Zwitterion functionalized gold nanoclusters for multimodal near infrared fluorescence and photoacoustic imaging

Gold nanoclusters (Au NCs) are an emerging type of theranostic agents combining therapeutic and imaging features with reduced toxicity. Au NCs stabilized by a zwitterion ligand with a fine control of the metal core size and the ligand coverage were synthesized by wet chemistry. Intense fluorescence signal is reported for the highest ligand coverage, whereas photoacoustic signal is stronger for the largest metal core. The best Au NC candidate with an average molecular weight of 17 kDa could be detected with high sensitivity on a 2D-near-infrared imaging instrument (limit of detection (LOD) = 2.3 μM μM ) and by photoacoustic imaging. In vitro and in vivo experiments demonstrate an efficient cell uptake in U87 cell lines, a fast renal clearance (t 1/2α t1/2α = 6.5 ± 1.3 min), and a good correlation between near infrared fluorescence and photoacoustic measurements to follow the early uptake of Au NCs in liver

Combining metal nanoparticles and nanobodies to boost the biomedical imaging in neurodegenerative diseases

Introduction: In the study of neurodegenerative diseases, the possibility to follow the fate of specific cells or molecules within the whole body would be a milestone to better understand the complex evolution of disease mechanisms and to monitor the effects of therapies. The techniques available today do not allow the visualization of disease-relevant cells within the whole tridimensional biological context at high spatial resolution.Methods: Here we show the results from the first validation steps of a novel approach: by combining the conjugate nanobodies anti-glial fibrillary acidic protein (GFAP) and metal-nanoparticles (i.e. 2 nm gold NP) with X-ray phase contrast tomography (XPCT) we would be able to obtain a tridimensional visualization and identification of cells of interest together with the surrounding tissue and the vascular and neuronal networks.Results: By exploiting the X-ray attenuation properties of metal nanoparticles and the specific targeting capabilities of nanobodies, we could give XPCT the specificity it presently lacks, making it no longer a pure morphological but a molecular and targeted imaging technique. In our case, we synthesized and characterized Gold-NP/GFAP nanobody to target the astrocytes of mouse brain.Discussion: The results of the first tests presented in this paper have provided us with information on the feasibility of the approach, encouraging us to carry out further experiments in order to achieve the ultimate goal of setting up this new imaging technique

Dissolution and passivation of aluminide coatings on model and Ni-based superalloy

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Structure-based design of human immuno- and constitutive proteasomes inhibitors

International audienceStarting from the X-ray structure of our previous tripeptidic linear mimics of TMC-95A in complex with yeast 20S proteasome, we introduced new structural features to induce a differential inhibition between human constitutive and immunoproteasome 20S particles. Libraries of 24 tripeptidic and 6 dipeptidic derivatives were synthesized. The optimized preparation of 3-hydroxyoxindolyl alanine residues from tryptophan and their incorporation in peptides were described. Several potent inhibitors of human constitutive proteasome and immunoproteasome acting at the nanomolar level (IC50 = 7.1 nM against the chymotrypsin-like activity for the best inhibitor) were obtained. A cytotoxic effect at the submicromolar level was observed against 6 human cancer cell lines

A NIR-II-emitting gold nanocluster-based drug delivery system for smartphone-triggered photodynamic theranostics with rapid body clearance

Nanomedicine has grown structurally complex in order to perform multiple tasks at a time. However, their unsatisfied reliability, uniformity and reproducibility account for the high rates of attrition in translational research. So far, most studies have been one-sidedly focused on the treatment efficacy of inorganic nanoparticles as cancer therapeutics, but overlook their elimination from the body – a key factor in getting regulatory approval. Instead of developing a new drug nanocarrier with uncertain future in medical practice, we therefore choose to leverage the utility of promising and translatable gold nanoclusters (AuNCs) for designing a simple but robust “all-in-one” nanocluster drug delivery system, where the AuNCs not only strengthen the renal clearance of neutral red (NR) as a model drug, but also aid its passive tumor targeting via the enhanced permeability and retention (EPR) effect. More interestingly, NR can stimulate the production of reactive oxygen species (ROS) to suppress tumor growth under ultralow-level radiation with a smartphone's torch (fluence rate: 8 mW/cm2). This finding is especially valuable to low- and middle-income countries lacking resources in healthcare settings. By means of first-principles simulations, we also study in-depth the energies, structural and electronic properties of the AuNCs emitting in the second near-infrared window (NIR-II, 1000–1700 nm). In brief, our model fulfills safety, effectiveness and cost-effectiveness requirements for translational development

Combining metal nanoparticles and nanobodies to boost the biomedical imaging in neurodegenerative diseases

Introduction: In the study of neurodegenerative diseases, the possibility to follow the fate of specific cells or molecules within the whole body would be a milestone to better understand the complex evolution of disease mechanisms and to monitor the effects of therapies. The techniques available today do not allow the visualization of disease-relevant cells within the whole tridimensional biological context at high spatial resolution. Methods: Here we show the results from the first validation steps of a novel approach: by combining the conjugate nanobodies anti-glial fibrillary acidic protein (GFAP) and metal-nanoparticles (i.e. 2 nm gold NP) with X-ray phase contrast tomography (XPCT) we would be able to obtain a tridimensional visualization and identification of cells of interest together with the surrounding tissue and the vascular and neuronal networks. Results: By exploiting the X-ray attenuation properties of metal nanoparticles and the specific targeting capabilities of nanobodies, we could give XPCT the specificity it presently lacks, making it no longer a pure morphological but a molecular and targeted imaging technique. In our case, we synthesized and characterized Gold-NP/GFAP nanobody to target the astrocytes of mouse brain. Discussion: The results of the first tests presented in this paper have provided us with information on the feasibility of the approach, encouraging us to carry out further experiments in order to achieve the ultimate goal of setting up this new imaging technique

A NIR-II-emitting gold nanocluster-based drug delivery system for smartphonetriggered photodynamic theranostics with rapid body clearance

International audienceNanomedicine has grown structurally complex in order to perform multiple tasks at a time. However, their unsatisfied reliability, uniformity and reproducibility account for the high rates of attrition in translational research. So far, most studies have been one-sidedly focused on treatment efficacy of inorganic nanoparticles as cancer therapeutics, but overlook their elimination from the bodya key factor in getting regulatory approval. Instead of developing a new drug nanocarrier with uncertain future in medical practice, we therefore choose to leverage the utility of promising and translatable gold nanoclusters (AuNCs) for designing a simple but robust "all-in-one" nanocluster drug delivery system, where the AuNCs not only strengthen renal clearance of neutral red (NR) as a model drug, but also aid its passive tumor targeting via the enhanced permeability and retention (EPR) effect. More interestingly, NR can stimulate the production of reactive oxygen species (ROS) to suppress tumor growth under ultralow-level radiation with a smartphone's torch (fluence rate: 8.0 mW/cm 2). This finding is especially valuable to low-and middle-income countries lacking resources in healthcare settings. By means of first-principles simulations, we also study indepth the energies, structural and electronic properties of the AuNCs emitting in the second near-infrared window (1000 to 1700 nm). In brief, our model fulfills safety, effectiveness and cost-effectiveness requirements for translational development

DataSheet1_Combining metal nanoparticles and nanobodies to boost the biomedical imaging in neurodegenerative diseases.docx

Introduction: In the study of neurodegenerative diseases, the possibility to follow the fate of specific cells or molecules within the whole body would be a milestone to better understand the complex evolution of disease mechanisms and to monitor the effects of therapies. The techniques available today do not allow the visualization of disease-relevant cells within the whole tridimensional biological context at high spatial resolution.Methods: Here we show the results from the first validation steps of a novel approach: by combining the conjugate nanobodies anti-glial fibrillary acidic protein (GFAP) and metal-nanoparticles (i.e. 2 nm gold NP) with X-ray phase contrast tomography (XPCT) we would be able to obtain a tridimensional visualization and identification of cells of interest together with the surrounding tissue and the vascular and neuronal networks.Results: By exploiting the X-ray attenuation properties of metal nanoparticles and the specific targeting capabilities of nanobodies, we could give XPCT the specificity it presently lacks, making it no longer a pure morphological but a molecular and targeted imaging technique. In our case, we synthesized and characterized Gold-NP/GFAP nanobody to target the astrocytes of mouse brain.Discussion: The results of the first tests presented in this paper have provided us with information on the feasibility of the approach, encouraging us to carry out further experiments in order to achieve the ultimate goal of setting up this new imaging technique.</p