Prólogo

SOLONESKI, S.; LARRAMENDY, M. L.

Nanomaterials. Toxicity and Risk Assessment

INTECH Publisher

Lugar: Rijeka; Año: 2015; p. 7 - 8

The nanoscience revolution started in the 1990s, with this emerging area of science having the potential to generate radical new products and processes. It has been estimated that production of nanomaterials will increase by 2020 to 25 times what it is today. Nanoparticles have dimensions ranging from 1 to 100 nanometers, and they present physicochemical characteristics and coatings that impart upon them unique electrical, thermal, mechanical, and imaging properties that make them highly attractive for applications within the commercial, pharmaceutical, medical, food packaging, cosmetics, household appliance, and environmental sectors. Today, the challenge to create awareness and gain acceptance of the use of nanomaterials in an extensive range of available products, including specifically those engineered for applications in human welfare, has issued serious public concern, mostly related to their use. Potential occupational and public exposure to nanomaterials will increase considerably due to the ability of nanoparticles to improve the quality and the performance of many daily consumer products as well as the development of medical therapies and tests that use nanoparticles. Now, they represent an imperative research target for discovering whether they represent a potential hazard to human health and the environment. In recent years, proactive multidisciplinary research initiatives have been established by regulatory institutions such as the U.S. Environmental Protection Agency, the National Institute of Environmental Health, and the International Agency of Research on Cancer, who are charged with the protection of human health and the environment, and ensuring that the employ of engineered nanotechnological products can occur without unreasonable harm to either. Concerns as to the risk of natural and anthropogenic nanomaterials on numerous parameters, such as physical and chemical properties, uptake, distribution, absorption, and interactions with organs, the immune system, and the environment, require that the adequacy of current toxicity bioassays for nanoscale materials be assessed to develop an effective approach for further evaluation of nanomaterial toxicity. Workers who use nanomaterials in research or in nanotechnology-related industries may be exposed to several nanoparticles through dermal contact, inhalation, or ingestion, depending upon how employees use and handle them. Occupational health risks associated with manufacturing and using nanomaterials are not yet clearly understood. Minimal information is currently available on dominant exposure routes, potential exposure levels, and material toxicity of nanoscale materials. Although the potential health effects of such exposure are not entirely understood at this time, research investigations indicate that at least some of these nanomaterials are biologically active and may readily penetrate intact human epithelium, and they have produced toxicological reactions in the lungs of exposed experimental animals. There is general recognition that the in vitro, in vivo, and in silico testing strategies and safety assessments currently in place can be used as well for nanomaterials as for any other chemicals to obtain relevant data to develop guidelines for regulating the exposure of nanomaterials in the environment. Research in the field of emerging nanomaterials and nanotechnologies is of increasing importance; most scientific databases reveal increasing numbers of publications such as books, papers, reviews, and even patents, and there is an increasing market share of nanotechnology products in the thousands of billon U.S. dollars worldwide. Furthermore, only the number of publications on the topic of nanomaterials has increased at an almost exponential rate since the early 1990s, reaching about 192,000 in the year 2014, as indicated by a search on the Scopus database. However, more efforts are clearly needed to improve the toxicity screening of the increasing number of nanomaterials.This book, NANOMATERIALS: TOXICITY AND RISK ASSESSMENT, comprising nine chapters, provides is a collection of current research and information on numerous advances on the toxicity and hazard aspects of nanomaterials, including theoretical and experimental approaches as well as nanotechnology applications in the field of medicine, pharmacology, and the manufacture of nanoscale materials. Based on the large number of nanomaterial applications, a careful understanding of the associated systemic and local toxicity is critically required. We aimed to compress information from a diversity of sources into a single volume. The first chapter includes details of the advances in the field of nanoparticle-mediated cancer treatment, with special attention devoted to the use of magnetite and silver nanoparticles. The second chapter is a comprehensive review of recent developments and an outline of future strategies for nanotechnology-based medicines requested by the National Cancer Institute, with special attention on in vivo and in vitro trial systems employing biocompatibility and immunological studies. The third chapter provides a good review summarizing the current literature dealing with the direct interaction of nanoparticles with human neutrophils as well as recent data showing the murine air pouch model of inflammation for evaluation of nanoparticle toxicity. The fourth and fifth chapters of this book provide, respectively, an in vitro chronic study on respiratory cells exposed to nanoparticles to study the physiologically relevant exposure of prolonged contact to nanoparticles by respiratory exposure and a detailed update of in vivo and in vitro methodologies in nanomaterial toxicity evaluation, focusing on different testing strategies currently in place to find the appropriate analysis methods and the cautions that should be taken in the design of experiments that will contribute to the better understanding of the mechanisms of nanomaterial toxicity. The sixth chapter provides an in vitro study employing single-walled carbon nanohorns for the estimation of several cytotoxic parameters on human liver cell lines, with special emphasis on the apoptosis mechanism observed in metabolically active liver-like HepG2 cells. The seventh chapter highlights the current progress in the genotoxicity evaluation of engineered nanomaterials with a focus on results from standard genotoxicity bioassays, possible mechanisms underlying the genotoxicity of engineered nanomaterials, the suitability of current genotoxicity bioassays for engineered nanomaterial evaluation, and the application of engineered nanomaterial genotoxicity data for risk assessment. The eighth chapter includes the advances in medical aspects related to the nanomaterial toxicity. Finally, the last chapter addresses investigations into the manufacture of several kinds of nanocomposites, e.g., gold nanoparticles, inorganic?organic hybrid composites, graphene oxide nanocomposites, and supramolecular gels via functionalized imide amphiphiles/binary mixtures, focusing on the potential perspective for the design and fabrication of new nanomaterials and nanocomposites. This book will serve as a textbook for the research community, academia, and the industry, and will provide up-to-date state-of-the-art information presented by recognized international experts in the field of the nanotoxicology. They have contributed to the publication of this book of high importance to researchers, scientists, engineers, and graduate students who make use of these different investigations to understand the hazard implications in the use of manufactured and natural nanomaterials. Finally, we expect that the information content in the present book will continue to meet the expectations and needs of all interested in the different aspects of human and environmental risk toxicities associated with exposure to nanomaterials. The publishing Web platform provided by the publisher InTech is gratefully acknowledged.