New strategies to fight bacterial adhesion

Initial adhesion of bacteria to biomaterials' surface is assumed to be an important stage in their colonization which may to lead to severe infections and loss of medical devices. Thus, the knowledge of how these microorganisms adhere and which factors affect this phenomenon proves to be of great importance in order to avoid their colonization. Hydrophobicity, charge, roughness and chemical composition of surfaces can rule the adhesion process. A better understanding of all these features is crucial for an effective microorganism’s adhesion control. In this context, it is possible to modify the biomaterials’ surfaces through coatings doped with an antimicrobial agent, in order to prevent biofilm formation. So, this mini-review gives a brief account of aspects involved in bacterial attachment to a surface, highlighting the interactions involved and presenting mechanisms that are being used to fight pathogens adhesion. For this intent, hydrophobicity, morphology and topography of doped silver coatings will be exploited as a new approach for the development of antibacterial surfaces

The Territorial Agenda 2030: Towards a common language? A review of a conceptual framework

The Territorial Agenda 2030 aims to provide multi-level strategic orientation to increase cohesion and overcome the 21st century pressing challenges. In multilingual contexts, the ideas and concepts communicated in such agendas must be clear and well-defined. In our study, we conducted a content analysis of the concepts of environment, inequality, justice, sustainability, territory and transition in contrast with former versions of this agenda. We found that, since 1983, the Territorial Agenda conceptual framework changed significantly in its meaning and semantic universe of reference.info:eu-repo/semantics/publishedVersio

Street space allocation – new tools and methods, with a Lisbon application [Full paper]

The allocation of space to different uses in busy city streets is a complex and conten-tious process. Decisions to reallocate streetspace are usually based on public consulta-tion and modelling of a few street redesign options, but results are not compared sys-tematically. In addition, the set of options considered is usually incomplete. This paper proposes a new process for streetspace reallocation, including option generation (with online and physical tools), estimation of performance indicators (with microsimula-tion), and comparison of options (with a new appraisal tool). The process was applied to the redesign of a busy street in Lisbon. Several options were generated, all involving reducing the space allocated to general motorised traffic. Microsimulation showed that allocating more space to some street uses also bring benefits to other uses. The option to allocate more space to both bus users and pedestrians does not deteriorate move-ment by other modes. However, appraisal showed that some redesign options go against technical/design standards or political priorities

PVD-grown antibacterial Ag-TiN films on piezoelectric PVDF substrates for sensor applications

This work reports on Ti1-xAgx and Ag-TiNx electrodes deposited by dc/pulsed dc magnetron sputtering at room temperature on poly (vinylidene fluoride) (PVDF) with the purpose to develop sensors for prosthesis. In Ti1-xAgx electrodes, silver content was varied from 0 to 100 at.%; and for Ag-TiNx electrodes, the nitrogen content was varied between 34 to 43 at.% and the Ti/Ag ratio changed from 12.2 to 5.2. The antibacterial activity of the samples was assessed by agar diffusion method. Interestingly, samples from the Ag-TiNx series presented antibacterial activity, in contrast to the samples from Ti1-xAgx series. XPS results showed that the as-deposited samples from the Ag-TiNx series exhibited silver clusters smaller than 4 nm. In order to deepen the results obtained, samples were analysed after the Halo test (antibacterial test), and XPS analyses showed the disappearance of these Ag clusters in agreement with the SEM results, which displayed a visible aggregation and a significant decrease in the number of Ag clusters, suggesting that silver nanoparticles aggregated and diffused through the agar killing bacteria or inhibiting their grown in the vicinity. All results show that Ag-TiNx electrodes are more promising candidates to be used in PVDF sensor protection than Ti1-xAgx electrodesS. M. Marques gratefully acknowledges the funding from the Portuguese National funds through the FCT - Fundacao para a Ciencia e a Tecnologia, (project SFRH/BD/71259/2010). Also, the authors thank the support of FEDER through the COMPETE Programme and of the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PEST-C/FIS/UI607/2014 and the project Matepro-Optimizing Materials and Processes, ref. NORTE-07-0124-FEDER-000037", co-funded by the "Programa Operacional Regional do Norte" (ON.2 - O Novo Norte), under the "Quadro de Referencia Estrategico Nacional" (QREN), through the "Fundo Europeu de Desenvolvimento Regional" (FEDER).The authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes", REF. NORTE-07-0124-FEDER-000028 co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER.The authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the Project "BioHealth Biotechnology and Bioengineering approaches to improve health quality", Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER.The authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the Project "BioEnv Biotechnology and Bioengineering for a sustainable world", REF. NORTE-07-0124-FEDER-000048, co-funded by the Programa Operacional Regional do Norte (ON.2 0 Novo Norte), QREN, FEDER

A life cycle stakeholder management framework for enhanced collaboration between stakeholders with competing interests

This is a postprint version of the Book Chapter. Information regarding the official publication is available from the link below - Copyright @ 2011 SpringerImplementation of a Life Cycle Sustainability Management (LCSM) strategy can involve significant challenges because of competing or conflicting objectives between stakeholders. These differences may, if not identified and managed, hinder successful adoption of sustainability initiatives. This article proposes a conceptual framework for stakeholder management in a LCSM context. The framework identifies the key sustainability stakeholder groups and suggests strategic ambiguity as a management tool to harness dysfunctional conflict into constructive collaboration. The framework is of practical value as it can be used as a guideline by managers who wish to improve collaboration with stakeholders along the supply chain. The article also fills a gap in the academic literature where there is only limited research on sustainability stakeholder management through strategic ambiguity

Influence of Au on antibacterial activity of Ag-TiCN coatings

The increasing demand for sustainable products requires the development of new knowledge-based materials with advanced properties. These products are then expected to: last longer, have a better performance, be safe, and be more efficient. These requirements, gain particular importance when dealing with applications involving the human body: the so-called biomaterials. Thus, the main aim of these investigations is to contribute to the development of new biomaterials that are able to prevent biofilm formation, since those complex microbial communities are responsible for the undesired reactions such as inflammation and infection, and consequently medical devices rejection. This work reports the development of Ag-TiCN coatings doped with gold. One series of samples was prepared by DC reactive magnetron sputtering using two targets, Ti and Ti+Ag, in an Ar + C2H2 + N2 atmosphere. Silver pellets were placed in the erosion area of Ti target in order to obtain a silver content up to 10 at. %. A second series of samples was deposited with the same conditions but with the Ti target doped with one Au piece. Extended physical, chemical and structural characterization such as the study of composition, grain size and texture phase evolution, phase composition, film surface topography and morphology, will be achieved resorting to surface analysis techniques, such as, Electron Probe Microanalysis (EPMA), X-ray diffraction (XRD), Atomic Force Microscopy (AFM), scanning electron microscopy (SEM-EDS). The galvanic couple formed between gold and silver, accelerates silver ion release and should provide more pronounced antibacterial activity. Staphylococcus epidermidis was selected to study coatings' antibacterial activity, and fibroblasts were used to test the cytotoxicity. Bacteria adhesion and biofilm formation on coatings were assessed by crystal violet staining, which quantifies total amount of biomass. Animal cell (fibroblasts) death was determined by MTS assay

Electrochemical vs antibacterial characterization of ZrCN-Ag coatings

Nowadays, antibacterial properties are becoming a viable feature to be introduced in biomaterials due to the possibility of modifying the materials' surface used in medical devices in a micro/nano metric scale. As a result, it is mandatory to understand the mechanisms of the antimicrobial agents currently used and their possible failures. In this work, the antibacterial activity of ZrCNAg films is studied, taking into consideration the ability of silver nanoparticles to be dissolved when embedded into a ceramic matrix. The study focuses on the silver release evaluated by glow discharge optical emission spectroscopy and the effect of the fluid composition on this release. The results revealed a very low silver release of the films, leading to non-antibacterial activity of such materials. The silver release was found to be dependent on the electrolyte composition. NaCl (8.9 g L? 1) showed the lowest spontaneously silver ionization, while introducing the sulfates in Hanks' balanced salt solution (HBSS) such ionization is increased; finally, the proteins incorporated to the (HBSS) showed a reduction of the silver release, which also explains the low ionization in the culture medium (tryptic soy broth) that contains high quantities of proteins.This research is partially sponsored by the FEDER funds through the program COMPETE - Programa Operacional Factores de Competitividade and by the Portuguese national funds through FCT-Fundacao para a Ciencia e a Tecnologia, under the projects ANTIMICROBCOAT - PTDC/CTM/102853/2008 and in the framework of the Strategic Projects PEST-C/FIS/UI607/2011, PEST-C/EME/UI0285/2011 and SFRH/BD/80947/2011.This work has also been supported by the Ministerio de Ciencia e Innovacion of Spain through the Consolider-Ingenio 2010 Programme (CSD2008-00023) and through project RyC2007-0026

Development of Ag/TiO2NM-treated leathers with antibacterial activity for footwear industry

This work aims to contribute to the industrial development of safer and advanced leathers using nanomaterials (NMs) that are based in titanium oxide doped with silver (Ag-TiO2NMs). These NMs present an ecological alternative to volatile organic biocides and organic solvents, frequently used nowadays. Safe application of these NMs brings added value to footwear and leather products and reduces the bulk chemical wide pollution. These newly developed materials are expected to be useful for footwear manufacturing (for common or professional use) with advanced protection against bacteria and fungus, which are the most common cause of feet infections, for either common or professional use. Hence, the main aim of this work is the improvement of leather footwear in order to overcome the feet infections and ensure minimum risk of human skin penetration. In order to accomplish the main aim, the cytotoxicity, antimicrobial and self-cleaning properties of leather surface, treated with Ag-TiO2NMs by sputtering deposition were assessed. The Ag-TiO2 coatings were deposited onto leather substrates by DC-pulsed reactive magnetron sputtering using two targets, Ti and Ag, in an Ar + O2 atmosphere. Compositional analysis was achieved by X-ray energy dispersive spectrometry (EDX). Contact angle of the coatings was measured and the results show that with the introduction of silver in TiO2 microstructure promotea an increase in hydrophobicity. The antibacterial activity of the samples was assessed by agar diffusion method and the results point out to a silver antibacterial activity