Multiplex Evaluation of Biointerface-Targeting Abilities and Affinity of Synthetized Nanoparticles-A Step Towards Improved Nanoplatforms for Biomedical Applications.

To obtain versatile nanoplatforms comparable for various bio-applications, synthesis and functionalization of two inorganic nanoparticles (NPs), i.e., gold (AuNPs) and iron oxide (SPIONs), are described for different NP diameters.

Raman spectroscopy of large extracellular vesicles derived from human microvascular endothelial cells to detect benzo[a]pyrene exposure.

Extracellular vesicles (EVs) have shown great potential as biomarkers since they reflect the physio-pathological status of the producing cell. In the context of cytotoxicity, it has been found that exposing cells to toxicants leads to changes in protein expression and the cargo of the EVs they produce. Here, we studied large extracellular vesicles (lEVs) derived from human microvascular endothelial cells (HMEC-1) to detect the modifications induced by cell exposure to benzo[a]pyrene (B[a]P).

Multimodal Analytical Platform on a Multiplexed Surface Plasmon Resonance Imaging Chip for the Analysis of Extracellular Vesicle Subsets.

Extracellular vesicles (EVs) are membrane-derived, tiny vesicles produced by all cells that range from 50 to several hundreds of nanometers in diameter and are used as a means of intercellular communication. They are emerging as promising diagnostic and therapeutic tools for a variety of diseases. There are two main biogenesis processes used by cells to produce EVs with differences in size, composition, and content.

Microfluidics for High Pressure: Integration on GaAs Acoustic Biosensors with a Leakage-Free PDMS Based on Bonding Technology.

Microfluidics integration of acoustic biosensors is an actively developing field. Despite significant progress in "passive" microfluidic technology, integration with microacoustic devices is still in its research state. The major challenge is bonding polymers with monocrystalline piezoelectrics to seal microfluidic biosensors.

[Extracellular vesicles: Definition, isolation and characterization].

Extracellular vesicles (EVs) originate from eukaryotic and prokaryotic cells and play a crucial role in intercellular communications. They are found in the environment of cells and tissues, and contribute to the complexity of different biological media, in particular biofluids. Due to their high diversity of cell origin, size range, concentration and composition, EVs offer some of the most important challenges in (pre-)analytical fields.

Development of extracellular vesicle-based medicinal products: A position paper of the group "Extracellular Vesicle translatiOn to clinicaL perspectiVEs - EVOLVE France".

Extracellular vesicles (EV) are emergent therapeutic effectors that have reached clinical trial investigation. To translate EV-based therapeutic to clinic, the challenge is to demonstrate quality, safety, and efficacy, as required for any medicinal product. EV research translation into medicinal products is an exciting and challenging perspective.

Regenerable ZnO/GaAs Bulk Acoustic Wave Biosensor for Detection of in "Complex" Biological Medium.

A regenerable bulk acoustic wave (BAW) biosensor is developed for the rapid, label-free and selective detection of in liquid media. The geometry of the biosensor consists of a GaAs membrane coated with a thin film of piezoelectric ZnO on its top surface. A pair of electrodes deposited on the ZnO film allows the generation of BAWs by lateral field excitation.

Topology Challenge for the Assessment of Living Cell Deposits with Shear Bulk Acoustic Biosensor.

Shear bulk acoustic type of resonant biosensors, such as the quartz crystal microbalance (QCM), give access to label-free in-liquid analysis of surface interactions. The general understanding of the sensing principles was inherited from past developments in biofilms measurements and applied to cells while keeping the same basic assumptions. Thus, the biosensor readouts are still quite often described using 'mass' related terminology.

Assessment of Shear-Dependent Kinetics of Primary Haemostasis With a Microfluidic Acoustic Biosensor.

Primary haemostasis is a complex dynamic process, which involves in-flow interactions between platelets and sub-endothelial matrix at the area of the damaged vessel wall. It results in a first haemostatic plug, which stops bleeding, before coagulation ensues and consolidates it. The diagnosis of primary haemostasis defect would benefit from evaluation of the whole sequence of mechanisms involved in platelet plug formation in flow.

Molecular and nanoscale evaluation of N-cadherin expression in invasive bladder cancer cells under control conditions or GW501516 exposure.

N-cadherin is a transmembrane glycoprotein expressed by mesenchymal origin cells and is located at the adherens junctions. It regulates also cell motility and contributes to cell signaling. In previous studies, we identified that its anomalous expression in bladder carcinoma was a tumor progression marker.

NanoBioAnalytical characterization of extracellular vesicles in 75-nm nanofiltered human plasma for transfusion: A tool to improve transfusion safety.

Plasma transfusion induces some transfusion related acute lung injury (TRALI) mediated through neutrophil extracellular traps (NETs). We investigated whether extracellular vesicles (EVs) present in plasma or obtained from resting (N-PEVs) or thrombin activated platelets (T-PEVs) can trigger NETs, and whether 75 nm-nanofiltration, to partially remove EVs, prohibits NETs formation. EVs size and concentration were determined by conventional biophysical approaches and by an original NanoBioAnalytical (NBA) platform based on EV immunocapture biochip, combining Surface Plasmon Resonance Imaging (SPRi) and Atomic Force Microscopy (AFM) exploration.

Formation Kinetics of Mixed Self-Assembled Monolayers of Alkanethiols on GaAs(100).

We report on the formation kinetics of mixed self-assembled monolayers (SAMs) comprising 16-mercaptohexadecanoic acid (MHDA) and 11-mercapto-1-undecanol (MUDO) thiols on GaAs(100) substrates. These compounds were selected for their potential in constructing highly selective and efficient architectures for biosensing applications. The molecular composition and quality of one-compound and mixed SAMs were determined by the Fourier transform infrared absorption spectroscopy measurements.

Development of a NanoBioAnalytical platform for "on-chip" qualification and quantification of platelet-derived microparticles.

Blood microparticles (MPs) are small membrane vesicles (50-1000nm), derived from different cell types. They are known to play important roles in various biological processes and also recognized as potential biomarkers of various health disorders. Different methods are currently used for the detection and characterization of MPs, but none of these methods is capable to quantify and qualify total MPs at the same time, hence, there is a need to develop a new approach for simultaneous detection, characterization and quantification of microparticles.

ERα dimerization: a key factor for the weak estrogenic activity of an ERα modulator unable to compete with estradiol in binding assays.

Estrothiazine (ESTZ) is a weak estrogen sharing structural similarities with coumestrol. ESTZ failed to compete with [H]17β-estradiol ([H]17β-E) for binding to the estrogen receptor α (ERα), questioning its ability to interact with the receptor. However, detection by atomic force spectroscopy (AFS) of an ESTZ-induced ERα dimerization has eliminated any remaining doubts.

Regeneration of a thiolated and antibody functionalized GaAs (001) surface using wet chemical processes.

Wet chemical processes were investigated to remove alkanethiol self-assembled monolayers (SAMs) and regenerate GaAs (001) samples studied in the context of the development of reusable devices for biosensing applications. The authors focused on 16-mercaptohexadecanoic acid (MHDA) SAMs that are commonly used to produce an interface between antibodies or others proteins and metallic or semiconductor substrates. As determined by Fourier transform infrared absorption spectroscopy, among the investigated solutions of HCl, H2O2, and NH4OH, the highest efficiency in removing alkanethiol SAM from GaAs was shown by NH4OH:H2O2 (3:1 volume ratio) diluted in H2O.

Enhanced chemiluminescence-based detection on gold substrate after electrografting of diazonium precursor-coated gold nanoparticles.

Since it was demonstrated that nanostructured surfaces are more efficient for the detection based on the specific capture of analytes, there is a real need to develop strategies for grafting nanoparticles onto flat surfaces. Among the different routes for the functionalization of a surface, the reduction of diazonium salts appears very attractive for the covalent immobilization of nanoparticles because this method does not require a pre-treatment of the surface. For achieving this goal, gold nanoparticles coated by precursor of diazonium salts were synthesized by reduction of gold salt in presence of mercaptoaniline.

Influence of a Thiolate Chemical Layer on GaAs (100) Biofunctionalization: An Original Approach Coupling Atomic Force Microscopy and Mass Spectrometry Methods.

Widely used in microelectronics and optoelectronics; Gallium Arsenide (GaAs) is a III-V crystal with several interesting properties for microsystem and biosensor applications. Among these; its piezoelectric properties and the ability to directly biofunctionalize the bare surface, offer an opportunity to combine a highly sensitive transducer with a specific bio-interface; which are the two essential parts of a biosensor. To optimize the biorecognition part; it is necessary to control protein coverage and the binding affinity of the protein layer on the GaAs surface.

Micro structuration of gaas surface by wet etching: towards a specific surface behavior.

Resonant microelectromechanical systems are promising devices for real time and highly sensitive measurements. The sensitivity of such sensors to additional mass loadings which can be increased thanks to the miniaturisation of devices is of prime importance for biological applications. The miniaturisation of structures passes through a photolithographic process and wet chemical etching.

A step further toward glyphosate-induced epidermal cell death: involvement of mitochondrial and oxidative mechanisms.

A deregulation of programmed cell death mechanisms in human epidermis leads to skin pathologies. We previously showed that glyphosate, an extensively used herbicide, provoked cytotoxic effects on cultured human keratinocytes, affecting their antioxidant capacities and impairing morphological and functional cell characteristics. The aim of the present study, carried out on the human epidermal cell line HaCaT, was to examine the part of apoptosis plays in the cytotoxic effects of glyphosate and the intracellular mechanisms involved in the apoptotic events.

Glyphosate-induced stiffening of HaCaT keratinocytes, a Peak Force Tapping study on living cells.

The skin is the first physiological barrier, with a complex constitution, that provides defensive functions against multiple physical and chemical aggressions. Glyphosate is an extensively used herbicide that has been shown to increase the risk of cancer. Moreover there is increasing evidence suggesting that the mechanical phenotype plays an important role in malignant transformation.

Morphological damages of a glyphosate-treated human keratinocyte cell line revealed by a micro- to nanoscale microscopic investigation.

Among the molecules to which the human skin is exposed, glyphosate is used as an herbicide. Glyphosate has been shown to induce in vitro cutaneous cytotoxic effects, concomitant with oxidative disorders. In this following study, we focused on dynamic events of the loss of HaCaT cell integrity appearing after a glyphosate treatment.

Conformational adaptability of Redbeta during DNA annealing and implications for its structural relationship with Rad52.

Single-strand annealing proteins, such as Redbeta from lambda phage or eukaryotic Rad52, play roles in homologous recombination. Here, we use atomic force microscopy to examine Redbeta quaternary structure and Redbeta-DNA complexes. In the absence of DNA, Redbeta forms a shallow right-handed helix.

Nanobioengineering and Characterization of a Novel Estrogen Receptor Biosensor.

We constructed an original supramolecular assembly on a surface of sensor composed of an innovative combination of an engineered cytochrome b5 and a modified nucleic acid bound to a synthetic lipid hemimembrane. The protein/DNA block, called (PDNA) 2, was synthesized and purified before its immobilization onto a hybrid bilayer reconstituted on a gold surface. Surface plasmon resonance (SPR) and atomic force microscopy (AFM) were engaged in parallel on the same substrates in order to better understand dynamic events that occur at the surface of the biosensor.

Straight GDP-tubulin protofilaments form in the presence of taxol.

Microtubules exist in dynamic equilibrium, growing and shrinking by the addition or loss of tubulin dimers from the ends of protofilaments. The hydrolysis of GTP in beta-tubulin destabilizes the microtubule lattice by increasing the curvature of protofilaments in the microtubule and putting strain on the lattice. The observation that protofilament curvature depends on GTP hydrolysis suggests that microtubule destabilizers and stabilizers work by modulating the curvature of the microtubule lattice itself.