Lasing nanoparticles around the room

Via KurzweilAI.net — This is a pretty astounding feat.

From the link:

Researchers from Australian National University have developed the ability to move particles  over distances of up to 1.5 meters, using a hollow laser beam to trap light-absorbing particles in a “dark core.” The particles are then moved up and down the beam of light, which acts like an optical “pipeline.”

“When the small particles are trapped in this dark core very interesting things start to happen,” said Professor Andrei Rode. “As gravity, air currents, and random motions of air molecules around the particle push it out of the center, one side becomes illuminated by the laser while the other lies in darkness. This creates a tiny thrust, known as a photophoretic force that effectively pushes the particle back into the darkened core. In addition to the trapping effect, a portion of the energy from the beam and the resulting force pushes the particle along the hollow laser pipeline.”

Practical applications for this technology include directing and clustering nanoparticles in air, micro-manipulation of objects, sampling of atmospheric aerosols, and low-contamination/non-touch handling of sampling materials for transport of dangerous substances and microbes in small amounts, he said.

More info: Australian National University news

Cool nanotech image — the perfect nanocube

Check this out …

Caption: These electron microscope images show perfect-edged nanocubes produced in a one-step process created at NIST that allows careful control of the cubes’ size, shape and composition.

Credit: NIST

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Related news release: The perfect nanocube: Precise control of size, shape and composition

And:

Caption: These electron microscope images show perfect-edged nanocubes produced in a one-step process created at NIST that allows careful control of the cubes’ size, shape and composition.

Credit: NIST

Usage Restrictions: None

Related news release: The perfect nanocube: Precise control of size, shape and composition

Head below the fold for the accompanying release:

Latest advance in nanoscience research

News like this is important because a lot of the science of nanotechnology is so new it’s essentially a high-wire act without a net. Working to set some baselines in nanoscience help to improve the entire field.

The release:

University of Toronto chemists make breakthrough in nanoscience research

TORONTO, ON – A team of scientists led by Eugenia Kumacheva of the Department of Chemistry at the University of Toronto has discovered a way to predict the organization of nanoparticles in larger forms by treating them much the same as ensembles of molecules formed from standard chemical reactions.

“Currently, no model exists describing the organization of nanoparticles,” says Kumacheva. “Our work paves the way for the prediction of the properties of nanoparticle ensembles and for the development of new design rules for such structures.”

The focus of nanoscience is gradually shifting from the synthesis of individual nanoparticles to their organization in larger structures. In order to use nanoparticle ensembles in functional devices such as memory storage devices or optical waveguides, it is important to achieve control of their structure.

According to the researchers’ observations, the self-organization of nanoparticles is an efficient strategy for producing nanostructures with complex, hierarchical architectures. “The past decade has witnessed great progress in nanoscience – particularly nanoparticle self-assembly – yet the quantitative prediction of the architecture of nanoparticle ensembles and of the kinetics of their formation remains a challenge,” she continues. “We report on the remarkable similarity between the self-assembly of metal nanoparticles and chemical reactions leading to the formation of polymer molecules. The nanoparticles act as multifunctional single units, which form reversible, noncovalent bonds at specific bond angles and organize themselves into a highly ordered polymer.”

“We developed a new approach that enables a quantitative prediction of the architecture of linear, branched, and cyclic self-assembled nanostructures, their aggregation numbers and size distribution, and the formation of structural isomers.”

Kumacheva was joined in the research by postdoctoral fellows Kun Liu, Nana Zhao and Wei Li, and former doctoral student Zhihong Nie, along with Professor Michael Rubinstein of the University of North Carolina. As polymer chemists, the team took an unconventional look at nanoparticle organization.

“We treated them as molecules, not particles, which in a process resembling a polymerization reaction, organize themselves into polymer-like assemblies,” says Kumacheva. “Using this analogy, we used the theory of polymerization and predicted the architecture of the so-called ‘molecules’ and also found other, unexpected features that can find interesting applications.”

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The findings were published in a report titled “Step-Growth Polymerization of Inorganic Nanoparticles” in the July 9 issue of Science. The research was funded with support from an NSERC Discovery Grant from the Natural Sciences and Engineering Research Council of Canada and Canada Research Chair funding.

Drug delivery system, electromagnetic fields and nanotech

Medical news about nanotechnology.

The release:

Researchers develop drug delivery system using nanoparticles triggered by electromagnetic field

KINGSTON, R.I. July 8, 2010 – A new system for the controlled delivery of pharmaceutical drugs has been developed by a team of University of Rhode Island chemical engineers using nanoparticles embedded in a liposome that can be triggered by non-invasive electromagnetic fields.

The discovery by URI professors Geoffrey Bothun and Arijit Bose and graduate student Yanjing Chen was published in the June issue of ACS Nano.

According to Bothun, liposomes are tiny nanoscale spherical structures made of lipids that can trap different drug molecules inside them for use in delivering those drugs to targeted locations in the body. The superparamagnetic iron oxide nanoparticles the researchers embed in the shell of the liposome release the drug by making the shell leaky when heat-activated in an alternating current electromagnetic field operating at radio frequencies.

“We’ve shown that we can control the rate and extent of the release of a model drug molecule by varying the nanoparticle loading and the magnetic field strength,” explained Bothun. “We get a quick release of the drug with magnetic field heating in a matter of 30 to 40 minutes, and without heating there is minimal spontaneous leakage of the drug from the liposome.”

Bothun said that the liposomes self-assemble because portions of the lipids are hydrophilic – they have a strong affinity for water – and others are hydrophobic – they avoid water. When he mixes lipids and nanoparticles in a solvent, adds water and evaporates off the solvent, the materials automatically assemble themselves into liposomes. The hydrophobic nanoparticles and lipids join together to form the shell of the liposome, while the water-loving drug molecules are captured inside the spherical shell.

“The concept of loading nanoparticles within the hydrophobic shell to focus the activation is brand new,” Bothun said. “It works because the leakiness of the shell is ultimately what controls the release of the drugs.”

The next step in the research is to design and optimize liposome/nanoparticle assemblies that can target cancer cells or other disease-causing cells. In vitro cancer cell studies are already underway in collaboration with URI pharmacy professor Matthew Stoner.

“We are functionalizing the liposomes by putting in different lipids to help stabilize and target them so they can seek out particular cancer cell types,” he said. “We are building liposomes that will attach to particular cells or tumor regions.”

Bothun said that research on nanomedicine shows great promise, but there are still many challenges to overcome, and the targeting of appropriate cells may be the greatest challenge.

“Any ability to target the drug is better than a drug that goes everywhere in your system and generates off-target effects,” he said, noting that the hair loss and nausea from anti-cancer drugs are the result of the high drug concentrations needed for treatment and the drug’s affect on non-target cells. “If you can get an assembly to a targeted site without losing its contents in the process, that’s the holy grail.”

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Lithium-air battery news

Good news, that is. A nanotech catalyst improves the efficiency of lithium-air batteries to record levels and gets them that much closer to practical application in places like electric vehicles.

From the link:

A catalyst developed by researchers at MIT makes rechargeable lithium-air batteries significantly more efficient–a step toward making these high-energy-density batteries practical for use in electric vehicles and elsewhere.

The catalyst consists of nanoparticles of a gold and platinum alloy; in testing it was able to return 77 percent of the energy used to charge the battery as electricity when discharged. That’s up from the previously published record of about 70 percent, the researchers say. The work, which was reported online this week in the Journal of the American Chemical Society, suggests a new approach to lithium-air battery catalysts that could lead to the even higher efficiencies of 85 to 90 percent needed for commercial batteries.

Lithium-air batteries, which generate electricity by reacting lithium metal and oxygen from the air, are attractive for their potential to store vast amounts of energy. They could be a practical way to store more than three times as much energy, by weight, as today’s lithium-ion batteries, extending the range of electric vehicles, for example.

Air catalyst: Gold and platinum alloy nanoparticles (the dark areas) sit on top of a carbon black substrate (the lighter patterns); together, these materials improve the efficiency of lithium-air batteries.
Credit: Yi-Chun Lu

Cancer killing nanotech assassins

Nanotechnology is proving to have many medical applications, and the bulk of those apps are in cancer research. Here’s the latest from Cornell.

The release:

Like little golden assassins, ‘smart’ nanoparticles identify, target and kill cancer cells

ITHACA, N.Y. – Another weapon in the arsenal against cancer: Nanoparticles that identify, target and kill specific cancer cells while leaving healthy cells alone.

Led by Carl Batt, the Liberty Hyde Bailey Professor of Food Science, the researchers synthesized nanoparticles – shaped something like a dumbbell – made of gold sandwiched between two pieces of iron oxide. They then attached antibodies, which target a molecule found only in colorectal cancer cells, to the particles. Once bound, the nanoparticles are engulfed by the cancer cells.

To kill the cells, the researchers use a near-infrared laser, which is a wavelength that doesn’t harm normal tissue at the levels used, but the radiation is absorbed by the gold in the nanoparticles. This causes the cancer cells to heat up and die.

“This is a so-called ‘smart’ therapy,” Batt said. “To be a smart therapy, it should be targeted, and it should have some ability to be activated only when it’s there and then kills just the cancer cells.”

The goal, said lead author and biomedical graduate student Dickson Kirui, is to improve the technology and make it suitable for testing in a human clinical trial. The researchers are now working on a similar experiment targeting prostate cancer cells.

“If, down the line, you could clinically just target the cancer cells, you could then spare the health surrounding cells from being harmed – that is the critical thing,” Kirui said.

Gold has potential as a material key to fighting cancer in future smart therapies. It is biocompatible, inert and relatively easy to tweak chemically. By changing the size and shape of the gold particle, Kirui and colleagues can tune them to respond to different wavelengths of energy.

Once taken up by the researchers’ gold particles, the cancer cells are destroyed by heat – just a few degrees above normal body temperature – while the surrounding tissue is left unharmed. Such a low-power laser does not have any effect on surrounding cells because that particular wavelength does not heat up cells if they are not loaded up with nanoparticles, the researchers explained.

Using iron oxide – which is basically rust – as the other parts of the particles might one day allow scientists to also track the progress of cancer treatments using magnetic resonance imaging, Kirui said, by taking advantage of the particles’ magnetic properties.

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The research was funded by the Sloan Foundation and the Ludwig Institute for Cancer Research, which has been a partner with Cornell since 1999 to bring laboratory work to clinical testing. The research is reported in the Feb. 15 online edition of the journal Nanotechnology.

Text by Anne Ju, Cornell Chronicle

Nanoparticle self-assembly news

Via KurzweilAI.net — here’s the latest in nanotech news.

New Route To Nano Self-assembly Found

ScienceDaily, Oct. 25, 2009 Researchers at Lawrence Berkeley National Laboratory have found a way to induce nanoparticles to assemble themselves into complex arrays, using block copolymers with surfactants as mediator molecules. Read Original Article>>

More nanoparticle caution

I’ve blogged on nanotechnology drawbacks before, and here’s a new release providing a little more caution on nanotech. Sounds like this research may be more alarmist than truly useful. Be sure to take your grain of salt here.

The release:

Nanoparticles trigger cell death?

Nanoparticles that are one milliard of a metre in size are widely used, for example, in cosmetics and food packaging materials. There are also significant amounts of nanoparticles in exhaust emissions. However, very little is yet known of their health effects, because only a very small portion of research into nanoparticles is focused on their health and safety risks. Nanoparticles have even been dubbed the asbestos of the 2000s bys some researchers, and therefore a considerable threat to people’s health. While the use of nanoparticles in consumer products increases, their follow-up procedures and legislation are lagging behind. The European Union chemicals directive REACH does not even touch upon nanomaterials.

The research teams of Professor Ilpo Vattulainen (Department of Physics, Tampere University of Technology, Finland) and academy researcher Emppu Salonen (Department of Applied Physics, Helsinki University of Technology, Finland) have together with Professor Pu-Chun Ke’s (Clemson University, SC, USA) team researched how carbon-based nanoparticles interact with cells. The results provided strong biophysical evidence that nanoparticles may alter cell structure and pose health risks.

It emerged from the research that certain cell cultures are not affected when exposed to fullerenes, i.e. nano-sized molecules that consist of spherical, ellipsoid, or cylindrical arrangement of carbon atoms. Cells are also not affected when exposed to gallic acid, an organic acid that is found in almost all plants and, for instance, in tea. However, when fullerenes and gallic acid are present in the cell culture at the same time, they interact to form structures that bind to the cell surface and cause cell death.

The research demonstrates how difficult it is to map out the health effects of nanoparticles. Even if a certain nanoparticle does not appear toxic, the interaction between this nanoparticle and other compounds in the human body may cause serious problems to cell functions. Since the number of possible combinations of nanoparticles and various biomolecules is immense, it is practically impossible to research them systematically.

 

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The research on cell death caused by fullerenes and gallic acid was recently published in the nanoscience journal Small [E. Salonen, S. Lin, M. L. Reid, M. Allegood, X. Wang, A. M. Rao, I. Vattulainen, P.-C. Ke. Real-time translocation of fullerene reveals cell contraction. Small 4, 1986-1992 (2008)].

Descriptions of group leaders and their research groups:

Professor Pu-Chun Ke:
Prof. Pu Chun Ke won a Career Award from the National Science Foundation for his research addressing the fate of nanomaterials in biological systems and the environment. His research lab has first demonstrated the delivery of RNA using single-walled carbon nanotubes and invented the use of lysophospholipids for obtaining biocompatible nanomaterials. Based at Clemson University, USA, the Single-Molecule Biophysics and Polymer Physics Laboratory led by Prof. Ke (http://people.clemson.edu/~pcke11/) also examines topics in DNA damage and repair, microscopy, and fundamental and applied soft matter physics.

Professor Ilpo Vattulainen:
The Biological Physics Group (http://www.tut.fi/biophys/ and http://www.fyslab.hut.fi/bio/) of 26 people located at the Department of Physics at Tampere University of Technology, Finland, is directed by Prof. Ilpo Vattulainen. The Group is part of the Computational Nanoscience team selected as a Center of Excellence by the Academy of Finland. The Group is also an affiliate member of the MEMPHYS Center for Biomembrane Physics in the University of Southern Denmark, selected as a Center of Excellence by The Danish National Research Foundation. The Biological Physics Group focuses on computational and theoretical studies of biological systems, the topics including biomembranes, nanomaterials, lipoproteins, drugs, and carbohydrates.

Academy researcher (Dr.) Emppu Salonen:
The Computational Soft Matter Research Group (http://www.fyslab.hut.fi/soft/) is based at the Department of Applied Physics, Helsinki University of Technology (TKK). The group is headed by Dr. Emppu Salonen, who currently has a Research Fellow position with the Academy of Finland. The focus of the group’s research is in environmental and biological effects of nanomaterials, most importantly carbon-based nanomaterials such as fullerenes and carbon nanotubes. The current nanomaterial-biomaterial research of the group is funded by the Academy of Finland.

Nanoparticles in the home

No, not nanotech, just nanoscale particles released by household devices.

The release:

Nanoparticles in the home: More and smaller than previously detected

Extremely small nanoscale particles are released by common kitchen appliances in abundant amounts, greatly outnumbering the previously detected, larger-size nanoparticles emitted by these appliances, according to new findings* by researchers at the National Institute of Standards and Technology (NIST). So-called “ultrafine particles” (UFP) range in size from 2 to 10 nanometers. They are emitted by motor vehicles and a variety of indoor sources and have attracted attention because of increasing evidence that they can cause respiratory and cardiovascular illnesses.

NIST researchers conducted a series of 150 experiments using gas and electric stoves and electric toaster ovens to determine their impacts on indoor levels of nano-sized particles. Previous studies have been limited to measuring particles with diameters greater than 10 nm, but new technology used in these experiments allowed researchers to measure down to 2 nm particles—approximately 10 times the size of a large atom.

This previously unexplored range of 2 to 10 nm contributed more than 90 percent of all the particles produced by the electric and gas stovetop burners/coils. The gas and electric ovens and the toaster oven produced most of their UFP in the 10 nm to 30 nm range.

The results of this test should affect future studies of human exposure to particulates and associated health effects, particularly since personal exposure to these indoor UFP sources can often exceed exposure to the outdoor UFP.

Researchers will continue to explore the production of UFP by indoor sources. Many common small appliances such as hair dryers, steam irons and electric power tools include heating elements or motors that may produce UFP. People often use these small appliances at close range for relatively long times, so exposure could be large even if the emissions are low.

The experiments were conducted in a three-bedroom test house at NIST that is equipped to measure ventilation rates, environmental conditions and contaminant concentrations.

 

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* L. Wallace, F. Wang, C. Howard-Reed and A. Persily. Contribution of gas and electric stoves to residential ultrafine particle concentrations between 2 and 64 nm: Size distributions and emission and coagulation rates. Environmental Science and Technology, DOI 10.1021/es801402v, published online Oct. 30, 2008.

Nanotechnology does have drawbacks

As wonderful as all the various nanotechnology applications in medicine, science, technology and other industries are, there are drawbacks. Such as the well-known “gray goo” scenario.

Here’s another potential health issue with nanoparticles.

The release:

When particles are so small that they seep right through skin

Scientists are finding that particles that are barely there – tiny objects known as nanoparticles that have found a home in electronics, food containers, sunscreens, and a variety of applications – can breech our most personal protective barrier: The skin.

The particles under scrutiny by Lisa DeLouise, Ph.D., are almost unfathomably tiny. The particles are less than one five-thousandth the width of a human hair. If the width of that strand of hair were equivalent to the length of a football field, a typical nanoparticle wouldn’t even belly up to the one-inch line.

In the September issue of the journal Nano Letters, a team led by DeLouise at the University of Rochester Medical Center published a paper showing that nanoparticles pass through the skin of a living organism, a type of mouse commonly used as a model to study the damaging effects of sunlight.

It’s the strongest evidence yet indicating that some nanoparticles are so small that they can actually seep through skin, especially when the skin has been damaged.

The health implications of nanoparticles in the body are uncertain, said DeLouise, an assistant professor of Dermatology and Biomedical Engineering and an expert on the properties of nanoparticles. Other scientists have found that the particles can accumulate in the lymph system, the liver, the nervous system, and in other areas of the body. In her study, she found that the particles accumulate around the hair follicles and in tiny skin folds.

DeLouise, a chemist, points out that her study did not directly address the safety of nanoparticles in any way. “We simply wanted to see if nanoparticles could pass through the skin, and we found that they can under certain conditions,” she said.

DeLouise’s work is part of a broad field known as nanomedicine that is a strategic area at the University of Rochester Medical Center. The area includes research, like hers, looking at the properties of nanoparticles, as well as possibilities like new forms of drug delivery and nano-sensors that can immediately identify microbes and other threats to our health.

While nanoparticles are becoming widely used in the manufacture of consumer products, they are also under a great deal of study in research labs, and there are some processes – including ordinary candle flames – that produce them naturally. Some of the particles are so small, less than 10 nanometers wide (a nanometer is one-millionth of a millimeter), that they are nearly as small as the natural gaps between some skin cells.

In its paper in Nano Letters, the team studied the penetration of nanoparticles known as quantum dots that fluoresce under some conditions, making them easier to see and track compared to other nanoparticles. The scientists looked at the distribution of quantum dots in mice whose skin had been exposed to about the same amount of ultraviolet light as might cause a slight sunburn on a person. The team showed that while the nanoparticles were able to breech the skin of all the mice, the particles passed more quickly through skin that had been damaged by ultraviolet light.

Part of the explanation likely lies with the complex reaction of skin when it’s assaulted by the Sun’s rays. In response to ultraviolet light, cells proliferate, and molecules in the skin known as tight-junction proteins loosen so that new cells can migrate to where they’re needed. Those proteins normally act as gatekeepers that determine which molecules to allow through the skin and into the body, and which molecules to block. When the proteins loosen up, they become less selective than usual, possibly giving nanoparticles an opportunity to pass through the barrier.

In the future, DeLouise plans to study titanium dioxide and zinc oxide, two materials that are widely used in sunscreens and other cosmetic products to help block the damaging effects of ultraviolet light. In recent years the size of the metal oxide particles used in many consumer products has become smaller and smaller, so that many now are nanoparticles. The effects of the smaller particle size are visible to anyone who takes a walk on the beach or stops by the cosmetics counter at a department store: The materials are often completely transparent when applied to skin. A transparent lip gloss that protects against UV light, for example, or a see-through sunscreen may contain nanoparticles, DeLouise says.

“A few years ago, a lifeguard at the swimming pool wearing sunscreen might have had his nose completely covered in white. Older sunscreens have larger particles that reflect visible light. But many newer sunscreens contain nanoparticles that are one thousand times smaller, that do not reflect visible light,” said DeLouise, who noted that many people apply sunscreens after their skin has been damaged by sunlight.

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Initial funding from two sources allowed the team to gather the evidence necessary to expand the project dramatically. DeLouise’s project was first funded by the University’s Environmental Health Sciences Center, which supported graduate student Luke Mortensen during his research. The University’s Clinical and Translational Science Institute has also awarded $100,000 to the team, and DeLouise has just received $394,000 from the National Science Foundation to expand the project for the next three years. She will be working with dermatologist Lisa Beck, M.D., who is an expert in allergic skin disorders.

In addition to DeLouise and Mortensen, authors of the paper include Günter Oberdörster, Ph.D., professor of Environmental Medicine and a widely recognized authority on the bio-effects of nanoparticles. Oberdörster is director of the Particulate Matter Center, funded by the Environmental Protection Agency, where scientists study the link between tiny air particles we breathe every day and our cardiovascular health. Dermatologist Alice Pentland, M.D., professor and chair of the Department of Dermatology and an expert on how sunlight brings about skin cancer, was also an author.

PhysOrg covered this story here.

New ‘Pyrex’ nanoparticle

This nanotech breakthrough looks to have a number of important applications, particularly in medicine.

From the link: 

Researchers in Switzerland have developed a new method to fabricate borosilicate glass nanoparticles. Used in microfluidic systems, these “Pyrex”-like nanoparticles are more stable when subjected to temperature fluctuations and harsh chemical environments than currently used nanoparticles made of polymers or silica glass. Their introduction could extend the range of potential nanoparticle applications in biomedical, optical and electronic fields.

Thanks to their large surface-to-volume ratio, nanoparticles have generated wide interest as potential transporters of antibodies, drugs, or chemicals for use in diagnostic tests, targeted drug therapy, or for catalyzing chemical reactions.

Nanoparticles fight cancer with targeted doses

Another nanotech advance in cancer treatment.

From KurzweilAI.net:

Nanoparticle delivery sytem for anti-tumor toxins reduces drug dose 1,000 times

KurzweilAI.net, April 3, 2008Washington University School of Medicine researchers using drug-coated nanoparticles to deliver fumagillin (a fungal toxin cancer treatment) to tumors found that a drug dose 1,000 times lower than used previously still significantly slowed tumor growth. Fumagillin can have neurotoxic side effects at the high doses required with standard methods. The fumagillin nanoparticles were effective in very low doses because they were designed to concentrate where tumors create new blood vessels. Washington University School of Medicine News Release

Tracking nanoparticles in three dimensions

From KurzweilAI.net:

All Done With Mirrors: NIST Microscope Tracks Nanoparticles In 3-D

Photonics Online, Mar. 10, 2008A new microscope design allows nanotechnology researchers at the National Institute of Standards and Technology (NIST) to track the motions of nanoparticles in solution as they dart around in three dimensions. Four side views of a nanoparticle floating in solution (left) are reflected up. A microscope above the well sees the real particle (center, right) and four reflections that show the particle‘s vertical position. A simple calculation correlates the horizontal and vertical images to determine each particle‘s 3-D path. The technology may lead to a better understanding of the dynamics of nanoparticles in fluids and, ultimately, process control techniques for “directed self-assembly.” This capitalizes on physical properties and chemical affinities of nanoparticles in solutions to induce them to gather and arrange themselves in desired structures at desired locations. Potential products include extraordinarily sensitive chemical and biological sensor arrays, and new medical and diagnostic materials based on quantum dots and other nanoscale materials. Read Original Article>>