Category Archives: nanotechnology

Identifying minute amounts of nanomaterial in environmental samples

It’s been a while since I’ve had a story from one of Germany’s Franhaufer Institutes. Their stories are usually focused on research that’s about to commercialized but that’s not the case this time according to an April 28, 2016 news item on Nanowerk,

It is still unclear what the impact is on humans, animals and plants of synthetic nanomaterials released into the environment or used in products. It’s very difficult to detect these nanomaterials in the environment since the concentrations are so low and the particles so small. Now the partners in the NanoUmwelt project have developed a method that is capable of identifying even minute amounts of nanomaterials in environmental samples.

An April 28, 2016 Fraunhofer Institute press release, which originated the news item, provides more detail about the technology and about the NanoUmwelt project along with a touch of whimsy,

Tiny dwarves keep our mattresses clean, repair damage to our teeth, stop eggs sticking to our pans, and extend the shelf life of our food. We are talking about nanomaterials – “nano” comes from the Greek word for “dwarf”. These particles are just a few billionths of a meter small, and they are used in a wide range of consumer products. However, up to now the impact of these materials on the environment has been largely unknown, and information is lacking on the concentrations and forms in which they are present there. “It’s true that many laboratory studies have examined the effect of nanomaterials on human and animal cells. To date, though, it hasn’t been possible to detect very small amounts in environmental samples,” says Dr. Yvonne Kohl from the Fraunhofer Institute for Biomedical Engineering IBMT in Sulzbach.

A millionth of a milligram per liter 

That is precisely the objective of the NanoUmwelt project. The interdisciplinary project team is made up of eco- and human toxicologists, physicists, chemists and biologists, and they have just managed to take their first major step forward in achieving their goal: they have developed a method for testing a variety of environmental samples such as river water, animal tissue, or human urine and blood that can detect nanomaterials at a concentration level of nanogram per liter (ppb – parts per billion). That is equivalent to half a sugar cube in the volume of water contained in 1,000 competition swimming pools. Using the new method, it is now possible to detect not just large amounts of nanomaterials in clear fluids, as was previously the case, but also very few particles in complex substance mixtures such as human blood or soil samples. The approach is based on field-flow fractionation (FFF), which can be used to separate complex heterogeneous mixtures of fluids and particles into their component parts – while simultaneously sorting the key components by size. This is achieved by the combination of a controlled flow of fluid and a physical separation field, which acts perpendicularly on the flowing suspension.

For the detection process to work, environmental samples have to be appropriately processed. The team from Fraunhofer IBMT’s Bioprocessing & Bioanalytics Department prepared river water, human urine, and fish tissue to be fit for the FFF device. “We prepare the samples with special enzymes. In this process, we have to make sure that the nanomaterials are not destroyed or changed. This allows us to detect the real amounts and forms of the nanomaterials in the environment,” explains Kohl. The scientists have special expertise when it comes to providing, processing and storing human tissue samples. Fraunhofer IBMT has been running the “German Environmental Specimen Bank (ESB) – Human Samples”since January 2012 on behalf of Germany’s Environment Agency (UBA). Each year the research institute collects blood and urine samples from 120 volunteers in four cities in Germany. Individual samples are a valuable tool for mapping the trends over time of human exposure to pollutants. ”In addition, blood and urine samples have been donated for the NanoUmwelt project and put into cryostorage at Fraunhofer IBMT. We used these samples to develop our new detection method,” says Dr. Dominik Lermen, manager of the working group on Biomonitoring & Cryobanks at Fraunhofer IBMT. After approval by the UBA, some of the human samples in the ESB archive may also be examined using the new method.

Developing new cell culture models

Nanomaterials end up in the environment via different pathways, inter alia the sewage system. Human beings and animals presumably absorb them through biological barriers such as the lung or intestine. The project team is simulating these processes in petri dishes in order to understand how nanomaterials are transported across these barriers. “It’s a very complex process involving an extremely wide range of cells and layers of tissue,” explains Kohl. The researchers replicate the processes in a way as realistic as possible. They do this by, for instance, measuring the electrical flows within the barriers to determine the functionality of these barriers – or by simulating lung-air interaction using clouds of artificial fog. In the first phase of the NanoUmwelt project, the IBMT team succeeded in developing several cell culture models for the transport of nanomaterials across biological barriers. IBMT worked together with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME, which used pluripotent stem cells to develop a model for investigating cardiotoxicity. Empa, the Swiss partner in the project, delivered a placental barrier model for studying the transport of nanomaterials between mother and child.

Next, the partners want to use their method to measure the concentrations of nanoparticles in a wide variety of environmental samples. They will then analyze the results obtained so as to be in a better position to assess the behavior of nanomaterials in the environment and their potential danger for humans, animals, and the environment. “Our next goal is to detect particles in even smaller quantities,” says Kohl. To achieve this, the scientists are planning to use special filters to remove distracting elements from the environmental samples, and they are looking forward to develop new processing techniques.
NanoUmwelt – the objective

The NanoUmwelt research project was launched in October 2014 and will last for 36 months. Its objective is to develop methods for detecting minute amounts of nanomaterials in environmental samples. Using this information, the project partners will assess the effect of nanomaterials on humans, animals, and the environment. They are focusing on commercially significant, slowly degradable, metallic (silver, titanium dioxide), carbonic (carbon nanotubes) and polymer-based (polystyrene) nanomaterials.

http://www.nanopartikel.info/projekte/laufende-projekte/nanoumwelt

NanoUmwelt – the partners

The German Federal Ministry for Education and Research (BMBF) is providing the NanoUmwelt project with 1.8 million euros of funding as part of its NanoCare program. Led by Postnova Analytics GmbH, ten further partners are collaborating together on the project. Besides the Fraunhofer Institutes for Biomedical Engineering IBMT and for Molecular Biology and Applied Ecology IME, these partners include Germany’s Environment Agency, Empa (the Swiss Federal Laboratories for Materials Science and Technology), PlasmaChem GmbH, Senova GmbH (biological sciences and engineering), fzmb GmbH (Research Centre of Medical Technology and Biotechnology), the universities of Trier and Frankfurt, and the Rhine Water Control Station in Worms.

http://www.nanopartikel.info/projekte/laufende-projekte/nanoumwelt

How small is nano?

A nanometer (nm) is a billionth of a meter. To put this into context: the size of a single nanoparticle relative to a football is the same as that of a football relative to the earth. In the main, nanoscopic particles are not new materials. It’s simply that the increased overall surface area of these tiny particles gives them new functionalities as against larger particles of the same material.


The German Environmental Specimen Bank  

The German Environmental Specimen Bank (ESB) provides the country’s Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) with a scientific basis both for adopting appropriate measures concerning environment and nature conservation and for monitoring the success of those measures. The human samples collected by the Fraunhofer Institute for Biomedical Engineering IBMT on behalf of Germany’s Environment Agency (UBA) give an overview of human exposure to environmental pollutants.

https://www.umweltprobenbank.de/de

Assuming I’ve understood this correctly, the NanoUmwelt project will be ending in 2017 (36 months in total) and the researchers have expended 1/2 of the time (18 months) allotted to developing a technique for measuring nanomaterials of heretofore unheard of quantities in environmental samples. With that done, researchers are now going to use the technique with human samples over the next 18 months.

Possible nanoparticle-based vaccine/microbiocide for herpes simplex virus-2

An April 27, 2016 news item on ScienceDaily describes a new therapeutic and preventative technology for herpes,

An effective vaccine against the virus that causes genital herpes has evaded researchers for decades. But now, researchers from the University of Illinois at Chicago [UIC] working with scientists from Germany have shown that zinc-oxide nanoparticles shaped like jacks can prevent the virus from entering cells, and help natural immunity to develop.

“We call the virus-trapping nanoparticle a microbivac, because it possesses both microbicidal and vaccine-like properties,” says corresponding author Deepak Shukla, professor of ophthalmology and microbiology & immunology in the UIC College of Medicine. “It is a totally novel approach to developing a vaccine against herpes, and it could potentially also work for HIV and other viruses,” he said.

The particles could serve as a powerful active ingredient in a topically-applied vaginal cream that provides immediate protection against herpes virus infection while simultaneously helping stimulate immunity to the virus for long-term protection, explained Shukla.

An April 27, 2016 UIC news release (also on EurekAlert), which originated the news item, provides more context for the work,

Herpes simplex virus-2, which causes serious eye infections in newborns and immunocompromised patients as well as genital herpes, is one of the most common human viruses. According to the Centers for Disease Control and Prevention, about 15 percent of people from ages 14-49 carry HSV-2, which can hide out for long periods of time in the nervous system. The genital lesions caused by the virus increase the risk for acquiring human immunodeficiency virus, or HIV.

“Your chances of getting HIV are three to four times higher if you already have genital herpes, which is a very strong motivation for developing new ways of preventing herpes infection,” Shukla said.

Treatments for HSV-2 include daily topical medications to suppress the virus and shorten the duration of outbreaks, when the virus is active and genital lesions are present. However, drug resistance is common, and little protection is provided against further infections. Efforts to develop a vaccine have been unsuccessful because the virus does not spend much time in the bloodstream, where most traditional vaccines do their work.

The news release goes on to provide technical details,

The tetrapod-shaped zinc-oxide nanoparticles, called ZOTEN, have negatively charged surfaces that attract the HSV-2 virus, which has positively charged proteins on its outer envelope. ZOTEN nanoparticles were synthesized using technology developed by material scientists at Germany’s Kiel University and protected under a joint patent with UIC.

When bound to the nanoparticles, HSV-2 cannot infect cells. But the bound virus remains susceptible to processing by immune cells called dendritic cells that patrol the vaginal lining. The dendritic cells “present” the virus to other immune cells that produce antibodies. The antibodies cripple the virus and trigger the production of customized killer cells that identify infected cells and destroy them before the virus can take over and spread.

The researchers showed that female mice swabbed with HSV-2 and an ointment containing ZOTEN had significantly fewer genital lesions than mice treated with a cream lacking ZOTEN. Mice treated with ZOTEN also had less inflammation in the central nervous system, where the virus can hide out.

The researchers were able to watch immune cells pry the virus off the nanoparticles for immune processing, using high-resolution fluorescence microscopy.

“It’s very clear that ZOTEN facilitates the development of immunity by holding the virus and letting the dendritic cells get to it,” Shukla said.

If found safe and effective in humans, a ZOTEN-containing cream ideally would be applied vaginally just prior to intercourse, Shukla said. But if a woman who had been using it regularly missed an application, he said, she may have already developed some immunity and still have some protection. Shukla hopes to further develop the nanoparticles to work against HIV, which like HSV-2 also has positively charged proteins embedded in its outer envelope.

ZOTEN particles are uniform in size and shape, making them attractive for use in other biomedical applications. The novel flame transport synthesis technology used to make them allows large-scale production, said Rainer Adelung, professor of nanomaterials at Kiel University. And, because no chemicals are used, the production process is green.

Adelung hopes to begin commercial production of ZOTEN through a startup company that will be run jointly with his colleagues at UIC.

Here’s an image of the particles, courtesy of UIC,

Zinc oxide tetrapod nanoparticles. Credit: Deepak Shukla

Zinc oxide tetrapod nanoparticles. Credit: Deepak Shukla

Here’s a link to and a citation for the paper,

Intravaginal Zinc Oxide Tetrapod Nanoparticles as Novel Immunoprotective Agents against Genital Herpes by Thessicar E. Antoine, Satvik R. Hadigal, Abraam M. Yakoub, Yogendra Kumar Mishra, Palash Bhattacharya, Christine Haddad, Tibor Valyi-Nagy, Rainer Adelung, Bellur S. Prabhakar, and Deepak Shukla. The Journal of Immunology April 27, 2016 1502373  doi: 10.4049/jimmunol.1502373 Published online before print April 27, 2016

This paper is behind a paywall.

One final comment, it’s a long from a mouse vagina in this study to a human one.

“One minus one equals zero” has been disproved

Two mirror-image molecules can be optically active according to an April 27, 2016 news item on ScienceDaily,

In 1848, Louis Pasteur showed that molecules that are mirror images of each other had exactly opposite rotations of light. When mixed in solution, they cancel the effects of the other, and no rotation of light is observed. Now, a research team has demonstrated that a mixture of mirror-image molecules crystallized in the solid state can be optically active.

An April 26, 2016 Northwestern University news release (also on EurekAlert), which originated the news item, expands on the theme,

In the world of chemistry, one minus one almost always equals zero.

But new research from Northwestern University and the Centre National de la Recherche Scientifique (CNRS) in France shows that is not always the case. And the discovery will change scientists’ understanding of mirror-image molecules and their optical activity.

Now, Northwestern’s Kenneth R. Poeppelmeier and his research team are the first to demonstrate that a mixture of mirror-image molecules crystallized in the solid state can be optically active. The scientists first designed and made the materials and then measured their optical properties.

“In our case, one minus one does not always equal zero,” said first author Romain Gautier of CNRS. “This discovery will change scientists’ understanding of these molecules, and new applications could emerge from this observation.”

The property of rotating light, which has been known for more than two centuries to exist in many molecules, already has many applications in medicine, electronics, lasers and display devices.

“The phenomenon of optical activity can occur in a mixture of mirror-image molecules, and now we’ve measured it,” said Poeppelmeier, a Morrison Professor of Chemistry in the Weinberg College of Arts and Sciences. “This is an important experiment.”

Although this phenomenon has been predicted for a long time, no one — until now — had created such a racemic mixture (a combination of equal amounts of mirror-image molecules) and measured the optical activity.

“How do you deliberately create these materials?” Poeppelmeier said. “That’s what excites me as a chemist.” He and Gautier painstakingly designed the material, using one of four possible solid-state arrangements known to exhibit circular dichroism (the ability to absorb differently the “rotated” light).

Next, Richard P. Van Duyne, a Morrison Professor of Chemistry at Northwestern, and graduate student Jordan M. Klingsporn measured the material’s optical activity, finding that mirror-image molecules are active when arranged in specific orientations in the solid state.

Here’s a link to and a citation for the paper,

Optical activity from racemates by Romain Gautier, Jordan M. Klingsporn, Richard P. Van Duyne, & Kenneth R. Poeppelmeier. Nature Materials (2016) doi:10.1038/nmat4628 Published online 18 April 2016

This paper is behind a paywall.

Gold nanoparticles and two different collective oscillations

An April 27, 2016 news item on phys.org describes research into gold nanoparticles and Surface Plasmon Resonance at Hokkaido University and the University of Tsukuba (Japan),

The research group of Professor Hiroaki Misawa of Research Institute for Electronic Science, Hokkaido University and Assistant Professor Atsushi Kubo of the Faculty of Pure and Applied Sciences, University of Tsukuba, have successfully observed the dephasing time of the two different types of collective motions of electrons generated on the surface of a gold nanoparticle for the first time in the world, by combining a laser that emits ultrashort light pulses with a photoemission electron microscope.

An April 26, 2016 Hokkaido University press release, which originated the news item, explains further,

When gold is reduced to the size in nanometer scale, its color is red instead of gold. When gold nanoparticles are exposed to light, the collective oscillations of electrons existing on the localized surface of the gold causes red light to be strongly absorbed and dispersed.

This phenomenon is called Surface Plasmon Resonance. The red color of stained glass is also a result of this phenomenon. Recently, gold nanoparticles have been widely used in various fields, such as application in pregnancy tests.

This collective oscillations of electrons on the surface of gold nanoparticles caused by light was considered to be a phenomenon that sustained only for an extremely short time, and difficult to measure due to this shortness.

Our research group developed a methodology to measure the dephasing time of the collective oscillations of electrons occurring on the surface of gold nanoparticles by combining a laser that emits ultrashort light pulses of a few femtoseconds (1 femtosecond: 1´10-15 seconds), and a photoemission electron microscope in high spatial resolution.

When measured by this technique, the different dephasing times of the two different collective oscillations, namely dipole and quadrupole surface plasmon modes, could be resolved and identified as 5 femtoseconds and 9 femtoseconds, respectively.

Research using gold nanoparticles as optical antennae to harvest light for photovoltaic cell and an artificial photosynthesis system that can split water to obtain hydrogen is progressing. The successful measurement of the dephasing time of the collective oscillations of electrons is considered to be a useful guideline in developing these systems.

Here’s a link to and a citation for the paper,

Dissecting the Few-Femtosecond Dephasing Time of Dipole and Quadrupole Modes in Gold Nanoparticles Using Polarized Photoemission Electron Microscopy by Quan Sun†, Han Yu, Kosei Ueno, Atsushi Kubo, Yasutaka Matsuo, and Hiroaki Misawa. ACS Nano, 2016, 10 (3), pp 3835–3842 DOI: 10.1021/acsnano.6b00715Publication Date (Web): February 15, 2016

Copyright © 2016 American Chemical Society

This paper appears to be open access.

Exploring the science of Iron Man (prior to the opening of Captain America: Civil War, aka, Captain America vs. Iron Man)

Not unexpectedly, there’s a news item about science and Iron Man (it’s getting quite common for the science in movies to be promoted and discussed) just a few weeks before the movie Captain America: Civil War or, as it’s also known, Captain America vs. Iron Man opens in the US. From an April 26, 2016 news item on phys.org,

… how much of our favourite superheros’ power lies in science and how much is complete fiction?

As Iron Man’s name suggests, he wears a suit of “iron” which gives him his abilities—superhuman strength, flight and an arsenal of weapons—and protects him from harm.

In scientific parlance, the Iron man suit is an exoskeleton which is worn outside the body to enhance it.

An April 26, 2016 posting by Chris Marr on the ScienceNetwork Western Australia blog, which originated the news item, provides an interesting overview of exoskeletons and some of the scientific obstacles still to be overcome before they become commonplace,

In the 1960s, the first real powered exoskeleton appeared—a machine integrated with the human frame and movements which provided the wearer with 25 times his natural lifting capacity.

The major drawback then was that the unit itself weighed in at 680kg.

UWA [University of Western Australia] Professor Adrian Keating suggests that some of the technology seen in the latest Marvel blockbuster, such as controlling the exoskeleton with simple thoughts, will be available in the near future by leveraging ongoing advances of multi-disciplinary research teams.

“Dust grain-sized micromachines could be programmed to cooperate to form reconfigurable materials such as the retractable face mask, for example,” Prof Keating says.

However, all of these devices are in need of a power unit small enough to be carried yet providing enough capacity for more than a few minutes of superhuman use, he says.

Does anyone have a spare Arc Reactor?

Currently, most exoskeleton development has been for medical applications, with devices designed to give mobility to amputees and paraplegics, and there are a number in commercial production and use.

Dr Lei Cui, who lectures in Mechatronics at Curtin University, has recently developed both a hand and leg exoskeleton, designed for use by patients who have undergone surgery or have nerve dysfunction, spinal injuries or muscular dysfunction.

“Currently we use an internal battery that lasts about two hours in the glove, which can be programmed for only four different movement patterns,” Dr Cui says.

Dr Cui’s exoskeletons are made from plastic, making them light but offering little protection compared to the titanium exterior of Stark’s favourite suit.

It’s clear that we are a long way from being able to produce a working Iron Man suit at all, let alone one that flies, protects the wearer and has the capacity to fight back.

This is not the first time I’ve featured a science and pop culture story here. You can check out my April 28, 2014 posting for a story about how Captain America’s shield could be a supercapacitor (it also has a link to a North Carolina State University blog featuring science and other comic book heroes) and there is my May 6, 2013 post about Iron Man 3 and a real life injectable nano-network.

As for ScienceNetwork Western Australia, here’s more from their About SWNA page,

ScienceNetwork Western Australia (SNWA) is an online science news service devoted to sharing WA’s achievements in science and technology.

SNWA is produced by Scitech, the state’s science and technology centre and supported by the WA Government’s Office of Science via the Department of the Premier and Cabinet.

Our team of freelance writers work with in-house editors based at Scitech to bring you news from all fields of science, and from the research, government and private industry sectors working throughout the state. Our writers also produce profile stories on scientists. We collaborate with leading WA institutions to bring you Perspectives from prominent WA scientists and opinion leaders.

We also share news of science-related events and information about the greater WA science community including WA’s Chief Scientist, the Premier’s Science Awards, Innovator of the Year Awards and information on regional community science engagement.

Since our commencement in 2003 we have grown to share WA’s stories with local, national and global audiences. Our articles are regularly republished in print and online media in the metropolitan and regional areas.

Bravo to the Western Australia government! I wish there  initiatives of this type in Canada, the closest we have is the French language Agence Science-Presse supported by the Province of Québec.

Bacteria and an anti-superbug coating from Ireland’s Sligo Institute of Technology

Unlike today’s (April 28, 2016) earlier piece about dealing with bacteria, the focus for this research is on superbugs and not the bacteria which form biofilm on medical implants and such. An April 21, 2016 news item on RTE News makes the announcement about a new means of dealing with superbugs,

A discovery by a team of scientists in Ireland could stem the spread of deadly superbugs predicted to kill millions of people worldwide over the coming decades.

The research has found an agent that can be baked into everyday items like smart-phones and door handles to combat the likes of MRSA and E. coli.

The nanotechnology has a 99.9 % kill rate of potentially lethal and drug-resistant bacteria, they say.

Lead scientist Professor Suresh C. Pillai, of Sligo Institute of Technology’s Nanotechnology Research Group, says the discovery is the culmination of 12 years work.

“This is a game changer,” he said.

“This breakthrough will change the whole fight against superbugs. It can effectively control the spread of bacteria.”

An April 21, 2016 Sligo Institute of Technology press release provides some context for the work and a few details about the coating,

News of the discovery comes just days after UK Chancellor of the Exchequer George Osborne warned that superbugs could become deadlier than cancer and are on course to kill 10 million people globally by 2050.

Speaking at the International Monetary Fund (IMF) in Washington, Mr Osborne warned that the problem would slash global GDP by around €100 trillion if it was not tackled.

Using nanotechnology, the discovery is an effective and practical antimicrobial solution — an agent that kills microorganisms or inhibits their growth — that can be used to protect a range of everyday items.

Items include anything made from glass, metallics and ceramics including computer or tablet screens, smartphones, ATMs, door handles, TVs, handrails, lifts, urinals, toilet seats, fridges, microwaves and ceramic floor or wall tiles.

It will be of particular use in hospitals and medical facilities which are losing the battle against the spread of killer superbugs.

Other common uses would include in swimming pools and public buildings, on glass in public buses and trains, sneeze guards protecting food in delis and restaurants as well as in clean rooms in the medical sector.

“It’s absolutely wonderful to finally be at this stage. This breakthrough will change the whole fight against superbugs. It can effectvely control the spread of bacteria,” said Prof. Pillai.

He continued: “Every single person has a sea of bacteria on their hands. The mobile phone is the most contaminated personal item that we can have. Bacteria grows on the phone and can live there for up to five months. As it is contaminated with proteins from saliva and from the hand, It’s fertile land for bacteria and has been shown to carry 30 times more bacteria than a toilet seat.”

The research started at Dublin Institute of Technology (DIT)’s CREST and involves scientists now based at IT Sligo, Dublin City University (DCU) and the University of Surrey. Major researchers included Dr Joanna Carroll and Dr Nigel S. Leyland.

It has been funded for the past eight years by John Browne, founder and CEO of Kastus Technologies Ltd, who is bringing the product to a global market. He was also supported by significant investment from Enterprise Ireland.

As there is nothing that will effectively kill antibiotic-resistant superbugs completely from the surface of items, scientists have been searching for a way to prevent the spread.

This has been in the form of building or ‘baking’ antimicrobial surfaces into products during the manufacturing process.

However, until now, all these materials were toxic or needed UV light in order to make them work. This meant they were not practical for indoor use and had limited commercial application.

“The challenge was the preparation of a solution that was activated by indoor light rather than UV light and we have now done that,” said Prof Pillai.

The new water-based solution can be sprayed onto any glass, ceramic or metallic surface during the production process, rendering the surface 99.9 per cent resistant to superbugs like MRSA, E. coli and other fungi. [emphasis mine]

The solution is sprayed on the product — such as a smartphone glass surface — and then ‘baked’ into it, forming a super-hard surface. The coating is transparent, permanent and scratch resistant and actually forms a harder surface than the original glass or ceramic material.

The team first developed the revolutionary material to work on ceramics and has spent the last five years adapting the formula – which is non-toxic and has no harmful bi-products ‑- to make it work on glass and metallic surfaces.

Research is now underway by the group on how to adapt the solution for use in plastics and paint, allowing even wider use of the protective material.

Prof Pillai, Kastus and the team have obtained a US and a UK patent on the unique process with a number of global patent applications pending. It is rare for such an academic scientific discovery to have such commercial viability.

“I was sold on this from the first moment I heard about it. It’s been a long road to here but it was such a compelling story that it was hard to walk away from so I had to see it through to the end,” said John Browne, Kastus CEO.

He continued: “This is a game changer. The uniqueness of antimicrobia surface treatment means that the applications for it in the real world are endless. The multinational glass manufacturers we are in negotiations with to sell the product to have been searching for years to come up with such a solution but have failed.”

If the coating kills 99.9%, doesn’t that mean 0.1% are immune? If that’s the case, won’t they reproduce and eventually establish themselves as a new kind of superbug?

Here’s a link to and a citation for the paper,

Highly Efficient F, Cu doped TiO2 anti-bacterial visible light active photocatalytic coatings to combat hospital-acquired infections by Nigel S. Leyland, Joanna Podporska-Carroll, John Browne, Steven J. Hinder, Brid Quilty, & Suresh C. Pillai. Scientific Reports 6, Article number: 24770 (2016) doi:10.1038/srep24770 Published online: 21 April 2016

This paper is open access.

Bacteria and an anti-biofilm coating from Ben Gurion University of the Negev (Israel)

This anti-biofilm acts as an anti-adhesive and is another approach to dealing with unwanted bacteria on medical implants and on marine equipment. From an April 25, 2016 news item about the Israeli research on ScienceDaily,

Researchers at Ben-Gurion University of the Negev (BGU) have developed an innovative anti-biofilm coating, which has significant anti-adhesive potential for a variety of medical and industrial applications.

According to the research published in Advanced Materials Interfaces, anti-adhesive patches that are developed from naturally occurring biomaterials can prevent destructive bacterial biofilm from forming on metal surfaces when they are immersed in water and other damp environments.

An April 25, 2016 American Associates Ben Gurion University of the Negev news release (also on EurekAlert), which originated the news item, describes the research further without adding much detail (Note: A link has been removed),

“Our solution addresses a pervasive need to design environmentally friendly materials to impede dangerous surface bacteria growth,” the BGU researchers from the Avram and Stella Goldstein-Goren Department of Biotechnology Engineering explain. “This holds tremendous potential for averting biofilm formed by surface-anchored bacteria and could have a tremendous impact.”

biofouling

Above: SEM micrographs of A. baumannii, P. aeruginosa (PA14), S. marcescens and P.stuartii biofilm architectures. The untreated control surface shows intricate bacteria densely embedded in the matrix. Biofilms were grown statically on the different surfaces.

The anti-adhesive could be used on medical implants, devices and surgical equipment where bacteria can contribute to chronic diseases, resist antibiotic treatment and thereby compromise the body’s defense system. The prevention of aquatic biofouling on ships and bridges is one of the industrial applications.

Here’s a link to and a citation for the paper,

Novel Anti-Adhesive Biomaterial Patches: Preventing Biofilm with Metal Complex Films (MCF) Derived from a Microalgal Polysaccharide by Karina Golberg, Noa Emuna, T. P. Vinod, Dorit van Moppes, Robert S. Marks, Shoshana Malis Arad, and Ariel Kushmaro. Advanced Materials DOI: 10.1002/admi.201500486 Article first published online: 17 MAR 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This article is behind a paywall.

Study nanomaterial toxicity without testing animals

The process of moving on from testing on animals is laborious as new techniques are pioneered and, perhaps more arduously, people’s opinions and habits are changed. The People for the Ethical Treatment of Animals (PETA) organization focusing the research end of things has announced a means of predicting carbon nanotube toxicity in lungs according to an April 25, 2016 news item on Nanowerk (Note: A link has been removed),

A workshop organized last year [2015] by the PETA International Science Consortium Ltd has resulted in an article published today in the journal Particle and Fibre Toxicology (“Aerosol generation and characterization of multi-walled carbon nanotubes [MWCNTs] exposed to cells cultured at the air-liquid interface”). It describes aerosol generation and exposure tools that can be used to predict toxicity in human lungs following inhalation of nanomaterials.

An April 25, 2016 PETA press release on EurekAlert, which originated the news item, explains further without much more detail,

Nanomaterials are increasingly being used in consumer products such as paints, construction materials, and food packaging, making human exposure to these materials more likely. One of the common ways humans may be exposed to these substances is by inhalation, therefore, regulatory agencies often require the toxicity of these materials on the lungs to be tested. These tests usually involve confining rats to small tubes the size of their bodies and forcing them to breathe potentially toxic substances before they are killed. However, time, cost, scientific and ethical issues have led scientists to develop methods that do not use animals. The tools described in the new article are used to deposit nanomaterials (or other inhalable substances) onto human lung cells grown in a petri dish.

Co-authors of the Particle and Fibre Toxicology article are scientists from the PETA Science Consortium , The Dow Chemical Company, Baylor University, and the U.S. NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM).

“Promoting non-animal methods to assess nanotoxicity has been a focus of the PETA International Science Consortium”, said Dr. Monita Sharma, co-author of the publication and Nanotechnology Specialist at the Consortium, “we organized an international workshop last year on inhalation testing of nanomaterials and this review describes some of the tools that can be used to provide a better understanding of what happens in humans after inhaling these substances.” During the workshop, experts provided recommendations on the design of an in vitro test to assess the toxicity of nanomaterials (especially multi-walled carbon nanotubes) in the lung, including cell types, endpoints, exposure systems, and dosimetry considerations. Additional publications summarizing the outcomes of the workshop are forthcoming.

Here’s a link to and a citation for the paper,

Aerosol generation and characterization of multi-walled carbon nanotubes exposed to cells cultured at the air-liquid interface by William W. Polk, Monita Sharma, Christie M. Sayes, Jon A. Hotchkiss, and Amy J. Clippinger. Particle and Fibre Toxicology201613:20 DOI: 10.1186/s12989-016-0131-y Published: 23 April 2016

This is an open access paper.

How many nanoparticle-based drugs does it take to kill a cancer tumour? More than 1%

According to an April 27, 2016 news item on Nanowerk researchers at the University of Toronto (Canada) along with their collaborators in the US (Harvard Medical School) and Japan (University of Tokyo) have determined that less than 1% of nanoparticle-based drugs reach their intended destination (Note: A link has been removed),

Targeting cancer cells for destruction while leaving healthy cells alone — that has been the promise of the emerging field of cancer nanomedicine. But a new meta-analysis from U of T’s [University of Toronto] Institute of Biomaterials & Biomedical Engineering (IBBME) indicates that progress so far has been limited and new strategies are needed if the promise is to become reality.

“The amount of research into using engineered nanoparticles to deliver cancer drugs directly to tumours has been growing steadily over the last decade, but there are very few formulations used in patients. The question is why?” says Professor Warren Chan (IBBME, ChemE, MSE), senior author on the review paper published in Nature Reviews Materials (“Analysis of nanoparticle delivery to tumours”). “We felt it was time to look at the field more closely.”

An April 25, 2016 U of T news release, which originated the news item, details the research,

Chan and his co-authors analysed 117 published papers that recorded the delivery efficiency of various nanoparticles to tumours — that is, the percentage of injected nanoparticles that actually reach their intended target. To their surprise, they found that the median value was about 0.7 per cent of injected nanoparticles reaching their targets, and that this number has not changed for the last ten years. “If the nanoparticles do not get delivered to the tumour, they cannot work as designed for many nanomedicines,” says Chan.

Even more surprising was that altering nanoparticles themselves made little difference in the net delivery efficiency. “Researchers have tried different materials and nanoparticle sizes, different surface coatings, different shapes, but all these variations lead to no difference, or only small differences,” says Stefan Wilhelm, a post-doctoral researcher in Chan’s lab and lead author of the paper. “These results suggest that we have to think more about the biology and the mechanisms that are involved in the delivery process rather than just changing characteristics of nanoparticles themselves.”

Wilhelm points out that nanoparticles do have some advantages. Unlike chemotherapy drugs which go everywhere in the body, drugs delivered by nanoparticles accumulate more in some organs and less in others. This can be beneficial: for example, one current treatment uses nanoparticles called liposomes to encapsulate the cancer drug doxorubicin.

This encapsulation reduces the accumulation of doxorubicin in the heart, thereby reducing cardiotoxicity compared with administering the drug on its own.

Unfortunately, the majority of injected nanoparticles, including liposomes, end up in the liver, spleen and kidneys, which is logical since the job of these organs is to clear foreign substances and poisons from the blood. This suggests that in order to prevent nanoparticles from being filtered out of the blood before they reach the target tumour, researchers may have to control the interactions of those organs with nanoparticles.

It may be that there is an optimal particle surface chemistry, size, or shape required to access each type of organ or tissue.  One strategy the authors are pursuing involves engineering nanoparticles that can dynamically respond to conditions in the body by altering their surfaces or other properties, much like proteins do in nature. This may help them to avoid being filtered out by organs such as the liver, but at the same time to have the optimal properties needed to enter tumors.

More generally, the authors argue that, in order to increase nanoparticle delivery efficiency, a systematic and coordinated long-term strategy is necessary. To build a strong foundation for the field of cancer nanomedicine, researchers will need to understand a lot more about the interactions between nanoparticles and the body’s various organs than they do today. To this end, Chan’s lab has developed techniques  to visualize these interactions across whole organs using 3D optical microscopy, a study published in ACS Nano this week.

In addition to this, the team has set up an open online database, called the Cancer Nanomedicine Repository that will enable the collection and analysis of data on nanoparticle delivery efficiency from any study, no matter where it is published. The team has already uploaded the data gathered for the latest paper, but when the database goes live in June, researchers from all over the world will be able to add their data and conduct real-time analysis for their particular area of interest.

“It is a big challenge to collect and find ways to summarize data from a decade of research but this article will be immensely useful to researchers in the field,” says Professor Julie Audet (IBBME), a collaborator on the study.

Wilhelm says there is a long way to go in order to improve the clinical translation of cancer nanomedicines, but he’s optimistic about the results. “From the first publication on liposomes in 1965 to when they were first approved for use in treating cancer, it took 30 years,” he says. “In 2016, we already have a lot of data, so there’s a chance that the translation of new cancer nanomedicines for clinical use could go much faster this time. Our meta-analysis provides a ‘reality’ check of the current state of cancer nanomedicine and identifies the specific areas of research that need to be investigated to ensure that there will be a rapid clinical translation of nanomedicine developments.”

I made time to read this paper,

Analysis of nanoparticle delivery to tumours by Stefan Wilhelm, Anthony J. Tavares, Qin Dai, Seiichi Ohta, Julie Audet, Harold F. Dvorak, & Warren C. W. Chan. Nature Reviews Materials 1, Article number: 16014 (2016  doi:10.1038/natrevmats.2016.14 Published online: 26 April 2016

It appears to be open access.

The paper is pretty accessible but it does require that you have some tolerance for your own ignorance (assuming you’re not an expert in this area) and time. If you have both, you will find a good description of the various pathways scientists believe nanoparticles take to enter a tumour. In short, they’re not quite sure how nanoparticles gain entry. As well, there are discussions of other problems associated with the field such as producing enough nanoparticles for general usage.

More than an analysis, there’s also a proposed plan for future action (from Analysis of nanoparticle delivery to tumours ),

UofT_30yrCancerMedicine

Current research in using nanoparticles in vivo has focused on innovative design and demonstration of utility of these nanosystems for imaging and treating cancer. The poor clinical translation has encouraged the researchers in the field to investigate the effect of nanoparticle design (for example, size, shape and surface chemistry) on its function and behaviour in the body in the past 10 years. From a cancer-targeting perspective, we do not believe that nanoparticles will be successfully translated to human use if the current ‘research paradigm’ of nanoparticle targeting continues because the delivery efficiency is too low. We propose a long-term strategy to increase the delivery efficiency and enable nanoparticles to be translated to patient care in a cost-effective manner from the research stage. A foundation for the field will be built by obtaining a detailed view of nanoparticle–organ interaction during nanoparticle transport to the tumour, using computational strategies to organize and simulate the results and the development of new tools to assess nanoparticle delivery. In addition, we propose that these results should be collected in a central database to allow progress in the field to be monitored and correlations to be established. A 30-year strategy was proposed and seemed to be a reasonable time frame because the first liposome system was reported in 1965 (Ref. 122) and the first liposome formulation (Doxil) was approved by the US Food and Drug Administration (FDA) in 1995 (Refs 91,92). This 30-year time frame may be shortened as a research foundation has already been established but only if the community can parse the immense amount of currently published data. NP, nanoparticle.

Another paper was mentioned in the news release,

Three-Dimensional Optical Mapping of Nanoparticle Distribution in Intact Tissues by Shrey Sindhwani, Abdullah Muhammad Syed, Stefan Wilhelm, Dylan R Glancy, Yih Yang Chen, Michael Dobosz, and Warren C.W. Chan.ACS Nano, Just Accepted Manuscript Publication Date (Web): April 21, 2016 DOI: 10.1021/acsnano.6b01879

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Finally, Melanie Ward in an April 26, 2016 article for Science News Hub has another approach to describing the research. Oddly, she states this,

However, the study warns about the lack of efficiency despite major economic investments (more than one billion dollars in the US in the past decade).

She’s right; the US has spent more than $1B in the last decade. In fact, they’ve allocated over $1B every year to the National Nanotechnology Initiative (NNI) for almost two decades for a total of more than $20B. You might want to apply some caution when reading. BTW, I think that’s a wise approach for everything you read including the blog postings here.

Want better energy storage materials? Add salt

An April 22, 2016 news item on Nanowerk reveals a secret to better energy storage materials,

The secret to making the best energy storage materials is growing them with as much surface area as possible. Like baking, it requires just the right mixture of ingredients prepared in a specific amount and order at just the right temperature to produce a thin sheet of material with the perfect chemical consistency to be useful for storing energy. A team of researchers from Drexel University, Huazhong University of Science and Technology (HUST) and Tsinghua University recently discovered a way to improve the recipe and make the resulting materials bigger and better and soaking up energy — the secret? Just add salt.

An April 22, 2016 Drexel University news release (also on EurekAlert), which originated the news item, provides more detail,

The team’s findings, which were recently published in the journal Nature Communications, show that using salt crystals as a template to grow thin sheets of conductive metal oxides make the materials turn out larger and more chemically pure — which makes them better suited for gathering ions and storing energy.

“The challenge of producing a metal oxide that reaches theoretical performance values is that the methods for making it inherently limit its size and often foul its chemical purity, which makes it fall short of predicted energy storage performance,” said Jun Zhou, a professor at HUST’s Wuhan National Laboratory for Optoelectronics and an author of the research. Our research reveals a way to grow stable oxide sheets with less fouling that are on the order of several hundreds of times larger than the ones that are currently being fabricated.”

In an energy storage device — a battery or a capacitor, for example — energy is contained in the chemical transfer of ions from an electrolyte solution to thin layers of conductive materials. As these devices evolve they’re becoming smaller and capable of holding an electric charge for longer periods of time without needing a recharge. The reason for their improvement is that researchers are fabricating materials that are better equipped, structurally and chemically, for collecting and disbursing ions.

In theory, the best materials for the job should be thin sheets of metal oxides, because their chemical structure and high surface area makes it easy for ions to attach — which is how energy storage occurs. But the metal oxide sheets that have been fabricated in labs thus far have fallen well short of their theoretical capabilities.

According to Zhou, Tang [?] and the team from HUST, the problem lies in the process of making the nanosheets — which involves either a deposition from gas or a chemical etching — often leaves trace chemical residues that contaminate the material and prevent ions from bonding to it. In addition, the materials made in this way are often just a few square micrometers in size.

Using salt crystals as a substrate for growing the crystals lets them spread out and form a larger sheet of oxide material. Think of it like making a waffle by dripping batter into a pan versus pouring it into a big waffle iron; the key to getting a big, sturdy product is getting the solution — be it batter, or chemical compound — to spread evenly over the template and stabilize in a uniform way.

“This method of synthesis, called ‘templating’ — where we use a sacrificial material as a substrate for growing a crystal — is used to create a certain shape or structure,” said Yury Gogotsi, PhD, University and Trustee Chair professor in Drexel’s College of Engineering and head of the A.J. Drexel Nanomaterials Institute, who was an author of the paper. “The trick in this work is that the crystal structure of salt must match the crystal structure of the oxide, otherwise it will form an amorphous film of oxide rather than a thing, strong and stable nanocrystal. This is the key finding of our research — it means that different salts must be used to produce different oxides.”

Researchers have used a variety of chemicals, compounds, polymers and objects as growth templates for nanomaterials. But this discovery shows the importance of matching a template to the structure of the material being grown. Salt crystals turn out to be the perfect substrate for growing oxide sheets of magnesium, molybdenum and tungsten.

The precursor solution coats the sides of the salt crystals as the oxides begin to form. After they’ve solidified, the salt is dissolved in a wash, leaving nanometer-thin two-dimensional sheets that formed on the sides of the salt crystal — and little trace of any contaminants that might hinder their energy storage performance. By making oxide nanosheets in this way, the only factors that limit their growth is the size of the salt crystal and the amount of precursor solution used.

“Lateral growth of the 2D oxides was guided by salt crystal geometry and promoted by lattice matching and the thickness was restrained by the raw material supply. The dimensions of the salt crystals are tens of micrometers and guide the growth of the 2D oxide to a similar size,” the researchers write in the paper. “On the basis of the naturally non-layered crystal structures of these oxides, the suitability of salt-assisted templating as a general method for synthesis of 2D oxides has been convincingly demonstrated.”

As predicted, the larger size of the oxide sheets also equated to a greater ability to collect and disburse ions from an electrolyte solution — the ultimate test for its potential to be used in energy storage devices. Results reported in the paper suggest that use of these materials may help in creating an aluminum-ion battery that could store more charge than the best lithium-ion batteries found in laptops and mobile devices today.

Gogotsi, along with his students in the Department of Materials Science and Engineering, has been collaborating with Huazhong University of Science and Technology since 2012 to explore a wide variety of materials for energy storage application. The lead author of the Nature Communications article, Xu Xiao, and co-author Tiangi Li, both Zhou’s doctoral students, came to Drexel as exchange students to learn about the University’s supercapacitor research. Those visits started a collaboration, which was supported by Gogotsi’s annual trips to HUST. While the partnership has already yielded five joint publications, Gogotsi speculates that this work is only beginning.

“The most significant result of this work thus far is that we’ve demonstrated the ability to generate high-quality 2D oxides with various compositions,” Gogotsi said. “I can certainly see expanding this approach to other oxides that may offer attractive properties for electrical energy storage, water desalination membranes, photocatalysis and other applications.”

Here’s a link to and a citation for the paper,

Scalable salt-templated synthesis of two-dimensional transition metal oxides by Xu Xiao, Huaibing Song, Shizhe Lin, Ying Zhou, Xiaojun Zhan, Zhimi Hu, Qi Zhang, Jiyu Sun, Bo Yang, Tianqi Li, Liying Jiao, Jun Zhou, Jiang Tang, & Yury Gogotsi. Nature Communications 7, Article number:  11296 doi:10.1038/ncomms11296 Published 22 April 2016

This is an open access paper.