Surface disinfections: present and future

The propagation of antibiotic resistance increases the chances of major infections for patients during hospitalization and the spread of health related diseases. Therefore finding new and effective solutions to prevent the proliferation of pathogenic microorganisms is critical, in order to protect hospital environment, such as the surfaces of biomedical devices. Modern nanotechnology has proven to be an effective countermeasure to tackle the threat of infections. On this note, recent scientific breakthroughs have demonstrated that antimicrobial nanomaterials are effective in preventing pathogens from developing resistance. Despite the ability to destroy a great deal of bacteria and control the outbreak of infections, nanomaterials present many other advantages. Moreover, it is unlikely for nanomaterials to develop resistance due to their multiple and simultaneous bactericidal mechanisms. In recent years, science has explored more complex antimicrobial coatings and nanomaterials based on graphene have shown great potential in antibacterial treatment. The purpose of this article is to deepen the discussion on the threat of infections related to surface disinfection and to assess the state of the art and potential solutions, with specific focus on disinfection procedures using nanomaterials

Antimicrobial activity of carbon-based fillers

Diplomová práce se zabývá vlivem uhlíkatého plniva na životaschopnost a produkci extracelulárních látek vybrané bakterie Bacillus subtilis (CCM 1999) a kvasinky Yarrowia lipolytica (CCY 29-26-52). Antimikrobiální aktivita těchto částic, přítomných v kultivačním mediu, byla sledována pomocí následujících parametrů: růst daného mikroorganismu, produkce extracelulárních proteinů a v poslední řadě byla monitorována produkce extracelulárních polymerních substancí, které mají úzkou souvislost s tvorbou biofilmu. Suspenze materiálů (0,135 mg/mL) byly připraveny ve dvou rozdílných kultivačních mediích; tzn. živné medium s obsahem glukózy pro Bacillus subtilis a bazální medium s přídavkem Tweenu 80 pro Yarrowia lipolytica, a media byla inokulována příslušným typem mikroorganismu. Experimenty probíhaly po dobu 6 dnů při rychlosti třepání 160 rpm a teplotě 30 °C pro Bacillus subtilis a 28 °C pro Yarrowia lipolytica. Testovány byly celkem tři typy uhlíkatého nanomateriálu, získané z Katedry anorganické chemie, Vysoké školy chemicko-technologické v Praze. Tyto materiály specifikované jako materiál “A”, “B” a “C” se navzájem lišily velikostí částic a stupněm oxidace. Na základě skríningových studií byla vybrána koncentrace testovaného materiálu 0,135 mg/mL a rychlost třepání 160 rpm. Metodou měření optické hustoty vzorku při 600 nm byly sestaveny a porovnány růstové křivky obou mikroorganismů v přítomnosti testovaných nanočástic po dobu 5 dní. Tímto způsobem bylo zjištěno, že přítomnost nanočástic v mediu nemá velký vliv na růst zkoumaného mikroorganismu. Tato metoda, je však pouze orientační, protože se nevyhneme chybě díky přítomnosti mrtvých buněk. Dále byla testována produkce celkových a extracelulárních proteinů daným mikroorganismem v přítomnosti testovaných nanočástic. Nebyla však pozorována výrazná odchylka hodnot od hodnot kontrolního vzorku, který neobsahoval testovaný materiál. Na základě metod počítání kolonií (Bacillus subtilis) a buněk (Yarrowia lipolytica) byly určeny ztráty životaschopnosti mikroorganismu ve 3 časech (6, 48 a 144 hodin); v kratším časovém intervalu byl růst spíše podporován. Dále byla monitorována produkce extracelulárních polymerních substancí (EPS), tedy proteinů, redukujících substancí a polysacharidů. Tyto látky byly vylučovány daným mikroorganismem do prostředí v průběhu 24 hodin. Bacillus subtilis produkoval EPS ve větší míře než Yarrowia lipolytica. Předpokládáme, že produkce EPS by mohla souviset s tvorbou biofilmu, který chrání buňky před toxicitou nanočástic.The aim of this diploma thesis is focused on the impact of carbon-based fillers on viability and extracellular substances production by bacterium Bacillus subtilis (CCM 1999) and yeast Yarrowia lipolytica (CCY 29-26-52). Antimicrobial activity of these particles, present in cultivation nutrient medium was examined using following parameters: growth of mentioned microorganisms, production of extracellular proteins and finally extracellular polymeric substances production, which is strongly connected with biofilm formation. Nanomaterials suspension (0.135 mg/mL) was prepared in two different cultivation media i.e. nutrient medium supplemented with glucose for Bacillus subtilis and basal medium with the addition of 2% (vol.) Tween 80 for Yarrowia lipolytica and media were inoculated by appropriate type of microorganism. Experiments were performed for 6 days under shaking rate at 160 rpm and at temperature of 30 °C for Bacillus subtilis and 28 °C for Yarrowia lipolytica. Three types of carbon nanomaterials obtained from Department of Inorganic Chemistry, Institute of Chemical Technology, Prague were examined. These materials specified as material “A”, “B” and “C” are mutually different by the size of its particles and the degree of oxidation. Based on the screening studies the tested material concentration of 0.135 mg/mL and shaking rate of 160 rpm were chosen. According to the optical density measurement at 600 nm, the growth curves of both microorganisms in the presence of tested nanoparticles during 5 days period were compared. It was find out, that the presence of nanoparticles don’t have a significant influence on tested microorganisms growth, by this technique. However, this method is just wider point of view, due to mistakes caused by presence of dead cells. Further, production of total cells proteins and extracellular proteins by microorganisms in presence of tested nanoparticles was examined. There was not observed any significant deviation from control samples values, where the tested materials were absent. Based on colony counting method (used for Bacillus subtilis) and cells counting in Bürker counting chamber (used for Yarrowia lipolytica), loss of microorganism viability was determined in 3 cultivation periods (6, 48 and 144 hours); there was observed a support of growth of microorganisms rather in shorter incubation period. Thereafter the extracellular polymeric substances (EPS) production that means proteins, reducing substances and polysaccharides was monitored. These substances were secreted into the medium by mentioned microorganisms during 24 hours of incubation. Bacillus subtilis cells produce much more EPS than Yarrowia lipolytica cells. We suppose that the EPS production could be closely associated with production of biofilm, which protects cells against nanoparticles toxicity.

Science and Technology Governance and Ethics - A Global Perspective from Europe, India and China

This book analyzes the possibilities for effective global governance of science in Europe, India and China. Authors from the three regions join forces to explore how ethical concerns over new technologies can be incorporated into global science and technology policies. The first chapter introduces the topic, offering a global perspective on embedding ethics in science and technology policy. Chapter Two compares the institutionalization of ethical debates in science, technology and innovation policy in three important regions: Europe, India and China. The third chapter explores public perceptions of science and technology in these same three regions. Chapter Four discusses public engagement in the governance of science and technology, and Chapter Five reviews science and technology governance and European values. The sixth chapter describes and analyzes values demonstrated in the constitution of the People’s Republic of China. Chapter Seven describes emerging evidence from India on the uses of science and technology for socio-economic development, and the quest for inclusive growth. In Chapter Eight, the authors propose a comparative framework for studying global ethics in science and technology. The following three chapters offer case studies and analysis of three emerging industries in India, China and Europe: new food technologies, nanotechnology and synthetic biology. Chapter 12 gathers all these threads for a comprehensive discussion on incorporating ethics into science and technology policy. The analysis is undertaken against the backdrop of different value systems and varying levels of public perception of risks and benefits. The book introduces a common analytical framework for the comparative discussion of ethics at the international level. The authors offer policy recommendations for effective collaboration among the three regions, to promote responsible governance in science and technology and a common analytical perspective in ethics

The multi-facets of sustainable nanotechnology : lessons from a nanosafety symposium

An international symposium for nanosafety was held recently at the Nanyang Technological University in Singapore. Topics relating to understanding nanomaterial properties, tools, and infrastructure required for predicting hazardous outcomes, measuring nanomaterial exposure levels, systems approach for risk assessment and public's perception of nanotechnology were covered. The need for a multidisciplinary approach, across both natural and social sciences, for developing sustainable nanotechnology solutions was heavily emphasized. This commentary highlights the major issues discussed and the commitment of the nanosafety research community in Singapore to contribute collectively to realise the vision of sustainable nanotechnology

Trust as Glue in Nanotechnology Governance Networks

This paper reflects on the change of relations among participants in nanotechnology governance through their participation in governance processes such as stakeholder dialogues. I show that policymaking in practice—that is, the practice of coming and working together in such stakeholder dialogues—has the potential for two-fold performative effects: it can contribute to the development of trust and mutual responsibility on the part of the involved actors, and it may bring about effects on the formation of boundaries of what is sayable and thinkable in nanotechnology governance. Three vignettes about the work of the German NanoKommission indicate the development of new relations of trust, recognition and mutual responsibility among actors. It is concluded that governance in practice can assemble new collectives in which relations of trust are the glue holding the complex structure together. While such a consensus-based progress may be favourable for smooth technology development, it can be considered problematic if evaluated against the ideals of deliberative democracy, which often form the premises on which public engagement is based. Stakeholder forums were set in place with the intention of including various actors, but this is Janus-faced: if a dialogue becomes encapsulated in new governance networks, new exclusions can arise. For example, a policing of which information is released to a wider audience can occur

Ethics, Nanotechnology and Elite Sport - The Need For A Precautionary Approach

Elite sport is a competitive industry, with athletes continuously striving for innovative ways to gain advantages over their competitors. The increasing impact of sport sciences over recent decades has contributed much to this ethos, and has recently been witnessed in the application of sports engineering, working to integrate new technologies in order to enhance levels of athletic performance and also athlete safety. The application of nanotechnology offers a sport engineer the potential to improve equipment used both in and out of competition. Nevertheless, despite its emerging integration into sports sciences, limited attention has been paid to the ethical impacts this technology may have on elite sport. To address this problem, an eclectic normative approach is pursued, allowing for the range of nanotechnological application to elite sport to be considered, in order to generate critical ethical evaluations in relation to its current and potential use within elite sport. The issues were framed variously through consequentialist and deontological analysis. Three nanotechnological case studies are presented, highlighting potential benefits and disbenefits that nanotechnology may present, and to additionally determine whether, and if so, what, deontologically framed regulatory action were required to govern its use within elite sport. The first case study considered nanotechnology's application to the sport of road cycling; the second considered nanotechnology's application to performance analysis; and the third considered nanotechnology's application to horse race betting. The analysis of the case studies revealed that nanotechnology presents a number of benefits for elite sport, such as improved levels of performance and enhanced safety; but also disbenefits, such as those relating to fairness and corruption. Despite this, it is argued that, at present, nanotechnology does not pose a significant risk to the integrity of sport. But in order to reduce any future risk, the disbenefits should be addressed. A case is consequently argued for the application of a weak version of the Precautionary Principle applied through an original ethical analytical tool, in order to govern the initial integration phase of nanotechnology. The work concludes by outlining more specific regulatory actions that could be taken in order to inform the development of a 'nano' specific regulatory framework, in order to govern nanotechnology's continued long term safe and ethical use within elite sport

Evaluation of existing control measures in reducing health and safety risks of engineered nanomaterials

While the risk management of engineered nanomaterials (ENMs) receives significant attention, there is still a limited understanding of how to select optimal risk management measures (RMMs) for controlling and mitigating the risks associated with exposure to ENMs. Clearly, there exists a need to expand current risk management practices to ensure safe production, handling and use of ENMs. Moreover, the performance of the existing RMMs should be re-evaluated for ENMs since control options that are proven to be effective for preventing or limiting risks associated with traditional particles might give unsatisfactory results in the case of nano-scale particles. This paper has brought together the evidence on the adequacy of traditional controls to minimize potential health and environmental risks resulting from exposure to ENMs. The aim here is to advance our understanding of the risk management approaches relevant for ENMs, and ultimately to support the selection of the most suitable RMMs when handling ENMs. To that end, evaluative evidence collected from the review of relevant literature and survey of nanotechnology institutions are combined and summarised to understand the level of protection offered by each control measure, as well as the relative costs of their implementation. The findings suggest that most relevant risk control options are based on isolating people from hazard through engineering measures (e.g. ventilation and chemical fume hoods) or personal protective equipment (PPE), rather than eliminating hazard at source (e.g. substitution). Although control measures related to the modification of ENMs have high efficiency in the occupational risk control hierarchy, they are not widely employed since there is currently a high degree of uncertainty regarding the impact of manipulating nano-characteristics on the performance of final product. Lastly, despite its low cost, PPE is the least effective category in the occupational risk control hierarchy and should not be used on its own when significant risk reduction is required. Clearly, further quantitative data is needed to fully assess the feasibility and cost-effectiveness of risk control options to prevent risks from exposure to ENMs. When there is little information on the efficiency of control measures specific to ENMs, the default efficiencies can be used for initial assessment purposes although it should not be considered exhaustive

Environmental and Societal Impact of Nanotechnology

The ability to measure, understand, manipulate, organize, engineer and control matter on the nanoscale has been opening up the wealth of possibilities that were otherwise non - existent at higher scales. At this scale, basic research principles and tools in biology, physics, chemistry, and engineering converge and have led to all-inclusive applications of nanotechnology. Despite the innovative applications and promising potentials of nanotechnology, there are concerns about its short and long-lasting impacts on humans, nature and the environment. In an attempt to address these concerns, a number of researches have been conducted. Evaluations of studies addressing the issues of nanotechnologies and their impacts are necessary to give insights for further studies that will advance the technology for the true benefit of mankind and nature. This study, thus, provides a detailed review of studies on nanotechnology applications and the positions of stakeholders on the impact of nanotechnology. Among other things, the outcome of this survey shows that there are numerous successful applications of nanotechnology. Public perceptions are pivotal in determining the extent of revolution and transformation that nanotechnology will have on the environment. Religious beliefs and moral concerns; trust in governmental regulatory agencies and the industry; the level of inclusion of the society in the product design, development, and commercialization process is critical to the extent of acceptance of nanotechnology inventions. Expression of objective views concerning the benefits, limitations & risks, and adequate education of the public, risk regulators & all stakeholders are crucial in determining the fate of nanotechnolog

Nanoparticles in wastewaters: hazards, fate and remediation

The increasing use of nanoparticleswill inevitably result in their release into the aquatic environment and thereby cause the exposure of living organisms. Due to their larger surface area, high ratio of particle number tomass, enhanced chemical reactivity, and potential for easier penetration of cells, nanoparticles may be more toxic than larger particles of the same substance. Some researchers have been showing some relations between nanoparticles and certain diseases. However, the doses, surface shapes, material toxicity and persistence of nanoparticles may all be factors in determining harmful biological effects. In order to better evaluate their risks, potential exposure route of nanoparticles has to be taken into consideration aswell. Finally, a brief summary of techniques for nanoparticle removal inwaters andwastewaters is presented, but it seems that no treatment can absolutely protect the public from exposure to a large-scale dissemination of nanomaterials