The system uses a pair of linked particles with magnetic properties. In the presence of a magnetic field the paired particles begin to tumble across a surface with first one particle
and then the other making contact in effect walking across the surface. So far the work has been carried out on a model cell surface on a functionalized microscope slide
The particles naturally migrate toward high-friction regions where they could then be induced to interact with a surface by active molecules attached to them.
The use of a pattern that localizes particles may be useful to enhance the localization of particles with specific properties.
#Nanoparticles get a magnetic handle A long-sought goal of creating particles that can emit a colorful fluorescent glow in a biological environment
And finally the particles could have a coating of a bioreactive substance that could seek out
For one thing he says such particles have been too large to make practical probes of living tissue: They ve tended to have wasted a lot of volume Bawendi says.
In addition previous efforts were unable to produce particles of uniform and predictable size which could also be an essential property for diagnostic or therapeutic applications.
The new method produces the combination of desired properties in as small a package as possible Bawendi says which could help pave the way for particles with other useful properties such as the ability to bind with a specific type of bioreceptor or another
The magnetic particles cluster at the center while fluorescent particles form a uniform coating around them.
That puts the fluorescent molecules in the most visible location for allowing the nanoparticles to be tracked optically through a microscope.
Initially at least the particles might be used to probe basic biological functions within cells Bawendi suggests.
As the work continues later experiments may add additional materials to the particles coating so that they interact in specific ways with molecules or structures within the cell either for diagnosis or treatment.
Melanie Gonick/MIT The ability to manipulate the particles with electromagnets is key to using them in biological research Bawendi explains:
The tiny particles could otherwise get lost in the jumble of molecules circulating within a cell.
A silica coating on the particles allows additional molecules to attach causing the particles to bind with specific structures within the cell.
which particles can be ejected. Higher currents thus promise more-efficient manufacturing and more-nimble satellites.
which is broken into particles by chemical reactions with both the substrate and the environment. Then they expose the array to a plasma rich in carbon.
The nanotubes grow up under the catalyst particles which sit atop them until the catalyst degrades.
and bacteriophage particles that bind to the bacteria and inject the genes. Both of these carriers successfully spread the CRISPR genes through the population of drug-resistant bacteria.
what counts as infected red blood cells versus some dust particles stuck on the plate. It really takes a lot of practice he says.
but if another magnetic particle such as hemozoin is present this synchrony is disrupted through a process called relaxation.
The more magnetic particles are present the more quickly the synchrony is disrupted. What we are trying to really measure is how the hydrogen s nuclear magnetic resonance is affected by the proximity of other magnetic particles Han says.
For this study the researchers used a 0. 5-tesla magnet much less expensive and powerful than the 2
For example human nasal passages are lined with cilia small hairs that sway back and forth to remove dust and other foreign particles.
Others have designed such magnetically actuated materials by infusing polymers with magnetic particles. However Wang says it s difficult to control the distribution and therefore the movement of particles through a polymer.
MIT engineers show their magnetic microhairs in action. Video: Melanie Gonick/MIT Instead she and Zhu chose to manufacture an array of microscopic pillars that uniformly tilt in response to a magnetic field.
or particles move across them. The work might enable new kinds of biomedical or microfluidic devices or solar panels that could automatically clean themselves of dust and grit.
or other forces to move fluids or particles. Varanasi s team decided to use external fields such as magnetic fields to make surfaces active exerting precise control over the behavior of particles
or droplets moving over them. The system makes use of a microtextured surface with bumps
or ridges just a few micrometers across that is then impregnated with a fluid that can be manipulated for example an oil infused with tiny magnetic particles or ferrofluid
When droplets of water or tiny particles are placed on the surface a thin coating of the fluid covers them forming a magnetic cloak.
or particle along as the layer itself is drawn magnetically across the surface. Tiny ferromagnetic particles approximately 10 nanometers in diameter in the ferrofluid could allow precision control
when it s needed such as in a microfluidic device used to test biological or chemical samples by mixing them with a variety of reagents.
While other researchers have developed systems that use magnetism to move particles or fluids these require the material being moved to be magnetic and very strong magnetic fields to move them around.
and particles slide around with virtually no friction needs much less force to move these materials.
Hepatocytes grab onto these particles because they resemble the fatty droplets that circulate in the blood after a high-fat meal is consumed. he liver is a natural destination for nanoparticles,
The new MIT particles consist of three or more concentric spheres made of short chains of a chemically modified polymer.
and released once the particles enter a target cell. Gene silencing A key feature of the MIT system is that the scientists were able to create a ibraryof many different materials
400 variants of their particles in cervical cancer cells by measuring whether they could turn off a gene coding for a fluorescent protein that had been added to the cells.
With the best-performing particles, the researchers reduced gene expression by more than 50 percent, for a dose of only 0. 20 milligrams per kilogram of solution about one-hundredth of the amount required with existing endothelial
but the particles also successfully delivered RNA to the kidneys and heart, among other organs.
Although the particles did penetrate endothelial cells in the liver, they did not enter liver hepatocytes. hat interesting is that by changing the chemistry of the nanoparticle you can affect delivery to different parts of the body,
The researchers plan to test additional potential targets in hopes that these particles could eventually be deployed to treat cancer, atherosclerosis,
For this project, Hammond and her graduate student, Stephen Morton, devised dozens of candidate particles. The most effective were a type of particle called liposomes spherical droplets surrounded by a fatty outer shell.
The MIT team designed their liposomes to carry doxorubicin inside the particle core, with erlotinib embedded in the outer layer.
The particles are coated with a polymer called PEG, which protects them from being broken down in the body
or filtered out by the liver and kidneys. Another tag folate, helps direct the particles to tumor cells,
which express high quantities of folate receptors. Once the particles reach a tumor and are taken up by cells, the particles start to break down.
Erlotinib, carried in the outer shell, is released first, but doxorubicin release is delayed and takes more time to seep into cells,
giving erlotinib time to weaken the cellsdefenses. here a lag of somewhere between four and 24 hours between
The researchers tested the particles in mice implanted with two types of human tumors: triple-negative breast tumors and non-small-cell lung tumors.
even when those drugs were given in a time-staggered order. his particle delivery system not only provides a platform for time-staggered treatment strategies in cancer,
As a next step before possible clinical trials in human patients, the researchers are now testing the particles in mice that are programmed genetically to develop tumors on their own,
they also created smaller particles (tens of microns long) that can be injected through a needle.
After injection these particles clump together to form a solid sensor. DDMPS absorbs molecular oxygen
The knee now used by thousands of patients worldwide utilizes iron particles suspended in oil between steel plates
The particles determine how energy moves at the nanoscale. The efficiency of devices such as photovoltaics and LEDS depends on how well excitons move within the material he adds.
An exciton which travels through matter as though it were a particle pairs an electron
The particles themselves don t move but the boosted energy gets passed along from one to another.
#Tiny particles could help verify goods Some 2 to 5 percent of all international trade involves counterfeit goods, according to a 2013 United nations report.
smartphone-readable particle that they believe could be deployed to help authenticate currency, electronic parts, and luxury goods, among other products.
The particles, which are invisible to the naked eye, contain colored stripes of nanocrystals that glow brightly
These particles can easily be manufactured and integrated into a variety of materials, and can withstand extreme temperatures, sun exposure,
the senior author of a paper describing the particles in the April 13 issue of Nature Materials.
'A massive encoding capacity'The new particles are about 200 microns long and include several stripes of different colored nanocrystals,
To manufacture the particles, the researchers used stop-flow lithography, a technique developed previously by Doyle.
a reaction is set off that forms a solid polymeric particle. In this case, each polymer stream contains nanocrystals that emit different colors,
allowing the researchers to form striped particles. So far, the researchers have created nanocrystals in nine different colors,
With particles that contain six stripes, there are 1 million different possible color combinations; this capacity can be enhanced exponentially by tagging products with more than one particle.
For example, if the researchers created a set of 1, 000 unique particles and then tagged products with any 10 of those particles,
there would be 1030 possible combinations far more than enough to tag every grain of sand On earth. t really a massive encoding capacity,
while on the technical staff at Lincoln Lab. ou can apply different combinations of 10 particles to products from now until long past our time
Versatile particles The microparticles could be dispersed within electronic parts or drug packaging during the manufacturing process,
The researchers demonstrated the versatility of their approach by using two polymers with radically different material properties one hydrophobic and one hydrophilic o make their particles.
suggesting that the process could easily be adapted to many types of products that companies might want to tag with these particles,
Another advantage to these particles is that they can be read without an expensive decoder like those required by most other anti-counterfeiting technologies.
anyone could image the particles after shining near-infrared light on them with a laser pointer. The researchers are also working on a smartphone app that would further process the images
and reveal the exact composition of the particles. The research was funded by the U s. Air force, the Office of the Assistant Secretary of defense for Research and Engineering, the Singapore-MIT Alliance, the National Science Foundation, the U s army Research Office,
Based on Lu graduate school research at MIT, the assay uses biological particles called bacteriophages, or phages,
and for other means across other industries. hages are the most abundant biological particle On earth.
These particles are very strong antioxidants that scavenge oxygen radicals and other highly reactive molecules produced by light
Wrapping the particles in polyacrylic acid a highly charged molecule, allows the particles to penetrate the fatty, hydrophobic membranes that surrounds chloroplasts.
In these chloroplasts, levels of damaging molecules dropped dramatically. Using the same delivery technique, the researchers also embedded semiconducting carbon nanotubes,
it alters the tube fluorescence. e could someday use these carbon nanotubes to make sensors that detect in real time, at the single-particle level,
and Institute for Medical Engineering and Science is the senior author of a paper describing the particles in the Proceedings of the National Academy of Sciences the week of Feb 24.
These particles congregate at tumor sites where MMPS cleave hundreds of peptides which accumulate in the kidneys
However these instruments are not readily available in the developing world so the researchers adapted the particles
Nonliving particles of similar size and shape show no such effect the team found nor do nonmotile bacteria that are swept along passively by the water.
Previous studies have revealed that when foreign particles such as the dye bind to albumin immune cells in the lymph nodes efficiently capture the albumin. e realized that might be an approach that you could try to copy in a vaccine design a vaccine molecule that binds to albumin
and then coat it with particles about 100 times smaller. Using that approach, they produced textured surfaces that could be heated to temperatures at least 100 degrees Celsius higher than smooth ones before droplets bounced.
To decouple those two effects, the researchers coated the surface featuring spaced-out microscale posts with nanoscale particles.
This icro-nanosurface texture provides both the extensive surface area of the tiny particles and the wide spacing of the posts to let the vapor flow.
#Self-steering particles go with the flow MIT chemical engineers have designed tiny particles that can teerthemselves along preprogrammed trajectories
Such particles could make it more feasible to design lab-on-a-chip devices, which hold potential as portable diagnostic devices for cancer and other diseases.
Much of that extra instrumentation is needed to keep the particles flowing single file through the center of the channel,
or by flowing two streams of liquid along the outer edges of the channel, forcing the particles to stay in the center.
and takes advantage of hydrodynamic principles that can be exploited simply by altering the shapes of the particles.
when a particle is confined in a narrow channel, it has strong hydrodynamic interactions with both the confining walls and any neighboring particles.
These interactions, which originate from how particles perturb the surrounding fluid, are powerful enough that they can be used to control the particlestrajectory as they flow through the channel.
The MIT researchers realized that they could manipulate these interactions by altering the particlessymmetry. Each of their particles is shaped like a dumbbell
but with a different-size disc at each end. When these asymmetrical particles flow through a narrow channel, the larger disc encounters more resistance,
or drag, forcing the particle to rotate until the larger disc is lagging behind. The asymmetrical particles stay in this slanted orientation as they flow.
Because of this slanted orientation, the particles not only move forward, in the direction of the flow, they also drift toward one side of the channel.
As a particle approaches the wall, the perturbation it creates in the fluid is reflected back by the wall,
just as waves in a pool reflect from its wall. This reflection forces the particle to flip its orientation and move toward the center of the channel.
Slightly asymmetrical particles will overshoot the center and move toward the other wall, then come back toward the center again until they gradually achieve a straight path.
Very asymmetrical particles will approach the center without crossing it, but very slowly. But with just the right amount of asymmetry, a particle will move directly to the centerline in the shortest possible time. ow that we understand how the asymmetry plays a role,
we can tune it to what we want. If you want to focus particles in a given position,
you can achieve that by a fundamental understanding of these hydrodynamic interactions, Eral says. he paper convincingly shown that shape matters,
and swarms can be redirected provided that shapes are designed well, says Patrick Tabeling, a professor at the École Supérieure de Physique et de Chimie Industrielles in Paris,
who was not part of the research team. he new and quite sophisticated mechanism may open new routes for manipulating particles and cells in an elegant manner.
In 2006, Doyle lab developed a way to create huge batches of identical particles made of hydrogel, a spongy polymer.
To create these particles, each thinner than a human hair, the researchers shine ultraviolet light through a mask onto a stream of flowing building blocks,
or oligomers. Wherever the light strikes, solid polymeric particles are formed in the shape of the mask, in a process called photopolymerization.
During this process, the researchers can also load a fluorescent probe such as an antibody at one end of the dumbbell.
The other end is stamped with a barcode a pattern of dots that reveals the particle target molecule.
This type of particle can be useful for diagnosing cancer and other diseases, following customization to detect proteins
scientists can read the fluorescent signal as the particles flow by in single file. elf-steering particles could lead to simplified flow scanners for point-of-care devices,
When the particles encounter thrombin the thrombin cleaves the peptides at a specific location releasing fragments that are excreted then in the animals urine.
Light interaction with graphene produces particles called plasmons while light interacting with hbn produces phonons.
In this so-called low battery, the electrodes are suspensions of tiny particles carried by a liquid
it is composed of a similar semisolid, colloidal suspension of particles. Chiang and Carter refer to this as a emisolid battery. impler manufacturing processthis approach greatly simplifies manufacturing,
Having the electrode in the form of tiny suspended particles instead of consolidated slabs greatly reduces the path length for charged particles as they move through the material a property known as ortuosity.
maybe they could use our particles as well, Brandl says. hen we came up with the idea to use our particles to remove toxic chemicals, pollutants,
or hormones from water, because we saw that the particles aggregate once you irradiate them with UV LIGHT. trap for ater-fearingpollutionthe researchers synthesized polymers from polyethylene glycol,
a widely used compound found in laxatives, toothpaste, and eye drops and approved by the Food and Drug Administration as a food additive,
the stabilizing outer shell of the particles is shed, and now nrichedby the pollutants they form larger aggregates that can then be removed through filtration, sedimentation,
For example, it might be possible to attach a targeting molecule to the Pop surface that would enable cancer cells to take up the particles,
Yingnan Zhao decided to use nanometre-sized colloidal palladium particles, as their dimensions can be controlled easily.
These particles are fixed to a surface, so they do not end up in the mains water supply. However, it is important to stop them clumping together,
Unfortunately, these stabilizers tend to shield the surface of the palladium particles, which reduces their effectiveness as a catalyst.
#Researchers find exposure to nanoparticles may threaten heart health Nanoparticles extremely tiny particles measured in billionths of a meter are increasingly everywhere and especially in biomedical products.
We also wanted to use nanoparticles as a model for ultrafine particle (UFP) exposure as cardiovascular disease risk factors.
A recent update from the American Heart Association also suggested that fine particles in air pollution leads to elevated risk for cardiovascular diseases.
However more research was needed to examine the role of ultrafine particles (which are much smaller than fine particles) on atherosclerosis development and cardiovascular risk.
For example using an optically active particle like gold (Au) will provide excellent contrast in near infrared (NIR) imaging
Magnetically active particles like iron (Fe) can enable physical therapies by generating heat when exposed to alternating magnetic fields causing cell death (magnetic hyperthermia).
Mechanochemical Stimulation of MCF7 Cells with Rod-shaped Fe Au Janus Particles Induces Cell Death Through Paradoxical Hyperactivation of ERK.
By using a protein recognised by the immune system to effectively disguise carbon nanoparticles we will be able to deploy these tiny particles to target hard-to-reach areas without damaging side effects to the patient.
And ultimately we want to look at ways of controlling the placement of particles on the photosensitive film in patterns other than uniform arrays.
The paper Sculpting Asymmetric Hollow-Core Three-dimensional Nanostructures Using Colloidal Particles was published online Dec 8 in the journal Small l
but direct imaging of sub-10-nanometer particles is nearly impossible. That's where we came up with the idea of using templates based on channels with gradually varying widths says co-author Mohamed Asbahi.
After depositing a monolayer of 8-nanometer particles in the template they used scanning electron microscopy to identify any emergent width-dependent patterns.
The success of DSA-n depends on the positioning accuracy of the particles says Yang. By exploiting the rich set of structural geometries that exist between ordered states we can design templates that guide particles into complex periodic and nonperiodic structures s
#Lengthening the life of high capacity silicon electrodes in rechargeable lithium batteries A new study will help researchers create longer-lasting higher-capacity lithium rechargeable batteries
The coated silicon particles lasted at least five times longer#uncoated particles died by 30 cycles but the coated ones still carried a charge after 150 cycles.
and is currently the only group that can create alucone-coated silicon particles#took high magnification images of the particles in an electron microscope.
But Wang's team has a microscope that can view the particles in action while they are being charged and discharged.
and limits how much lithium the particle can take in when a battery charges. At the same time they found that the alucone coating softens the particles making it easier for them to expand
and shrink with lithium. And the microscopic images revealed something else#the rubbery alucone replaces the hard oxide.
But this molecular deposition method that coats the particles completely changed the protective layer. In addition the particles with the oxide shells tend to merge together during charging increasing their size
and preventing lithium from permeating the silicon. The rubbery coating kept the particles separated allowing them to function optimally.
In the future the researchers would like to develop an easier method of coating the silicon nanoparticles. Explore further:
With this technology a low-power laser beam is directed at the tumor where a small amount of magnetic iron-oxide nanoparticles are present either by injecting the particles directly into the tumor
whereby the particles find and bind to the abnormal cancer cells via cell-specific targeting. Sufficient heat is generated then locally by the laser light raising the tumor temperature rapidly to above 43 degrees Celsius
and unlock their florescent particles so they can be detected by a photon laser light. The laser light heats the nanoparticles to at least 43 degrees Celsius to kill the cancer cells ultimately leaving all the other cells in the body unharmed.
This new biomarker which has immense potential for drug development is made from a nanophosphor particle ten thousand times smaller than a grain of sand.
these particles can form dangerous, highly reactive chemicals called free radicals that can damage DNA. Because light does not reach the human body's interior,
"We didn't set out to test the safety of the particles themselveshat's for someone else to determine,
Gaharwar and his colleagues employ two-dimensional, disc-shaped particles known as synthetic silicate nanoplatelets. Because of their shape, these platelets have a high surface area,
The structure, composition and arrangement of the platelets result in both positive and negative charges on each particle.
Through this project Fan developed a faster way of treating the biochar particles using a new technology called plasma activation.
which cover conductive titanium dioxide particles. The dyes absorb photons and produce electrons that flow out of the cell for use;
titanium dioxide and light-capturing organic dye particles, the largest cells were only 350 microns thickhe equivalent of about two sheets of papernd could be flexed easily and repeatedly.
These tiny platelet-shaped particles that behave just like their human counterparts can be added to the blood flow to supply
According to Anselmo's investigations for the same surface properties and shape nanoscale particles can perform even better than micron-size platelets.
Additionally this technology allows for customization of the particles with other therapeutic substances medications therapies
Particles could be made to fulfill certain requirements to travel to certain parts of the body across the blood-brain barrier for instance for better diagnostics
On a technical level they're talking about magnetic particles so you'd assume that'd be made something of iron
In Professor Graham's view there are two serious hurdles for nanotechnologists to overcome before particle-based biosensing becomes a reality:
So for Google's biomonitor they need to work out how to keep the particles in the body
The team used a laser to excite the plasmonic resonance of specific particles produced in the reaction.
Then the reaction can be repeated to produce more of the desired broken-symmetry particles based on their plasmonic signature.
#A quantum leap in nanoparticle efficiency (Phys. org) New research has unlocked the secrets of efficiency in nanomaterials that is materials with very tiny particles
In an international study University of Melbourne and the National Institute of Standards and Technology in the US found that pairs of closely spaced nano particles made of gold can act as optical antennas.
These antennae concentrate the light shining on them into tiny regions located in the gap between the nano particles.
what gap was required between particles to best concentrate the light but we now have the technology to test it.
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