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International audience; More environmentally relevant nanoplastic models are urgently needed. Models of environmental plastics are used to develop analytical methods to get an accurate picture of how nanoplastics behave in natural systems, and to generate data on nanoplastics’ environmental fate and impact on living organisms. Despite the recent progress in developing models to mimic nanoplastics, the models that are available do not yet show enough diversity to represent the wide heterogeneity in the physical and chemical properties of environmental nanoplastics. In this paper, we report on the strategy we developed to obtain environmentally relevant nanoplastics by mechanical abrasion and sonication of weathered plastics collected from the natural environment (on the beach, and floating in the water). An organic matter degradation protocol was devised to eliminate any potential organic residues that were initially present on the collected plastic samples. The final nanoplastic suspension contains an average of 400 mg carbon L-1, allowing the surface properties to be characterized by XPS, BET analysis, and potentiometric titration. The size distribution of nanoplastics ranges from 200 to 500 nm, with a heterogenous shape and composition (polyethylene or polypropylene) similar to the nanoplastics observed in marine, coastline, and soil systems..

Artificial ageing of polymeric insulation jackets is routinely performed in order to assess end-of-life material characteristics. Practical constraints including high temperatures/ short times ageing treatments lead to strong influence of diffusion-limited oxidation (DLO) resulting in unreliable life-time predictions. This study proposes a new experimental approach to the investigation of cable insulation ageing, exploiting analytical techniques capable of resolving chemistry at the length scale relevant for DLO (nano-microscale). When studying the potential effects of DLO using time of flight secondary ion mass spectrometry (ToF-SIMS) sample preparation becomes crucial. This paper presents the development of a methodology to generate suitable specimens to investigate the DLO effect using ToF-SIMS. A reference polymeric material has been thermally aged in various DLO conditions. Cross sections of aged samples were generated using three different methods. In order to assess the most suitable approach for this study, cross-section topography were scanned using a profilometer and the surface chemistry was investigated using ToF-SIMS together with multivariate analysis methods.

Hypothesis In this original work, we aim to control both the surface wetting and fluorescence properties of extremely ordered and porous conducting polymer nanotubes prepared by soft template electropolymerization and post-grafting. For reaching this aim, various substituents of different hydrophobicity and fluorescence were post-grafted and the post-grafting yields were evaluated by surface analyses. We show that the used polymer is already fluorescent before post-grafting while the post-grafting yield and as a consequence the surface hydrophobicity highly depend on the substituent. Experiments Here, we have chosen to chemically grafting various fluorinated and aromatic substituents using a post-grafting in order to keep the same surface topography. Flat conducting polymer surfaces with similar properties have been also prepared for determining the surface energy with the Owens-Wendt equation and estimating the post-grafting yield by X-ray Photoemission Spectroscopy (XPS) and Time of Flight Secondary Emission Spectrometry (ToF-SIMS). For example, using fluorinated chains of various length (C4F9, C6F13 and C8F17), it is demonstrated that the surface hydrophobicity and oleophobicity do not increase with the fluorinated chain length due to the different post-grafting yields and because of the presence of nanoroughness after post-grafting. Findings These surfaces have high apparent water contact angle up to 130.5° but also strong water adhesion, comparable to rose petal effect even if there are no nanotubes on petal surface. XPS and ToF-SIMS analyses provided a detailed characterisation of the surface chemistry with a qualitative classification of the grafted surfaces (F6 > F4 > F8). SEM analysis shows that grafting does not alter the surface morphology. Finally, fluorescence analyses show that the polymer surfaces before post-treatment are already nicely fluorescent. Although the main goal of this paper was and is to understand the role of surface chemistry in tailoring the wetting properties of these surfaces rather than provide specific application examples, we believe that the obtained results can help the development of specific nanostructured materials for potential applications in liquid transport, or in stimuli responsive antimicrobial surfaces.

The present paper assesses the heterogeneous nucleation of a small-molecule drug and its relationship with the surface chemistry of engineered heteronucleants. The nucleation of aspirin (ASA) was tuned by different functional groups exposed by self-assembled monolayers (SAMs) immobilized on glass surfaces. Smooth topographies and defect-free surface modification allowed the deconvolution of chemical and topographical effects on nucleation. The nucleation induction time of ASA in batch crystallization was mostly enhanced by methacrylate and amino groups, whereas it was repressed by thiol groups. In this perspective, we also present a novel strategy for the evaluation of surface-drug interactions by confining drug crystallization to thin films and studying the preferential growth of crystal planes on different surfaces. Crystallization by spin coating improved the study of oriented crystallization, enabling reproducible sample preparation, minimal amounts of drug required, and short processing time. Overall, the acid surface tension of SAMs dictated the nucleation kinetics and the extent of relative growth of the ASA crystal planes. Moreover, the face-selective action of monolayers was investigated by force spectroscopy and attributed to the preferential interaction of exposed groups with the (100) crystal plane of ASA.

In this paper, fabrication of a new material is reported, the so-called Aero-Ga2O3 or Aerogallox, which represents an ultra-porous and ultra-lightweight three-dimensional architecture made from interconnected microtubes of gallium oxide with nanometer thin walls. The material is fabricated using epitaxial growth of an ultrathin layer of gallium nitride on zinc oxide microtetrapods followed by decomposition of sacrificial ZnO and oxidation of GaN which according to the results of X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS) characterizations, is transformed gradually in β-Ga2O3 with almost stoichiometric composition. The investigations show that the developed ultra-porous Aerogallox exhibits extremely low reflectivity and high transmissivity in an ultrabroadband electromagnetic spectrum ranging from X-band (8–12 GHz) to several terahertz which opens possibilities for quite new applications of gallium oxide, previously not anticipated.

A variety of methods used to prepare nano-objects for surface analysis are described along with information about when they might be best applied. Intrinsic properties of NPs that complicate their characterization and need to be considered when planning for surface or other analyses of NPs are identified, including challenges associated with reproducible synthesis and functionalization of the particles as well as their dynamic nature. The relevant information about the sample preparation processes along with analysis details and data that need to be added to the collection of material provenance information is identified. Examples of protocols that have been successfully used for preparation of nano-objects for surface analysis are included in an annex.

Nanometer-sized structures, surfaces and sub-surface phenomena have played an enormous role in science and technological applications and represent a driving-force of current interdisciplinary science. Recent developments include the atomic-scale characterization of nanoparticles, molecular reactions at surfaces, magnetism at the atomic scale, photoelectric characterization of nanostructures as well as two-dimensional solids. Research and development of smart nanostructured materials governed by their surface properties is a rapidly growing field. The main challenge is to develop an accurate and robust electronic structure description. The density of surface-related trap states is analyzed by transient UV photoconductivity and temperature-dependent admittance spectroscopy. An advanced application of thin films on shaped substrates is the deposition of catalytic layers on hollow glass microspheres for hydrogen storage controlled exothermal hydrolytic release. Surface properties of thin films including dissolution and corrosion, fouling resistance, and hydrophilicity/hydrophobicity are explored to improve materials response in biological environments and medicine. Trends in surface biofunctionalization routes based on vacuum techniques, together with advances in surface analysis of biomaterials, are discussed. Pioneering advances in the application of X-ray nanodiffraction of thin film cross-sections for characterizing nanostructure and local strain including in-situ experiments during nanoindentation are described. Precise measurements and control of plasma properties are important for fundamental investigations and the development of next generation plasma-based technologies. Critical control parameters are the flux and energy distribution of incident ions at reactive surfaces; it is also crucial to control the dynamics of electrons initiating non-equilibrium chemical reactions. The most promising approach involves the exploitation of complementary advantages in direct measurements combined with specifically designed numerical simulations. Exciting new developments in vacuum science and technology have focused on forward-looking and next generation standards and sensors that take advantage of photonics based measurements. These measurements are inherently fast, frequency based, easily transferrable to sensors based on photonics and hold promise of being disruptive and transformative. Realization of Pascal, the SI unit for pressure, a cold-atom trap based ultra-high and extreme high vacuum (UHV and XHV) standard, dynamic pressure measurements and a photonic based thermometer are three key examples that are presented.

Multi-functionalized nanoparticles are of great interest in biotechnology and biomedicine, especially for diagnostic and therapeutic purposes. However, at the moment the characterization of complex, multi-functional nanoparticles is still challenging and this hampers the development of advanced nanomaterials for biological applications. In this work, we have designed a model system consisting of gold nanoparticles functionalized with two differentially-terminated poly(ethylene oxide) ligands, providing both "stealth" properties and protein-binding capabilities to the nanoparticles. We use a combination of techniques (Centrifugal Liquid Sedimentation, Dynamic Light Scattering, Flow Field Flow Fractionation, Transmission Electron Microscopy, and Circular Dichroism) to: (i) monitor and quantify the ratios of ligand molecules per nanoparticle; (ii) determine the effect of coating density on non-specific protein adsorption; (iii) to assess the number and structure of the covalently-bound proteins. This article aims at comparing the complementary outcomes from typical and orthogonal techniques used in nanoparticle characterization by employing a versatile nanoparticle-ligands-biomolecule model system.

Biocompatible coating based on bovine serum albumin (BSA) was applied on two different TiO2 nanoparticles (aeroxide P25 and food grade E171) to investigate properties and stability of resulting TiO2@BSA composites, under the final perspective to create a “Safe-by-Design” coating, able to uniform, level off and mitigate surface chemistry related phenomena, as naturally occurring when nano-phases come in touch with proteins enriched biological fluids. The first step towards validating the proposed approach is a detailed characterization of surface chemistry with the quantification of amount and stability of BSA coating deposited on nanoparticles’ surfaces. At this purpose, we implemented an orthogonal multi-techniques characterization platform, providing important information on colloidal behavior, particle size distribution and BSA-coating structure of investigated TiO2 systems. Specifically, the proposed orthogonal approach enabled the quantitative determination of bound and free (not adsorbed) BSA, a key aspect for the design of intentionally BSA coated nano-structures, in nanomedicine and, overall, for the control of nano-surface reactivity. In fact, the BSA-coating strategy developed and the orthogonal characterisation performed can be extended to different designed nanomaterials in order to further investigate the protein-corona formation and promote the implementation of BSA engineered coating as a strategy to harmonize the surface reactivity and minimize the biological impact.

We propose a novel method for determining the structural and thermodynamic properties of nanoparticle-protein complexes under physiological conditions. The method consists of collecting a full set of small-angle X-ray and neutron-scattering measurements in solutions with different concentrations of nanoparticles and protein. The nanoparticle-protein dissociation process is described in the framework of the Hill cooperative model, based on which the whole set of X-ray and neutron-scattering data is fitted simultaneously. This method is applied to water solutions of gold nanoparticles in the presence of human serum albumin without any previous manipulation and can be, in principle, extended to all systems. We demonstrate that the protein dissociation constant, the Hill coefficient, and the stoichiometry of the nanoparticle-protein complex are obtained with a high degree of confidence.

Porous silicon (PSi) is a versatile matrix with tailorable surface reactivity, which allows the processing of a range of multifunctional films and particles. The biomedical applications of PSi often require a surface capping with organic functionalities. This work shows that visible light can be used to catalyze the assembly of organosilanes on the PSi, as demonstrated with two organosilanes: aminopropyl-triethoxy-silane and perfluorodecyl-triethoxy-silane. We studied the process related to PSi films (PSiFs), which were characterized by X-ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectroscopy (ToF-SIMS) and field emission scanning electron microscopy (FESEM) before and after a plasma patterning process. The analyses confirmed the surface oxidation and the anchorage of the organosilane backbone. We further highlighted the surface analytical potential of 13 C, 19 F and 29 Si solid-state NMR (SS-NMR) as compared to Fourier transformed infrared spectroscopy (FTIR) in the characterization of functionalized PSi particles (PSiPs). The reduced invasiveness of the organosilanization regarding the PSiPs morphology was confirmed using transmission electron microscopy (TEM) and FESEM. Relevantly, the results obtained on PSiPs complemented those obtained on PSiFs. SS-NMR suggests a number of siloxane bonds between the organosilane and the PSiPs, which does not reach levels of maximum heterogeneous condensation, while ToF-SIMS suggested a certain degree of organosilane polymerization. Additionally, differences among the carbons in the organic (non-hydrolyzable) functionalizing groups are identified, especially in the case of the perfluorodecyl group. The spectroscopic characterization was used to propose a mechanism for the visible light activation of the organosilane assembly, which is based on the initial photoactivated oxidation of the PSi matrix, We acknowledge MSC funding provided by the European Commission through FP7 grant THINFACE (ITN GA 607232) and by Ministerio de Economía y Competitividad through grant NANOPROST (RTC-2016-4776-1)

The lead authors failed to name two collaborators as co-authors. The authors listed should include: Miss Claudia L. Compean-Gonzalez (ORCID: 0000-0002-2367-8450) and Dr. Giacomo Ceccone (ORCID: 0000-0003-4637-0771). These co-authors participated in VAMAS project A27, provided data that were analyzed and presented in this publication (and supporting information), and reviewed the manuscript before submission.

Amorphous carbon films exhibit attractive optical and surface properties. In this work, modified amorphous carbon films incorporating nitroxide groups (α-CNO) have been obtained by searching for a condensed analogue to classical soft antifouling materials. Thin films deposited by reactive magnetron sputtering in air discharges at varying power conditions were characterized by ellipsometry, atomic force microscopy, and water contact angle. Plasma power was observed to activate the densification and roughness of nanograined films. Most hydrophilic films deposited at 30 W exhibited the lowest refractive index, negligible optical absorption in the vis-IR, and presented a close to stoichiometric C2NO composition, as derived from X-ray photoelectron spectroscopy. Micropatterns prepared by photolithography validated the transparency-hydrophilicity of the α-CNO, as observed by water condensation contrast imaging. An albumin adsorption experiment evaluated through fluorescence revealed that α-CNO behaves as antifouling with respect to Si. Such thin antifouling films are of interest for the initiation of immobilization cascades in imaging surface plasmon resonance, where they have confirmed their antifouling contrast enhancement role. These results illustrate that the combination of a nanorough surface with nitroxide chemistry induces an antifouling behavior. In association with the optical transparency, the results invite the exploration of the bioengineering dimension of α-CNO films.

Diamond is a promising material for a number of bio-applications, including the fabrication of platforms for attachment and investigation of neurons and of neuroprostheses, such as retinal implants. In the current work ultrananocrystalline diamond (UNCD) films were deposited by microwave plasma chemical vapor deposition, modified by UV/O-3 treatment or NH3 plasma, and comprehensively characterized with respect to their bulk and surface properties, such as crystallinity, topography, composition and chemical bonding nature. The interactions of insect circadian pacemaker neurons with UNCD surfaces with H-, O- and NH2-terminations were investigated with respect to cell density and viability. The fast and strong attachment achieved without application of adhesion proteins allowed for advantageous modification of dispersion protocols for the preparation of primary cell cultures. Centrifugation steps, which are employed for pelletizing dispersed cells to separate them from dispersing enzymes, easily damage neurons. Now centrifugation can be avoided since dispersed neurons quickly and strongly attach to the UNCD surfaces. Enzyme solutions can be easily washed off without losing many of the dispersed cells. No adverse effects on the cell viability and physiological responses were observed as revealed by calcium imaging. Furthermore, the enhanced attachment of the neurons, especially on the modified UNCD surfaces, was especially advantageous for the immunocytochemical procedures with the cell cultures. The cell losses during washing steps were significantly reduced by one order of magnitude in comparison to controls. In addition, the integration of a titanium grid structure under the UNCD films allowed for individual assignment of physiologically characterized neurons to immunocytochemically stained cells. Thus, employing UNCD surfaces free of foreign proteins improves cell culture protocols and immunocytochemistry with cultured cells. The fast and strong attachment of neurons was attributed to a favorable combination of topography, surface chemistry and wettability. (C) 2016 Elsevier B.V. All rights reserved.

The controlled modification of surface properties represents a pervasive requirement to be fulfilled when developing new technologies. In this paper, we propose an easy-to-implement protocol for the functionalization of glass with self-assembled monolayers (SAMs). The adaptivity of the synthesis route was demonstrated by the controlled anchoring of thiol, amino, glycidyloxy, and methacrylate groups onto the glass surface. The optimization of the synthetic pathway was mirrored by extremely smooth SAMs (approximately 150 pm roughness), layer thickness comparable to the theoretical molecule length, absence of silane islands along the surface, quasi-unitary degree of packing, and tailored wettability and charge. The functionalization kinetics of two model silanes, 3-mercapto- and 3-amino-propyltrimethoxysilane, was determined by cross-comparing x-ray photoelectron spectroscopy and time of flight secondary ion mass spectrometry data. Our SAMs with tailored physicochemical attributes will be implemented as supports for the crystallization of pharmaceuticals and biomolecules in upcoming studies. Here, the application to a small molecule drug model, namely aspirin, was discussed as a proof of concept.

In this paper, fabrication of a new material is reported, the so-called Aero-Ga2O3 or Aerogallox, which represents an ultra-porous and ultra-lightweight three-dimensional architecture made from interconnected microtubes of gallium oxide with nanometer thin walls. The material is fabricated using epitaxial growth of an ultrathin layer of gallium nitride on zinc oxide microtetrapods followed by decomposition of sacrificial ZnO and oxidation of GaN which according to the results of X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS) characterizations, is transformed gradually in β-Ga2O3 with almost stoichiometric composition. The investigations show that the developed ultra-porous Aerogallox exhibits extremely low reflectivity and high transmissivity in an ultrabroadband electromagnetic spectrum ranging from X-band (8–12 GHz) to several terahertz which opens possibilities for quite new applications of gallium oxide, previously not anticipated.

The deposition of polymeric thin layers bearing reactive functional groups is a promising solution to provide functionality on otherwise inert surfaces, for instance, for bioconjugation purposes. Atmospheric pressure plasma (AP plasma) deposition technology offers many advantages, such as fast deposition rates, low costs, low waste generation and suitability for coating various kind of material surfaces. In this work, the AP plasma-assisted copolymerization of methyl methacrylate (MMA) with a vinyl derivative of L-DOPA was studied in order to deposit coatings with reactive catechol/quinone groups suitable for protein covalent immobilization. The effect of adding a chemical cross-linker, between 0 and 2 mol%, to the monomer mixture is also studied in order to prepare robust plasma PMMA-based layers in liquid physiological media. The layer prepared with 0.2 mol% of cross-linker shows the best balance between stability in saline-buffered media and surface functionalization. Bioconjugation via the grafting of Ranaspumin-2 recombinant, a naturally occurring surfactant protein, is carried out in a single step after plasma deposition. Protein immobilization is corroborated by Quartz Crystal Microbalance with Dissipation (QCM-D) and Surface Plasmon Resonance (SPR) analyses and confirmed via Epicocconone staining, X-Ray Photoemission Spectroscopy (XPS) and Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) measurements and surface wettability characterizations. The bio-functionalized layers presented an enhanced activity against the adhesion of Human Serum Albumin (HSA), indicating the grafting potential of the Ranaspumin-2 bio-surfactant to produce anti-biofouling functional coatings.

In this study we used 5 nm gold nanoparticles as delivery platforms to target cancer cells expressing the immune receptor Tim-3 using single chain antibodies. Gold surfaces were also covered with the cytotoxic drug rapamycin which was immobilised using a glutathione linker. These nanoconjugates allowed highly specific and efficient delivery of cytotoxic rapamycin into human malignant blood cells.

Biotechnological processes harnessing living organisms' metabolism are low-cost routes to nanostructured materials for applications in photonics, electronics, and nanomedicine. In the pursuit of photonic biohybrids, diatoms microalgae are attractive given the properties of the porous micro-to-nanoscale structures of the biosilica shells (frustules) they produce. The investigations have focused on in vivo incorporation of tailored molecular fluorophores into the frustules of Thalassiosira weissflogii diatoms, using a procedure that paves the way for easy biotechnological production of photonic nanostructures. The procedure ensures uniform staining of shells in the treated culture and permits the resulting biohybrid photonic nanostructures to be isolated with no damage to the dye and periodic biosilica network. Significantly, this approach ensures that light emission from the dye embedded in the isolated biohybrid silica is modulated by the silica's nanostructure, whereas no modulation of photoluminescence is observed upon grafting the fluorophore onto frustules by an in vitro approach based on surface chemistry. These results pave the way to the possibility of easy production of photonic nanostructures with tunable properties by simple feeding the diatoms algae with tailored photoactive molecules.

Refraction and absorption properties of soft X-rays provide distinct advantages for ‘fast’ imaging of matter consisting of light elements, as biological samples, with sensitivity better than conventional light microscopy. This is very attractive for nanotoxicology, in particular for rapid screening of nanoparticle distribution and their effects on exposed cells at submicrometer length scales. In this paper, we report on the first trials demonstrating the potential of scanning transmission X-ray microscopy to monitor morphological and chemical changes induced in Balb 3T3 mouse fibroblast cells exposed to CoFe2O4 nanoparticles. This research uses the complementary imaging methods of an advanced synchrotron soft X-ray microscopy instrument implementing a novel approach based on high-resolution absorption and phase contrast imaging for the identification of important cellular changes induced by the presence of nanoparticles. Copyright © 2015 John Wiley & Sons, Ltd.

We propose a simple method to determine the structure and morphology of nanoparticle protein complexes. By combining a separation method with online size measurements, density measurements and circular dichroism, we could identify the number of proteins bound to each nanoparticle and their secondary structure changes in the complex. This method provides much-needed experimental information on the interaction of proteins with nanoparticles and on the behavior of nanoparticles in biological systems.

The integration of gold nanoparticles (Au NPs) or nanostructures on solid surfaces for developing nanostructured biointerfaces has become a major research topic in the field of nanobiotechnology in particular for the development of a new generation of multifunctional bioanalytical platforms. This has led to considerable research efforts for developing quick and direct nanofabrication methods capable of producing well-ordered 2D nanostructured arrays with tunable morphological, chemical and optical properties. In this paper, we propose a simple and fast nanofabrication method enabling the creation of Au NP patterns on a non-adhesive and cell repellent plasma-deposited poly(ethyleneoxide) (PEO-like) coating. The immobilization of Au NPs on PEO-like coatings does not require any prior chemical modifications. By varying the size and the concentration of the Au NPs it is possible to control the Au NP number and density, and the average inter-particle distance on the PEO-like coated surface with direct effects on the bio-functionality of the surface. These nanostructured surfaces have been tested for protein bio-recognition analysis and as a cell culture platform. The developed nanostructured platform has many potential applications in the field of protein-nanoparticle and cell-nanoparticle interaction studies, nanotoxicology and bioengineering.

In this paper, the authors have investigated the effects of different cleaning methods (centrifugation and dialysis) on the surface chemistry and composition of 15 nm sodium citrate stabilized gold nanoparticles. The nuclear magnetic resonance (NMR) results indicate that three centrifugation cycles are sufficient to remove most of the citrate molecules, while centrifuged liquid sedimentation and dynamic light scattering data reveal some degree of nanoparticle aggregation when three centrifugation cycles are exceeded. Regarding the dialysis procedure, NMR analysis demonstrated that after nine cleaning cycles, the citrate concentration is comparable to that measured after the first centrifugation (about 6 × 10−4 M) but with an increase in the dispersion polydispersivity index as determined by dynamic light scattering. X-ray photoelectron spectroscopy results support the NMR findings and revealed a major hydrocarbon contamination after the nanoparticles cleaning process. The impact of cleaning on surface fun...

Acute myeloid leukemia (AML) is a severe and often fatal systemic malignancy. Malignant cells are capable of escaping host immune surveillance by inactivating cytotoxic lymphoid cells. In this work we discovered a fundamental molecular pathway, which includes ligand-dependent activation of ectopically expressed latrophilin 1 and possibly other G-protein coupled receptors leading to increased translation and exocytosis of the immune receptor Tim-3 and its ligand galectin-9. This occurs in a protein kinase C and mTOR (mammalian target of rapamycin)-dependent manner. Tim-3 participates in galectin-9 secretion and is also released in a free soluble form. Galectin-9 impairs the anti-cancer activity of cytotoxic lymphoid cells including natural killer (NK) cells. Soluble Tim-3 prevents secretion of interleukin-2 (IL-2) required for the activation of cytotoxic lymphoid cells. These results were validated in ex vivo experiments using primary samples from AML patients. This pathway provides reliable targets for both highly specific diagnosis and immune therapy of AML.

This work presents the development and optimization of two fabrication methods that combine plasma polymerization and electron beam lithography techniques for producing chemical patterns at the sub-micro scale. The first method uses sacrificial resist as mask to produce the functionalization of the bioadhesive areas and the second method consists in the direct EBL writing of adhesive regions on a non-adhesive plasma deposited PEO-like film. The produced patterned surfaces exhibit high binding capacity as tested by Surface Plasmon Resonance Imaging with Human Serum Albumin. Furthermore, we show that adsorption on the structured surfaces is similar to that observed on a flat surface with a direct proportionality to the active area. This work shows the efficiency and suitability of the developed chemical patterning techniques and their high potential applicability for the study of protein surface interactions and miniaturized biosensing device development.

Diamond and diamond-like carbon (DLC) films possess a set of excellent physical and chemical properties which together with a high biocompatibility make them attractive candidates for a number of medical and biotechnological applications. In the current work thin ultrananocrystalline diamond (UNCD) and DLC films were comparatively investigated with respect to cell attachment and proliferation after different surface modifications. The UNCD films were prepared by microwave plasma enhanced chemical vapor deposition, the DLC films by pulsed laser deposition (PLD). The films were comprehensively characterized with respect to their basic properties, e.g. crystallinity, morphology, chemical bonding nature, etc. Afterwards the UNCD and DLC films were modified applying O2 or NH3/N2 plasmas and UV/O3 treatments to alter their surface termination. The surface composition of as-grown and modified samples was studied by X-ray photoelectron spectroscopy (XPS). Furthermore the films were characterized by contact angle measurements with water, formamide, 1-decanol and diiodomethane; from the results obtained the surface energy with its dispersive and polar components was calculated. The adhesion and proliferation of MG63 osteosarcoma cells on the different UNCD and DLC samples were assessed by measurement of the cell attachment efficiency and MTT assays. The determined cell densities were compared and correlated with the surface properties of as-deposited and modified UNCD and DLC films.

Ultraviolet (UV) radiation, temperature, and time can degrade proteins. Here, the authors show that gold nanoparticles significantly protect human serum albumin from denaturation when exposed to “stressing” conditions such as UV irradiation and sustained exposure in suboptimal conditions. In particular, the authors show that gold nanoparticles significantly reduce the decrease in secondary structure induced by UV irradiation or extended exposure to ambient temperature.

This multi-centre investigation explores the variability that results from using the power/flow rate ratio (W/F) to describe plasma treatment and plasma polymerization processes. Results from fourteen reactors of different design and spread across ten laboratories, showed that the chemistry of the treated and deposited polymer/plasma polymer films is highly variable between reactor systems, and that there was no clear pattern linking these variations to other properties of the reactor systems (e.g. pressure, volume, electrode configuration). Although W/FM provides a useful rule-of-thumb for process optimization within a single system, it does not provide sufficient information to enable the same plasma polymer to be produced on a different system.

Synchrotron radiation (SR) X-ray microscopy combined with X-ray fluorescence (XRF) microspectroscopy provides unique information that have pushed the frontiers of biological research, particularly when investigating intracellular mechanisms. This work reports an SR-XRF microspectroscopy investigation on the distribution and the potential toxicity of Fe2O3 and CoFe2O4 nanoparticles (NPs) in U87MG glioblastoma-astrocytoma cells. The U87MG cells exposed to NPs concentrations ranging from 5 to 250 µg/ml for 24 h were analyzed in order to monitor both morphological and chemical changes. The SR-XRF maps complemented with XRM absorption and phase contrast images have revealed different intracellular distribution patterns for the two nanoparticles types allowing different mechanism of toxicity to be deduced. Copyright © 2013 John Wiley & Sons, Ltd.

Characterisation of engineered nanomaterials (NMs) is of outmost importance for the assessment of the potential risks arising from their extensive use. NMs display indeed a large variety of physico-chemical properties that drastically affect their interaction with biological systems. Among them, hydrophobicity is an important property that is nevertheless only slightly covered by the current physico-chemical characterisation techniques. In this work, we developed a method for the direct characterisation of NM hydrophobicity. The determination of the nanomaterial hydrophobic character is carried out by the direct measurement of the affinity of the NMs for different collectors. Each collector is an engineered surface designed in order to present specific surface charge and hydrophobicity degrees. Being thus characterised by a combination of surface energy components, the collectors enable the NM immobilisation with surface coverage in relation to their hydrophobicity. The experimental results are explained by using the extended DLVO theory, which takes into account the hydrophobic forces acting between NMs and collectors. Graphical abstractDetermination of hydrophobicity character of nanomaterials by measuring their affinity to engineered surfaces. Electronic supplementary material The online version of this article (doi:10.1007/s11051-017-3804-z) contains supplementary material, which is available to authorized users.

We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) inter-laboratory study on the measurement of the shell thickness and chemistry of nanoparticle coatings. Peptide-coated gold particles were supplied to laboratories in two forms: a colloidal suspension in pure water and; particles dried onto a silicon wafer. Participants prepared and analyzed these samples using either X-ray photoelectron spectroscopy (XPS) or low energy ion scattering (LEIS). Careful data analysis revealed some significant sources of discrepancy, particularly for XPS. Degradation during transportation, storage or sample preparation resulted in a variability in thickness of 53 %. The calculation method chosen by XPS participants contributed a variability of 67 %. However, variability of 12 % was achieved for the samples deposited using a single method and by choosing photoelectron peaks that were not adversely affected by instrumental transmission effects. The study identified a need for more consistency in instrumental transmission functions and relative sensitivity factors, since this contributed a variability of 33 %. The results from the LEIS participants were more consistent, with variability of less than 10 % in thickness and this is mostly due to a common method of data analysis. The calculation was performed using a model developed for uniform, flat films and some participants employed a correction factor to account for the sample geometry, which appears warranted based upon a simulation of LEIS data from one of the participants and comparison to the XPS results.

The following work presents a simple, reliable and scalable seeding-growth methodology to prepare silica nanoparticles (SiO2 NPs) (20, 30, 50 and 80 nm) directly in aqueous phase, both as plain- as well as fluorescent-labeled silica. The amount of fluorescent label per particle remained constant regardless of size, which facilitates measurements in terms of number-based concentrations. SiO2 NPs in dispersion were functionalized with an epoxysilane, thus providing a flexible platform for the covalent linkage of wide variety of molecules under mild experimental conditions. This approach was validated with ethylenediamine, two different amino acids and three akylamines to generate a variety of surface modifications. Accurate characterization of particle size, size distributions, morphology and surface chemistry is provided, both for as-synthesized particles and after incubation in cell culture medium. The impact of physicochemical properties of SiO2 NPs was investigated with human alveolar basal epithelial cells (A549) such as the effect in cytotoxicity, cell internalization and membrane interaction.

We have investigated the stability of the surface termination of ultrananocrystalline diamond/amorphous carbon (UNCD/a-C) composite films after their modification with UV/O 3 treatments or NH 3 -containing plasmas. The films were prepared by microwave plasma chemical vapor deposition from CH 4 /N 2 mixtures and possess the H-termination typical for all CVD grown diamond films. The treatment with UV/O 3 or NH 3 /N 2 plasma resulted in a change of the surface termination as revealed by contact angle measurements and X-ray photoelectron spectroscopy (XPS). Both processes rendered the as-grown hydrophobic UNCD surface hydrophilic; the influence of the treatment time as well as that of the carrier gas (N 2 or Ar) for the plasma process were investigated. The main task of this investigation was to determine the stability of the surface termination with storage time and storage conditions and upon exposure to standard organic solvents, like acetone, ethanol and i-propanol. It was found that for the UV/O 3 treated UNCD surfaces the storage in air, and after NH 3 /N 2 plasma modification package under reduced pressure preserved to a great extent the achieved hydrophilic properties in a period up to three months. The changes that occur predominantly during the first days after the modification step were due mostly to interchange of surface groups with the ambient. Similar processes were observed after exposure of the UNCD surfaces to standard organic solvents.

Ultrananocrystalline diamond (UNCD) films have been deposited by microwave plasma chemical vapor deposition from 17% CH4/N2 mixtures. In order to change the original hydrogen termination of the UNCD surfaces, the films have subsequently been subjected either to the so-called UV/O3 treatment which leads to OH-terminated surfaces, or to NH3/N2 plasmas which introduces NH2 groups but also a certain amount of OH groups. These three types of surfaces have been characterized by X-ray photoelectron spectroscopy, contact angle and ζ-potential measurements. The contact angle measurements have shown that as-grown UNCD surfaces are highly hydrophobic but became highly hydrophilic after both treatments. The ζ-potential measurements revealed that the isoelectric point of the H-terminated as-grown surface is distinctively higher than that of either UV/O3 or NH3/N2 plasma treated surfaces. Finally, the interactions of these surfaces with neurons of the cockroach Leucophaea maderae have been investigated. These studies have shown that especially the two treated surfaces allow for a fast, strong attachment of these cells without compromising their viability and without changing their normal physiological responses. These results will be discussed in terms of those obtained with the different surface characterization techniques.

International audience; In this paper, we report a novel, efficient and versatile process to produce high concentrations of silver nanoprisms, while controlling their size (prism height) and size dispersity, using a "modified polyol process" (microwave-assisted process). If the formation of silver spherical particles, nanocubes or nanowires has already been reported using the classical polyol process (reduction of AgNO3 by ethylene glycol and in presence of PVP), here we show that the production of silver nanoprisms/nanoplates is possible by a careful choice in the process parameters and in particular in the reducing agent (ethylene glycol should be replaced by a reducing agent containing only one hydroxyl reducing group such as ethylene glycol monoalkyl ethers). The synthesis, characterization, the influence of parameters and the mechanism of formation are discussed in order to correlate the operational conditions with the shape and the dimension of the nanoparticles.

Functionalized polymeric surfaces have been intensively studied over the last two decades for their wide use in biomedical applications. Two main approaches are usually used to produce such surfaces by plasma-based techniques: the first one is a plasma modification of polymeric materials and the second one is a deposition of plasma polymer films. The plasma discharge allows several functional groups like hydroxy or aldehyde groups to be grafted to the surface, but most attention has been given to carboxylated and aminated surfaces. In particular, amino-rich surfaces are often used as a chemically reactive platforms for covalent immobilization of biomolecule although they can also interact with biological entities by electrostatic interactions at physiological pH. In the literature, two main approaches for the production of amino rich coatings can be found. The first one is based on plasma polymerization of monomers containing NH2 groups or mixture of NH3/hydrocarbon monomer in mild plasma conditions. Using such methods, NH2/C ratios up to 20% can be reached but the deposition rate is usually very low and the stability of the films in aqueous solution decreases with increasing amount of primary amines. A second possibility is a plasma treatment of polymeric surfaces in NH3 or N2/H2 plasma. Plasma treatment is usually a very fast process (several tens of seconds) with amino selectivity, denoted as NH2/N, up to 100%. On the other hand, the total amount of nitrogen on the surface is quite low and the surface density of primary amines, also denoted in the literature as ‘amine efficiency’ and expressed by the NH2/C ratio, typically does not exceed a few percent. In this work it was decided to combine these two approaches. In a first step, a nitrogen-rich film was deposited followed by a plasma post-treatment to enhance primary amine concentration. For the production of the nitrogen-rich film, RF magnetron sputtering of nylon 6.6 in a mixture of Ar and nitrogen was chosen, and the plasma Full Paper

The effect of the concentration of cobalt ferrite (CoFe 2 O 4 ) nanoparticles (NPs) on their intracellular location and distribution has been explored by synchrotron radiation X-ray and fluorescence microscopy (SR-XRF) monitoring the evolution of NPs elemental composition as well. In cells exposed to low concentrations of CoFe 2 O 4 NPs, the NPs preferentially segregate in the perinuclear region preserving their initial chemical content. At concentrations exceeding 500 μM the XRF spectra indicate the presence of Co and Fe also in the nuclear region, accompanied by sensible changes in the cellular morphology. The increase of the Co/Fe ratio measured in the nuclear compartment indicates that above certain concentrations the CoFe 2 O 4 NPs intracellular distribution could be accompanied by biodegradation resulting in Co accumulation in the nucleus.