Integrated Scenario-based Design Methodology for Collaborative Technology Innovation

The paper presents a scenario-based methodology developed and tested throughout cooperative research and development projects. It is aimed at supporting information technology innovation with an end-to-end Human and Social Sciences assistance. This methodology provides an integrated approach combining a vision of the potential users, business aspects and technological challenges throughout the design process. An original combination of different methods is proposed and experimented: user-centred design, scenario-based design, user and functional requirements analysis, business value analysis, user acceptance studies, and visualization methods. This methodology has been implemented in three European R&D projects, in the domain of the telecommunications and Internet infrastructure. The key contributions of this approach are that it unifies brings together visions of the users, potential business value and technology challenges thanks to scenario construction.Scenario-based design ; user requirements ; business economics ; functional requirements ; visualization

Impact of the chemical composition of poly-substituted hydroxyapatite particles on the in vitro pro-inflammatory response of macrophages

International audienceTo improve the biological properties of calcium phosphate (CaP) bone substitute, new chemical compositions are under development. In vivo such materials are subject to degradation that could lead to particles release and inflammatory reactions detrimental to the bone healing process. This study aimed at investigating the interactions between a murine macrophage cell line (RAW 264.7) and substituted hydroxyapatite particles presenting promising biological properties. Micron size particles of stoichiometric and substituted hydroxyapatites (CO 3 substitution for PO 4 and OH; SiO 4 substitution for PO 4; CO 3 and SiO 4 co-substitution) were obtained by aqueous precipitation followed by spray drying. Cells, incubated with four doses of particles ranging from 15 to 120 µg/mL, revealed no significant LDH release or ROS production, indicating no apparent cytotoxicity and no oxidative stress. TNF-α production was independent of the chemistry of the particles; however the particles elicited a significant dose-dependent pro-inflammatory response. As micron size particles of these hydroxyapatites could be at the origin of inflammation, attention must be paid to the degradation 2 behavior of substituted hydroxyapatite bone substitute in order to limit, in vivo, the generation of particulate debris

Cartographier l’évolution du contenu de la revue Archives au moyen des techniques de fouille de textes et de bibliométrie

À l’occasion du 50e anniversaire de l’Association des archivistes du Québec (AAQ), cinq professionnels de l’archivistique ont réalisé une analyse du contenu de la revue Archives à partir d’une approche basée sur des techniques de fouille de textes, complétée par une analyse bibliométrique. Ces techniques facilitent le traitement de grandes quantités de données afin d’en extraire automatiquement certaines caractéristiques qui les ont renseignés tant sur l’évolution thématique de la revue que sur la place qu’occupe sa production dans l’espace archivistique scientifique et professionnel québécois et international. Leur article offre une occasion de revenir sur les principales thématiques abordées dans la revue depuis les vingt dernières années en rendant compte de l’évolution des objets de recherche étudiés et, plus généralement, de la profession archivistique. Il permet également de s’interroger sur les liens existants entre les auteurs et leurs institutions, et de faire le point sur l’académisation ou la professionnalisation de la revue

Modélisation de la nanostructure d'un élastomère chargé

National audienceLes matériaux élastomères chargés en Noir de Carbone constituant la gomme des matériaux pneumatiques sont habituellement considérés comme homogènes à l'échelle de la structure. À une échelle plus fine, de l'ordre du micromètre ils présentent une structure hétérogène. Cette microstructure biphasée (matrice + inclusions) caractérise le mélange polymère-Noir de Carbone (NC). Les propriétés mécaniques macroscopiques du matériau élastomère chargé dépendent très fortement de ses caractéristiques microstructurales. On cherche à établir le lien existant entre les deux échelles d'étude (structure et microstructure). On identifie la microstructure par la morphologie des charges de Noir de Carbone dans la matrice polymère et par les propriétés mécaniques de chacun des constituants. On modélise ici la morphologie du matériau d'étude à l'échelle microscopique pour laquelle les deux phases sont mises en jeu (matrice polymère + NC). La modélisation choisie s'appuie sur des outils de la morphologie mathématique et a largement été étudiée dans de nombreux travaux. L'observation et la caractérisation de la microstructure à modéliser s'effectue à l'aide d'outils tels que la microscopie à transmission ou encore l'analyse d'images

New insight into artifactual phenomena during <i>in vitro</i> toxicity assessment of engineered nanoparticles: Study of TNF-α adsorption on alumina oxide nanoparticle

International audienceBiomolecules can be adsorbed on nanoparticles (NPs) and degraded during in vitro toxicity assays. These artifactual phenomena could lead to misinterpretation of biological activity, such as false-negative results. To avoid possible underestimation of cytokine release after contact between NP and cells, we propose a methodology to account for these artifactual phenomena and lead to accurate measurements. We focused on the pro-inflammatory cytokine tumor necrosis factor TNF-α. We studied well-characterized boehmite engineered NP [aluminum oxide hydroxide, AlO(OH)]. The rate of TNF-α degradation and its adsorption (on boehmite and on the walls of wells) were determined in cell-free conditions by adding a known TNF-α concentration (1500 pg/ml) under various experimental conditions. After a 24-h incubation, we quantified that 7 wt.% of the initial TNF-α was degraded over time, 6 wt.% adsorbed on the walls of 96-well plates, and 13 wt.% adsorbed on the boehmite surface. Finally, boehmite NP were incubated with murine macrophages (RAW 264.7 cell line). The release of TNF-α was assessed for boehmite NP and the experimental data were corrected considering the artifactual phenomena, which accounted for about 20-30% of the tota

Quantification of nanoparticle endocytosis based on double fluorescent pH-sensitive nanoparticles

International audienceAmorphous silica is a particularly interesting material because of its inertness and chemical stability. Silica nanoparticles have been recently developed for biomedical purposes but their innocuousness must be carefully investigated before clinical use. The relationship between nanoparticles physicochemical features, their uptake by cells and their biological activity represents a crucial issue, especially for the development of nanomedicine. This work aimed at adapting a method for the quantification of nanoparticle endocytosis based on pH-sensitive and double fluorescent particles. For that purpose, silica nanoparticles containing two fluorophores: FITC and pHrodoTM were developed, their respective fluorescence emission depends on the external pH. Indeed, FITC emits a green fluorescence at physiological pH and pHrodoTM emits a red fluorescence which intensity increased with acidification. Therefore, nanoparticles remained outside the cells could be clearly distinguished from nanoparticles uptaken by cells as these latter could be spotted inside cellular acidic compartments (such as phagolysosomes, micropinosomes...). Using this model, the endocytosis of 60 nm nanoparticles incubated with the RAW 264.7 macrophages was quantified using time-lapse microscopy and compared to that of 130 nm submicronic particles. The amount of internalized particles was also evaluated by fluorimetry. The biological impact of the particles was also investigated in terms of cytotoxicity, pro-inflammatory response and oxidative stress. Results clearly demonstrated that nanoparticles were more uptaken and more reactive than submicronic particles. Moreover, we validated a method of endocytosis quantification

Detection and analysis of nanoparticles in patients: A critical review of the status quo of clinical nanotoxicology

International audienceOn the cusp of massive commercialization of nanotechnology-enhanced products and services, the physical and chemical analysis of nanoparticles in human specimens merits immediate attention from the research community as a prerequisite for a confident clinical interpretationof their occurrence in the human organism. In this review, we describe the caveats in current practices of extracting and isolating nanoparticles from clinical samples and show that they do not help truly define the clinical significance of any detected exogenous nano-sized objects. Finally, we suggest a systematic way of tackling these demanding scientific tasks. More specifically, a precise and true qualitative evaluation of nanoparticles in human biological samples still remains difficult to achieve because of various technical reasons. Such a procedure is more refined when the nature of the pollutants is known, like in the case of nano-sized wear debris originating from biomedical prostheses. Nevertheless, nearly all available analytical methods provide unknown quantitative accuracy and qualitative precision due to the challenging physical and chemical nature of nanoparticles. Without trustworthy information to detect and describe the nanoparticulate load of clinical samples, it is impossible to accurately assess its pathological impact on isolated cases or allow for relevant epidemiological surveys on large populations. Therefore, we suggest that the many and various specimens stored in hospitals be used for the refinement of methods of exhaustive quantitative and qualitative characterization of prominent nanoparticles in complex human milieu

Quantification of microsized fluorescent particles phagocytosis to a better knowledge of toxicity mechanisms

International audienceBackground: The use of micro- or nanometric particles is in full expansion for the development of new technologies. These particles may exhibit variable toxicity levels depending on their physicochemical characteristics. We focused our attention on macrophages (MA), the main target cells of the respiratory system responsible for the phagocytosis of the particles. The quantification of the amount of phagocytosed particles seems to be a major element for a better knowledge of toxicity mechanisms. The aim of this study was to develop a quantitative evaluation of uptake using both flow cytometry (FCM) and confocal microscopy to distinguish entirely engulfed fluorescent microsized particles from those just adherent to the cell membrane and to compare these data to in vitro toxicity assessments. Methods: Fluorescent particles of variable and well-characterised sizes and surface coatings were incubated with MA (RAW 264.7 cell line). Analyses were performed using confocal microscopy and FCM. The biological toxicity of the particles was evaluated [lactate dehydrogenase (LDH) release, tumor necrosis factor (TNF)-α, and reactive oxygen species (ROS) production]. Results and conclusion: Confocal imaging allowed visualization of entirely engulfed beads. The amount of phagocytic cells was greater for carboxylate 2-µm beads (49±11%) than for amine 1-µm beads (18±5%). Similarly, side scatter geometric means, reflecting cellular complexity, were 446±7 and 139±12, respectively. These results confirm that the phagocytosis level highly depends on the size and surface chemical groups of the particles. Only TNF-α and global ROS production varied significantly after 24-h incubation. There was no effect on LDH and H2O2 production

Quantitative cellular uptake of double fluorescent core-shelled model submicronic particles

International audienceThe relationship between particles' physicochemical parameters, their uptake by cells and their degree of biological toxicity represent a crucial issue, especially for the development of new technologies such as fabrication of micro- and nanoparticles in the promising field of drug delivery systems. This work was aimed at developing a proof-of-concept for a novel model of double fluorescence submicronic particles that could be spotted inside phagolysosomes. Fluorescein isothiocyanate (FITC) particles were synthesized and then conjugated with a fluorescent pHrodo™ probe, red fluorescence of which increases in acidic conditions such as within lysosomes. After validation in acellular conditions by spectral analysis with confocal microscopy and dynamic light scattering, quantification of phagocytosis was conducted on a macrophage cell line in vitro. The biological impact of pHrodo functionalization (cytotoxicity, inflammatory response, and oxidative stress) was also investigated. Results validate the proof-of-concept of double fluorescent particles (FITC + pHrodo), allowing detection of entirely engulfed pHrodo particles (green and red labeling). Moreover incorporation of pHrodo had no major effects on cytotoxicity compared to particles without pHrodo, making them a powerful tool for micro- and nanotechnologies

Size of submicrometric and nanometric particles affect cellular uptake and biological activity of macrophages in vitro

International audienceBackground: Micrometric and nanometric particles are increasingly used in different fields and may exhibit variable toxicity levels depending on their physicochemical characteristics. The aim of this study was to determine the impact of the size parameter on cellular uptake and biological activity, working with well-characterized fluorescent particles. We focused our attention on macrophages, the main target cells of the respiratory system responsible for the phagocytosis of the particles. Methods: FITC fluorescent silica particles of variable submicronic sizes (850, 500, 250 and 150 nm) but with similar surface coating (COOH) were tailored and physico-chemically characterized. These particles were then incubated with the RAW 264.7 macrophage cell line. After microscopic observations (SEM, TEM, confocal), a quantitative evaluation of the uptake was carried out. Fluorescence detected after a quenching with trypan blue allows us to distinguish and quantify entirely engulfed fluorescent particles from those just adhering to the cell membrane. Finally, these data were compared to the in vitro toxicity assessed in terms of cell damage, inflammation and oxidative stress (evaluated by LDH release, TNF-α and ROS production respectively). Results and conclusion: Particles were well characterized (fluorescence, size distribution, zeta potential, agglomeration and surface groups) and easily visualized after cellular uptake using confocal and electron microscopy. The number of internalized particles was precisely evaluated. Size was found to be an important parameter regarding particles uptake and in vitro toxicity but this latter strongly depends on the particles doses employed