Peptidomimetic inhibitors targeting the membrane-binding site of the neutrophil proteinase 3

Proteinase 3 (PR3), together with other serine proteases, such as neutrophil elastase (NE) and cathepsin G (CG), regulates inflammatory and immune responses. However, in comparison with NE and CG, there is increasing evidence that PR3 functions significantly differ. In particular, PR3 can bind to cell membranes and such membrane-bound PR3 (mbPR3) might be differently involved in the activation of cytokines, growth factors, cellular receptors, and in the regulation of cell apoptosis. For instance, PR3 membrane binding can block some “eat me” signals, notably, phosphatidylserine membrane lipid, and facilitate non-resolving inflammation. Based on the clear evidence that PR3 membrane binding affects the biological functions of PR3, we designed peptidomimetic inhibitors that can remove mbPR3 from the membrane surface in vitro without influencing PR3 catalytic activity. Such inhibitors, which specifically target PR3 binding to membranes, are still lacking. In particular, we found peptidomimetics that inhibit binding of PR3 to POPC:PS liposomes, which mimic the biological environment of PR3.publishedVersio

Gold nanoparticles prepared by laser ablation in aqueous biocompatible solutions: assessment of safety and biological identity for nanomedicine applications

International audienceGold nanoparticles prepared by laser ablation in aqueous biocompatible solutions: assessment of safety and biological identity for nanomedicine applications Abstract: Due to excellent biocompatibility, chemical stability, and promising optical properties , gold nanoparticles (Au-NPs) are the focus of research and applications in nanomedicine. Au-NPs prepared by laser ablation in aqueous biocompatible solutions present an essentially novel object that is unique in avoiding any residual toxic contaminant. This paper is conceived as the next step in development of laser-ablated Au-NPs for future in vivo applications. The aim of the study was to assess the safety, uptake, and biological behavior of laser-synthesized Au-NPs prepared in water or polymer solutions in human cell lines. Our results showed that laser ablation allows the obtaining of stable and monodisperse Au-NPs in water, polyethylene glycol, and dextran solutions. The three types of Au-NPs were internalized in human cell lines, as shown by transmission electron microscopy. Biocompatibility and safety of Au-NPs were demonstrated by analyzing cell survival and cell morphology. Furthermore, incubation of the three Au-NPs in serum-containing culture medium modified their physicochemical characteristics , such as the size and the charge. The composition of the protein corona adsorbed on Au-NPs was investigated by mass spectrometry. Regarding composition of complement C3 proteins and apolipoproteins, Au-NPs prepared in dextran solution appeared as a promising drug carrier. Altogether, our results revealed the safety of laser-ablated Au-NPs in human cell lines and support their use for theranostic applications

Synthesis of novel nanomaterials for biomedical applications by ultrashort laser ablation in liquids

De nos jours, les nanomatériaux inorganiques sont devenus des objets importants pour de nombreuses applications. En même temps la pureté du matériau employé est le facteur clé, et souvent les méthodes de synthèse chimiques ne peuvent assurer l'absence d'une contamination résiduelle. Dans ce contexte, nous avons investigué et développé la synthèse par laser de nanoparticules d'or et de silicium en contrôlant leurs taille et composition. Cette technique se révèle être une approche entièrement physique de la fabrication des nanoparticules pures et exemptes d'agents tensioactifs et de sous-produits toxiques. L'approche engagé comprend deux étapes : 1) la génération de la suspension de micro- et nanoparticules par broyage mécanique, et par ablation préliminaire d'une cible solide ; 2) la fragmentation laser ultra-rapide de colloïdes en suspension qui aboutit à la formation de nanoparticules stables, non agrégées, cristallines et avec une faible dispersion de taille. Ce travail se concentre sur la synthèse de nanoparticules d'or de taille contrôlable entre 7 et 50 nm en absence de ligands. De plus, cette technique nous permet d'obtenir des nano-alliages bimétalliques et d'effectuer un couplage in situ de nanoparticules d'or avec des molécules organiques. Ensuite nous montrons la possibilité d'ajuster la taille moyenne et l'épaisseur de la couche d'oxyde des nanoparticules de Si en variant la concertation des particules initiale, le pH et la quantité d'oxygène dissoutes. Enfin, nous démontrons les propriétés optiques et plasmoniques des nanoparticules obtenues au cours de ce travail et leur potentiel pour les applications catalytiques et biomédicales.Inorganic nanomaterials are of a major interest for numerous applications, specifically bioimaging, biomedicine, catalysis, and also surface enhanced Raman scattering spectroscopy. In most cases, the purity of the employed material is a key factor. Often the conventional chemical ways of synthesis cannot provide the desirable cleanliness. The aim of this thesis is to investigate and develop a laser-based synthetic concept for the fabrication of Au and Si-based nanoparticles with controlled parameters, free of surfactants and toxic by-products. The engaged approach includes two steps: 1) the generation of a raw suspension of micro- and nanoparticles by either mechanical milling or preliminary ablation of a target; 2) ultrafast laser-induced fragmentation from the suspended colloids leading to the formation of stable, non-aggregated, low-size dispersed and crystalline nanoparticles. In particular, we focus on the technique of the synthesis of bare Au nanoparticles with tunable size between 7 and 50 nm in the absence of any ligands. Moreover, this technique allows performing the in situ coupling of the Au nanoparticles with organic molecules and alloying at the nanoscale. Furthermore, we show the possibility of tuning the mean size and the thickness of the oxide shell of Si nanoparticles by varying the initial concentration of microparticles, the pH and the amount of dissolved oxygen. Finally, we demonstrate the optic and plasmonic properties of the nanoparticles synthesized by the techniques established in our work and their potential for the applications in catalysis and biomedicine

Peptidomimetic inhibitors targeting the membrane-binding site of the neutrophil proteinase 3

Proteinase 3 (PR3), together with other serine proteases, such as neutrophil elastase (NE) and cathepsin G (CG), regulates inflammatory and immune responses. However, in comparison with NE and CG, there is increasing evidence that PR3 functions significantly differ. In particular, PR3 can bind to cell membranes and such membrane-bound PR3 (mbPR3) might be differently involved in the activation of cytokines, growth factors, cellular receptors, and in the regulation of cell apoptosis. For instance, PR3 membrane binding can block some “eat me” signals, notably, phosphatidylserine membrane lipid, and facilitate non-resolving inflammation. Based on the clear evidence that PR3 membrane binding affects the biological functions of PR3, we designed peptidomimetic inhibitors that can remove mbPR3 from the membrane surface in vitro without influencing PR3 catalytic activity. Such inhibitors, which specifically target PR3 binding to membranes, are still lacking. In particular, we found peptidomimetics that inhibit binding of PR3 to POPC:PS liposomes, which mimic the biological environment of PR3

Korekciniai veiksniai, į kuriuos atsižvelgiama nustatant žemės sklypų nuomos mokestį, kaip biudžeto užpildymo įrankį savivaldybėje (Čeliabinsko miesto pavyzdys)

There is a lack of common and clear methods for calculating correction factors in determining the amount of rent for use of land plots located in the territory of the municipality on state property, and the rate of rent is therefore not delimited. Land plots which are under municipal ownership objectively necessitate the perfection of a technique of defining rent for use of land plots, taking into account the interests of both the tenants and the municipality as lessor. This often comes at the expense of correction coefficients which, on the one hand, can lead to the deterioration of the investment climate in the municipality due to the overestimated value of the coefficients. On the other hand, they can lead to a significant decrease in budgetary revenues due to the underestimated value of these coefficients in lease of land plots.Nėra bendrų ir aiškių korekcinių koeficientų apskaičiavimo metodų, kuriais remiantis būtų galima nustatyti savivaldybės teritorijoje esančių žemės sklypų nuomos mokesčio dydį. Neatriboti valstybei ir savivaldybei priklausantys žemės sklypai sukelia objektyvią būtinybę tobulinti žemės sklypų nuomos mokesčių nustatymo būdus. Reikalinga atsižvelgti į tiek nuomininkų, tiek savivaldybės, kaip nuomotojo, interesus per korekcinius koeficientus, kurie pablogina investicinį klimatą savivaldybėje, iš vienos pusės, dėl pervertintos apskaičiuotų koeficientų vertės, antrą vertus, dėl reikšmingo biudžeto pajamų sumažėjimo dėl žemės sklypų nuomos

Size-controllable synthesis of bare gold nanoparticles by femtosecond laser fragmentation in water

International audienceWe report a size-controllable synthesis of stable aqueous solutions of ultrapure low-size-dispersed Au nanoparticles by methods of femtosecond laser fragmentation from preliminary formed colloids. Such approach makes possible the tuning of mean nanoparticle size between a few nm and several tens of nm under the size dispersion lower than 70% by varying the fluence of pumping radiation during the fragmentation procedure. The efficient size control is explained by 3D geometry of laser fragmentation by femtosecond laser-induced white light super-continuum and plasma-related phenomena. Despite the absence of any protective ligands, the nanoparticle solutions demonstrate exceptional stability due to electric repulsion effect associated with strong negative charging of formed nanoparticles. Stable aqueous solutions of bare gold nanoparticles present a unique object with a variety of potential applications in catalysis, surface-enhanced Raman spectroscopy, photovoltaics, biosensing and biomedicine

Silk patterns made by direct femtosecond laser writing

Silk patterns in a film of amorphous water-soluble fibroin are created by tailored exposure to femtosecond-laser pulses (1030 nm/230 fs) without the use of photo-initiators. This shows that amorphous silk can be used as a negative tone photo-resist. It is also shown that water insoluble crystalline silk films can be precisely ablated from a glass substrate achieving the patterns of crystalline silk gratings on a glass substrate. Bio-compatible/degradable silk can be laser structured to achieve conformational transformations as demonstrated by infrared spectroscopy

Light-Tunable Plasmonic Nanoarchitectures Using Gold Nanoparticle-Azobenzene-Containing Cationic Surfactant Complexes

International audienceWhen arranged in a proper nanoaggregate architecture, gold nanoparticles can offer controllable plasmon-related absorption/scattering, yielding distinct color effects that depend critically on the relative orientation and distance between nanoparticle constituents. Herein, we report on the implementation of novel plasmonic nanoarchitectures based on complexes between gold nanoparticles and an azobenzene-modified cationic surfactant that can exhibit a light-tunable plasmonic response. The formation of such complexes becomes possible through the use of strongly negatively charged bare gold nanoparticles (similar to 10-nm diameter) prepared by the method of laser ablation in deionized water. Driven by electrostatic interactions, the cationic surfactant molecules attach and form a shell around the negatively charged nanoparticles, resulting in neutralization of the particle charge or even overcompensation beyond which the nanoparticles become positively charged. At low and high surfactant concentrations, Au nanoparticles are negatively and positively charged, respectively, and are represented by single species due to electric repulsion effects having absorption peaks around 523-527 nm, whereas at intermediate concentrations, the Au nanoparticles become neutral, forming nanoscale 100-nm clusterlike aggregates and exhibiting an additional absorption peak at gimel > 600 nm and a visible change in the color of the solution from red to blue. Because of the presence of the photosensitive azobenzene unit in the surfactant tail that undergoes trans-to-cis isomerization under irradiation with UV light, we then demonstrate a light-controlled nanoclustering of nanoparticles, yielding a switch in the plasmonic absorption band and a related change in the solution color. The formed hybrid architectures with a light-controlled plasmonic response could be important for a variety of tasks, including biomedical, surface-enhanced Raman spectroscopy (SERS), data transmission, and storage applications

Femtosecond pulse laser cleaning of Makrana marble

We studied femtosecond pulse lasers for cleaning Makrana marble, used in the construction of Soami Bagh Samadh, Agra, India. We investigated laser irradiation at different wavelengths (1029 nm, 515 nm, and 343 nm) and found that ultraviolet radiation had the lowest ablation threshold at 0.23 J cm−2, followed by green at 0.34 J·cm−2, and infrared at 1.3 J·cm−2. Green irradiation was the most efficient, ablating marble at 0.9 mm3·(min W)–1 at 4 J·cm−2 compared to 0.73 mm3·(min W)–1 at 12 J·cm−2 for 343 and 1029 nm. We evaluated the wavelength's effect on the stone. Infrared irradiation, having a higher ablation threshold, allowed for a broader range of laser fluence for the safe removal of contaminants, without risking inducing any chemical or morphological changes to the stone, and thus was selected for cleaning. We explored the cleaning effectiveness of infrared femtosecond laser pulses on a sculpted Makrana marble covered by environmental soiling. Optical and scanning electron microscopy, optical profilometry, Raman spectroscopy, and colorimetry demonstrated that satisfactory cleaning was achieved, with the removal of the unwanted layers without causing damage or chemical alteration to the marble structure. This study demonstrates the potential of femtosecond lasers for safe and effective heritage marble cleaning.</p