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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Biodistribution and biological impact of nanoparticles using multimodality imaging techniques : (Magnetic resonance imaging)

Faraj, Achraf Al 30 June 2009 (has links) (PDF)
As novel engineered nanoparticles such as single-walled carbon nanotubes (SWCNT) are extensively used in nanotechnology due to their superior properties, it becomes critical to fully understand their biodistribution and effect when accidently inhaled. There fore, development of animaging technique which allow longitudinal in vivo follow-up of SWCNT effect based on their intrinsic properties is highly desirable. Non invasive free-breathing hyperpolarized 3He lung MRI protocol was developed complementary to proton systemic MR protocol to allow monitoring SWCNT based on their intrinsic iron impurities after intrapulmonary exposition. Combined toproton lung MRI and ex vivo optical and electron microscopy at different time points, this protocol represents a powerful multimodality imaging techniques which allows a full characterization of the biodistribution and biological impacts of iron containing SWCNT. SWCNT was found to produce granulomatous and inflammatory reactions in a time and dose dependent manner with their bio persistenc eafter intrapulmonary exposition.From biological impact evaluations after intrapulmonary exposition towards biomedical applications, SWCNT hold promise for applications in nanomedicine field with their distinct architecture and their novel physicochemical properties. The biodistribution and pharmacological profile of various well-dispersed pristine and functionalized SWCNT were assessed in blood and target tissues after their intra venous administration by longitudinal in vivo susceptibility weighted MRI and their potential effect on liver metabolism by ex vivo HRMAS 1H NMR. No presence ofacute toxicological effect (variation in liver metabolism) was observed confirmed by the absence of clustering in NMR spectra using Principal Component Analysis (specific biomarkers of toxicity).
2

Biodistribution and biological impact of nanoparticles using multimodality imaging techniques : (Magnetic resonance imaging) / Biodistribution et effet biologique des nanoparticules utilisant des techniques d’imagerie multimodale : (Imagerie de résonance magnétique)

Faraj, Achraf Al 30 June 2009 (has links)
En raison de leurs propriétés uniques, des nanoparticules industriellement fabriquées comme les nanotubes de carbone (NTC) ont révolutionné le domaine de la nanotechnologie. Il apparait nécessaire de développer des techniques d’investigation in vivo basées sur les propriétés intrinsèques de ces particules et permettant un suivi longitudinal pour évaluer leur risque après inhalation accidentelle par voie respiratoire. Un protocole d’IRM pulmonaire non-invasive utilisant l’hélium-3 hyper polarisé sous respiration spontanée a été développé en complément d’un protocole d’IRM systémique proton pour permettre la détection des NTC grâce à l’effet de susceptibilité magnétique induit par les impuretés de fer, associées aux nanotubes après leur exposition intra pulmonaire. Combiné avec l’IRM pulmonaire proton et des analyses en microscopie optique et électronique à différents temps d’investigation, ce protocole d’imagerie multimodale permet d’évaluer la biodistribution et l’impact biologique des NTC bruts après exposition intra pulmonaire.Une accentuation des réactions inflammatoires (granulomes multifocaux, dépôt de fibres de collagène…) avec le temps et la dose administrée a été observée.De l’évaluation de l’impact biologique des NTC après une exposition intra pulmonaire vers leurs applications biomédicales, les nanotubes de carbone avec leurs propriétés physicochimiques fascinantes et leur forme spécifique laissent entrevoir des applications potentielles en nanomédecine. La bio distribution et le profil pharmacologique des différents types de NTC ont été évalués longitudinalement par IRM et dosage dans le sang et les organes cibles après une injection intraveineuse, et leur impact biologique sur le métabolisme du foie a été examiné ex vivo par RMN haute résolution à l’angle magique (HR-MAS). Aucun signe de toxicité aiguë (variation du métabolisme du foie) n’a été observé et les analyses statistiques conduits sur les spectres RMN (tests PCA) ne montrent aucune différence entre les échantillons analysés et donc l’absence de discrimination entre les différents groupes par rapport aux animaux contrôles. / As novel engineered nanoparticles such as single-walled carbon nanotubes (SWCNT) are extensively used in nanotechnology due to their superior properties, it becomes critical to fully understand their biodistribution and effect when accidently inhaled. There fore, development of animaging technique which allow longitudinal in vivo follow-up of SWCNT effect based on their intrinsic properties is highly desirable. Non invasive free-breathing hyperpolarized 3He lung MRI protocol was developed complementary to proton systemic MR protocol to allow monitoring SWCNT based on their intrinsic iron impurities after intrapulmonary exposition. Combined toproton lung MRI and ex vivo optical and electron microscopy at different time points, this protocol represents a powerful multimodality imaging techniques which allows a full characterization of the biodistribution and biological impacts of iron containing SWCNT. SWCNT was found to produce granulomatous and inflammatory reactions in a time and dose dependent manner with their bio persistenc eafter intrapulmonary exposition.From biological impact evaluations after intrapulmonary exposition towards biomedical applications, SWCNT hold promise for applications in nanomedicine field with their distinct architecture and their novel physicochemical properties. The biodistribution and pharmacological profile of various well-dispersed pristine and functionalized SWCNT were assessed in blood and target tissues after their intra venous administration by longitudinal in vivo susceptibility weighted MRI and their potential effect on liver metabolism by ex vivo HRMAS 1H NMR. No presence ofacute toxicological effect (variation in liver metabolism) was observed confirmed by the absence of clustering in NMR spectra using Principal Component Analysis (specific biomarkers of toxicity).

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