Tag Archives: nanoparticles

Air pollution can contaminate your heart cells with metal nanoparticles from infancy

Researchers are uncovering further evidence of the adverse health effects of air pollution.

Smog in Warsaw, 2015.
Image via Pixabay.

Toxic metallic nanoparticles from such pollution can find their way into the mitochondria of our hearts, a new paper reports, with a negative impact on our health. Mitochondria provide the power that keeps our cells going; damaging them will thus damage our cells.

This effect was seen in the hearts of people living in polluted cities and could be an important cause of cardiac stress, the team adds.

Poor air, poor health

“It’s been known for a long time that people with high exposure to particulate air pollution experience increased levels and severity of heart disease,” says Professor Barbara Maher of Lancaster University, lead author of the paper. “We found these metal particles inside the heart of even a three-year-old.”

“It’s really urgent to reduce emissions of ultrafine particles from our vehicles and from industry before we give heart disease to the next generation, too,” she adds.

The team analyzed the hearts retrieved from two young people who had died in accidents and lived in the Mexico City area. Air pollution levels here often exceed health guidelines, the authors explain.

They found metallic nanoparticles associated with air pollution (such as iron and titanium-rich particles) inside damaged heart cells of a 26- and 3-year-old, randomly selected from 63 previously-investigated children and young adults.

Dark-field scanning/transmission electron microscopy image of heart tissue in the left ventricle, with F showing the iron-rich particles highlighted in A and D.
Image credits B.A. Maher et al., (2020), Environmental Research.

Using high-resolution transmission electron microscopy and X-ray analysis, they found that mitochondria containing iron-rich nanoparticles were damaged, showing ruptured membranes or deformities. Such particles were associated with the development of heart disease, as they cause oxidative stress which chemically damages cells, even in very young tissues.

The team found “abundant presence of rounded, electron-dense nanoparticles, mostly ~15–40 nanometers, most frequently inside mitochondria”. They note that the presence of iron inside mitochondria can alter their chemical mechanism to produce highly reactant oxygen species which attack proteins.

The particles are “indistinguishable from the iron-rich nanoparticles so abundant and pervasive in urban and roadside air pollution”, the team notes.

The results show that such nanoparticles may jump-start heart disease in early life and cardiovascular illness later on. Air pollution can thus be responsible for the international “silent epidemic” of heart disease. It could also contribute to the high death rates from COVID-19 seen in areas with poor air quality.

Another point of concern is the magnetic properties of these particles. It’s possible that, should they build-up in the heart in large amounts, these will react to the magnetic fields produced by appliances and electronics. Exposure could cause cell damage and lead to heart dysfunction. People who work jobs that expose them to magnetic fields, such as welders or certain branches of engineering, could also be at risk.

The paper “Iron-rich air pollution nanoparticles: An unrecognized environmental risk factor for myocardial mitochondrial dysfunction and cardiac oxidative stress” has been published in the journal Environmental Research.

New shape-shifting metal particles shred drug-resistant bacteria to bits

New research at RMIT University is looking into liquid metals as a solution to drug-resistant bacteria.

Image credits Aaron Elbourne et al., (2020), ACS Nano.

The approach the team is working on involves using magnetic particles of liquid metals to physically destroy bacteria, side-stepping the use of antibiotics entirely. The study describes how this technique can be used to destroy both bacteria and bacterial biofilms — protective, layered structures that house bacteria — without harming human cells.

A shred of hope

“We’re heading to a post-antibiotic future, where common bacterial infections, minor injuries and routine surgeries could once again become deadly,” says Dr Aaron Elbourne, a Postdoctoral Fellow in the Nanobiotechnology Laboratory at RMIT, and the paper’s lead author.

“It’s not enough to reduce antibiotic use, we need to completely rethink how we fight bacterial infections.”

The rising levels of antibiotic resistance recorded throughout the world is a very scary development, one that we’ll have to tackle sooner rather than later. Modern antibiotics fundamentally changed the rules of life for us when they were first developed 90 years ago. Before that, any infection was basically the luck of the draw: even a routine medical intervention or the most unassuming of wounds could become infected, and even the humblest infection could kill.

They still can, but modern antibiotics offer us a level of protection that people in the past could only pray for. Still, overuse and misuse of these compounds are forcing pathogens to adapt and survive, and they’re doing so much faster than we can develop new, more powerful drugs. It’s estimated that antibiotic-resistant bacteria cause in excess of 700,000 deaths per year, a figure which could reach 10 million a year by 2050 (which would make it deadlier than cancer). Bacteria’s ability to form biofilms further complicates the matter, as such structures render them virtually immune to all existing antibiotics.

Antibiotics are chemical compounds that prevent bacteria from functioning properly. They can do this through a range of methods: by blocking their ability to form proteins, by breaking down their membrane, or by interfering with their ability to reproduce. Human cells and bacterial cells are similar but different enough that antibiotics can be made to target the latter and leave the former unaffected.

The team wanted to develop a whole new method to attack pathogens, one that does away completely with chemical means (which bacteria can adapt to).

“Bacteria are incredibly adaptable and over time they develop defences to the chemicals used in antibiotics, but they have no way of dealing with a physical attack,” Dr. Elbourne explains.

“Our method uses precision-engineered liquid metals to physically rip bacteria to shreds and smash through the biofilm where bacteria live and multiply.”

The team’s approach involves the use of nano-sized droplets of liquid metal. When exposed to a low-intensity magnetic field, these droplets change shape and grow sharp edges.

To check how effective they would be at the task, the team placed droplets in contact with a bacterial biofilm then made them change shape. The sharp edges broke down the biofilm and physically ruptured the bacterial cells inside, the team found. They proved effective against both Gram-positive and Gram-negative bacterial biofilms. After 90 minutes of exposure to the particles, both biofilms were destroyed and 99% of the bacteria inside were killed, the team explains, suggesting that they would be effective as a wide-range treatment option. Human cells were left unaffected by the nanoparticles.

The team says that their method is versatile enough to be used in multiple settings and approaches. For example, a coating of the nanoparticles could be sprayed on implants to help prevent infections for hip or knee replacements. They also plan to explore its effectiveness against fungal infections, cancerous tumors, and build-ups such as cholesterol plaques.

“There’s also potential to develop this into an injectable treatment that could be used at the site of infection,” said Dr Vi Khanh, a Postdoctoral Research Fellow at the North Carolina State University and co-author of the paper.

The nanoparticles are currently undergoing preclinical trials in animals. If all goes well, human trials could start in a few years.

The paper “Antibacterial Liquid Metals: Biofilm Treatment via Magnetic Activation” has been published in the journal ACS Nano.

Real life invisibility cloaks are closer than we think

It might not be the Harry Potter’s invisibility cloak just yet, but researchers from Queen Mary University of London (QMUL) have successfully created a practical cloaking device using nano-size particles to make curved surfaces appear flat to electromagnetic waves.

Image credit Luigi La Spada

Image credit Luigi La Spada

In addition to its potential to someday lead to the creation of a real-life invisibility cloak, the team believes that the device could help broaden the potential ways that antennas can be tethered to platforms, allowing for the utilization of different sized and shaped antennas in awkward places.

“The design is based upon transformation optics, a concept behind the idea of the invisibility cloak,” said Yang Hao, a professor from QMUL’s School of Electronic Engineering and Computer Science and co-author of the study. “Previous research has shown this technique working at one frequency. However, we can demonstrate that it works at a greater range of frequencies making it more useful for other engineering applications, such as nano-antennas and the aerospace industry.”

The team took a curved surface roughly the size of a tennis ball and coated it with nano-particles to form seven unique layers, creating a material called a graded index nanocomposite medium. This material features varying electric properties in each layer depending on their position.

The result is the “cloaking” of the curved object by preventing it from scattering electromagnetic waves through the reduction of its electromagnetic signature.

The manipulation of surface waves seen in the new invisibility cloak is an important achievement for the development of numerous technological solutions and the advancement of many fields of science.

“We demonstrated a practical possibility to use nanocomposites to control surface wave propagation through advanced additive manufacturing,” said Luigi La Spada, also of QMUL and first author of the study. “Perhaps most importantly, the approach used can be applied to other physical phenomena that are described by wave equations, such as acoustics. For this reason, we believe that this work has a great industrial impact.”

Journal Reference: Surface Wave Cloak from Graded Refractive Index Nanocomposites. 15 July 2016. 10.1038/srep29363

New plasma printing technique can deposit nanomaterials on flexible, 3D substrates

A new nanomaterial printing method could make it both easier and cheaper to create devices such as wearable chemical and biological sensors, data storage and integrated circuits — even on flexible surfaces such as paper or cloth. The secret? Plasma.

The nozzle firing a jet of carbon nanotubes with helium plasma off and on. When the plasma is off, the density of carbon nanotubes is small. The plasma focuses the nanotubes onto the substrate with high density and good adhesion.
Image credits NASA Ames Research Center.

Printing layers of nanoparticles of nanotubes onto a substrate doesn’t necessarily require any fancy hardware — in fact, the most common method today is to use an inkjet printer very similar to the one you might have in your home or office. Although these printers are cost efficient and have stood the test of time, they’re not without limitations. They can only print on rigid materials with liquid ink — and not all materials can be easily made into a liquid. But probably the most serious limitation is that they can only print on 2D objects.

Aerosol printing techniques solve some of these problems. They can be employed to deposit smooth, thin films of nanomaterials on flexible substrates. But because the “ink” has to be heated to several hundreds of degrees to dry, using flammable materials such as paper or cloth remains a big no-no.

A new printing method developed by researchers from NASA Ames and SLAC National Accelerator Laboratory works around this issue. The plasma-based printing system doesn’t a heat-treating phase — in fact, the whole takes place at temperatures around 40 degrees Celsius. It also doesn’t require the printing material to be liquid.

“You can use it to deposit things on paper, plastic, cotton, or any kind of textile,” said Mayya Meyyappan of NASA’s Ames Research Center.

“It’s ideal for soft substrates.”

The team demonstrated their technique by covering a sheet of paper in a layer of carbon nanotubes. To do this, they blasted a mixture of carbon nanotubes and helium-ion plasma through a nozzle directly onto the paper. Because the plasma focuses the particles onto the paper’s surface, they form a well consolidated layer without requiring further heat-treatment.

They then printed two simple chemical and biological sensors. By adding certain molecules to the nanotube-plasma cocktail, they can change the tubes’ electrical resistance and response to certain compounds. The chemical sensor was designed to detect ammonia gas and the biological one was tailored to respond to dopamine, a neurotransmitter linked to disorders like Parkinson’s and epilepsy.

But these are just simple proof-of-concept constructs, Meyyappan said.

“There’s a wide range of biosensing applications,” she added.

Applications like monitoring cholesterol levels, checking for pathogens or hormonal imbalances, to name a few.

This method is very versatile and can easily be scaled up — just add more nozzles. For example, a shower-head type system could print large surfaces at once. Alternatively, it could be designed to act like a hose, spraying nanomaterials on 3D surfaces.

“It can do things inkjet printing cannot do,” Meyyappan said. “But [it can do] anything inkjet printing can do, it can be pretty competitive.”

Meyyappan said that the method is ready for commercial applications, and should be relatively simple and inexpensive to develop. The team is now tweaking their technique to allow for other printing materials, such as copper. This would allow them to print materials used for batteries onto thin sheets of metal such as aluminum. The sheet can then be rolled up to make very tiny, very powerful batteries for cellphones or other devices.

The full paper, titled “Plasma jet printing for flexible substrate” has been published online in the journal Applied Physics Letters and can be read here.

Soon, oncologists will use shapeshifting to fight cancer

University of Toronto researchers have developed a molecular delivery system to administer chemotherapy drugs with as little collateral damage as possible.

Chemotherapy today could be compared to a shotgun — while effective in killing cancerous cells, once in the blood they’re impossible to aim and are just as prone to attacking your own fast-growing cells. This includes hair follicles, skin cells and the ones lining your digestive system, giving chemo patients their distinctive look.

This level of collateral damage — especially in a patient already suffering from a condition as physically and psychically draining as cancer — is unacceptable to Professor Warren Chan. He spent the last ten years working on finding a way to deliver chemotherapy drugs into tumors, and nowhere else.

Professor Warren Chan has spent the last decade figuring out how to deliver chemotherapy drugs into tumours — and nowhere else.
Image credits NSERC

His work and that of his team has culminated in a set of nanoparticles with strands of DNA attached to them, that can change shape to penetrate into diseased tissue.

“Your body is basically a series of compartments. Think of it as a giant house with rooms inside,” Chan says.

“We’re trying to figure out how to get something that’s outside, into one specific room. One has to develop a map and a system that can move through the house where each path to the final room may have different restrictions such as height and width.”

No two cancerous tumors are identical. Early-stage pancreatic cancer for example responds differently to treatment than prostate cancer, or even pancreatic cancer at a more advanced stage. They not only respond differently, but are different structurally. As such, whether a particle can enter the tumor or not depends on its size, shape or surface chemistry.

Chan and his team have studied the way these factors interact to dictate who gets in and who doesn’t, and have designed the perfect party-crasher molecular delivery system — one that can get in no matter how big the bouncer is. Their system relies on sets of modular nanoparticles that can alter their shape, size and chemical properties when they come in contact with specific DNA sequences.

“We’re making shape-changing nanoparticles,” says Chan.

“They’re a series of building blocks, kind of like a LEGO set.”

These blocks are actually tiny pieces of metal with DNA strands attached. They can be built in a myriad of shapes and have exposed or hidden binding sites. Chan envisions that the nanoparticles will float around harmlessly in the blood until their DNA strand binds to a sequence of marker DNA, known to be indicative of cancer.

As this happens, the particle changes shape and then carries out its function, either attacking the cell with a drug molecule, tagging it with a signal molecule, or whatever else Chan’s team has designed the nanoparticle to do.

“We were inspired by the ability of proteins to alter their conformation — they somehow figure out how to alleviate all these delivery issues inside the body,” says Chan.

“Using this idea, we thought, ‘Can we engineer a nanoparticle to function like a protein, but one that can be programmed outside the body with medical capabilities?'”

Nanotechnology and material sciences are still newcomers in the field of medicine, but Chan thinks there’s promise in their use.

“Here’s how we look at these problems: it’s like you’re going to Vancouver from Toronto, but no one tells you how to get there, no one gives you a map, or a plane ticket, or a car — that’s where we are in this field,” he says.

“The idea of targeting drugs to tumors is like figuring out how to go to Vancouver. It’s a simple concept, but to get there isn’t simple if not enough information is provided.”

The team is now working on a way to deliver enough nanoparticles to tumors to allow for efficient treatment. But Chen is confident their system is sound and that they’ll solve all the teething problems soon.

“We’ve only scratched the surface of how nanotechnology ‘delivery’ works in the body, so now we’re continuing to explore different details of why and how tumors and other organs allow or block certain things from getting in,” Chan concludes.

The full paper, titled “Tailoring nanoparticle designs to target cancer based on tumor pathophysiology” has been published online in the journal Proceedings of the National Academy of Sciences and can be found here.

As cells squeeze through a narrow channel, tiny holes open in their membranes, allowing large molecules such as RNA to pass through. Image: Armon Sharei and Emily Jackson

New method allows large molecules to get squeezed through cell membranes

A group of researchers at MIT have devised a new method for infiltrating cells with large molecules such as nanoparticles or proteins that is a lot more non-intrusive and doesn’t damage the cell. Imaging target cells or growing more stable stem cells might thus be possible with this method.

As cells squeeze through a narrow channel, tiny holes open in their membranes, allowing large molecules such as RNA to pass through. Image: Armon Sharei and Emily Jackson

As cells squeeze through a narrow channel, tiny holes open in their membranes, allowing large molecules such as RNA to pass through.
Image: Armon Sharei and Emily Jackson

Every cell has a membrane, which is put to great use as it protects the cell’s inner environment by regulating what gets in and what gets out. Typically, you don’t want foreign molecules entering your cells, but sometimes you do. Various methods have been employed to breach cell membranes and introduce other bodies, however these tend to be intrusive and sometimes can lead to the damaging and even destruction of the cell.

The MIT method of introducing large molecules in cell is a lot safer and efficient and implies squeezing the cell through a narrow construction just enough for tiny, yet temporary, gaps to surface. Prior to squeezing the cell, large molecules – be it RNA, proteins or nanoparticles – are tasked to float outside cell, such that when the holes pop these slide through the membrane instantly.

Through this technique the MIT researchers were able to deliver reprogramming proteins which turned the target cells into pluripotent stem cells – notoriously difficult to generate efficiently – with a success rate 10 to 100 times better than any other existing method. A simply massive advancement. Also, they’ve also tested the method with other large molecules like special nanoparticles, like carbon nanotubes or quantum dots, to image cells and thus monitor their activity.

“It’s very useful to be able to get large molecules into cells. We thought it might be interesting if you could have a relatively simple system that could deliver many different compounds,” says Klavs Jensen, the Warren K. Lewis Professor of Chemical Engineering, professor of materials science and engineering, and a senior author of a paper describing the new device in this week’s issue of the Proceedings of the National Academy of Sciences.

The team’s fantastic research builds upon previous work, when Jensen and Robert Langer, the David H. Koch Institute Professor at MIT and also a study lead author, forced molecules into cells as they flowed through a microfluidic device. The process was slow and not very effective, but it was during this time that the researchers learned that if you squeeze a cell just right now, tiny holes will appear – pure windows of opportunity.

Capitalizing on this, the scientists then proceeded to adjust their set-up and devised some rectangular microfluidic chips, no larger than a quarter, fitted with 40 to 70 parallel channels.  Cells are suspended in a solution with the material to be delivered and flowed through the channel at high speed — about one meter per second. Halfway through the channel, the cells pass through a constriction about 30 to 80 percent smaller than the cells’ diameter. The cells don’t suffer any irreparable damage, and they maintain their normal functions after the treatment.

“This appears to be a very broadly applicable approach for loading a diversity of different compounds into a diversity of different cells,” says Mark Prausnitz, a professor of chemical and biomolecular engineering at Georgia Tech, who was not part of the research team. “It’s a really nice example of taking devices from the world of engineering and microelectronics and using them in quite different ways to solve problems in medicine that could have really great impact.”

 

source: MIT

The particles (brown) are coated with peptides (blue) that are cleaved by enzymes (green) found at the disease site

Detecting biomarkers in urine could allow for earlier cancer diagnosis

By detecting specific biomarkers (proteins) produced by cancer cells, physicians can diagnose a tumor, however these are so diluted in the bloodstream that only after they’re sufficiently present can they be observed. Usually this happens many years after the tumor had already the chance to develop. Now, scientists at MIT have proposed a novel method involving nanoparticles specially developed to interact with cancer biomarkers to multiply the latter sufficiently enough to become visible. This allow for a much earlier cancer diagnosis by analyzing urine samples.

Cancer cells often produce large quantities of enzymes called proteases or MMPs that cleave proteins into smaller fragments allowing  cancer cells to escape their original positions and spread through out the body, breaking the proteins of the extracellular matrix that would otherwise bind them in place.

Studying cancer signals

The particles (brown) are coated with peptides (blue) that are cleaved by enzymes (green) found at the disease site

The particles (brown) are coated with peptides (blue) that are cleaved by enzymes (green) found at the disease site. (c) Justin H. Lo

The  MIT team, working with researchers from Beth Israel Deaconess Medical Center, developed special nanoparticles which they coated with peptides (protein fragments) targeted by the MMP proteases. The modified nanoparticles were found to accumulate at tumor sites, before making their way through the leaky blood vessels that surround tumors. From here on hundreds of peptides are released from the nanoparticles  which accumulate in the kidneys and are excreted in the urine. Using mass spectrometry these can then be detected in the urine sample.

 “Instead of being dependent on the body to naturally shed biomarkers, you’re sampling the site of interest and causing biomarkers that you engineered to be released,” says Gambhir, who was not part of the research team,” said Sanjiv Gambhir, chairman of the Department of Radiology at Stanford University School of Medicine.

There are numerous types of cancer however. The researchers thus designed their particles to express 10 different peptides, each of which is cleaved by a different one of the dozens of MMP proteases. Each is distinctly build in order to identify the various types of tumors.

To test their method, the scientists used the nanoparticles to detect the early stages of colorectal cancer in mice, and to monitor the progression of liver fibrosis. Typically this is done through a biopsy which is extremely complicated and requires surgery. The researchers found that they could offer more rapid feedback than biopsies. In ongoing studies, the team is studying the particles’ ability to measure tumor response to chemotherapy and to detect metastasis.

Findings were published in the journal Nature Biotechnology.

via

The solar steam device developed at Rice University has an overall energy efficiency of 24 percent, far surpassing that of photovoltaic solar panels. It may first be used in sanitation and water-purification applications in the developing world. (c) Jeff Fitlow

Nanoparticle-tech converts solar energy into steam with extreme efficiency

The solar steam device developed at Rice University has an overall energy efficiency of 24 percent, far surpassing that of photovoltaic solar panels. It may first be used in sanitation and water-purification applications in the developing world. (c) Jeff Fitlow

The solar steam device developed at Rice University has an overall energy efficiency of 24 percent, far surpassing that of photovoltaic solar panels. It may first be used in sanitation and water-purification applications in the developing world. (c) Jeff Fitlow

While current solar energy conversion technology is preoccupied with generating electricity with as much efficiency as possible, researchers at Rice University have invented a new technological set-up consisting of nanoparticles smaller than the the wavelength of light that can transform solar energy into steam almost instantly. Their findings show a registered efficiency of 24%, while current solar panel standards range at only 15%.

Since the heydays of the industrial revolution steam has been at the center of energy generation. Even today, 90% of the world’s electricity relies on steam power. Most of this steam is either generated by nuclear power plants or humongous industrial boilers, the Rice invention however is a lot more delicate in nature and has been developed for low-cost sanitation, water purification and human waste treatment for the developing world.

“This is about a lot more than electricity,” said LANP Director Naomi Halas, the lead scientist on the project. “With this technology, we are beginning to think about solar thermal power in a completely different way.”

The technology works by employing light absorbing nanoparticles submerged into water that convert solar energy into heat. Moreover  even when submerged into water stacked with ice, Neumann showed she could create steam from nearly frozen water, albeit a lens to concentrate sunlight was used. You can watch the experiment and more details about the project in the video below.

“We’re going from heating water on the macro scale to heating it at the nanoscale,” Halas said. “Our particles are very small — even smaller than a wavelength of light — which means they have an extremely small surface area to dissipate heat. This intense heating allows us to generate steam locally, right at the surface of the particle, and the idea of generating steam locally is really counterintuitive.”



Generating steam directly from solar energy

This is made possible since the nanoparticles after absorbing light instantly reach temperatures well above the boiling point of water, generating steam in the process at temperatures of 150°C (300°F) on the their surface. This is were the catch lies, as well, since the steam can only be generated over a very small surface, locally.

The technology converts about 80 percent of the energy coming from the sun into steam, which means it could generate electricity with an overall efficiency of 24 percent. The Rice researchers believe people in the developing world would be the first to benefit from this kind of technology, as there countless communities around the globe where access to grid electricity is non-existant. The scientists have already demonstrated that their technology can be used for sterilizing medical and dental instruments at clinics that lack electricity.

“Solar steam is remarkable because of its efficiency,” said Neumann, the lead co-author on the paper. “It does not require acres of mirrors or solar panels. In fact, the footprint can be very small. For example, the light window in our demonstration autoclave was just a few square centimeters.”

The findings were detailed in the journal ACS Nano.

source: Rice University

Intracellular controlled release of molecules within senescent cells was achieved using mesoporous silica nanoparticles (MSNs) capped with a galacto-oligosaccharide (GOS) to contain the cargo molecules (magenta spheres; see scheme). The GOS is a substrate of the senescent biomarker, senescence-associated β-galactosidase (SA-β-gal), and releases the cargo upon entry into SA-β-gal expressing cells.

Intelligent nanoparticles drop anti-aging cargo

A group of researchers have successfully tested a novel nanodevice treatment, in which intelligent nanoparticles selectively open and release drugs which target aging cells. The approach could render results when treating patients suffering from diseases involving tissue or cellular degeneration such as cancer, Alzheimer’s, Parkinson’s, accelerated aging disorders (progeria). It could also boosts results in the cosmetic industry, where anti-aging products are always welcomed.

Intracellular controlled release of molecules within senescent cells was achieved using mesoporous silica nanoparticles (MSNs) capped with a galacto-oligosaccharide (GOS) to contain the cargo molecules (magenta spheres; see scheme). The GOS is a substrate of the senescent biomarker, senescence-associated β-galactosidase (SA-β-gal), and releases the cargo upon entry into SA-β-gal expressing cells.

Intracellular controlled release of molecules within senescent cells was achieved using mesoporous silica nanoparticles (MSNs) capped with a galacto-oligosaccharide (GOS) to contain the cargo molecules (magenta spheres; see scheme). The GOS is a substrate of the senescent biomarker, senescence-associated β-galactosidase (SA-β-gal), and releases the cargo upon entry into SA-β-gal expressing cells.

Senescence is a physiological process of the body to eliminate aged cells or ones with alterations that may compromise their viability. In young, healthy bodies the senescence mechanisms prevents the accumulation of aged cells (senescent) in organs and tissues, which disrupts their proper functions, and sometimes lead to the apparition of tumors. As we continue to age, though, senescent accumulation is inevitable and age related diseases surface. The elimination of these cells would slow down the appearance of diseases associated with aging.

“The nanodevice that we have developed consists of mesoporous nanoparticles with a galactooligosaccharide outer surface that prevents the release of the load and that only selectively opens in degenerative phase cells or senescent cells. The proof of concept demonstrates for the first time that selected chemicals can be released in these cells and not in others,” says Ramón Martínez Máñez, researcher at the IDN Centre — Universitat Politècnica de València and CIBER-BBN member.

The scientists tested the new nanodevice in cell cultures derived of patients with accelerated aging syndrome dyskeratosis congenita. These cell cultures are characterized by a high concentration of senescent cells, due to high levels of beta-galactosidase activity – an enzyme which is associated with senescence. The researchers designed nanoparticles that open when the enzyme is detected release their contents in order to eliminate senescent cells, prevent deterioration or even reactivate for their rejuvenation.

“There are a number of diseases associated with premature aging of tissues, many of which affect very young patients and for whom there is no therapeutic alternative, as in the case of DC or aplastic anemia. Other diseases affect adults, as idiopathic pulmonary fibrosis or liver cirrhosis. These nanoparticles represent a unique opportunity to selectively deliver therapeutic compounds to affected tissues and rescue their viability and functionality” explains Rosario Perona, researcher at the Instituto de Investigaciones Biomédicas (CSIC/UAM) and CIBERER member.

The next step of this research is to test the devise with therapeutic agents and validate it in animal models.

“As far as we know this is the first time that a nanotherapy for senescent cells has been described. Although there is still far to go from these results to the possible elimination of senescent cells or rejuvenation therapies, we believe that our research may open new paths for developing therapies for the treatment of age-related diseases,” says Ramón Martínez Máñez.

Findings were published in the journal Angewandte Chemie International.

Candle light

A candle’s flame burns millions of diamond nano-particles every second

Candle lightDiamonds are for a nano-second – in the glitter of a candle light, that is. In a stroke of brilliance, Professor Wuzong Zhou, Professor of Chemistry at the University of St Andrews, has found millions of diamond nano-particles in the flickering light of a simple candle.

Since its invention in China thousands of years ago, people have always been fascinated by the candle’s light, inspiring numerous thinkers with its brilliant halo. Zhou’s research has unraveled the mystery that has baffled men for all these years.

As it burns, 1.5 million diamond particles are created every second within its flame. It was already known that at the candle flame’s base hydro-carbon molecules existed, which were ultimately converted into carbon dioxide by the top of the flame. However, the process in between these two states was up to now unbeknownst to scientists.

Professor Zhou, assisted by one of his students Mr Zixue Su, used a novel sampling technique, he developed himself, was able to extract particles from within the middle of the flame for studying. Much to his surprise, he found that a candle flame contains all four known forms of carbon. The whole event is a premier success, after other failed attempts by scientists in the past. Curiously enough, Professor Zhou entered this endevour after he received a challenge from a fellow scientist in combustion.

“A colleague at another university said to me: “Of course no-one knows what a candle flame is actually made of.

“I told him I believed science could explain everything eventually, so I decided to find out,” Dr Zhou said.

As such, there were discovered diamond nanoparticles and fullerenic particles, along with graphitic and amorphous carbon. Dr. Zhou believes that his research might funnel advances towards a better understanding and manufacturing of diamonds, a critical material in the industry. Cheaper, more environmental friendly alternatives might be developed.

Dr Zhou added: “Unfortunately the diamond particles are burned away in the process, and converted into carbon dioxide, but this will change the way we view a candle flame forever.”

image credit

Article source

Photograph of nanobots killing off cancer

cancer-nanobots

Take a really good look at this picture; you may just be looking at the very thing that will defeat cancer. The black dots are nanobots, practically delivering a killing blow to the cancerous cells, and only to those cells. According to Mark Davis, head of the research team that created the nanobot anti-cancer army at the California Institute of Technology, the above mentioned technology “sneaks in, evades the immune system, delivers the siRNA, and the disassembled components exit out”.

According to the study published in Nature, you can use as many of these nanobots as you wish, and they’ll keep on raiding and killing the cancerous cells and stoping tumours.

“The more [they] put in, the more ends up where they are supposed to be, in tumour cells.”

The technology has its roots on RNA interference, a discovery that brought Andrew Fire and Craig Mello the Nobel Prize in 2006.

“RNAi is a new way to stop the production of proteins,” says Davis. “What makes it such a potentially powerful tool, he adds, is the fact that its target is not a protein. The vulnerable areas of a protein may be hidden within its three-dimensional folds, making it difficult for many therapeutics to reach them. In contrast, RNA interference targets the messenger RNA (mRNA) that encodes the information needed to make a protein in the first place. In principle,” says Davis, “that means every protein now is druggable because its inhibition is accomplished by destroying the mRNA. And we can go after mRNAs in a very designed way given all the genomic data that are and will become available.”

This is just the first demonstration CalTech performed, but it went on perfectly, and the results are quite promising. We will hold our fingers crossed.

‘Holy Grail’ Of Nanoscience achieved ?!

nanoparticlesResearchers at at the U.S. Department of Energy’s Brookhaven National Laboratory have achieved something that many people call the Holy Grail of Nanoscience; this in fact reffers to the fact that they have used for the first time DNA to guide the creation of three-dimensional, ordered, crystalline structures of nanoparticles (particles with dimensions measured in billionths of a meter). What makes this so important is the fact that it’s essential to producing functional materials that take advantage of the unique properties that may exist at the nanoscale – for example, enhanced magnetism, improved catalytic activity, or new optical properties.

“From previous research, we know that highly selective DNA binding can be used to program nanoparticle interactions,” said Oleg Gang, a scientist at Brookhaven’s Center for Functional Nanomaterials (CFN), who led the interdisciplinary research team, which includes Dmytro Nykypanchuk and Mathew Maye of the CFN, and Daniel van der Lelie of the Biology Department. “But while theory has intriguingly predicted that DNA can guide nanoparticles to form ordered, 3-D phases, no one has accomplished this experimentally, until now.”

Their work relies on the attractive forces between complementary strands of DNA; first, the scientists attach to nanoparticles hair-like extensions of DNA with specific “recognition sequences” of complementary bases. Then they mix the DNA-covered particles in solution. When the recognition sequences find one another in solution, they bind together to link the nanoparticles.

“This work is the first step to demonstrate that it is possible to obtain ordered structures. But it opens so many avenues for researchers, and this is why it is so exciting,” Gang says.