Clément Roux

• Université Toulouse III - Paul Sabatier

Reducing the size of upconversion nanoparticles (UCNPs) down to a few nm yields luminescent materials containing a very small number of emitters. Considering the bottom limit of one activator per particle ultrasmall UCNPs offer an unprecedented platform to study the contributions of the different energy transfers at play in upconversion luminescenc...

Micropipette aspiration (MPA) is one of the gold standards for quantifying biological samples' mechanical properties, which are crucial from the cell membrane scale to the multicellular tissue. However, relying on the manipulation of individual home-made glass pipettes, MPA suffers from low throughput and no automation. Here, we introduce the slidi...

Reducing the size of upconversion nanoparticles (UCNPs) down to a few nm yields unique luminescent materials containing a very small number of emitters. Considering the bottom limit of one activator per particle, such ultrasmall UCNPs offer an unprecedented platform to study the contributions of the different energy transfer processes at play in up...

Micropipette aspiration (MPA) is one of the gold standards to quantify biological samples’ mechanical properties, which are crucial from the cell membrane scale to the multicellular tissue. However, relying on the manipulation of individual home-made glass pipettes, MPA suffers from low throughput and difficult automation. Here, we introduce the sl...

Free access to the article before 26th of July: https://authors.elsevier.com/a/1hCk9_L65sFNWn N-alkyl-D-galactonamides give biocompatible hydrogels that are very delicate and not injectable. To circumvent their mechanical fragility and the injectability issue, we have developed a method of injection based on solvent-water exchange. A solution of t...

This review aims at answering the following question: how can a researcher be sure to succeed in grafting a protein onto a polymer surface? Even if protein immobilization on solid supports has been used industrially for a long time, hence enabling natural enzymes to serve as a powerful tool, emergence of new supports such as polymeric surfaces for...

Rare-earth (RE) based inorganic nanoparticles (NPs) are emerging nanoprobes, have been widely explored. Single RENP as contrast agent for multimodal bioimaging is able to combine optical, ultrasonic, magnetic and electronic...

Reducing the size of rare earth, alkali metal fluoride crystals formulated as upconverting nanoparticles (UCNP) down to few nm can lead to unique luminescent devices due to a reduced number of emitters. The synthesis of such Na(Gd-Yb)F4:Tm nanocrystals is still challenging. The most critical issue is to keep detectable emission despite the high sur...

Lanthanide (Ln3+)-doped upconversion nanoparticles (UCNPs) often suffer from weak luminescence, especially when their sizes are ultrasmall (less than 10 nm). Enhancing the upconversion luminescence (UCL) efficiency of ultrasmall UCNPs has remained a challenge that must be undertaken if any practical applications are to be envisaged. Herein, we pres...

Planar Laser Induced Fluorescence with Inhibition (PLIF-I) is a powerful technique for studying the local gas/liquid oxygen mass transfer from a single rising bubble. However, to track oxygen in the liquid phase, it is necessary to use an oxygen sensitive luminescent probe, which needs to be unreactive toward the liquid phase. This article presents...

The occurrence of micro- and nanoplastics is a major environmental problem. Especially for nanoplastics due to their easy bioavailability and unknown impact on living organisms. The monitoring of these extremely...

Plastic pollution has become a significant concern in aquatic ecosystems, where photosynthetic microorganisms such as microalgae represent a major point of entry in the food chain. For this reason an important challenge is to better understand the consequences of plastic pollution on microalgae and the mechanisms underlying the interaction between...

The dynamics of radial A+B→C reaction fronts can be affected by buoyancy-driven convection. Motivated by recent advances in reaction-diffusion-advection (RDA) systems theory, we investigated experimentally a radial A+B→C RDA system under modulated gravity, using a Hele-Shaw cell setup onboard a parabolic flight. We evaluated characteristic properti...

The occurrence of micro- and nanoplastics is a major environmental problem. Especially for nanoplastics due to their easy bioavailability and unknown impact on living organisms. The monitoring of these extremely small particles during their ingestion, tissue translocation and transfer through the trophic chain remains very challenging. This study a...

Flow-driven precipitation experiments are performed in model porous media shaped within the confinement of a Hele-Shaw cell. Precipitation pattern formation and the yield of the reaction are investigated when borosilicate glass beads of different sizes are used in a mono-layer arrangement. The trend of the amount of precipitate produced in various...

The environmental fate and behavior of nanoplastics (NPs) and their toxicity against aquatic organisms are under current investigation. In this work, relevant physicochemical characterizations were provided to analyze the ecotoxicological risk of NPs in the aquatic compartment. For this purpose, heteroaggregates of 50 nm polystyrene nanospheres and...

The mechanic properties of cell membranes control many biological processes. The complexity of natural membranes is often dealt with by building synthetic vesicles (Giant Unilamellar Vesicles, GUVs), which can be thought as micron-sized minimal cells. Micropipette aspiration technique is the gold standard to characterize membrane mechanics, but it...

Plastic pollution has become a worldwide concern. It was demonstrated that plastic breaks down to nanoscale particles in the environment, forming so-called nanoplastics. It is important to understand their ecological impact but their structure is not elucidated. In this original work, we characterize the microstructure of oceanic polyethylene debri...

Photodynamic therapy is a technique already used in ophthalmology or oncology. It is based on the local production of reactive oxygen species through an energy transfer from an excited photosensitizer to oxygen present in the biological tissue. This review first presents an update, mainly covering the last five years, regarding the block copolymers...

Restricted and controlled drug delivery to the heart remains a challenge giving frequent off-target effects as well as limited retention of drugs in the heart. There is a need to develop and optimize tools to allow for improved design of drug candidates for treatment of heart diseases. Over the last decade, novel drug platforms and nanomaterials we...

Upconverting nanoparticles are a rising class of non-linear luminescent probes burgeoning since the beginning of the 2000’s, especially for their attractiveness in theranostics. However, the precise quantification of the light delivered remains a hot problem in order to estimate their impact on the biological medium. Sophisticated photophysical mea...

Restricted and controlled drug delivery to the heart remains a challenge giving frequent off-target effects as well as limited retention of drugs in the heart. There is a need to develop and optimize tools to allow for improved design of drug candidates for treatment of heart diseases. Over the last decade, novel drug platforms and nanomaterials we...

Upconverting nanoparticles are a rising class of non-linear luminescent probes burgeoning since the beginning of the 2000’s, especially for their attractiveness in biology. However, the precise quantification of the light delivered remains a hot problem in order to estimate the impact in biology, resulting in the development by a few teams of sophi...

In order to achieve a significant size reduction to get ultrasmall upconverting nanoparticles (UCNPs) following a thermal coprecipitation pathway, we identified two critical points the UCNP precursor mixing and high-temperature heating steps. Significant differences could be observed according to the way the inorganic sodium and fluoride sources we...

Since the advent of nanoscience, the grail of chemists is to perfectly and reproducibly elaborate nanoparticles (NPs) of fully defined size, shape, polydispersity, and surface state. It implies a total control of the experimental parameters affecting the synthesis. In the preparation of metal oxide nanoparticles using an organometallic approach, we...

Upon irradiation, the photosensitizer pheophorbide a causes dramatic morphological transitions in giant unilamellar lipid vesicles. The endocytosis-like process occurs only when the photoactive specie is encapsulated in a copolymer nanocarrier...

In recent years, there has been a growing interest in the formation of copolymers-lipids hybrid self-assemblies, which allow combining and improving the main features of pure lipids-based and copolymer-based systems known for their potential applications in the biomedical field. In this contribution we investigate the self-assembly behavior of dipa...

Atomic force microscopy (AFM) is emerging as an innovative tool to phenotype the brain. This study demonstrates the utility of AFM to determine nanomechanical and nanostructural features of the murine dorsolateral frontal cortex from weaning to adulthood. We found an increase in tissue stiffness of the primary somatosensory cortex with age, along w...

Stimuli-responsive hydrogels are essential for the future development of synthetic materials that could exchange information with living tissues. In this paper, we present the synthesis of biocompatible hydrogels with an unprecedented range of photocontrolled rigidity. The hydrogels are based on dual physical and chemical crosslinking. Chemical cro...

Analysis of nanoparticle size through a simple 2D plot is proposed in order to extract the correlation between length and width in a collection or a mixture of anisotropic particles. Compared to the usual statistics on the length associated with a second and independent statistical analysis of the width, this simple plot easily points out the vario...

The ability to self-assemble was evaluated for a large variety of amphiphilic block copolymers, including poly(ethyleneoxide-b-e-caprolactone), poly(ethyleneoxide-b-D,L-lactide), poly(ethyleneoxide-b-styrene), poly(ethyleneoxide-b-butadiene) and poly(ethyleneoxide-b-methylmethacrylate). Different methods of formation are discussed, such as cosolven...

The ability to self-assemble was evaluated for a large variety of amphiphilic block copolymers, including poly(ethyleneoxide-b-ε-caprolactone), poly(ethyleneoxide-b-d,l-lactide), poly(ethyleneoxide-b-styrene), poly(ethyleneoxide-b-butadiene) and poly(ethyleneoxide-b-methylmethacrylate). Different methods of formation are discussed, such as cosolven...

An essential issue in the development of materials presenting an accurately functionalized surface is to achieve control of layer structuring. Whereas the very popular method based on the spontaneous adsorption of alkanethiols on metal faces stability problems, the reductive electrografting of aryldiazonium salts yielding stable interface, struggle...

Protein nanofibers are emerging as useful biological nanomaterials for a number of applications, but to realize these applications requires a cheap and readily available source of fibril-forming protein material. We have identified fish lens crystallins as a feedstock for the production of protein nanofibers and report optimized methods for their p...

Resistance to commercially available antimalarial drugs is a public health problem. Since the end of the last century, no new antimalarial drugs have been introduced into clinical practice, and new drug development has been quite disappointing. There is therefore a real need to develop new class of antimalarial drugs that could be used alone or in...

Brush copolymers based on polyterthiophene have been synthesized with the aim of using them as electrically responsive layers in smart surfaces. A novel terthiophene monomer, which is polymerizable both chemically and electrochemically, was used to polymerize polyterthiophene backbones as precursors for grafting of sidechains. The precursor polymer...

The electroreduction of functionalized aryldiazonium salts combined with a protection-deprotection method was evaluated for the fabrication of organized mixed layers covalently bound onto carbon substrates. The first modification consists of the grafting of a protected 4-((triisopropylsilyl)ethynyl)benzene layer onto the carbon surface on which the...

A global strategy to prepare a versatile and robust reactive platform for immobilizing molecules on carbon substrates with controlled morphology and high selectivity is presented. The procedure is based on the electroreduction of a selected triisopropylsilyl (TIPS)-protected ethynyl aryldiazonium salt. It avoids the formation of multilayers and eff...

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Microarrays are frequently prepared on microscope glass slides. However, glass substrates can break or cut and thus can lead to the contamination of the manipulator during the analysis of biological samples. Alternately, bisphenol A polycarbonate (PC) is shock-resistant and, in addition, is easily eliminated by incineration. We show here that PC is...

We report on the use of patterned superhydrophobic silicon nanowire surfaces for the efficient, selective transfer of biological molecules and nanoparticles. Superhydrophilic patterns are prepared on superhydrophobic silicon nanowire surfaces using standard optical lithography. The resulting water-repellent surface allows material transfer and phys...

In orthopaedics and cardiovascular surgery, titanium has become the metal of choice, due to its excellent mechanical properties and biocompatibility. In many surgical operations, chemicals and/or biomolecules (such as antibiotics or growth factors) are used in conjunction with prostheses, so as to avoid or stimulate targeted biological events. Ofte...