Aquasomal drug delivery system: A special emphasis on the formulation techniques and applications / Sistema de administración de fármacos Aquasomal: Especial énfasis en las técnicas de formulación y aplicaciones

Introducción: Aquasome es un sistema portador de nanopartículas autoensamblado con tres capas. El sistema se compone de un núcleo sólido nanocristalino interno recubierto de oligómero polihidroxilado. Adsorbidas en la capa recubierta se encuentran moléculas de fármacos o compuestos bioquímicamente activos. El autoensamblaje en este sentido se refiere a la formación independiente de moléculas en patrones organizados, de larga duración y con enlaces no covalentes. nueva tecnología de administración de fármacos. El artículo aborda principalmente los procesos de formulación utilizados para crear nanoestructuras autoensambladas y sus diversas aplicaciones posibles. Método: En la búsqueda bibliográfica se utilizaron varias bases de datos en línea, incluidas Science Direct, Medline, Web of Science, Google Scholar y Scopus. Se realizaron búsquedas en los conjuntos de datos en busca de entradas de estudios hasta julio de 2023. El documento de revisión aborda especialmente muchos elementos de la formación de aquasomas por parte de varios investigadores que emplean métodos/técnicas modificadas como la coprecipitación, la autoprecipitación, la pulverización catódica, etc. También ilustra una variedad de campos de terapia en los que se ha reconocido que el aquasoma tiene una gran influencia, como el oxígeno y el transporte de extractos. Resultados: El núcleo sólido es responsable de brindar estabilidad estructural, mientras que el recubrimiento oligomérico es crucial para proteger contra la deshidratación y estabilizar las moléculas bioactivas. Este vehículo de administración de fármacos biodegradable a escala nanométrica muestra una tendencia a acumularse en el hígado y los músculos. La no modificación de la adsorción del fármaco en la superficie del aquasoma facilita una respuesta farmacológica rápida al permitir el reconocimiento sin obstrucciones del receptor en el sitio de acción. (AU)

Introduction: Aquasome is a self-assembled nanoparticulate carrier system with three layers. The system is made up of a polyhydroxy oligomer-coated inner nanocrystalline solid core. Adsorbed on the coated layer are drug mole-cules or biochemically active compounds. Self-assembly in this sense refers to the independent formation of mole-cules into organised, long-lasting, and non-covalently bonded patterns.This paper gives an overview of aquasome formation, covering structural properties, formulation methodologies, and the benefits and drawbacks of this novel drug delivery technology. The article primarily addresses the formulation processes used to create self-assembled nanostructures and their various possible applications.Method: Several online databases, including Science Direct, Medline, Web of Science, Google Scholar and Scopus, were used in the literature search. The datasets were searched for entries of studies up to July, 2023. The review paper especially addresses many elements of aquasome formation by various researchers employing methods/modified techniques such as co-precipitation, self-precipitation, sputtering, and and so forth. It also illustrates a variety of fields of therapy in which aquasome has been recognised to have a major influence, such as oxygen and extract carrier.Results: The solid core is responsible for providing structural stability, while the oligomeric coating is crucial for safeguarding against dehydration and stabilising the bioactive molecules. This biodegradable drug delivery vehicle at the nanoscale level exhibits a tendency to accumulate in the liver and muscles. The non-modification of drug adsorption onto the aquasome surface facilitates prompt pharmacological response by allowing unobstructed re-ceptor recognition at the action site. (AU)

Biosynthesis of gold nanoparticles by Penicillium rubens and catalytic detoxification of ochratoxin A and organic dye pollutants / Biosíntesis de nanopartículas de oro por Penicillium rubens y desintoxicación catalítica de ocratoxina A y contaminantes colorantes orgánicos

The environmental pollution caused by chemical dyes is a growing concern nowadays. Limitations of traditional methods opened the route for nanotechnology; owing to the versatile properties of nanomaterials, gold nanoparticles (AuNPs) became a potential strategy for different applications. In the present study, biosynthesis of gold nanoparticles (BioAuNPs) was carried out by reacting chloroauric acid (HAuCl4) with cell-free filtrate of Penicillium rubens sp. nov. NCIM 1937. The AuNPs were then characterized by UV–visible spectroscopy, HR-TEM, FTIR, and DLS analysis to further examine their efficacious biosynthesis and morphological properties including size, shape, and stability. The biogenic AuNPs are polydisperse in nature, with a mean size of 14.92 ± 5 nm. These AuNPs exhibited promising antimicrobial activity against Escherichia coli NCIM-2065, Bacillus subtilis NCIM-2010, and Penicillium verrucosum MTCC 4935. In vitro quantitative HPLC results revealed that BioAuNPs significantly inhibited the biosynthesis of ochratoxin A (OTA). Microbial fuel cells (MFCs) are intriguing for power generation and wastewater treatment since they can directly transform chemical energy stored in organic matter to electricity by extracellular electron transfer (EET) via membrane proteins. AuNPs also showed excellent potential for dye degradation of organic pollutants, viz., methylene blue (MB), phenol red (PR), bromothymol blue (BTB), Congo red (CR), and 4-nitrophenol (4-NP). All dye removal efficiencies were estimated and fitted to pseudo-first-order processes using kinetic rate constants (Ka).The present study reveals a simple, original, and eco-friendly method for the synthesis of multifunctional biogenic AuNPs that could be effective in OTA detoxification in food products and organic pollutant removal during wastewater treatment for a sustainable environment.(AU)

La Farmacia en pequeño: Aproximación al mundo de los nanomateriales en sus aplicaciones farmacéuticas / Small Pharmacy: Approach to the world of nanomaterials in their pharmaceutical applications

En las últimas décadas el desarrollo de resistencias bacterianas y sus implicaciones terapéuticas se ha convertido en una de las principales amenazas en la Salud Mundial. Se habla incluso de la aparición de una nueva “era postantibiótica” en la que el tratamiento antimicrobiano será inútil, dado el carácter multirresistente de numerosos microorganismos. La nanotecnología ha irrumpido con mucho éxito en el tratamiento de diversas enfermedades (principalmente el cáncer), llegando a una nueva concepción en los sistemas terapéuticos con un gran impacto tecnológico. En este sentido, este discurso se centra en el empleo de los nanomateriales en el tratamiento de la infección ósea mediante tres vertientes. Entre ellas las nanopartículas de sílice mesoporosa, capaces de dirigirse específicamente a las bacterias y/o al biofilm, liberar de manera controlada distintos fármacos, aumentando así su eficacia terapéutica y reduciendo los efectos secundarios. Sin duda, la nanotecnología parece tener un gran potencial para superar la problemática en el tratamiento de las infecciones y revolucionar tanto la prevención como el tratamiento de estas infecciones bacterianas, que serán discutidas en el discurso de ingreso. (AU)

In recent decades, the development of bacterial resistance and its therapeutic implications has become one of the main threats to global health. There is even talk of the emergence of a new “post-antibiotic era” in which antimicrobial treatment will be useless, given the multi-resistant nature of many microorganisms. Nanotechnology has broken with great success in the treatment of different diseases (mainly cancer), reaching a new conception in therapeutic systems with a great technological impact. In this sense, this talking focuses on the use of nanomaterials in the treatment of bone infection in three approaches. These include mesoporous silica nanoparticles, capable of specifically targeting bacteria and biofilm, releasing different drugs in a controlled manner, thus increasing their therapeutic efficacy and reducing side effects. Certainly, nanotechnology seems to have great potential to overcome the problem in the treatment of infections and revolutionise both the prevention and treatment of these bacterial infections, and these will be discussed in the introductory speech. (AU)

Legal aspects of nanotechnology vs. COVID 19 / Aspectos jurídicos de la nanotecnología frente a COVID 19

Despite the lack of specific regulatory guidelines, many nanomedicines are on the market and their number is growing steadily. These are mainly used in cancer therapy because they require persistent toxic compounds and the tumor landscape is very difficult, which hinders effective drug treatment. The lack of formal regulation of nanomedicines and the manufacture of nanomaterials for health-related applications is a worldwide problem. Inconsistency among differentgovernment agencies results in some nanomedicines being classified as medicaldevices and others as drugs. Therefore, a global consortium for nanomaterialsregulation should be formed to advance these agendas and issue formal guidance to the research communities. Currently, in the context of nanomaterials in the European Union, we are dealing with both binding legal acts and non-binding legal acts, such as recommendations on the fair conduct of scientific research or on the application of a uniform definition of nanomaterials.

A pesar de la falta de directrices regulatorias específicas, encontramos en el mercado un número creciente de nanomedicinas. Se utilizan, sobre todo, en la terapia del cáncer, ya que requieren compuestos tóxicos persistentes y el paisaje tumoral es muy difícil, lo que dificulta un tratamiento farmacológico eficaz. La falta de regulación oficial de los nanomedicamentos y la fabricación de nanomateriales para aplicaciones relacionadas con la salud es un problema mundial. La incoherencia entre las distintas agencias gubernamentales hace que algunas nanomedicinas se clasifiquen como dispositivos médicos y otras como fármacos. Por lo tanto, debería formarse un consorcio mundial para la regulación de los nanomateriales con el fin de avanzar en esta agenda y emitir orientaciones formales para las comunidades investigadoras. En la actualidad, en el contexto de los nanomateriales en la Unión Europea, encontramos tanto herramientas jurídicas vinculantes, como no vinculantes; tal es el caso de las recomendaciones sobre la adecuada realización de investigación científica o sobre la aplicación de una definición uniforme de los nanomateriales. (AU)

Grafeno y pulmón / Graphene and Lung

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[Translated article] Graphene and Lung / Grafeno y pulmón

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La Farmacia en pequeño: Aproximación al mundo de los nanomateriales en sus aplicaciones farmacéuticas / Small Pharmacy: Approach to the world of nanomaterials in their pharmaceutical applications

En las últimas décadas el desarrollo de resistencias bacterianas y sus implicaciones terapéuticas se ha convertido en una de las principales amenazas en la Salud Mundial. Se habla incluso de la aparición de una nueva "era postantibiótica" en la que el tratamiento antimicrobiano será inútil, dado el carácter multirresistente de numerosos microorganismos. La nanotecnología ha irrumpido con mucho éxito en el tratamiento de diversas enfermedades (principalmente el cáncer), llegando a una nueva concepción en los sistemas terapéuticos con un gran impacto tecnológico. En este sentido, este discurso se centra en el empleo de los nanomateriales en el tratamiento de la infección ósea mediante tres vertientes. Entre ellas las nanopartículas de sílice mesoporosa, capaces de dirigirse específicamente a las bacterias y/o al biofilm, liberar de manera controlada distintos fármacos, aumentando así su eficacia terapéutica y reduciendo los efectos secundarios. Sin duda, la nanotecnología parece tener un gran potencial para superar la problemática en el tratamiento de las infecciones y revolucionar tanto la prevención como el tratamiento de estas infecciones bacterianas, que serán discutidas en el discurso de ingreso

In recent decades, the development of bacterial resistance and its therapeutic implications has become one of the main threats to global health. There is even talk of the emergence of a new "post-antibiotic era" in which antimicrobial treatment will be useless, given the multi-resistant nature of many microorganisms. Nanotechnology has broken with great success in the treatment of different diseases (mainly cancer), reaching a new conception in therapeutic systems with a great technological impact. In this sense, this talking focuses on the use of nanomaterials in the treatment of bone infection in three approaches. These include mesoporous silica nanoparticles, capable of specifically targeting bacteria and biofilm, releasing different drugs in a controlled manner, thus increasing their therapeutic efficacy and reducing side effects. Certainly, nanotechnology seems to have great potential to overcome the problem in the treatment of infections and revolutionise both the prevention and treatment of these bacterial infections, and these will be discussed in the introductory speech

Nanotecnología e Inmunología: las dos caras de la moneda / No disponible

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Nanotecnología y seguridad alimentaria / Nanotechnology and food safety

La nanotecnología ofrece perspectivas muy interesantes para la industria alimentaria. Su utilización va en aumento debido a las ventajas que ofrecen las propiedades físicas y químicas de los nanomateriales, aunque su seguridad genera preocupación, sobre todo por el limitado conocimiento de sus efectos en la salud humana. Se ha revisado el estado actual de la nanotecnología, sus principales aplicaciones en el sector agroalimentario, los diferentes tipos de nanomateriales disponibles y su toxicidad, así como su riesgo y la legislación que les afecta. Se concluye que, con el fin de mantener un elevado nivel de seguridad alimentaria y de protección para la salud de los consumidores y del medioambiente, es preciso evaluar y gestionar adecuadamente los posibles riesgos que plantean estos nuevos tipos de materiales. Es por ello que las nuevas investigaciones deben ir ligadas a estudios de evaluación de riesgo de la aplicación de los nanomateriales en el sector agroalimentario

Nanotechnology offers very interesting perspectives for the food industry. Due to the benefits offered by the physical and chemical properties of nanomaterials, the use of these materials is increasing in the food industry. There is concern about the safety of nanomaterials, especially because of the limited knowledge about the effects of these materials on human health. A review of nanotechnology and its main applications in the food industry is carried out, including the different types of nanomaterials available, their toxicity, the risk assessments performed and the actual legal situation in Europe. It is concluded that, in order to maintain a high level of food safety and protect the health of consumers and environment, the potential risks of these new materials need to be properly evaluated and managed. Though, the research should be directed to develop risk assessment of the application of nanomaterials in the food industry

Nanomateriales: un acercamiento a lo básico / Nanomaterials: Being Closer to Basics

El término nanomaterial se refiere a una sustancia o conjunto de sustancias en la escala de los nanómetros donde los constituyentes son átomos y/o moléculas. Varios países comprometidos con iniciativas en nanotecnología ya han formulado una definición para nanomateriales, aunque aún no existe un amplio consenso frente a una única definición. Actualmente se debate sobre la conveniencia o no de contar con una definición consensuada y estandarizada a nivel global. Se puede argumentar que esta falta de consenso puede dificultar la tarea regulatoria y normativa, así como la búsqueda de acuerdos y estándares internacionales. En este trabajo, se realiza una revisión de las definiciones existentes sobre nanomateriales, su incorporación en la industria y los factores de riesgo por exposición ocupacional a estas entidades. Finalmente, se ofrecen algunas recomendaciones para adoptar criterios de evaluación del impacto de los nanomateriales en la salud humana y el medio ambiente

The concept of nanomaterial refers to a substance or group of substances on the nanometer scale where the components are atoms and/or molecules. Although there is not a broad consensus on a single definition of them yet, many countries committed to nanotechnology initiatives have already proposed a definition for nanomaterial. The need of a worldwide agreed and standardized definition is nowadays being discussed. It can be argued that this lack of consensus can obstruct the regulatory and normative enforcement, as well as the search for agreements and international standards. In this paper, a review is made based on the existing definitions of nanomaterial, their incorporation into the industry and the risk factors for occupational exposure to these agents. Finally, some recommendations are given in order to adopt criteria for evaluating the impact of nanomaterials on human health and the environment

Suturas funcionalizadas con nanomateriales para cirugía oral: revisión sistemática / Sutures functionalised with nanomaterials for oral surgery. A systematic review

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Predicted environmental concentration of engineering nanomaterials as emerging pollutants: baseline scenario / Predicción de la concentración ambiental de los nanomateriales de ingeniería como contaminantes emergentes: escenario de referencia

Nanotechnology is one of the fastest growing and most promising technologies in our society. Due to its potential to develop new added value products, a growing number of engineered nanomaterials (ENMs) are already available on the market. However, in contrast to their benefits, there is an on-going debate about their potential adverse effects on human health and the environment. Such rapid proliferation however entails a crucial environmental problem due to an expected increase of the concentration of ENMs in the environment. The current concentration of ENMs remains unknown and poorly researched. In addition, toxicological studies pointed out adverse effects on key species and communities. Activities supporting the characterization of the concentration of ENMs in the environment will improve the protection of the environment. This paper conducte a thorough review of current data on the concentration of ENMs in the environment, demonstrating the presence of ENMs in freshwater, where quantities above 76 µg/L were estimated in peer reviewed publications

La nanotecnología es una de las tecnologías de más rápido crecimiento y más prometedoras de nuestra sociedad. Debido a su potencial para desarrollar nuevos productos de valor agregado, un número creciente de nanomateriales de ingeniería (ENM) ya están disponibles en el mercado. No obstante, a diferencia de sus beneficios, hay un debate en curso sobre sus posibles efectos adversos en la salud humana y el medio ambiente. Esta rápida proliferación, sin embargo, conlleva un crucial problema ambiental debido al aumento esperado de la concentración de ENMs en el medio ambiente. La concentración actual de ENMs sigue siendo desconocida y poco investigada. Además, los estudios toxicológicos señalaron efectos adversos en especies clave y comunidades. Las actividades que apoyan la caracterización de la concentración de ENMs en el medio ambiente mejorarán la protección del medio ambiente. Este artículo realizó una revisión exhaustiva de los datos actuales sobre la concentración de ENMs en el medio ambiente, demostrando la presencia de ENMs en agua dulce,donde se estimaron cantidades superiores a 76 µg/L en publicaciones revisadas por pares

Nanocurcumin accords protection against acute hypobaric hypoxia induced lung injury in rats

Decline in oxygen availability experienced under hypobaric hypoxia (HH) mediates imbalance in lung fluid clearance and is a causative agent of acute lung injury. Here, we investigate the pathological events behind acute HH mediated lung injury and assess the therapeutic efficacy of nanocurcumin in its amelioration. We assess the protective efficacy of nanotized curcumin (nanocurcumin) in ameliorating HH induced lung injury and compare to curcumin. Rats exposed to acute HH (6, 12, 24, 48 and 72 h) were subjected to histopathology, blood-gas analysis and clinical biochemistry, cytokine response and redox damage. HH induced lung injury was analysed using markers of lung injury due to pulmonary vasoconstriction (ET-1/2/3 and endothelin receptors A and B) and trans-vascular fluid balance mediator (Na+/K+ ATPase). The protective efficacy of nanocurcumin was analysed by examination of Akt/Erk signalling cascade by western blot. HH induced lung injury was associated with discrete changes in blood analytes, differential circulatory cytokine response and severe pulmonary redox damages. Up-regulation of ET-1/2/3 and its receptors along with down-regulation of Na+/K+ ATPase confirmed defective pulmonary fluid clearance which promoted edema formation. Nanocurcumin treatment prevented lung edema formation and restored expression levels of ET-1/2/3 and its receptors while restoring the blood analytes, circulatory cytokines and pulmonary redox status better than curcumin. Modulation in Akt/Erk signalling pathway in rat lungs under HH confirmed the protective efficacy of nanocurcumin (AU)

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Genotoxicidad de los nanomateriales, grandes discrepancias y desafíos / Genotoxicity of nanomaterials, discrepancies and challenges

La nanotecnología es el estudio, diseño, creación, síntesis, manipulación y aplicación de materiales a través del control de la materia a escala nanométrica, entre 1 a 100 nanómetros. Se considera que la nanoteconología está revolucionando nuestro mundo. Los nanomateriales son ampliamente utilizados en diferentes campos por sus propiedades únicas pero también pueden causar efectos adversos tanto para la salud humana como para el ambiente, por lo que es necesario conocer los riesgos y los factores que incrementan estos efectos adversos. En esta revisión abordamos los nanomateriales y sus tipos, los aspectos tóxicos con énfasis en el efecto genotóxico, ya que por sus implicaciones de daños en el ADN pueden iniciar y promover la carcinogénesis, o afectar la fertilidad, ciertas consideraciones que deben tomarse en cuenta en el momento de la evaluación genotóxica de los NMs. Aunque existe cierta evidencia de alteraciones al exponer las células a los nanomateriales, todavía existen deficiencias e inconsistencias en la literatura y en las normativas para conocer las características físico-químicas de los nanomateriales, cómo actúan, y sus posibles cambios con el tiempo (AU)

Nanotechnology is the study, design, creation, synthesis, manipulation and application of materials through the control of matter at the nanometer scale, between 1-100 nanometers. Nanotechnology is revolutionizing our world. Nanomaterials are widely used in various fields thanks to their unique properties. However, nanomaterials can also result in adverse health effects and the environment, it is necessary to know the risks and factors that increase these effects. In this review we focus on nanomaterials and their types, the toxic aspects of nanoparticles; with emphasis on the genotoxic effects and DNA damage that can initiate or promote carcinogenesis or affect fertility as well as the guidelines for the application of genotoxicity tests. Although there is some evidence of changes that occur when cells are exposed to nanomaterials, there is still a dearth of consistent results in the literature and in regulatory documents in terms of physicochemical characteristics of nanomaterials, their mechanisms, and exposure (AU)

Repair of bone defect by nano-modified white mineral trioxide aggregates in rabbit: A histopathological study

BACKGROUND: Many researchers have tried to enhance materials functions in different aspects of science using nano-modification method, and in many cases the results have been encouraging. To evaluate the histopathological responses of the micro-/nano-size cement-type biomaterials derived from calcium silicate-based composition with addition of nano tricalcium aluminate (3CaO.Al2 O3 ) on bone healing response. MATERIAL AND METHODS: Ninety mature male rabbits were anesthetized and a bone defect was created in the right mandible. The rabbits were divided into three groups, which were in turn subdivided into five subgroups with six animals each based on the defect filled by: white mineral trioxide aggregate (WMTA), Nano-WMTA, WMTA without 3CaO.Al2 O3 , Nano-WMTA with 2% Nano-3CaO.Al2 O3 , and empty as control. Twenty, forty and sixty days postoperatively the animals were sacrificed and the right mandibles were removed for histopathological evaluations. Kruskal-Wallis test with post-hoc comparisons based on the LSMeans procedure was used for data analysis. RESULTS: All the experimental materials provoked a moderate to severe inflammatory reaction, which significantly differed from the control group (p< 0.05). Statistical analysis of bone formation and bone regeneration data showed significant differences between groups at 40- and 60- day intervals in all groups. Absence of 3CaO.Al2 O3 leads to more inflammation and foreign body reaction than other groups in all time intervals. CONCLUSIONS: Both powder nano-modification and addition of 2% Nano-3CaO.Al2 O3 to calcium silicate-based cement enhanced the favorable tissue response and osteogenesis properties of WMTA based materials

Riesgos para la salud y recomendaciones en el manejo de nanopartículas en entornos laborales / Health risks and recommendations on handling nanoparticles at workplaces

El incremento de la producción de nanomateriales en estos últimos años ha originado la aparición de patologías, frecuentemente pulmonares, asociadas a la exposición a nanopartículas (NPs), ya sean liberadas de forma natural o en procesos industriales. Estas pueden penetrar sobre todo por el sistema respiratorio y depositarse en los alvéolos, difundiéndose a través del sistema circulatorio hasta alcanzar diversos órganos, induciendo enfermedades. El principal mecanismo involucrado en la aparición de patología está relacionado con la producción de radicales libres e interferencia de las NPs con el metabolismo celular. Es necesario desarrollar mayor número de estudios orientados a determinar posibles efectos nocivos sobre la salud y herramientas que permitan establecer valores límites fiables, tanto para las exposiciones laborales como para la población general. Actualmente se utilizan modelos simplificados de evaluación cualitativa para evaluación de riegos, tanto inespecíficos para nanomateriales (ConsExpo) como específicos (herramientas de control banding). Las recomendaciones y medidas preventivas establecidas para la manipulación y gestión de residuos de sustancias químicas, humos y aerosoles, se presentan útiles en el manejo de nanopartículas

The increasing production of nanomaterials in recent years has led to the appearance of pathologies, often lung diseases, associated with the exposure to nanoparticles (NPs), released naturally or during industrial processes. These ones can penetrate the respiratory system and deposit in the alveoli. Thus they spread through the circulatory system and reach various organs, inducing diseases. The main mechanism involved in the pathology appearance is related to the production of free radicals and interference of NPs with cell metabolism. It is necessary to develop more studies aimed to determine possible adverse health effects as well as tools for establishing reliable limit’s values for both occupational and general population exposure. Currently, simplified models of qualitative risk evaluation are used, both non-specific for nanomaterials (ConsExpo) as well as specific (control banding tools). The recommendations and preventive measures established for handling and managing chemical waste, fumes, aerosols and sprays, appear to be helpful in handling nanoparticles

Basis for the toxicological evaluation of engineered nanomaterials / Bases para la evaluación toxicológica de los nanomateriales manufacturados

The increasing annual production of nanomaterials enhances the human and environmental exposure, as well as the possible impact on public concern. In order to regulate the production, international organizations such as the Organization for Economic Cooperation and Development (OECD) and the European Comission through the REACH regulation have established some measures to assess its health and environmental safety. This review tries to analyze these proposed measures according to the standard test used in toxicology, the different classification of nanomaterials and the main mechanisms of toxicity known for nanomaterials. Resulting from this analysis, it is considered convenient to continue the development of specific tests for nanomaterial evaluation, as the measures established by the organizations of reference are not enough to establish standard basis for testing nanomaterials. This is mainly due to the huge diversity of manufactured nanomaterials and the importance of its handling, techniques and experimental systems chosen in the toxicity results (AU)

El aumento de producción anual de nanomateriales eleva la exposición humana y ambiental, y tiene un posible impacto en la opinión pública. Con el fin de reglamentar esta producción, organizaciones internacionales como la Organización para la Cooperación y Desarrollo Económico (OECD) y la Comisión Europea a través de la reglamentación REACH han establecido algunas medidas para evaluar la seguridad para la salud y el medio ambiente de los nanomateriales. Esta revisión intenta analizar las medidas propuestas por estas instituciones de acuerdo con las pruebas estándar usadas en toxicología, las distintas clasificaciones de los nanomateriales y los principales mecanismos de toxicidad conocidos de los nanomateriales. Como resultado de este análisis se cree conveniente continuar desarrollando tests específicos para la evaluación de nanomateriales, ya que las medidas establecidas por las organizaciones de referencia no son suficientes para conseguir unas bases estándares para testar nanomateriales. En gran parte esto es debido a la gran diversidad de nanomateriales existentes y la importancia de la manipulación, técnicas y sistemas experimentales escogidos en los resultados de toxicidad (AU)

Informatic resources useful for the development of biomedical applications of nanomaterials and their toxicological evaluation / Recursos informáticos útiles en el desarrollo de aplicaciones biomédicas de nanomateriales y su evaluación toxicológica

The need for tools to process all the information generated in the field of nanotechnology has led to the development of a new discipline known as nanoinformatics. In the coming years, it is expected to have databases with information, not only on the physicochemical properties of nanomaterials, but also with information on the potential interactions with environment and biological systems, which will enable search for new biomedical applications of nanomaterials, without forgetting their toxicological aspects. In this review, various standardization resources, ontologies, databases, initiatives and partnerships that will help manage the information generated on nanomaterials are presented, especially those useful in biomedical research and the toxicology of nanomaterials. In addition, other complementary web resources are described with the aim of facilitating the process of self-learning and the development of curriculum contents of nanotechnology in higher education centers (AU)

La necesidad de herramientas informáticas para procesar toda la información generada en el ámbito de la nanotecnología ha originado el desarrollo de una nueva disciplina conocida como nanoinformática. En los próximos años es esperable poder disponer de bases de datos con información, no sólo de las propiedades físico-químicas de los nanomateriales, sino también con información de sus posibles interacciones con el medio ambiente y sistemas biológicos, lo que favorecerá la investigación de nuevas aplicaciones biomédicas de los nanomateriales, sin olvidar sus aspectos toxicológicos. En este artículo se presentan diversos recursos de estandarización, ontologías, bases de datos, iniciativas y colaboraciones que ayudan a gestionar la información generada sobre nanomateriales, especialmente orientados a favorecer la Investigación biomédica y la toxicología de los nanomateriales. Además, se presentan otros recursos web complementarios que facilitarán el proceso de autoaprendizaje y el desarrollo de contenidos curriculares en escuelas superiores y facultades, útiles en la formación de esta nueva disciplina, denominada nanotecnología (AU)

Effect of pH on compressive strength of some modification of mineral trioxide aggregate

Objectives: Recently, it was shown that NanoMTA improved the setting time and promoted a better hydration process which prevents washout and the dislodgment of this novel biomaterial in comparison with WTMA. This study analyzed the compressive strength of ProRoot WMTA (Dentsply), a NanoWMTA (Kamal Asgar Research Center), and Bioaggregate (Innovative Bioceramix) after its exposure to a range of environmental pH conditions during hydration. Study Design: After mixing the cements under aseptic condition and based on the manufacturers` recommendations, the cements were condensed with moderate force using plugger into 9 × 6 mm split molds. Each type of cement was then randomly divided into three groups (n=10). Specimens were exposed to environments with pH values of 4.4, 7.4, or 10.4 for 3 days. Cement pellets were compressed by using an Instron testing machine. Values were recorded and compared. Data were analyzed by using one-way analysis of variance and a post hoc Tukey's test. Results: After 3 days, the samples were solid when probed with an explorer before removing them from the molds. The greatest mean compressive strength 133.19±11.14 MPa was observed after exposure to a pH value of 10.4 for NanoWMTA. The values decreased to 111.41±8.26 MPa after exposure to a pH value of 4.4. Increasing of pH had a significant effect on the compressive strength of the groups (p<0.001). The mean compressive strength for the NanoWMTA was statistically higher than for ProRoot WMTA and Bioaggregate (p<0.001). Moreover, increasing of pH values had a significant effect on compressive strength of the experimental groups (p<0.001). Conclusion: The compressive strength of NanoWMTA was significantly higher than WMTA and Bioaggregate; the more acidic the environmental pH, the lower was the compressive strength (AU)

Nanostructural changes in dentine caused by endodontic irrigants

Objective: To study nanostructural dentinal changes produced by endodontic irrigants. Study Design: Experimental study. Nanoindentations were performed on peritubular (PD) and intertubular dentine (ID) with an atomic force microscopy. Stiffness and adhesion force were determined before and after application of 5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA). Normalized differences before and after treatment for stiffness and adhesion forces were calculated. A paired T-test was used to compare stiffnes and adhesion force before and after irrigants application. Results: After treatment with EDTA there was a 29.80% reduction in stiffness in ID and a 63.53% reduction in PD. Adhesion force was reduced by 21.22% and 8.21% respectively. After treatment with 5.25% NaOCI stiffness was reduced by 2.49% in ID and increased by 15.01% in PD. Adhesion force increased by 25.11% and 23.97% respectively. Conclusions: 17% EDTA reduced stiffness and adhesion force in ID and PD. Treatment with NaOCI at 5.25% had no significant effect on stiffness but did affect adhesion force in ID and PD (AU)