1,049 research outputs found

    In vitro approaches to assess the hazard of nanomaterials

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    The rapid development of engineered nanomaterials demands for a fast and reliable assessment of their health hazard potential. A plethora of experimental approaches have been developed and are widely employed in conventional toxicological approaches. However, the specific properties of nanomaterials such as smaller size but larger surface area, and high catalytic reactivity and distinctive optical properties compared to their respective bulk entities, often disable a straightforward use of established in vitro approaches. Herein, we provide an overview of the current state-of the art nanomaterial hazard assessment strategies using in vitro approaches. This perspective has been developed based on a thorough review of over 200 studies employing such methods to assess the biological response upon exposure to a diverse array of nanomaterials. The majority of the studies under review has been, but not limited to, engaged in the European 7th Framework Programme for Research and Technological Development and published in the last five years. Based on the most widely used methods and/or the most relevant biological endpoints, we have provided some general recommendations on the use of the selected approaches which would the most closely mimic realistic exposure scenarios as well as enabling to yield fast, reliable and reproducible data on the nanomaterial-cell response in vitro. In addition, the applicability of the approaches to translate in vitro outcomes to leverage those of in vivo studies has been proposed. It is finally suggested that an improved comprehension of the approaches with its limitations used for nanomaterials' hazard assessment in vitro will improve the interpretation of the existing nanotoxicological data as well as underline the basic principles in understanding interactions of engineered nanomaterials at a cellular level; this all is imperative for their safe-by- design strategies, and should also enable subsequent regulatory approvals

    A Comparison of Skills Competency Test Scores Among Philippine-educated Nursing Students After an Intensive Medical-surgical Course

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    Objective: This study examined the effect of a 10-week intensive medical-surgical course on ability to perform 16 common, acute care skills among Philippine educated nursing students seeking licensure in California. The aims of the study were to (1) determine competency in performing skills at the start of the medical-surgical course and (2) evaluate the effectiveness of the medical-surgical course in improving skill competency. Methods: Twenty-three Philippine educated nursing students participated in a 4-hour skills competency test procedure that involved 4 patient care stations and 16 common acute care skills. During the last week of the 10-week medical-surgical course that included 24 open simulation lab practice hours, these same 23 students repeated the testing procedure. Results: At the start of the course skill competency scores were low with many of the participants unable to complete the skills stations. A significant improvement occurred in scores for 14 of the 16 skills when tested in the final week of the medical-surgical nursing course under the same conditions (p \u3c .05). Conclusions: Conducting the nursing skills competency testing procedure at the start of the course informed faculty about the abilities of Philippine educated nursing student participants. Because of potential differences in nursing education abroad, graduates of nursing programs in the Philippines might benefit from competency testing to evaluate initial skill levels, followed by intensive review of commonly performed nursing skills in the United States, if warranted by initial results

    Nanofibers: Friend or Foe?

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    Since the early 1990s nanofibers, particularly those of a carbonaceous content [1] have received heightened interest due to their advantageous physico-chemical characteristics (e.g., high strength, stiffness, semi-conductor, increased thermal conductivity and one of the highest Young’s modulus [2]).[...

    Diesel exhaust: current knowledge of adverse effects and underlying cellular mechanisms

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    Diesel engine emissions are among the most prevalent anthropogenic pollutants worldwide, and with the growing popularity of diesel-fueled engines in the private transportation sector, they are becoming increasingly widespread in densely populated urban regions. However, a large number of toxicological studies clearly show that diesel engine emissions profoundly affect human health. Thus the interest in the molecular and cellular mechanisms underlying these effects is large, especially concerning the nature of the components of diesel exhaust responsible for the effects and how they could be eliminated from the exhaust. This review describes the fundamental properties of diesel exhaust as well as the human respiratory tract and concludes that adverse health effects of diesel exhaust not only emerge from its chemical composition, but also from the interplay between its physical properties, the physiological and cellular properties, and function of the human respiratory tract. Furthermore, the primary molecular and cellular mechanisms triggered by diesel exhaust exposure, as well as the fundamentals of the methods for toxicological testing of diesel exhaust toxicity, are described. The key aspects of adverse effects induced by diesel exhaust exposure described herein will be important for regulators to support or ban certain technologies or to legitimate incentives for the development of promising new technologies such as catalytic diesel particle filters

    Quantifying nanoparticle cellular uptake: which method is best?

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    As the range of engineered nanoparticles (NPs) designed as specific carriers increases, for example for cell targeting and drug delivery, the question on how many NPs are interacting or are taken up by cells is becoming increasingly important for any potential biomedical application. On one hand, the delivered dose of such NPs to the targeted cells is a key parameter in the assessment of their efficiency to perform the desired action (e.g., deliver the therapeutic substance or induce a specific effect), on the other hand, the assessment of intracellular NPs is crucial also from the safety aspect as NPs might come unintentionally in contact by untargeted cells. Particularly from the regulative perspective, it is important that reproducible and reliable analytical methods for the intracellular quantification of NPs are available at an early stage in the development in order to correlate the cell burden of NPs with their possible effects at a cellular level

    Assessing meso- and microplastic pollution in the Ligurian and Tyrrhenian Seas

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    As the production of plastic products continues to increase, determining the fate of plastic waste in the environment is of high importance. Densely populated areas, such as Mediterranean coastlines, represent locations of high pollution risk for surrounding environments. Thus, this study aims to assess the abundance, size, and composition of floating meso- and microplastics collected during four weeks in 2018 in the Ligurian and Tyrrhenian Seas. The results show average meso- and microplastic particle concentrations of 28,376 ± 28,917 particles km−2, and an average mass of 268.61 ± 421.18 g km−2. The particle shape ratio was 65% fragments, 19% films, 10% lines, 4% foams, and 2% pellets. Microplastic particles comprised 65% of the sample. Analysis with attenuated total reflection Fourier transform infrared spectroscopy showed predominant polymer types included polyethylene, polypropylene, polystyrene, and polyamide. These data are an important starting point for long-term monitoring of plastic pollution levels within this region

    Nanomaterials and the human lung: what is known and what must be deciphered to realise their potential advantages?

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    Due to the constant expansion within the nanotechnology industry in the last decade, nanomaterials are omnipresent in society today. Nanotechnology-based products have numerous different applications ranging from electronic (e.g., advanced memory chips) to industrial (e.g., coatings or composites) to biomedical (e.g., drug delivery systems, diagnostics). Although these new nanomaterials can be found in many “everyday” products, their effects on the human body have still to be investigated in order to identify not only their risk, but also their potential benefits towards human health. Since the lung is commonly thought to be the main portal of entry into the human body for nanomaterials released within the environment, this review will attempt to summarise the current knowledge and understanding of how nanomaterials interact with the respiratory tract. Furthermore, the advantages and disadvantages of different experimental model systems that are commonly used to study this exposure route to the human body will be discussed

    A rapid screening method to evaluate the impact of nanoparticles on macrophages

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    Nanotechnology is an emerging and highly promising field to develop new approaches for biomedical applications. There is however at present an unmet need for a rapid and universal method to screen nanoparticles (NP) for immunocompatibility at early stages of their development. Indeed, although many types of highly diverse NP are currently under investigation, their interaction with immune cells remains fairly unpredictable. Macrophages which are professional phagocytic cells are believed to be among the first cell types that take up NP, mediating inflammation and thus immunological responses. The present work describes a highly reproducible screening method to study the NP interaction with macrophages. Three essential questions are answered in parallel, in a single multiwell plate: Are the NP taken up by macrophages? Do the NP cause macrophage cell death? Do the NP induce inflammatory reactions? This assay is proposed as a standardized screening protocol to obtain a rapid overview of the impact of different types of NP on macrophages. Due to high reproducibility, this method also allows quality control assessment for such aspects as immune-activating contaminants and batch-to-batch variability
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