Structure-Function Relationship of Iron Oxide Nanoflowers: Optimal Sizes for Magnetic Hyperthermia Depending on Alternating Magnetic Field Conditions.

Iron oxide nanoflowers (IONFs) that display singular magnetic properties can be synthesized through a polyol route first introduced almost 2 decades ago by Caruntu et al., presenting a multi-core morphology in which several grains (around 10 nm) are attached together and sintered. These outstanding properties are of great interest for magnetic field hyperthermia, which is considered as a promising therapy against cancer.

Expanding the Palette of SWIR Emitting Nanoparticles Based on Au Nanoclusters for Single-Particle Tracking Microscopy.

Single-molecule localization microscopy has proved promising to unravel the dynamics and molecular architecture of thin biological samples down to nanoscales. For applications in complex, thick biological tissues shifting single-particle emission wavelengths to the shortwave infrared (SWIR also called NIR II) region between 900 to 2100 nm, where biological tissues are more transparent is key. To date, mainly single-walled carbon nanotubes (SWCNTs) enable such applications, but they are inherently 1D objects.

T Mapping From MPRAGE Acquisitions: Application to the Measurement of the Concentration of Nanoparticles in Tumors for Theranostic Use.

Background: The measurement of the concentration of theranostic agents in vivo is essential for the assessment of their therapeutic efficacy and their safety regarding healthy tissue. To this end, there is a need for quantitative T measurements that can be obtained as part of a standard clinical imaging protocol applied to tumor patients.

Purpose: To generate T maps from MR images obtained with the magnetization-prepared rapid gradient echo (MPRAGE) sequence.

Cellular and molecular mechanisms of NiONPs toxicity on eel hepatocytes HEPA-E1: An illustration of the impact of Ni release from mining activity in New Caledonia.

Anthropic activities such as open pit mining, amplify the natural erosion of metals contained in the soils, particularly in New Caledonia, leading to atmospheric emission of nickel oxide nanoparticles (NiONPs). These particles are produced during extraction end up in aquatic ecosystems through deposition or leaching in the rivers. Despite alarming freshwater Ni concentrations, only few studies have focused on the cellular and molecular mechanisms of NiONPs toxicity on aquatic organisms and particularly on eels.

NiONPs-induced alteration in calcium signaling and mitochondrial function in pulmonary artery endothelial cells involves oxidative stress and TRPV4 channels disruption.

In New Caledonia, anthropic activities, such as mining, increase the natural erosion of soils in nickel mines, which in turn, releases nickel oxide nanoparticles (NiONPs) into the atmosphere. Pulmonary vascular endothelial cells represent one of the primary targets for inhaled nanoparticles. The objective of this study was to assess the cytotoxic effects of NiONPs on human pulmonary artery endothelial cells (HPAEC).

Photo-Thermal Switching of Individual Plasmonically Activated Spin Crossover Nanoparticle Imaged by Ultrafast Transmission Electron Microscopy.

Spin crossover (SCO) is a promising switching phenomenon when implemented in electronic devices as molecules, thin films or nanoparticles. Among the properties modulated along this phenomenon, optically induced mechanical changes are of tremendous importance as they can work as fast light-induced mechanical switches or allow to investigate and control microstructural strains and fatigability. The development of characterization techniques probing nanoscopic behavior with high spatio-temporal resolution allows to trigger and visualize such mechanical changes of individual nanoscopic objects.

A Nano-Emulsion Platform Functionalized with a Fully Human scFv-Fc Antibody for Atheroma Targeting: Towards a Theranostic Approach to Atherosclerosis.

Atherosclerosis is at the onset of the cardiovascular diseases that are among the leading causes of death worldwide. Currently, high-risk plaques, also called vulnerable atheromatous plaques, remain often undiagnosed until the occurrence of severe complications, such as stroke or myocardial infarction. Molecular imaging agents that target high-risk atheromatous lesions could greatly improve the diagnosis of atherosclerosis by identifying sites of high disease activity.

Towards Polymeric Nanoparticles with Multiple Magnetic Patches.

Fabricating future materials by self-assembly of nano-building blocks programmed to generate specific lattices is among the most challenging goals of nanotechnology and has led to the recent concept of patchy particles. We report here a simple strategy to fabricate polystyrene nanoparticles with several silica patches based on the solvent-induced self-assembly of silica/polystyrene monopods. The latter are obtained with morphological yields as high as 99% by seed-growth emulsion polymerization of styrene in the presence of 100 nm silica seeds previously modified with an optimal surface density of methacryloxymethyl groups.

Transfer and Transcriptomic Profiling in Liver and Brain of European Eels (Anguilla anguilla) After Diet-borne Exposure to Gold Nanoparticles.

A nanometric revolution is underway, promising technical innovations in a wide range of applications and leading to a potential boost in environmental discharges. The propensity of nanoparticles (NPs) to be transferred throughout trophic chains and to generate toxicity was mainly assessed in primary consumers, whereas a lack of knowledge for higher trophic levels persists. The present study focused on a predatory fish, the European eel (Anguilla anguilla) exposed to gold NPs (AuNPs; 10 nm, polyethylene glycol-coated) for 21 d at 3 concentration levels in food: 0 (NP0), 1 (NP1), and 10 (NP10) mg Au kg .

In vitro study of carbon black nanoparticles on human pulmonary artery endothelial cells: effects on calcium signaling and mitochondrial alterations.

Human exposure to manufactured nanoparticles (NPs) is a public health concern. Endothelial cells lining the inner surface of arteries could be one of the primary targets for inhaled nanoparticles. Moreover, it is well known that alteration in calcium signaling is a critical event involved in the physiopathology of cardiovascular diseases.

Revealing the pulmonary surfactant corona on silica nanoparticles by cryo-transmission electron microscopy.

When inhaled, nanoparticles (NPs) deposit in alveoli and transit through the pulmonary surfactant (PS), a biofluid made of proteins and phospholipid vesicles. They form a corona reflecting the PS-nanomaterial interaction. Since the corona determines directly the NPs' biological fate, the question of its nature and structure is central.

Multimodal molecular imaging of atherosclerosis: Nanoparticles functionalized with scFv fragments of an anti-αIIbβ3 antibody.

Due to the wealth of actors involved in the development of atherosclerosis, molecular imaging based on the targeting of specific markers would substantiate the diagnosis of life-threatening atheroma plaques. To this end, TEG4 antibody is a promising candidate targeting the activated platelets (integrin αIIbβ3) highly represented within the plaque. In this study, scFv antibody fragments were used to functionalize multimodal imaging nanoparticles.

Bioaccumulation dynamics and gene regulation in a freshwater bivalve after aqueous and dietary exposures to gold nanoparticles and ionic gold.

Gold nanoparticles (AuNPs) are being developed and produced for a wide variety of industrial and biomedical applications, which raises the concern about their release and potential effects in the environment. In this study, we aim to assess the effects of PEGylated AuNPs and ionic gold on the freshwater bivalve Corbicula fluminea. As NP bioavailability is conditioned by many factors of variability, we focused on the determination of biodynamic parameters which control AuNP uptake and elimination in bivalves.

Data on iron oxide core oil-in-water nanoemulsions for atherosclerosis imaging.

The data presented in this article are related to the publication entitled "Iron oxide core oil-in-water nanoemulsion as tracer for atherosclerosis MPI and MRI imaging" (Prévot et al., 2017) [1]. Herein we describe the synthesis and the characteristics of the Superparamagnetic Iron Oxide Nanoparticles (SPION) loaded inside nanoemulsions (NEs).

Supported pulmonary surfactant bilayers on silica nanoparticles: formulation, stability and impact on lung epithelial cells.

Studies have shown that following exposure to particulate matter, ultrafine fractions (<100 nm) may deposit along the respiratory tract down to the alveolar region. To assess the effects of nanoparticles on the lungs, it is essential to address the question of their biophysicochemical interaction with the different pulmonary environments, including the lung lining fluids and the epithelia. Here we examine one of these interactive scenarios and study the role of supported lipid bilayers (SLB) in the effect of 40 nm fluorescent silica particles on living cells.

Robust raspberry-like metallo-dielectric nanoclusters of critical sizes as SERS substrates.

Raspberry-like nano-objects made of large plasmonic satellites (>10 nm) covering a central dielectric particle have many potential applications as photonic materials, superlenses and (bio-) sensors, but their synthesis remains challenging. Herein, we show how to build stable and robust raspberry-like nano-systems with close-packed satellites, by combining monodisperse silica particles (80 or 100 nm diameter) and oppositely charged noble metal nanoparticles (Au or Ag) with well-defined sizes (10-50 nm). The spectral characteristics of their associated plasmonic resonances (wavelength, linewidth, extinction cross-section) and the electromagnetic coupling between satellites were observed using the spatial modulation spectroscopy technique and interpreted through a numerical model.

In Vivo Imaging of Local Gene Expression Induced by Magnetic Hyperthermia.

The present work aims to demonstrate that colloidal dispersions of magnetic iron oxide nanoparticles stabilized with dextran macromolecules placed in an alternating magnetic field can not only produce heat, but also that these particles could be used in vivo for local and noninvasive deposition of a thermal dose sufficient to trigger thermo-induced gene expression. Iron oxide nanoparticles were first characterized in vitro on a bio-inspired setup, and then they were assayed in vivo using a transgenic mouse strain expressing the luciferase reporter gene under transcriptional control of a thermosensitive promoter. Iron oxide nanoparticles dispersions were applied topically on the mouse skin or injected subcutaneously with Matrigel™ to generate so-called pseudotumors.

Impact of surface grafting density of PEG macromolecules on dually fluorescent silica nanoparticles used for the in vivo imaging of subcutaneous tumors.

Background: In the context of systematically administered nanomedicines, the physicochemistry of NP surfaces must be controlled as a prerequisite to improve blood circulation time, and passive and active targeting. In particular, there is a real need to develop NP stealth and labelling for both in vivo and microscopic fluorescence imaging in a mice model.

Methods: We have synthesized NIR/red dually fluorescent silica nanoparticles of 19nm covalently covered by a PEG layer of different grafting density in the brush conformational regime by using a reductive amination reaction.

Calcium signalling induced by in vitro exposure to silicium dioxide nanoparticles in rat pulmonary artery smooth muscle cells.

The development and use of nanomaterials, especially engineered nanoparticles (NP), is expected to provide many benefits. But at the same time the development of such materials is also feared because of their potential human health risks. Indeed, NP display some characteristics similar to ultrafine environmental particles which are known to exert deleterious cardiovascular effects including pro-hypertensive ones.

Grafting of gold onto spin-crossover nanoparticles: SCO@Au.

Nanoparticles of gold were successfully grafted onto nanoparticles of a 1D polymeric spin-crossover material leading to singular SCO@Au hybrid particles. The result is equally obtained using a large range of gold-particle sizes, from 4 to 45 nm, which first allows definition of the best experimental conditions, notably in terms of gold-particle concentration, and then demonstrates the robustness and the efficiency of the method.

Templated growth of gold satellites on dimpled silica cores.

We synthesize robust clusters of gold satellites positioned with tetrahedral symmetry on the surface of a patchy silica core by adsorption and growth of gold on the patches. First we conduct emulsion polymerization of styrene in the presence of 52 nm silica seeds whose surface has been modified with methacryloxymethyltriethoxysilane (MMS). We derive four-dimple particles from the resulting silica/polystyrene tetrapods.

Polyelectrolyte assisted charge titration spectrometry: Applications to latex and oxide nanoparticles.

The electrostatic charge density of particles is of paramount importance for the control of the dispersion stability. Conventional methods use potentiometric, conductometric or turbidity titration but require large amount of samples. Here we report a simple and cost-effective method called polyelectrolyte assisted charge titration spectrometry or PACTS.