Upconverting/magnetic Janus-like nanoparticles integrated into spiropyran micelle-like nanocarriers for NIR light- and pH- responsive drug delivery, photothermal therapy and biomedical imaging.

The integration of multiple functionalities into single theranostic platforms offers new opportunities for personalized and minimally invasive clinical interventions, positioning these materials as highly promising tools in modern medicine. Thereby, magneto-luminescent Janus-like nanoparticles (JNPs) were developed herein, and encapsulated into near-infrared (NIR) light- and pH- responsive micelle-like aggregates (Mic) for simultaneous magnetic targeting, biomedical imaging, photothermal therapy, and pH- NIR-light activated drug delivery. The JNPs consisted of NaYF:Yb,Tm upconverting nanoparticles (UCNPs) on which a well-differentiated magnetite structure (MNPs) grew epitaxially.

Amphiphilic self-assembling peptides: formulation and elucidation of functional nanostructures for imaging and smart drug delivery.

The rational design of self-assembled peptide-based nanostructures for theranostics applications requires in-depth physicochemical characterization of the peptide nanostructures, to understand the mechanism and the interactions involved in the self-assembly, allowing a better control of the objects' physicochemical and functional properties for theranostic applications. In this work, several complementary characterization methods, such as dynamic light scattering, transmission electron microscopy, circular dichroism, Taylor dispersion analysis, and capillary electrophoresis, were used to study and optimize the self-assembly of pH-sensitive short synthetic amphiphilic peptides containing an RGD motif for active targeting of tumor cells and smart drug delivery. The combined methods evidenced the spontaneous formation of nanorods (L = 50 nm, d = 10 nm) at pH 11, stabilized by β-sheets.

Insights into diphenylalanine peptide self-assembled nanostructures for integration as nanoplatforms in analytical and medical devices.

New insights on the self-assembling process of diphenylalanine (FF) into nanostructures in view of its application as an alternative nanomaterial for bioanalytical and biomedical systems are presented in the frame of the present work. Experimental conditions, such as peptide concentration and solubilization medium pH, were explored to understand the hierarchical process involved in the formation of self-assembled nanostructures arising from the simple and short diphenylalanine peptide. Optical microscopic and TEM images supported by DLS data authenticated the hierarchical self-assembly outcoming from the original nature of the first nanostructures, showing individual nanotubes and vesicles stacking to grow well-defined microtubes.

Streamlined integrated protein isoelectric focusing using microfluidic paper-based device.

An innovative integrated paper-based microdevice was developed for protein separation by isoelectric focusing (IEF), allowing for robust design thanks to a 3D-printed holder integrating separation channel, reservoirs, and electrodes. To reach robustness and precision, the optimization focused on the holder geometry, the paper nature, the reservoir design, the IEF medium, and various focusing parameters. A well-established and stable pH gradient was obtained on a glass-fiber paper substrate with simple sponge reservoirs, and the integration of the electrodes in the holder led to a straightforward system.

A methodological approach by capillary electrophoresis coupled to mass spectrometry via electrospray interface for the characterization of short synthetic peptides towards the conception of self-assembled nanotheranostic agents.

Nanostructures formed by the self-assembling peptide building blocks are attractive materials for the design of theranostic objects due to their intrinsic biocompatibility, accessible surface chemistry as well as cavitary morphology. Short peptide synthesis and modification are straightforward and give access to a great diversity of sequences, making them very versatile building blocks allowing for the design of thoroughly controlled self-assembled nanostructures. In this work, we developed a new CE-DAD-ESI-MS method to characterize short synthetic amphiphilic peptides in terms of exact sequence and purity level in the low 0.

Recycling 3D Printed Residues for the Development of Disposable Paper-Based Electrochemical Sensors.

Here, we propose a recyclable approach using acrylonitrile-butadiene-styrene (ABS) residues from additive manufacturing in combination with low-cost and accessible graphite flakes as a novel and potential mixture for creating a conductive paste. The graphite particles were successfully incorporated in the recycled thermoplastic composite when solubilized with acetone and the mixture demonstrated greater adherence to different substrates, among which cellulose-based material made possible the construction of a paper-based electrochemical sensor (PES). The morphological, structural, and electrochemical characterizations of the recycled electrode material were demonstrated to be similar to those of the traditional carbon-based surfaces.

Rational Understanding of Loading and Release of Doxorubicin by UV-Light- and pH-Responsive Poly(NIPAM--SPMA) Micelle-like Aggregates.

A deep understanding of the interactions between micelle-like aggregates and antineoplastic drugs is paramount to control their adequate delivery. Herein, Poly(NIPAM--SPMA) copolymer nanocarriers were synthesized according to our previous published methodology, and the loading and release of poorly and highly water-soluble doxorubicin forms (Dox and Dox-HCl, respectively) were evaluated upon UV light irradiation and pH-variation stimuli. Capillary electrophoresis (CE) coupled to a fluorescence detector (LIF) allowed us to specifically characterize these systems and deeply study the loading and release processes.

Electrokinetic characterization of hybrid NOA 81-glass microchips: Application to protein microchip electrophoresis with indirect fluorescence detection.

A low-cost and straightforward hybrid NOA (Norland optical adhesive) 81-glass microchip electrophoresis device was designed and developed for protein separation using indirect fluorescence detection. This new microchip was first characterized in terms of surface charge density via electroosmotic mobility measurement and stability over time. A systematic determination of the electroosmotic mobility (μ ) over a wide pH range (2-10) and at various ionic strengths (20-50 mM) was developed for the first time via the neutral marker approach in an original simple frontal methodology.

Synthesis, Characterization and Evaluation of Peptide Nanostructures for Biomedical Applications.

There is a challenging need for the development of new alternative nanostructures that can allow the coupling and/or encapsulation of therapeutic/diagnostic molecules while reducing their toxicity and improving their circulation and in-vivo targeting. Among the new materials using natural building blocks, peptides have attracted significant interest because of their simple structure, relative chemical and physical stability, diversity of sequences and forms, their easy functionalization with (bio)molecules and the possibility of synthesizing them in large quantities. A number of them have the ability to self-assemble into nanotubes, -spheres, -vesicles or -rods under mild conditions, which opens up new applications in biology and nanomedicine due to their intrinsic biocompatibility and biodegradability as well as their surface chemical reactivity via amino- and carboxyl groups.

Speciation and quantitation of precious metals in model acidic leach liquors, theoretical and practical aspects of recycling.

Waste printed circuit boards are a major source of strategic materials such as platinum group metals since they are used for the fabrication of technological devices, such as hard drive discs, capacitors, and diodes. Because of the high cost of platinum, palladium, and gold (> 25 k€/kg), an economic and environmental challenge is their recycling from printed circuit boards that represent around 2% weight of electronic equipment. Hydrometallurgical treatments allow the recovery of these metals in solution, with a high recovery rate for a leaching liquor made of thiourea in hydrochloric acid.

Physicochemical Characterization of Phthalocyanine-Functionalized Quantum Dots by Capillary Electrophoresis Coupled to a LED Fluorescence Detector.

Capillary zone electrophoresis (CZE) complemented with Taylor Dispersion Analysis-CE (TDA-CE) was developed to physicochemically characterize phthalocyanine-capped core/shell/shell quantum dots (QDs) at various pH and ionic strengths. An LED-induced fluorescence detector was used to specifically detect the QDs. The electropherograms and taylorgrams allowed calculating the phthalocyanine-QDs (Pc-QDs) ζ-potential and size, respectively, and determining the experimental conditions for colloidal stability.

Characterization of New Cyclic D,L-α-Alternate Amino Acid Peptides by Capillary Electrophoresis Coupled to Electrospray Ionization Mass Spectrometry.

The self-assembly of peptide nanotubes (PNTs) depends on the structure and chemistry of cyclic peptide (CP) monomers, impacting on their properties, which makes the choice of their monomers and their characterization a high challenge. For this purpose, we developed for the first time a capillary electrophoresis coupled to electrospray ionization mass spectrometry (CE-ESI-MS) methodology and characterized a set of eight original CP sequences of 8, 10, and 12 D,L-α-alternate amino acids with a controlled internal diameter (from 7 to 13 Å) and various properties (diameter, global surface charge, hydrophobicity). This new CE-ESI-MS methodology allows verifying the structure, the purity, as well as the stability (when stored during several months) of interesting potential precursors for PNTs that could be employed as nanoplatforms in diagnostics or pseudo sieving tools for separation purposes.

Clickable-Zwitterionic Copolymer Capped-Quantum Dots for in Vivo Fluorescence Tumor Imaging.

In the last decades, fluorescent quantum dots (QDs) have appeared as high-performance biological fluorescent nanoprobes and have been explored for a variety of biomedical optical imaging applications. However, many central challenges still exist concerning the control of the surface chemistry to ensure high biocompatibility, low toxicity, antifouling, and specific active targeting properties. Regarding in vivo applications, circulation time and clearance of the nanoprobe are also key parameters to control the design and characterization of new optical imaging agents.

Electrokinetic Hummel-Dreyer characterization of nanoparticle-plasma protein corona: The non-specific interactions between PEG-modified persistent luminescence nanoparticles and albumin.

Nanoparticles (NPs) play an increasingly important role in the development of new biosensors, contrast agents for biomedical imaging and targeted therapy vectors thanks to their unique properties as well as their good detection sensitivity. However, a current challenge in developing such NPs is to ensure their biocompatibility, biodistribution, bioreactivity and in vivo stability. In the biomedical field, the adsorption of plasmatic proteins on the surface of NPs impacts on their circulation time in blood, degradation, biodistribution, accessibility, the efficiency of possible targeting agents on their surface, and their cellular uptake.

Photo-stimulation of persistent luminescence nanoparticles enhances cancer cells death.

Persistent luminescence nanoparticles made of ZnGaCrO (ZGO-NPs) are innovative nanomaterials that emit photons during long periods of time after the end of the excitation, allowing their use as diagnosis probes for in vivo optical imaging. During the excitation process, a part of the energy is stored in traps to further emit photons over long time. However, we observed in this study that some of the energy reduces molecular oxygen to produce reactive oxygen species (ROS).

Long-term toxicological effects of persistent luminescence nanoparticles after intravenous injection in mice.

The ZnGaCrO persistent luminescence nanoparticles offer the promise of revolutionary tools for biological imaging with applications such as cell tracking or tumor detection. They can be re-excited through living tissues by visible photons, allowing observations without any time constraints and avoiding the undesirable auto-fluorescence signals observed when fluorescent probes are used. Despite all these advantages, their uses demand extensive toxicological evaluation and control.

Aptamer entrapment in microfluidic channel using one-step sol-gel process, in view of the integration of a new selective extraction phase for lab-on-a-chip.

There is a great demand for integrating sample treatment into μTASs. In this context, we developed a new sol-gel phase for extraction of trace compounds in complex matrices. For this purpose, the incorporation of aptamers in silica-based gel within PDMS/glass microfluidic channels was performed for the first time by a one-step sol-gel process.

Characterization of phthalocyanine functionalized quantum dots by dynamic light scattering, laser Doppler, and capillary electrophoresis.

In this work, we characterized different phtalocyanine-capped core/shell/shell quantum dots (QDs) in terms of stability, ζ-potential, and size at various pH and ionic strengths, by means of capillary electrophoresis (CE), and compared these results to the ones obtained by laser Doppler electrophoresis (LDE) and dynamic light scattering (DLS). The effect of the phthalocyanine metallic center (Zn, Al, or In), the number (one or four), and nature of substituents (carboxyphenoxy- or sulfonated-) of functionalization on the phthalocyanine physicochemical properties were evaluated. Whereas QDs capped with zinc mono-carboxyphenoxy-phtalocyanine (ZnMCPPc-QDs) remained aggregated in the whole analyzed pH range, even at low ionic strength, QDs capped with zinc tetracarboxyphenoxy phtalocyanine (ZnTPPc-QDs) were easily dispersed in buffers at pH equal to or higher than 7.

Colorimetric analysis of the decomposition of S-nitrosothiols on paper-based microfluidic devices.

A disposable microfluidic paper-based analytical device (μPAD) was developed to easily analyse different S-nitrosothiols (RSNOs) through colorimetric measurements. RSNOs are carriers of nitric oxide (NO) that play several physiological and physiopathological roles. The quantification of RSNOs relies on their decomposition using several protocols and the colorimetric detection of the final product, NO or nitrite.

Online Capillary IsoElectric Focusing-ElectroSpray Ionization Mass Spectrometry (CIEF-ESI MS) in Glycerol-Water Media for the Separation and Characterization of Hydrophilic and Hydrophobic Proteins.

Capillary isoelectric focusing (CIEF) is a high-resolution technique for the separation of ampholytes, such as proteins, according to their isoelectric point. CIEF coupled online with MS is regarded as a promising alternative to 2-D PAGE for fast proteome analysis with high-resolving capabilities and enhanced structural information without the drawbacks of conventional slab-gel electrophoresis. However, online coupling has been rarely described, as it presents some difficulties.

Design, synthesis, and characterization of new cyclic d,l-α-alternate amino acid peptides by capillary electrophoresis coupled to electrospray ionization mass spectrometry.

The self-assembly of peptide nanotubes (PNTs) depends on the structure and chemistry of cyclic peptide (CP) monomers, having an impact on their properties, making the choice of their monomers and their characterization a great challenge. We synthesized for the first time a new set of eight original CP sequences of 8, 10, and 12 d,l-α-alternate amino acids with a controlled internal diameter from 7 to 13 Å. They present various properties (e.

Recent advances in the development of capillary electrophoresis methodologies for optimizing, controlling, and characterizing the synthesis, functionalization, and physicochemical, properties of nanoparticles.

This paper gives a critical overview of capillary electrophoresis (CE) methodologies recently developed for controlling and optimizing the synthesis of nanoparticles as well as characterizing their functionalization in terms of physicochemical properties. Thanks to their electrophoretic mobility, various parameters can be determined, such as NP size and charge distribution, ζ-potential, surface functionality, colloidal stability, grafting rates, and dissociation constants, allowing not only the complete characterization of new nanoprobes but also helping in their design and in the selection of chemical conditions for their storage and further manipulation. New strategies for the improvement of CE detection sensitivity are also described.

Functionalization and characterization of persistent luminescence nanoparticles by dynamic light scattering, laser Doppler and capillary electrophoresis.

Zinc gallate nanoparticles doped with chromium (III) (ZnGa1.995O4:Cr0.005) are innovative persistent luminescence materials with particular optical properties allowing their use for in vivo imaging.