Special Issue "Nanotoxicology"

Guest Editor
Prof. Dr. David Sheehan
Proteomic Research Laboratory, Department of Biochemistry, University College Cork, Western Gateway Building, Western Rd, Cork, Ireland
Website: http://www.ucc.ie/ucc/depts/biochemistry/staff/dsheehan.html
E-Mail: d.sheehan@ucc.ie
Phone: +35 321 420 5424
Fax: +35 321 427 4034
Interests: enzymology and evolution of glutathione transferases; application of proteomics to study of oxidative stress; implications of reactive oxygen and nitrogen species for kidney function; environmental toxicology; nanomaterials as emerging toxicological threats

Dear Colleagues,

Nanomaterials are defined as possessing at least one dimension less than 100nm. These include naturally-occurring products of combustion processes (e.g. volcanic dust) and man-made (anthropogenic) engineered materials. At least part of the appeal of nanomaterials arises from the fact that even relatively inert materials have interesting and different chemical properties on the nanoscale compared to the same material on the macroscale. These properties depend partly on chemical composition but also on aspects of nanoparticle geometry such as surface area. There is growing concern that at least some nanomaterials can readily cross biobarriers such as skin, lung epithelium and the blood-brain barrier and, in this way, may pose an emerging toxic threat to human health. Remarkably little is known about the fate of nanomaterials in the environment and study of issues such as dose-response, routes of exposure and appropriate benchmark controls are in their infancy. In addition, nanomaterials can become coated with a “corona” of proteins which have the potential to confer biospecific recognition properties on them, perhaps facilitating their internalisation into cells or interaction with biological targets. Notwithstanding this, the technological application of nanomaterials (nanotechnology) is one of the fastest-growing areas of materials science and is making contributions to new medical devices, electronics, automobile manufacture and new paints/varnishes. There is a general perception that applications research in nanotechnology is outpacing research into the new field of nanotoxicology. This special issue will address this research need by bringing together research articles and reviews focusing on aspects of nanotoxicology such as the need for rigorous nanoparticle physicochemical characterisation, the question of defined dose and contribution of composition, size and geometry to toxicity in biological systems.

Prof. Dr. David Sheehan
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. International Journal of Molecular Sciences is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1600 CHF (Swiss Francs).

• nanoparticles
• nanomaterials
• nanotechnology
• nanotoxicology
• dose-response

Title: Cytotoxicity and Genotoxicity of the Iron Oxide (Magnetite) Nanoparticles in A549 cells
Authors: Masatoshi Watanabe ¹, Misao Yoneda ², Ayaka Morohashi ¹, Yoshihiro Hamanaka ¹, Daisuke Kurioka ¹, Taizo Shiraishi ², Kazuaki Kawai ³, Hiroshi Kasai ³, Yukari Totsuka ⁴ and Keiji Wakabayashi ⁵
Affiliations: ¹ Laboratory for Medical Engineering, Division of Materials and Chemical Engineering, Graduate School of Engineering, Yokohama National University, Yokohama, Japan; E-Mail: mawata@ynu.ac.jp (M.W.)
² Department of Pathologic Oncology, Institute of Molecular and Experimental Medicine, Mie University Graduate School of Medicine, Tsu, Japan
³ Department of Environmental Oncology, Institute of Individual Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan
⁴ Devision of Cancer Development System, National Cancer Center Research Institute, Tokyo, Japan
⁵ Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan
Abstract: Superparamagnetic nanoparticles (NPs) such as Fe₃O₄-based superparamagnetic NPs have been attractive for medical applications including magnetic resonance imaging, drug delivery and hyperthermia due to their unique magnetic properties and their ability to interact with various biomolecules of interest. To understand the molecular mechanisms of toxicity of these nanoparticles is not enough. One of the frequently exdiscussed mechanisms is the induction of oxidative damage of cellular constituents, either by the generation of reactive oxygen species (ROS) or by inactivation of antioxidant defense system. The purpose of this study was to investigate the cytotoxicity and genotoxicity of iron oxide (Magnetite) nanoparticles in human lung epithelial cells, A549. Iron oxide (magnetite) nanoparticles induced dose-dependent cytotoxicity in A549 cells demonstrated by Alamar Blue and LDH assays. Magnetite nanoparticles were also found to induce oxidative stress evidenced by generation of reactive oxygen species (ROS). Further, DNA damage was detected in A549 cells exposed with magnetite nanoparticles using the comet assay and by measuring 8-hydroxy-2'-deoxyguanosine levels. Quantitative real-time PCR analysis demonstrated that the level of mRNA expressions of hOGG1 and SOD1 among antioxidant enzyme-related and repair genes were significantly down-regulated. These suggest that magnetite nanoparticles induced cytotoxicity and genotoxicity in A549 cells through ROS generation.