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Surface treatments that minimize biofouling in marine environments are of interest for a variety of applications such as environmental monitoring and aquaculture. We report on the effect of saccharide coatings on biomass accumulation at the surface of three materials that find applications in marine settings: stainless steel 316 (SS316), Nylon-6 (N-6), and poly(ether sulfone) (PES). Saccharides were immobilized via aryldiazonium chemistry; SS316 and N-6 samples were subjected to oxidative surface pretreatments prior to saccharide immobilization, whereas PES was modified via direct reaction of pristine surfaces with the aryldiazonium cations. Functionalization was confirmed by a combination of X-ray photoelectron spectroscopy, contact angle experiments, and fluorescence imaging of lectin–saccharide binding. Saccharide immobilization was found to increase surface hydrophilicity of all materials tested, while laboratory tests demonstrate that the saccharide coating results in reduced protein adsorption in the absence of specific protein–saccharide interactions. The performance of all three materials after modification with aryldiazonium saccharide films was tested in the field via immersion of modified coupons in coastal waters over a 20 day time period. Results from combined infrared spectroscopy, light microscopy, scanning electron and He-ion microscopy, and adenosine-triphosphate content assays show that the density of retained biomass at surfaces is significantly lower on carbohydrate modified samples with respect to unmodified controls. Therefore, functionalization and field test results suggest that carbohydrate aryldiazonium layers could find applications as fouling resistant coatings in marine environments.

The development and commercialization of direct methanol fuel cells (DMFCs) as energy conversion devices remains a challenge despite their advantages in terms of energy density and energy-conversion efficiency. The bottleneck for the development of DMFCs is mainly caused by the sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode of fuel cells, and the effect of the so-called methanol crossover in state-of-the-art Pt/C electrocatalysts. Herein, we report for the first time an easily scalable continuous flow method based on ultraspray pyrolysis (USP) for the preparation of Pt nanoparticles directly embedded on highly porous carbon spheres. A study on the effect that post-synthesis treatment procedures have on the level of graphitization and catalytic properties is described. Use of USP results in a substantial reduction of the final Pt content with respect to typical Pt/C electrocatalysts, while yielding also excellent durability and tolerance to methanol crossover under acidic conditions. These results demonstrate that the USP method reported herein is a good candidate for its use in the preparation of ORR catalysts in commercial applications.

Modification of carbon materials via incorporation of nitrogen has received much attention in recent years due to their performance as electrodes in applications ranging from electroanalysis to electrocatalysis for energy storage technologies. In this work we synthesized nitrogen-incorporated amorphous carbon thin film electrodes (a-C:N) with different degrees of nitrogenation via magnetron sputtering. Electrodes were characterized using a combination of spectroscopic and electrochemical methods, including X-ray photoelectron spectroscopy, ellipsometry, voltammetry, and impedance spectroscopy. Results indicate that low levels of nitrogenation yield carbon materials with narrow optical gaps and semimetallic character. These materials displayed fast electron-transfer kinetics to hexammine ruthenium(II)/(III), an outer-sphere redox couple that is sensitive to electronic properties near the Fermi level in the electrode material. Increasing levels of nitrogenation first decrease the metallic character of the e...

Polydimethylsiloxane (PDMS) is an extremely important and versatile polymeric material for biomedical and microfluidic devices due to a range of desirable properties. Control of the hydrophilicity of PDMS surfaces is of significant interest due to the potential for developing surfaces with tunable protein adsorption or cell adhesion properties. We report the formation of stable hydrophilic PDMS surfaces by covalent modification with glycans via aryldiazonium chemistry. The PDMS surface was modified by a two step-process including an activation of the PDMS surface, followed by reaction with aryldiazonium glycosides in aqueous solution. The functionalized PDMS was characterized by atomic force microscopy, infrared and X-ray photoelectron spectroscopy, water contact angle measurements and fluorescence microscopy. Our results demonstrate that glycans immobilized via this methodology have the dual function of imparting hydrophilicity and stabilizing the modified surface against hydrophobic recovery. Importantly, the presentation of thus immobilized glycosides makes them available to specific lectin-glycan binding interactions at the polymer-solution interface while, in the absence of specific binding interactions, leads to a reduction in albumin adsorption. This approach provides a novel and efficient route to stable hydrophilic PDMS surfaces with a broad range of applications.

This study evaluated the influence of ionic dissolution products of a novel Ca-enriched silicate bioactive glass compared to commercial available hydroxyapaptite samples (Endobonr) on cell activity and vascular endothelial growth factor (VEGF) release in vitro. Bone marrow stromal cells (ST-2) were cultivated with the supernatant of granules of different sizes and at different concentrations (0-1 wt/vol % of granules) for 48 h. In addition to in vitro studies, Ca-ion release from all as cell morphology observation revealed no cytotoxic effect of the released products from all tested materials. It was found that supernatants from granules in concentrations of 1 wt/vol %enhanced the VEGF release from ST2 cells, which is important as a marker of the vascularisation ability of the glass during the bone healing process.

Bacterial and fungal infections remain a major clinical challenge. Implant infections very often require complicated revision procedures that are troublesome to patients and costly to the healthcare system. Innovative approaches to tackle infections are urgently needed. We investigated the histological response of novel free P 2 O 5 glass-ceramic rods implanted in the jaws of beagle dogs. Due to the particular percolated morphology of this glass-ceramic, the dissolution of the rods in the animal body environment and the immature bone formation during the fourth months of implantation maintained the integrity of the glass-ceramic rod. No clinical signs of inflammation took place in any of the beagle dogs during the four months of implantation. This new glass-ceramic biomaterial with inherent bactericidal and fungicidal properties can be considered as an appealing candidate for bone tissue engineering., This work was supported by the Spanish Ministry of Science and Innovation (MICINN) under the projects MAT2012-38645. A.P. Tomsia work was supported by the National Institutes of Health/National Institute of Dental and Craniofacial Research (NIH/NIDCR) Grant No. 1R01DE015633.

This paper reports the fabrication, microstructural characterization, mechanical properties and antimicrobial activity of scaffolds obtained from a soda-lime glass powder constituted by micro-spheres belonging to the SiO-NaO-AlO-CaO - BO system. Scaffolds with a porosity > 90% were fabricated using the foam replication method in the temperature range of 750-850 °C. The highest compressive strength value (0.2 MPa) was obtained for the scaffolds sintered at 850 °C. The observed mechanical properties were rationalized considering the scaffold singular microstructure of the struts constituted by a dense packing of microspheres ranging from 4 to 30 μm interlocked by nepheline needle-like crystals. The antimicrobial test was performed against three different microorganisms: Escherichia coli, Staphylococcus aureus and Candida krusei (yeast). A 45S5 Bioglass® scaffold was also tested for comparison. A window glass scaffold was used as control. In all cases a safe disinfection was obtained (reduction > 99.9% = log of reduction > 3). The antimicrobial activity was found to be similar to that of 45S5 Bioglass® based scaffolds. However, the soda-lime scaffold sintered at 850 °C exhibited a higher antimicrobial activity (log of reduction > 5 = reduction > 99.999%) against C. krusei, which is a microorganism resistant to multiples biocides, than the Bioglass® scaffold (log of reduction < 2 = reduction > 99.0%)., This work was supported by the Spanish Ministry of Science and Innovation (MICINN) and CSIC under the Projects MAT2012-38645 and 201360E012 respectively. Thanks are due to the Spanish Society of Implantology (SEI) for their support. Kai Zheng acknowledges the scholarship from China Scholarship Council (CSC, NO. 201206740003).

A biocompatible glassy coating with a high antimicrobial activity (>3 log of reduction) versus the gram-bacterium Escherichia coli has been obtained. The substrates are based on new zirconia ceramic matrix composites reinforced with biological tolerant metals (3Y-TZP/Ta and 3Y-TZP/Nb biocermets). Biocompatibility was studied using NIH-3T3-cells (mouse embryonic fibroblast) and >70% viability was found. These results open up the possibility of using these materials in large panoply in orthopaedics, dentistry and other hard tissue replacement applications where biofunctional, structural and antimicrobial properties are required., This work was supported by the Spanish Ministry of Science and Innovation (MICINN) under the project MAT2012-38645. A. Smirnov has been supported by JAE-Pre Program 2010.

The prevention and treatment of post-surgical infections is an ongoing concern. Post-surgical infections often cannot be treated with commercially available antibiotic-loaded bone cement as because higher doses of antibiotics are required. We describe here an approach to prevent implant infection through the use of glass coatings combined with silver nanoparticles deposited by sedimentation and heat-treated at 980 °C on titanium alloys. Silver is nontoxic to the human tissue and has been used as an anti-infective for centuries. The glass/silver coatings are composed of a soda-lime glassy matrix containing silver nanoparticles ranging from 2.6 to 20. wt.%. Optimum firing conditions have been determined for the fabrication of coatings that adhere well to the metal implant. These final coatings do not crack or delaminate. The biocidal activity of these coatings was also investigated. Coatings containing 20. wt.% of silver nanoparticles exhibited excellent biocidal activity (log η> 5) against Gram+, Gram- bacteria, and yeast after 24 h. © 2012 Elsevier Ltd., This work has been supported by ITMA (Asturias, Spain) under contract number 20102141, Spanish MICINN, MAT2009-14542-C02-01 and by the National Institutes of Health (NIH/NIDCR) under grant number 5R01 DE015633.

José S. Moya...et al., It is shown that soda-lime glass powders (d 4, versus Gram-positive and Gram-negative bacteria, and yeasts. First, the glass particles are attached to the cell membrane; then, the Ca2+ lixiviated from the glass particles surface brings about membrane depolarization and subsequent death of the cells.

4 páginas, 4 figuras, 1 tabla., Diatom-nAg composites containing 1 wt.% of metallic silver nanoparticles (≤ 20 nm) have been obtained by a colloidal route and chemical reduction. This nanostructured powder has proved to be a selective green inorganic biocide which reduces the starting concentrations of Escherichia coli and Micrococcus luteus cultures by at least 5 orders of magnitude, while completely inactive against yeast. Diatom-nAg can be considered as a selective inorganic biocide particularly suitable for the food and pharmacological sectors. The silver nanoparticles are released from the diatom surface to the liquid media in a controlled manner, reaching a concentration (< 11 ppm) far below the toxicity limit for human cells., The authors acknowledge the funding through Project PC07-21 and ITMA-CISC contract agreement reference Nb. 20091053. F.M. acknowledges funding from Spanish Project BIO2008-03683.

Silver doped glass powders have been obtained starting from vitellinate/nAg and montmorillonite/ nAg. These powders have shown a high biocide activity against the three different types of microorganisms studied: Escherichia coli (gram-negative bacteria), Micrococcus luteus (gram-positive-bacteria), and Issatchenkia orientalis (yeast). It was found that these glasses keep constant the silver concentration even below the cytotoxic limit. Therefore we interpret that silver doped glasses play the role of dosing devices.

6 páginas.-- El pdf del artículo es el manuscrito de autor., Silver-hydroxyapatite nanocomposites containing 1 wt.% of metallic silver have been obtained by a colloidal chemical route and subsequent chemical reduction process. The silver nanoparticles are supported on the hydroxyapatite surface without a high degree of agglomeration. The bactericidal effect against common Gram-positive and Gram-negative bacteria, as well as antifungal activity against yeast have been investigated. The results indicated a high antimicrobial activity for E. coli, M. Luteus and I. Orientalis, so this material can be a promising antimicrobial biomaterial for implant and reconstructive surgery, among other applications.

This is an open access article distributed under the terms of the Creative Commons Attribution License.-- et al., [Objectives]: The aim of the present study is to evaluate, in a ligature-induced peri-implantitis model, the efficacy of three antimicrobial glassy coatings in the prevention of biofilm formation, intrasulcular bacterial growth and the resulting peri-implant bone loss. [Methods]: Mandibular premolars were bilaterally extracted from five beagle dogs. Four dental implants were inserted on each hemiarch. Eight weeks after, one control zirconia abutment and three with different bactericidal coatings (G1n-Ag, ZnO35, G3) were connected. After a plaque control period, bacterial accumulation was allowed and biofilm formation on abutments was observed by Scanning Electron Microscopy (SEM). Peri-implantitis was induced by cotton ligatures. Microbial samples and peri-implant crestal bone levels of all implant sites were obtained before, during and after the breakdown period. [Results]: During experimental induce peri-implantitis: colony forming units counts from intrasulcular microbial samples at implants with G1n-Ag coated abutment remained close to the basal inoculum; G3 and ZnO35 coatings showed similar low counts; and anaerobic bacterias counts at control abutments exhibited a logarithmic increase by more than 2. Bone loss during passive breakdown period was no statistically significant. Additional bone loss occurred during ligature-induce breakdown: 0.71 (SD 0.48) at G3 coating, 0.57 (SD 0.36) at ZnO35 coating, 0.74 (SD 0.47) at G1n-Ag coating, and 1.29 (SD 0.45) at control abutments; and statistically significant differences (p, This work was supported by the Spanish Ministry of Science and Innovation (MICINN) and The Spanish National Research Council (CSIC) under the projects MAT2012-38645 and 201360E012 respectively. B. Cabal acknowledges financial support from JAE-Doc program (CSIC, cofounded by FSE).

This is an open-access article distributed under the terms of the Creative Commons Attribution License., The aim of the present study was to evaluate bone loss at implants connected to abutments coated with a soda-lime glass containing silver nanoparticles, subjected to experimental peri-implantitis. Also the aging and erosion of the coating in mouth was studied. Five beagle dogs were used in the experiments. Three implants were placed in each mandible quadrant: in 2 of them, Glass/n-Ag coated abutments were connected to implant platform, 1 was covered with a Ti-mechanized abutment. Experimental peri-implantitis was induced in all implants after the submarginal placement of cotton ligatures, and three months after animals were euthanatized. Thickness and morphology of coating was studied in abutment cross-sections by SEM. Histology and histo-morphometric studies were carried on in undecalfied ground slides. After the induced peri-implantitis: 1.The abutment coating shown losing of thickness and cracking. 2. The histometry showed a significant less bone loss in the implants with glass/n-Ag coated abutments. A more symmetric cone of bone resorption was observed in the coated group. There were no significant differences in the peri-implantitis histological characteristics between both groups of implants. Within the limits of this in-vivo study, it could be affirmed that abutments coated with biocide soda-lime-glass-silver nanoparticles can reduce bone loss in experimental peri-implantitis. This achievement makes this coating a suggestive material to control peri-implantitis development and progression. © 2014 Martinez et al., This work was supported by the Spanish Ministry of Science and Innovation (MICINN) under the projects MAT2009-14542-C02-01 and MAT2012-38645. B. Cabal thanks the CSIC JAE-Doc Program for a postdoctoral contract.

This is an open access article distributed under the Creative Commons Attribution License.-- This article belongs to the Special Issue "Biologic Coatings for Orthopaedic Implant"., The present work presents new bactericidal coatings, based on two families of non-toxic, antimicrobial glasses belonging to B2O3-SiO2-Na2O-ZnO and SiO2-Na2O-Al2O3-CaO-B2O3 systems. Free of cracking, single layer direct coatings on different biomedical metallic substrates (titanium alloy, Nb, Ta, and stainless steel) have been developed. Thermal expansion mismatch was adjusted by changing glass composition of the glass type, as well as the firing atmosphere (air or Ar) according to the biomedical metallic substrates. Formation of bubbles in some of the glassy coatings has been rationalized considering the reactions that take place at the different metal/coating interfaces. All the obtained coatings were proven to be strongly antibacterial versus Escherichia coli (>4 log). © 2014 by the authors; licensee MDPI, Basel, Switzerland., This study has been supported by CSIC project reference number 201360E012 and by the Spanish Ministry of Science and Innovation MAT2012-38645. C. Prado and B. Cabal acknowledge financial support from JAE-Doc program (CSIC, cofounded by FSE)., We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License., In the attempt to find valid alternatives to classic antibiotics and in view of current limitations in the efficacy of antimicrobial-coated or loaded biomaterials, this work is focused on the development of a new glass-ceramic with antibacterial performance together with safe biocompatibility. This bactericidal glass-ceramic composed of combeite and nepheline crystals in a residual glassy matrix has been obtained using an antimicrobial soda-lime glass as a precursor. Its inhibitory effects on bacterial growth and biofilm formation were proved against five biofilm-producing reference strains. The biocompatibility tests by using mesenchymal stem cells derived from human bone indicate an excellent biocompatibility., This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under the projectMAT2012-38645, and by CSIC project ref. nu 201360E012. B. Cabal acknowledges financial support from JAE-Doc program (CSIC, cofounded by FSE).

A biocompatible soda-lime glass-ceramic in the SiO2-Na2O-Al2O3-CaO-B2O3 system containing combeite and nepheline as crystalline phases, has been obtained at 750°C by two different routes: (i) pressureless sintering and (ii) Spark Plasma Sintering. The SPS glass-ceramic showed a bending strength, Weibull modulus, and toughness similar values to the cortical human bone. This material had a fatigue limit slightly superior to cortical bone and at least two times higher than commercial dental glass-ceramics and dentine. The in vitro studies indicate that soda-lime glass-ceramic is fully biocompatible. The in vivo studies in beagle jaws showed that implanted SPS rods presented no inflammatory changes in soft tissues surrounding implants in any of the 10 different cases after four months implantation. The radiological analysis indicates no signs of osseointegration lack around implants. Moreover, the biocide activity of SPS glass-ceramic versus Escherichia coli, was found to be >4log indicating that it prevents implant infections. Because of this, the SPS new glass-ceramic is particularly promising for dental applications (inlay, crowns, etc). © 2014 Elsevier Ltd., This work was supported by the Spanish Ministry of Science and Innovation (MICINN) and CSIC under the Projects MAT2012-38645 and 201360E012 respectively.

In the present study we have studied the lixiviation kinetics of silver nanoparticles, as well as the solubility of a particulate system (, This study has been supported by CSIC project reference number 20136E012, the Spanish Ministry of Science and Innovation (MICINN) under the project MAT2012- 38645 and IPEN, Sao Paulo, Brazil.

A soda-lime glass with a strong biocide activity has been used to obtain titanium alloy and zircon oxide glass-ceramic coatings for dental applications. The mechanical stability, adherence to different substrates and the chemical stability in artificial saliva at 30 C have been studied. The biocide activity against a Gram-negative bacterium (Escherichia coli) has been determined. It has been proved that this biocide coating also promotes the precipitation of hydroxyapatite. © 2013 Elsevier B.V., This study has been supported by the CSIC Project Reference Number 201360E012 and by the Spanish Ministry of Science and Innovation MAT2012-38645.

Two types of antimicrobial glass fibers containing ZnO and CaO, with diameters ranging from tens of nanometers to 1 m, were successfully fabricated by a laser spinning technique. The antimicrobial performance was corroborated according to ISO 20743:2013, by using gram-negative (Escherichia coli) and gram-positive (Streptococcus oralis, Streptococcus mutans and Staphylococcus aureus) bacteria, and yeast (Candida krusei) (more than 3 logs of reduction). The metabolic activity and endosomal system of eukaryotic cells were not altered by using eluents of CaO glass submicrometric fibers and ZnO fibers at 1 : 10 dilution as cellular media (viability rates over 70%). A dental material was functionalized by embedding ZnO nanofibers above the percolation threshold (20% wt), creating a three-dimensional (3D) fiber network that added an antimicrobial profile. This new ZnO glass fiber composite is proved non-cytotoxic and preserved the antimicrobial effect after immersion in human saliva. This is the first time that a fiber-reinforced liner with strong antimicrobial-activity has been created to prevent secondary caries. The potential of developing new fiber-reinforced composites (FRCs) with antimicrobial properties opens up an extensive field of dental applications where most important diseases have an infectious origin.

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al., The objective of the present study is to evaluate bone loss at implant abutments coated with a soda-lime glass containing silver nanoparticles subjected to experimental peri-implantitis. Five beagle dogs were used in the experiments, 3 implants were installed in each quadrant of the mandibles. Glass/n-Ag coted abutments were connected to implant platform. Cotton floss ligatures were placed in a submarginal position around the abutment necks and the animals were subject to a diet which allowed plaque accumulation, and after 15 weeks the dogs were sacrificed. Radiographs of all implant sites were obtained at the beginning and at the end of the experimentally induced peri-implantitis. The radiographic examination indicated that significant amounts of additional bone loss occurred in implants without biocide coating, considering both absolute and relative values of bone loss. Percentages of additional bone loss observed in implants dressed with a biocide coated abutment were about 3 times lower (p, This work was supported by the Spanish Ministry of Science and Innovation under the project MAT2009-14542-C02-01 and Nanoker Research SL. BC thanks the Consejo Superior de Investigaciones Científicas JAE-Doc Program for a postdoctoral contract.

Gold monodispersed nanoparticles (smaller than 10 nm) have been embedded into sepiolite fibres and sintered by spark plasma sintering (SPS) in order to preserve their nanometre size. The optical properties of these nanoparticles have been measured showing the surface plasmon resonance. Plasmon absorption curves have been successfully fitted by using the quasistatic approximation for gold nanoparticles. It has been observed that the sintering process decreases the plasmon width. SPS sintered nanostructured compacts present large values of the non-linear third-order dielectric susceptibility related to the gold concentration. © 2009 Springer Science+Business Media, LLC., We would like to thank to the projects MAT 2006-10249-C02-01, PTR1995-0832-OP, TEC 2005-00074, and TEC 2008-01183 funded by the Spanish Ministry of Science and Innovation.

A new family of non-toxic biocides based on low melting point (1250°C) transparent glasses with high content of ZnO (15–40wt%) belonging to the miscibility region of the B2O3-SiO2-Na2O-ZnO system has been developed. These glasses have shown an excellent biocide activity (logarithmic reduction >3) against Gram- (E. coli), Gram+ (S. aureus) and yeast (C. krusei); they are chemically stable in different media (distilled water, sea-like water, LB and DMEN media) as well as biocompatible. The cytotoxicity was evaluated by the Neutral Red Uptake using NIH-3T3 (mouse embryonic fibroblast cells) and the cell viability was >80%. These new glasses can be considered in several and important applications in the field of inorganic non-toxic biocide agents such as medical implants, surgical equipment, protective apparels in hospitals, water purifications systems, food packaging, food storages or textiles., This study has been supported by Consejo Superior de Investigaciones Cientificas (CSIC) project reference number 201360E012 and by the Spanish Ministry of Science and Innovation MAT2012-38645. C. Prado and B. Cabal acknowledge financial support from JAE-Doc program (CSIC, cofounded by FSE).

The present work was focused on obtaining biocide coatings constituted by a glassy soda-lime matrix containing silver or copper nanoparticles on ceramic (alumina and zirconia based) substrates. Both glassy coatings showed a high biocide activity against Gram-, Gram+ bacteria and yeast, reducing cell numbers more than three logarithms. Silver nanoparticles had a significantly higher biocide activity than copper nanoparticles, since the lixiviation levels required to reduce cell numbers more than 3 logarithms was of almost 1-2 μg/cm 2 in the case of silver nanoparticles, and 10-15 μg/cm 2 for the copper nanoparticles., This work has been supported by Instituto Tecnológico de Materiales-Spanish National Research Council (ITMA-CSIC), (Asturias, Spain) under contract number 20102141 and by MAT2009-14542-C02-01.