Protocol for the high throughput Comet Assay. (A) Assembly of macrowell comet array. Agarose gel with microwells is sandwiched between a glass substrate and a bottomless 96-well plate and sealed with mechanical force. Approximately 300 arrayed microwells comprise the bottom of each macrowell. (B) Preparation of the nanoparticle suspension according to the protocol by Cohen at al. (C) Protocol for exposing the cells to the nanoparticles. (D) Loading of the exposed cell samples in the macrowells and running the microwell assay.
Nanomaterials are part of daily life. Although there is a wide range of methods to evaluate their potential toxic effects, there is no way to evaluate gene damage.
Scientists at Harvard University in the School of Public Health in collaboration with the research Group of Bevin P. Engelward at MIT, have developed a screening assay to detect the genotoxic potential of nanomaterials. Metal oxide nanoparticles in biological systems can generate reactive oxygen species, which can overwhelm innate antioxidant defenses and cause oxidative stress. Oxidative stress, among other factors, has been associated with DNA damage and mutations, precursors to cancer. As more and more commercial products contain nanomaterials consisting of metal oxides such as titanium dioxide and zinc oxide, screening assays such as these are crucial to reducing potential health hazards. Christa Watson, postdoctoral research fellow at HSPH, suggests that accurate toxicity assessments of nanomaterials before they are incorporated into consumer products can help us prevent similar consequences that we are currently facing from asbestos exposures such as mesothelioma. Current efforts are ongoing to understand the novel toxicities nanomaterials may pose on public safety. This research was recently published in ACS Nano February 14, 2014 DOI: 10.1021/nn404871p
ZnO is a widely used material in cosmetics and food applications. The ions however, that are leaching have been linked to potential adverse effects. In our center we developed a safer formulation concept to mitigate toxicity by encapsulating the materials in a thin layer of Silica.
One of the main constituents of sunscreen is the ZnO particles. ZnO nanoparticles are sought out for UV-filter applications thanks to their inherent optoelectronic properties and are, therefore, broadly used today in cosmetics and polymers. Preliminary toxicological data, however, point out that they can induce significant DNA damage and genotoxicity due to their Zn2+ ion leaching. It has become important for the nanotechnology industry, to devise scalable, safer-by-design approaches to minimize the ZnO nanoparticle dissolution and toxicity without altering their desired optoelectronic properties.
G. Sotiriou the lead author of the paper.
In their work, the researchers demonstrated a safer-by-design approach for ZnO nanorods using a scalable flame aerosol process. This technology allows for controlled synthesis of high-purity ZnO nanorods with highly crystalline core and a nanothin amorphous silica shell that improves their biocompatibility. The as-prepared nanorods exhibit high transparency in the visible range, but strong absorption in the UV rendering them suitable for use in sunscreens and polymers. Furthermore, it is demonstrated that the hermetic silica coating does not alter the desired optoelectronic properties of the core ZnO nanorods while their DNA damage potential has been 3-fold decreased.
You can read more at the Chemistry World news article or, directly the paper.
Please join us for our next meeting of the Massachusetts chapter of the New England Nanotechnology Association (NENA) to hear about some new developments in nanotechnology and nanotoxicology.
We’ll enjoy a continental breakfast, spend a little time networking, and hear about these new developments and other topics of interest. There is no cost to attend, so please RSVP today. Thank you and we look forward to seeing you soon.
8:30 – 9:00AM: Networking and refreshments
9:00 – 9:10AM: Welcome and introductions – William S. Rogers, Jr., Esq., Partner, Prince Lobel Tye LLP, Boston, MA
9:10-9:20AM: Speaker – Eric S. Howard, Corporate and Outreach Manager, NSF Center for High-rate Nanomanufacturing, Northeastern University, Boston, MA
9:20-9:35AM: Speaker – Philip Demokritou, Ph. D., Assoc. Professor and Director, Center for Nanotechnology and Nanotoxicology, Harvard School of Public Health, Cambridge, MA
9:35-9:45AM: Speaker – Joseph Brain, Ph.D., Cecil K. and Philip Drinker Professor of Environmental Physiology, Department of Environmental Health, Harvard School of Public Health, Cambridge, MA
9:45-10:00: Networking and adjourn
Click here to RSVP – deadline is 2/21/14
Can’t make the event? Join our LinkedIn Discussion Page.
We must have a complete list of attendees two days prior to the event in order to arrange visitor passes. No one can get in without a visitor’s pass.
If you have any questions, please don’t hesitate to contact me.
William S. Rogers, Jr.
Prince Lobel Tye LLP
New Challenges and Public Health Implications of Microbial Resistance to Biocidal Processes
Speaker: Dr. Gerald McDonnell, Vice President,
Research and Clinical Services Steris
Date: January 29, 2014
Time: 12:30-1:30 pm
Place: 665 Huntington Ave, Building 1, Room 1302, Boston, MA 02115
Abstract: The control of microorganisms and microbial growth is an important consideration in public health. This includes various disinfection and sterilization technologies that are used for the control of microorganisms on surfaces, in products/liquids or in air. These play important roles in our daily lives, including the provision of safe drinking water, production and preservation of products, use of medical devices, biosafety controls and decontamination of general surfaces. Various chemical (referred to as ‘biocides’) and physical inactivation methods are widely used to render surfaces and products safe. In most cases, the modes of action of these processes are quite distinct from the more specific mechanisms of action described for anti-infective agents such as antibiotics and antiviral agents. They generally demonstrate a much wider range of antimicrobial activity, corresponding with non-specific and varied modes of action. Despite these traditions, microbial control issues continue to challenge us. This presentation will discuss some recent examples of inactivation studies with viruses, bacteria, protozoa and prions (infectious proteins) that challenge our current definitions and expectations for disinfection/sterilization processes. These reports challenge our understanding of microbial resistance patterns and survival capabilities to established antimicrobial methods.
During their visit a delegation from Panasonic headed by Mr. Oketa continued their financial support to the Center of Nanotechnology and Nanotoxicology through a generous contribution to the Environmental Nanotechnology postdoctoral Fellowship.
The panasonic delegates that visited our center were Takemi Oketa, Mitsuhiro Sano and Yosuke Mizuyama.
In the image above Prof. Demokritou receives the gift from Mr. Oketa in front of Dr. Mizuyama, Pyrgiotakis and Mr. Sano.
Phil Demokritou et al. published recently a high impact paper at the Enviromental Science: Nano a new Journal from the Royal Society of Chemistry. Environmental Science: Nano covers the benefits and implications of nano-science and nanotechnology on environmental health and safety, and the sustainable design, development and use of nanotechnologies. This includes design, applications, life cycle implications, characterization in biological and environmental media, environmental and biological interactions and fate, transformations, transport, reactivity, biological uptake and ecotoxicity, and other areas of sustainable nanotechnology, such as interactions with pollutants and remediation of environmental contaminants by nanomaterials.
Our publication fits the objective of the journal and it was selected by the editors as the most innovative research article to decorate the cover of the first issue of the journal. You can find here the abstract of the paper and the link to the publisher. If you have access to the RSC you will be able to access the publications.
Abstract: Airborne pathogens are associated with the spread of infectious diseases and increased morbidity and mortality. Herein we present an emerging chemical free, nanotechnology-based method for airborne pathogen inactivation. This technique is based on transforming atmospheric water vapor into Engineered Water Nano-Structures (EWNS) via electrospray. The generated EWNS possess a unique set of physical, chemical, morphological and biological properties. Their average size is 25 nm and they contain reactive oxygen species (ROS) such as hydroxyl and superoxide radicals. In addition, EWNS are highly electrically charged (10 electrons per particle on average). A link between their electric charge and the reduction of their evaporation rate was illustrated resulting in an extended lifetime (over an hour) at room conditions. Furthermore, it was clearly demonstrated that the EWNS have the ability to interact with and inactivate airborne bacteria. Finally, inhaled EWNS were found to have minimal toxicological effects, as illustrated in an acute in-vivo inhalation study using a mouse model. In conclusion, this novel, chemical free, nanotechnology-based method has the potential to be used in the battle against airborne infectious diseases.
Dr. Jacqueline Isaacs
Department of Mechanical and Industrial Engineering Northeastern University, Boston, MA
Date: January 23, 2014
Place: 665 Huntington Ave,
Bldg 1, Room 1302,
Boston, MA 02115
Abstract: Responsible commercialization of nano-enabled products (NEPs) will encompass not only the successful development of economically viable manufacturing techniques, but also, a conscious and systematic consideration of short and long-term societal impacts to avoid unintended consequences. The US National Nanotechnology Initiative has urged for more effective use of life cycle analysis (LCA) in decision-making, which in turn demands greater consideration of the ethical, legal, and social impacts (ELSI) of nanomanufacturing as it scales to commercial production. As part of its mission to establish novel directed self-assembly processes and techniques for continuous and scalable nanomanufacturing, the NSF Nanoscale Science and Engineering Center for High-rate Nanomanufacturing (CHN at Northeastern University, the University of Massachusetts Lowell and the University of New Hampshire) is developing three CNT applications that will soon move to large-scale production: electromagnetic interference (EMI) shielding, batteries, and chemical- and bio- sensors. Our current research (involving researchers from NU, UML and Yale) leverages CHN’s technical efforts by developing knowledge about life cycle impacts of CNT-enabled products – from manufacturing, through use and end-of-life. Worker safety is considered during manufacture and at product disposal in light of the uncertain hazards of CNTs. Process economics that include various levels of protection are explored. Recycled nanomaterials are explored for technical viability. Exposure assessments during end-of-life processing offer options to avoid exposures. Policy issues for responsible, sustainable development of nano-enabled products are also concurrently assessed.