Long-Lived Two-Photon Excited Luminescence of Water-Soluble Europium Complex: Applications in Biological Imaging Using Two-Photon Scanning Microscopy.

International audienceA new europium complex presenting good solubility and stability in water, intense emission in the red (616 nm), long luminescence lifetime, and significant two-photon absorption cross-section in the biological window has been designed and successfully used for two-photon scanning microscopy bioimaging experiments on fixed cancer cells

Inflammatory response of endothelial cells to a human endogenous retrovirus associated with multiple sclerosis is mediated by TLR4.

The MSRV (multiple sclerosis-associated retrovirus) belongs to the human endogenous retrovirus HERV-W family. The envelope protein originating from the MSRV has been found in most patients with multiple sclerosis (MS). This protein (Env-ms) has pro-inflammatory properties for several types of immune cells and could therefore play a role in MS pathogenesis by promoting the leukocyte diapedesis observed in the central nervous system of patients. Our study aims to analyze the effects of Env-ms on the blood-brain barrier (BBB) at a molecular and functional level. We demonstrate that the recombinant MSRV envelope is able to stimulate several inflammatory parameters in a human BBB in vitro model, the HCMEC/D3 brain endothelial cell line. Indeed, Env-ms induces over-expression of ICAM-1, a major mediator of leukocyte adhesion to endothelial cells, in a dose-dependent manner as well as a strong dose-dependent production of the pro-inflammatory cytokines IL-6 and IL-8. Furthermore, using a silencing approach with siRNAs, we show that Env-ms is recognized via the Toll-like receptor 4 receptor, a pattern recognition receptor of innate immunity present on endothelial cells. We also show, using functional assays, that treatment of brain endothelial cells with Env-ms significantly stimulated the adhesion and the transmigration of activated immune cells through a monolayer of endothelial cells. These findings support the hypothesis that MSRV could be involved in the pathogenesis of MS disease or at least in maintenance of inflammatory conditions, thus fueling the auto-immune disorder. MSRV could also play a role in other chronic inflammatory diseases

Effect of energy storage on a combined wind and wave energy farm

The combined installation of wind and wave energy converters is being proposed more and more often as a solution to exploit the potential complementarity between these two natural resources and to share the costs of their offshore infrastructures. This paper uses real meteorological data to evaluate the difference in the power performance of a single wind turbine and a combined wind/wave energy farm. The proposed case study considers a wind turbine coupled to wave arrays including a different number of point absorbers and the importance of an optimized tuning of the Wave Energy Converters to maximize the output power is shown. As a further step it is assumed that the farm is equipped with an energy storage device. The impact of its power and energy rating and of its efficiency on the achievable smoothing of the output power is analyzed.Peer reviewe

Microstructuration of protein matrices by laser-induced photochemistry

International audienceWe report on the laser fabrication of BSA and type I collagen microstructures using Eosin Y or Rose Bengal photo sensitizers. Similar cross-linking results have been obtained by one-photon absorption or two-photon absorption using a green Q-switched microlaser or a near-infrared mode-locked Ti:sapphire laser, respectively. The microstructure resolution depends on the laser power, but is typically limited by the size of the laser beam within the sample. The cross-linking of type I collagen with Rose Bengal is obtained in acidic conditions with a large photosensitizer concentration in the millimole range. The biocompatibility of microstructures was demonstrated by observing the specific adhesion of cells on collagen lines

Design and synthesis of europium luminescent bio-probes featuring sulfobetaine moieties

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Unexpected Efficiency of a Luminescent Samarium(III) Complex for Combined Visible and Near-Infrared Biphotonic Microscopy

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Millisecond lifetime imaging with a europium complex using a commercial confocal microscope under one or two-photon excitation

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Two-photon multiplexing bio-imaging using a combination of Eu- and Tb-bioprobes

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Correction to “Terbium(iii) Luminescent Complexes as Millisecond-Scale Viscosity Probes for Lifetime Imaging”

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