 (2015)
Ref HAL: hal-01369239_v1
DOI: 10.1039/c4bm00433g
Résumé: The treatment of anterior cruciate ligament (ACL) failures remains a current clinical challenge. Thepresent study aims at providing suitable degradable scaffolds for ligament tissue engineering. First, wefocus on the design and the evaluation of poly(lactide)/poloxamer or poly(lactide)/poloxamine multiblockcopolymers selected and developed to have suitable degradation and mechanical properties to matchACL repair. In the second part, it is shown that the copolymers can be processed in the form ofmicrofibers and scaffolds consisting of a combination of twisted/braided fibers to further modulate themechanical properties and prepare scaffold prototypes suitable for ligament application. Finally, afterassessment of their cytocompatibility, the polymer scaffolds are associated with mesenchymal stem cells(MSCs). MSC differentiation toward a ligament fibroblast phenotype is promoted by a dual stimulationincluding an inductive culture medium and cyclic mechanical loads. RT-qPCR analyses confirm thepotential of our scaffolds and MSCs for ACL regeneration with upregulation of some differentiationmarkers including Scleraxis, Tenascin-C and Tenomodulin.
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Ingénierie tissulaire du ligament : association de copolymères dégradables et de cellules souches mésenchymateuses
Auteur(s): Leroy A.
(Thèses)
, 2013
Ref HAL: tel-01022842_v1
Résumé: L'ingénierie tissulaire est une discipline récente aux enjeux ambitieux et prometteurs : la régénération de tissus ou d'organes lésés voire détruits en mettant à profit des connaissances et compétences dans différents domaines à l'interface de la chimie et de la biologie. Pour répondre à la demande d'alternatives aux techniques chirurgicales actuelles de réparation du ligament antérieur croisé, nous avons décidé d'appliquer l'ingénierie tissulaire à ce tissu en associant matrices en polymères dégradables et cellules souches mésenchymateuses (CSM). Dans un premier temps, nous avons donc travaillé à la synthèse de polymères adaptés à l'application en cherchant à mettre l'accent sur l'obtention de propriétés élastiques. De nouveaux élastomères dégradables obtenus par des approches originales de photoréticulation chimique de poly(lactide) (PLA) et de poly(ε-caprolactone) (PCL) par voie nitrène ou thiol-yne ont notamment été développés avec des résultats prometteurs. En parallèle, des copolymères thermoplastiques multiblocs à base de PLA et poloxamine ou poloxamère nous ont permis de mener une étude plus appliquée. Ces copolymères ont en effet montré, en particulier au cours d'une étude de dégradation in vitro de 7 semaines, des propriétés, notamment thermiques et mécaniques, qui en font d'eux des candidats intéressants pour le conception d'une matrice ligamentaire. C'est pourquoi ils ont été utilisés pour la conception de prototypes de matrices de régénération textiles dont les propriétés mécaniques se sont révélées être très proches de celles du ligament. Après avoir démontré l'excellente cytocompatibilité de ces matrices avec des CSM, nous avons finalement mené des expériences de différenciation in vitro de ces CSM et sommes parvenus à favoriser leur orientation vers un phénotype ligamentocytaire, notamment grâce à un procédé de stimulation mécanique cyclique des cellules ensemencées sur les matrices textiles.
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Host sequences flanking the human T-cell leukemia virus type 1 provirus in vivo.
Auteur(s): Leclercq I, Mortreux F, Cavrois M, Leroy A., Gessain A, Wain-Hobson S, Wattel E
(Article) Publié:
Journal Of Human Virology, vol. p.2305-12 (2000)
Ref HAL: hal-00116159_v1
PMID 10666261
DOI: 10.1128/JVI.74.5.2305-2312.2000
Résumé: Human pathogenic retroviruses do not have common loci of integration. However, many factors, such as chromatin structure, transcriptional activity, DNA-protein interaction, CpG methylation, and nucleotide composition of the target sequence, may influence integration site selection. These features have been investigated by in vitro integration reactions or by infection of cell lines with recombinant retroviruses. Less is known about target choice for integration in vivo. The present study was conducted in order to assess the characteristics of cellular sequences targeted for human T-cell leukemia virus type 1 (HTLV-1) integration in vivo. Sequencing integration sites from >/=200 proviruses (19 kb of sequence) isolated from 29 infected individuals revealed that HTLV-1 integration is not random at the level of the nucleotide sequence. The virus was found to integrate in A/T-rich regions with a weak consensus sequence at positions within and without of the hexameric repeat generated during integration. These features were not associated with a preference for integration near active regions or repeat elements of the host chromosomes. Most or all of the regions of the genome appear to be accessible to HTLV-1 integration. As with integration in vitro, integration specificity in vivo seems to be determined by local features rather than by the accessibility of specific regions.
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High circulating proviral load with oligoclonal expansion of HTLV-1 bearing T cells in HTLV-1 carriers with strongyloidiasis.
Auteur(s): Gabet A S, Mortreux F, Talarmin A, Plumelle Y, Leclercq I, Leroy A., Gessain A, Clity E, Joubert M, Wattel E
(Article) Publié:
Oncogene, vol. p.4954-60 (2000)
Ref HAL: hal-00115859_v1
PMID 11042682
DOI: 10.1038/sj.onc.1203870
Résumé: Adult T cell leukemia (ATLL) develops in 3 - 5% of HTLV-1 carriers after a long period of latency during which a persistent polyclonal expansion of HTLV-1 infected lymphocytes is observed in all individuals. This incubation period is significantly shortened in HTLV-1 carrier with Strongyloides stercoralis (Ss) infection, suggesting that Ss could be a cofactor of ATLL. As an increased T cell proliferation at the asymptomatic stage of HTLV-1 infection could increase the risk of malignant transformation, the effect of Ss infection on infected T lymphocytes was assessed in vivo in HTLV-1 asymptomatic carriers. After real-time quantitative PCR, the mean circulating HTLV-1 proviral load was more than five times higher in HTLV-1 carriers with strongyloidiasis than in HTLV-1+ individuals without Ss infection (P<0.009). This increased proviral load was found to result from the extensive proliferation of a restricted number of infected clones, i.e. from oligoclonal expansion, as evidenced by the semiquantitative amplification of HTLV-1 flanking sequences. The positive effect of Ss on clonal expansion was reversible under effective treatment of strongyloidiasis in one patient with parasitological cure whereas no significant modification of the HTLV-1 replication pattern was observed in an additional case with strongyloidiasis treatment failure. Therefore, Ss stimulates the oligoclonal proliferation of HTLV-1 infected cells in HTLV-1 asymptomatic carriers in vivo. This is thought to account for the shortened period of latency observed in ATLL patients with strongyloidiasis. Oncogene (2000) 19, 4954 - 4960
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