Tag Archives: nanoparticles

Injectable bandages for internal bleeding and hydrogel for the brain

This injectable bandage could be a gamechanger (as they say) if it can be taken beyond the ‘in vitro’ (i.e., petri dish) testing stage. A May 22, 2018 news item on Nanowerk makes the announcement (Note: A link has been removed),

While several products are available to quickly seal surface wounds, rapidly stopping fatal internal bleeding has proven more difficult. Now researchers from the Department of Biomedical Engineering at Texas A&M University are developing an injectable hydrogel bandage that could save lives in emergencies such as penetrating shrapnel wounds on the battlefield (Acta Biomaterialia, “Nanoengineered injectable hydrogels for wound healing application”).

A May 22, 2018 US National Institute of Biomedical Engineering and Bioengiineering news release, which originated the news item, provides more detail (Note: Links have been removed),

The researchers combined a hydrogel base (a water-swollen polymer) and nanoparticles that interact with the body’s natural blood-clotting mechanism. “The hydrogel expands to rapidly fill puncture wounds and stop blood loss,” explained Akhilesh Gaharwar, Ph.D., assistant professor and senior investigator on the work. “The surface of the nanoparticles attracts blood platelets that become activated and start the natural clotting cascade of the body.”

Enhanced clotting when the nanoparticles were added to the hydrogel was confirmed by standard laboratory blood clotting tests. Clotting time was reduced from eight minutes to six minutes when the hydrogel was introduced into the mixture. When nanoparticles were added, clotting time was significantly reduced, to less than three minutes.

In addition to the rapid clotting mechanism of the hydrogel composite, the engineers took advantage of special properties of the nanoparticle component. They found they could use the electric charge of the nanoparticles to add growth factors that efficiently adhered to the particles. “Stopping fatal bleeding rapidly was the goal of our work,” said Gaharwar. “However, we found that we could attach growth factors to the nanoparticles. This was an added bonus because the growth factors act to begin the body’s natural wound healing process—the next step needed after bleeding has stopped.”

The researchers were able to attach vascular endothelial growth factor (VEGF) to the nanoparticles. They tested the hydrogel/nanoparticle/VEGF combination in a cell culture test that mimics the wound healing process. The test uses a petri dish with a layer of endothelial cells on the surface that create a solid skin-like sheet. The sheet is then scratched down the center creating a rip or hole in the sheet that resembles a wound.

When the hydrogel containing VEGF bound to the nanoparticles was added to the damaged endothelial cell wound, the cells were induced to grow back and fill-in the scratched region—essentially mimicking the healing of a wound.

“Our laboratory experiments have verified the effectiveness of the hydrogel for initiating both blood clotting and wound healing,” said Gaharwar. “We are anxious to begin tests in animals with the hope of testing and eventual use in humans where we believe our formulation has great potential to have a significant impact on saving lives in critical situations.”

The work was funded by grant EB023454 from the National Institute of Biomedical Imaging and Bioengineering (NIBIB), and the National Science Foundation. The results were reported in the February issue of the journal Acta Biomaterialia.

The paper was published back in April 2018 and there was an April 2, 2018 Texas A&M University news release on EurekAlert making the announcement (and providing a few unique details),

A penetrating injury from shrapnel is a serious obstacle in overcoming battlefield wounds that can ultimately lead to death.Given the high mortality rates due to hemorrhaging, there is an unmet need to quickly self-administer materials that prevent fatality due to excessive blood loss.

With a gelling agent commonly used in preparing pastries, researchers from the Inspired Nanomaterials and Tissue Engineering Laboratory have successfully fabricated an injectable bandage to stop bleeding and promote wound healing.

In a recent article “Nanoengineered Injectable Hydrogels for Wound Healing Application” published in Acta Biomaterialia, Dr. Akhilesh K. Gaharwar, assistant professor in the Department of Biomedical Engineering at Texas A&M University, uses kappa-carrageenan and nanosilicates to form injectable hydrogels to promote hemostasis (the process to stop bleeding) and facilitate wound healing via a controlled release of therapeutics.

“Injectable hydrogels are promising materials for achieving hemostasis in case of internal injuries and bleeding, as these biomaterials can be introduced into a wound site using minimally invasive approaches,” said Gaharwar. “An ideal injectable bandage should solidify after injection in the wound area and promote a natural clotting cascade. In addition, the injectable bandage should initiate wound healing response after achieving hemostasis.”

The study uses a commonly used thickening agent known as kappa-carrageenan, obtained from seaweed, to design injectable hydrogels. Hydrogels are a 3-D water swollen polymer network, similar to Jell-O, simulating the structure of human tissues.

When kappa-carrageenan is mixed with clay-based nanoparticles, injectable gelatin is obtained. The charged characteristics of clay-based nanoparticles provide hemostatic ability to the hydrogels. Specifically, plasma protein and platelets form blood adsorption on the gel surface and trigger a blood clotting cascade.

“Interestingly, we also found that these injectable bandages can show a prolonged release of therapeutics that can be used to heal the wound” said Giriraj Lokhande, a graduate student in Gaharwar’s lab and first author of the paper. “The negative surface charge of nanoparticles enabled electrostatic interactions with therapeutics thus resulting in the slow release of therapeutics.”

Nanoparticles that promote blood clotting and wound healing (red discs), attached to the wound-filling hydrogel component (black) form a nanocomposite hydrogel. The gel is designed to be self-administered to stop bleeding and begin wound-healing in emergency situations. Credit: Lokhande, et al. 1

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

Nanoengineered injectable hydrogels for wound healing application by Giriraj Lokhande, James K. Carrow, Teena Thakur, Janet R. Xavier, Madasamy Parani, Kayla J. Bayless, Akhilesh K. Gaharwar. Acta Biomaterialia Volume 70, 1 April 2018, Pages 35-47
https://doi.org/10.1016/j.actbio.2018.01.045

This paper is behind a paywall.

Hydrogel and the brain

It’s been an interesting week for hydrogels. On May 21, 2018 there was a news item on ScienceDaily about a bioengineered hydrogel which stimulated brain tissue growth after a stroke (mouse model),

In a first-of-its-kind finding, a new stroke-healing gel helped regrow neurons and blood vessels in mice with stroke-damaged brains, UCLA researchers report in the May 21 issue of Nature Materials.

“We tested this in laboratory mice to determine if it would repair the brain in a model of stroke, and lead to recovery,” said Dr. S. Thomas Carmichael, Professor and Chair of neurology at UCLA. “This study indicated that new brain tissue can be regenerated in what was previously just an inactive brain scar after stroke.”

The brain has a limited capacity for recovery after stroke and other diseases. Unlike some other organs in the body, such as the liver or skin, the brain does not regenerate new connections, blood vessels or new tissue structures. Tissue that dies in the brain from stroke is absorbed, leaving a cavity, devoid of blood vessels, neurons or axons, the thin nerve fibers that project from neurons.

After 16 weeks, stroke cavities in mice contained regenerated brain tissue, including new neural networks — a result that had not been seen before. The mice with new neurons showed improved motor behavior, though the exact mechanism wasn’t clear.

Remarkable stuff.

Quantum dots derived from tea leaves inhibit growth of lung cancer cells

A May 21, 2018 news item on phys.org announces some intriguing work borne of a UK-India research collaboration,

Nanoparticles derived from tea leaves inhibit the growth of lung cancer cells, destroying up to 80% of them, new research by a joint Swansea University and Indian team has shown.

The team made the discovery while they were testing out a new method of producing a type of nanoparticle called quantum dots. These are tiny particles which measure less than 10 nanometres. A human hair is 40,000 nanometres thick.

A May 21, 2018 Swansea University (UK) press release (also on EurekAlert but dated May 20, 2018), which originated the news item, fills in the details,

Although nanoparticles are already used in healthcare, quantum dots have only recently attracted researchers’ attention.  Already they are showing promise for use in different applications, from computers and solar cells to tumour imaging and treating cancer.

600 x 292

Picture: Size comparison of quantum dots with football and with human hair, in nanometers.

Quantum dots can be made chemically, but this is complicated and expensive and has toxic side effects.  The Swansea-led research team were therefore exploring a non-toxic plant-based alternative method of producing the dots, using tea leaf extract.

Tea leaves contain a wide variety of compounds, including polyphenols, amino acids, vitamins and antioxidants.   The researchers mixed tea leaf extract with cadmium sulphate (CdSO4) and sodium sulphide (Na2S) and allowed the solution to incubate, a process which causes quantum dots to form.   They then applied the dots to lung cancer cells.

The researchers found: 

  • Tea leaves are a simpler, cheaper and less toxic method of producing quantum dots, compared with using chemicals, confirming the results of other research in the field.
  • Quantum dots produced from tea leaves inhibit the growth of lung cancer cellsThey penetrated into the nanopores of the cancer cells and destroyed up to 80% of them.  This was a brand new finding, and came as a surprise to the team.

The research, published in “Applied Nano Materials”, is a collaborative venture between Swansea University experts and colleagues from two Indian universities.

600 x 281

Picture: microscope images of A549 lung cancer cells:  left, untreated; right, treated with quantum dots

Dr Sudhagar Pitchaimuthu of Swansea University, lead researcher on the project, and a Ser Cymru-II Rising Star Fellow, said:

“Our research confirmed previous evidence that tea leaf extract can be a non-toxic alternative to making quantum dots using chemicals.

The real surprise, however, was that the dots actively inhibited the growth of the lung cancer cells.  We hadn’t been expecting this.

The CdS quantum dots derived from tea leaf extract showed exceptional fluorescence emission in cancer cell bioimaging compared to conventional CdS nanoparticles.

Quantum dots are therefore a very promising avenue to explore for developing new cancer treatments.

They also have other possible applications, for example in anti-microbial paint used in operating theatres, or in sun creams.”

Dr Pitchaimuthu outlined the next steps for research:

“Building on this exciting discovery, the next step is to scale up our operation, hopefully with the help of other collaborators.   We want to investigate the role of tea leaf extract in cancer cell imaging, and the interface between quantum dots and the cancer cell.

We would like to set up a “quantum dot factory” which will allow us to explore more fully the ways in which they can be used.”

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

Green-Synthesis-Derived CdS Quantum Dots Using Tea Leaf Extract: Antimicrobial, Bioimaging, and Therapeutic Applications in Lung Cancer Cells by Kavitha Shivaji, Suganya Mani, Ponnusamy Ponmurugan, Catherine Suenne De Castro, Matthew Lloyd Davies, Mythili Gnanamangai Balasubramanian, and Sudhagar Pitchaimuthu. ACS Appl. Nano Mater., 2018, 1 (4), pp 1683–1693 DOI: 10.1021/acsanm.8b00147 Publication Date (Web): March 9, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

German scientists battle tough mucus

A December 15, 2017 news item on ScienceDaily highlights cystic fibrosis research being done in Germany,

Around one in 3,300 children in Germany is born with Mucoviscidosis [cystic fibrosis; CF]. A characteristic of this illness is that one channel albumen on the cell surface is disturbed by mutations. Thus, the amount of water of different secretions in the body is reduced which creates a tough mucus. As a consequence, inner organs malfunction. Moreover, the mucus blocks the airways. Thus, the self regulatory function of the lung is disturbed, the mucus is colonized by bacteria and chronic infections follow. The lung is so significantly damaged that patients often die or need to have a lung transplant. The average life expectancy of a patient today is around 40 years. This is due to medical progress. Permanent treatment with inhaled antibiotics play a considerable part in this. The treatment can’t avoid the colonization by bacteria completely but it can keep it in check for a longer period of time. However, the bacteria defend themselves with a development of resistance and with the growth of so-called biofilms underneath the layer of mucus, which mostly block off the bacteria in the lower rows like a protective shield.

A complex way to the Pathogens

Scientists of the Friedrich Schiller University Jena, Germany succeeded in developing a much more efficient method to treat the airway infections which are often lethal. Crucial are nanoparticles that transport the antibiotics more efficiently to their destination….

A December 15, 2017 Friedrich Schiller University Jena press release (also on EurekAlert), which originated the news item, expands on the theme,

“Typically, the drugs are applied by inhalation in the body. Then they make a complicated way through the body to the pathogens and many of them don’t make it to their destination,” states Prof. Dr Dagmar Fischer of the chair for Pharmaceutical Technology at the University of Jena, who supervised the project together with her colleague Prof. Dr Mathias Pletz, a pulmonologist and infectious diseases physician, from the Center for Infectious Diseases and Infection Control at the Jena University Hospital. The project was supported by the Deutsche Forschungsgemeinschaft. First of all, the active particles need to have a certain size to be able to reach the deeper airways and not to bounce off somewhere else before. Ultimately, they have to penetrate the thick layer of mucus on the airways as well as the lower layers of the bacteria biofilm.

Nanoparticles travel more efficiently

To overcome the strong defense, the researchers encapsulated the active agents, like the antibiotic Tobramycin, in a polyester polymer. Thus, they created a nanoparticle which they then tested in the laboratory where they beforehand had simulated the present lung situation, in a static as well as in a dynamic state, i. e. with simulated flow movements. Therefore Pletz’s research group had developed new test systems, which are able to mimick the situation of the chronically infected CF-lung. The scientists discovered that their nanoparticle travels more easily through the sponge-like net of the mucus layer and is finally able to kill off the pathogens without any problems. Moreover, an additionally applied coating of polyethylenglycol makes it nearly invisible for the immune system. “All materials of a nanocarrier are biocompatible, biodegradable, nontoxic and therefore not dangerous for humans,” the researcher informs.

However, the Jena scientists don’t know yet exactly why their nanoparticle fights the bacteria so much more efficiently. But they want to finally get clarification in the year ahead. “We have two assumptions: Either the much more efficient transport method advances significantly larger amounts of active ingredients to the center of infection, or the nanoparticle circumvents a defense mechanism, which the bacterium has developed against the antibiotic,” the Jena Pharmacist Fischer explains. “This would mean, that we succeeded in giving back its impact to an antibiotic, which had already lost it through a development of resistance of the bacteria.”

“More specifically, we assume that bacteria from the lower layers of the biofilm transform into dormant persisters and hardly absorb any substances from outside. In this stadium, they are tolerant to most antibiotics, which only kill off self-dividing bacteria. The nanoparticles transport the antibiotics more or less against their will to the inner part of the cell, where they can unfold their impact,” Mathias Pletz adds.

Additionally, the Jena research team had to prepare the nanoparticles for the inhalation. Because at 200 nanometers the particle is too small to get into the deeper airways. “The breathing system filters out particles that are too big as well as those which are too small,” Dagmar Fischer explains. “So, we are left with a preferred window of between one and five micrometers.” The Jena researchers also have promising ideas for resolving this problem.

Coating of Nanoparticles enhances the impact of Antibiotics against Biofilms

The scientists from Jena are at this point already convinced to have found a very promising method to fight respiratory infections of patients with mucoviscidosis. Thus they may be able to contribute to a higher life expectancy of those affected. “We were able to show that the nanoparticle coating improves the impact of the antibiotics against biofilm by a factor of 1,000,” the pulmonologist and infectious diseases physician is happy to say.

It’s exciting news and I wish the researchers great success. Perhaps, one day, they will publish a paper about their work.

Europe’s cathedrals get a ‘lift’ with nanoparticles

That headline is a teensy bit laboured but I couldn’t resist the levels of wordplay available to me. They’re working on a cathedral close to the leaning Tower of Pisa in this video about the latest in stone preservation in Europe.

I have covered the topic of preserving stone monuments before (most recently in my Oct. 21, 2014 posting). The action in this field seems to be taking place mostly in Europe, specifically Italy, although other countries are also quite involved.

Finally, getting to the European Commission’s latest stone monument preservation project, Nano-Cathedral, a Sept. 26, 2017 news item on Nanowerk announces the latest developments,

Just a few meters from Pisa’s famous Leaning Tower, restorers are defying scorching temperatures to bring back shine to the city’s Cathedral.

Ordinary restoration techniques like laser are being used on much of the stonework that dates back to the 11th century. But a brand new technique is also being used: a new material made of innovative nanoparticles. The aim is to consolidate the inner structure of the stones. It’s being applied mainly on marble.

A March 7, 2017 item on the Euro News website, which originated the Nanowerk news item, provides more detail,

“Marble has very low porosity, which means we have to use nanometric particles in order to go deep inside the stone, to ensure that the treatment is both efficient while still allowing the stone to breathe,” explains Roberto Cela, civil engineer at Opera Della Primaziale Pisana.

The material developed by the European research team includes calcium carbonate, which is a mix of calcium oxide, water and carbon dioxide.

The nano-particles penetrate the stone cementing its decaying structure.

“It is important that these particles have the same chemical nature as the stones that are being treated, so that the physical and mechanical processes that occur over time don’t lead to the break-up of the stones,” says Dario Paolucci, chemist at the University of Pisa.

Vienna’s St Stephen’s is another of the five cathedrals where the new restoration materials are being tested.

The first challenge for researchers is to determine the mechanical characteristics of the cathedral’s stones. Since there are few original samples to work on, they had to figure out a way of “ageing” samples of stones of similar nature to those originally used.

“We tried different things: we tried freeze storage, we tried salts and acids, and we decided to go for thermal ageing,” explains Matea Ban, material scientist at the University of Technology in Vienna. “So what happens is that we heat the stone at certain temperatures. Minerals inside then expand in certain directions, and when they expand they build up stresses to neighbouring minerals and then they crack, and we need those cracks in order to consolidate them.”

Consolidating materials were then applied on a variety of limestones, sandstones and marble – a selection of the different types of stones that were used to build cathedrals around Europe.

What researchers are looking for are very specific properties.

“First of all, the consolidating material has to be well absorbed by the stone,” says petrologist Johannes Weber of the University of Applied Arts in Vienna. “Then, as it evaporates, it has to settle properly within the stone structure. It should not shrink too much. All materials shrink when drying, including consolidating materials. They should adhere to the particles of the stone but shouldn’t completely obstruct its pores.”

Further tests are underway in cathedrals across Europe in the hope of better protecting our invaluable cultural heritage.

There’s a bit more detail about Nano-Cathedral on the Opera della Primaziale Pisana (O₽A) website (from their Nano-Cathedral project page),

With the meeting of June 3 this year the Nano Cathedral project kicked off, supported by the European Union within the nanotechnology field applied to Horizon 2020 cultural heritage with a fund of about 6.5 million euro.

A total of six monumental buildings will be for three years under the eyes and hands of petrographers, geologists, chemists and restorers of the institutes belonging to the Consortium: five cathedrals have been selected to represent the cultural diversity within Europe from the perspective of developing shared values and transnational identity, and a contemporary monumental building entirely clad in Carrara marble, the Opera House of Oslo.

Purpose: the testing of nanomaterials for the conservation of marble and the outer surfaces of our ‘cathedrals’.
The field of investigation to check degradation, testing new consolidating and protective products is the Cathedral of Pisa together with the Cathedrals of Cologne, Vienna, Ghent and Vitoria.
For the selection of case studies we have crosschecked requirements for their historical and architectural value but also for the different types of construction materials – marble, limestone and sandstone – as well as the relocation of six monumental buildings according to European climates.

The Cathedral of Pisa is the most southern, fully positioned in Mediterranean climate, therefore subject to degradation and very different from those which the weather conditions of the Scandinavian peninsula recorded; all the intermediate climate phases are modulated through Ghent, Vitoria, Cologne and Vienna.

At the conclusion of the three-year project, once the analysis in situ and in the laboratory are completed and all the experiments are tested on each different identified portion in each monumental building, an intervention protocol will be defined in detail in order to identify the mineralogical and petrographic characteristics of stone materials and of their degradation, the assessment of the causes and mechanisms of associated alteration, including interactions with factors of environmental pollution. Then we will be able to identify the most appropriate method of restoration and testing of nanotechnology products for the consolidation and protection of different stone materials.

In 2018 we hope to have new materials to protect and safeguard the ‘skin’ of our historic buildings and monuments for a long time.

Back to my headline and the second piece of wordplay, ‘lift’ as in ‘skin lift’ in that last sentence.

I realize this is a bit off topic but it’s worth taking a look at ORA’s home page,

Gabriele D’Annunzio effectively condenses the wonder and admiration that catch whoever visits the Duomo Square of Pisa.

The Opera della Primaziale Pisana (O₽A) is a non-profit organisation which was established in order to oversee the first works for the construction of the monuments in the Piazza del Duomo, subject to its own charter which includes the protection, promotion and enhancement of its heritage, in order to pass the religious and artistic meaning onto future generations.

«L’Ardea roteò nel cielo di Cristo, sul prato dei Miracoli.»
Gabriele d’Annunzio in Forse che sì forse che no (1910)

If you go to the home page, you can buy tickets to visit the monuments surrounding the square and there are other notices including one for a competition (it’s too late to apply but the details are interesting) to construct four stained glass windows for the Pisa cathedral.

Nanoparticles from tattoo inks circulate through your body

English: Tattoo of Hand of Fatima,. Model: Casini. Date: 4 July 2017, 18:13:41. Source : Own work. Author: Stephencdickson.

For those who like their news in video format, there’s this Canadian Broadcasting Corporation (CBC) news item broadcast on Sep. 11, 2017 (after the commercials),

For those who like text and more detail, scientists at the European Synchrotron Radiation Facility (ESRF) have produced a study of the (at the nanoparticle scale) inks in tattoos. From a Sept. 12, 2017 news item on phys.org,

The elements that make up the ink in tattoos travel inside the body in micro and nanoparticle forms and reach the lymph nodes, according to a study published in Scientific Reports on 12 September [2017] by scientists from Germany and the ESRF, the European Synchrotron, Grenoble (France). It is the first time researchers have found analytical evidence of the transport of organic and inorganic pigments and toxic element impurities as well as in depth characterization of the pigments ex vivo in tattooed tissues. Two ESRF beamlines were crucial in this breakthrough.

A Sept. 12, 2017 ESRF press release (also on EurkeAlert), which originated the news item, explains further,

The reality is that little is known about the potential impurities in the colour mixture applied to the skin. Most tattoo inks contain organic pigments, but also include preservatives and contaminants like nickel, chromium, manganese or cobalt. Besides carbon black, the second most common ingredient used in tattoo inks is titanium dioxide (TiO2), a white pigment usually applied to create certain shades when mixed with colorants. Delayed healing, along with skin elevation and itching, are often associated with white tattoos, and by consequence with the use of TiO2. TiO2 is also commonly used in food additives, sun screens and paints. Scientists from the ESRF, the German Federal Institute for Risk Assessment, Ludwig-Maximilians University, and the Physikalisch-Technische Bundesanstalt have managed to get a very clear picture on the location of titanium dioxide once it gets in the tissue. This work was done on the ESRF beamlines ID21 and ID16B.

drawing tattookinetics.jpg

Translocation of tattoo particles from skin to lymph nodes. Upon injection of tattoo inks, particles can be either passively transported via blood and lymph fluids or phagocytized by immune cells and subsequently deposited in regional lymph nodes. After healing, particles are present in the dermis and in the sinusoids of the draining lymph nodes. Credits: C. Seim.

The hazards that potentially derive from tattoos were, until now, only investigated by chemical analysis of the inks and their degradation products in vitro. “We already knew that pigments from tattoos would travel to the lymph nodes because of visual evidence: the lymph nodes become tinted with the colour of the tattoo. It is the response of the body to clean the site of entrance of the tattoo. What we didn’t know is that they do it in a nano form, which implies that they may not have the same behaviour as the particles at a micro level. And that is the problem: we don’t know how nanoparticles react”, explains Bernhard Hesse, one of the two first authors of the study (together with Ines Schreiver, from the German Federal Institute for Risk Assessment) and ESRF visiting scientist.

titaniumdistribution.jpg

Particle mapping and size distribution of different tattoo pigment elements.  a, d) Ti and the Br containing pigment phthalocyanine green 36 are located next to each other. b, e) Log scale mappings of Ti, Br and Fe in the same areas as displayed in a) and d) reveal primary particle sizes of different pigment species. c, f) Magnifications of the indicated areas in b) and e), respectively. Credits: C. Seim.

X-ray fluorescence measurements on ID21 allowed the team to locate titanium dioxide at the micro and nano range in the skin and the lymphatic environment. They found a broad range of particles with up to several micrometres in size in human skin, but only smaller (nano) particles transported to the lymph nodes. This can lead to the chronic enlargement of the lymph nodes and lifelong exposure. Scientists also used the technique of Fourier transform infrared spectroscopy to assess biomolecular changes in the tissues in the proximity of the tattoo particles.

ESRF16_Tattoo-1low.jpg

Ines Schreiver doing experiments on ID16B with Julie Villanova. Credits: B. Hesse.

Altogether the scientists report strong evidence for both migration and long-term deposition of toxic elements and tattoo pigments as well as for conformational alterations of biomolecules that are sometimes linked to cutaneous adversities upon tattooing.

Then next step for the team is to inspect further samples of patients with adverse effects in their tattoos in order to find links with chemical and structural properties of the pigments used to create these tattoos.

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

Synchrotron-based ν-XRF mapping and μ-FTIR microscopy enable to look into the fate and effects of tattoo pigments in human skin by Ines Schreiver, Bernhard Hesse, Christian Seim, Hiram Castillo-Michel, Julie Villanova, Peter Laux, Nadine Dreiack, Randolf Penning, Remi Tucoulou, Marine Cotte, & Andreas Luch. Scientific Reports 7, Article number: 11395 (2017) doi:10.1038/s41598-017-11721-z Published online: 12 September 2017

This paper is open access.

Measurably fewer nanoparticles in São Paulo’s (Brazil) air after ethanol use

An Aug. 28, 2017 news item on Nanotechnology Now features news about nanoparticles and the environment in São Paulo, Brazil,

When ethanol prices at the pump rise for whatever reason, it becomes economically advantageous for drivers of dual-fuel vehicles to fill up with gasoline. However, the health of the entire population pays a high price: substitution of gasoline for ethanol leads to a 30% increase in the atmospheric concentration of ultrafine particulate matter, which consists of particles with a diameter of less than 50 nanometers (nm).

An Aug. 23, 2017 Fundação de Amparo à Pesquisa do Estado de São Paulo (The São Paulo Research Foundation [FAPESP]) press release, which originated the news item, explains further,

The phenomenon was detected in São Paulo City, Brazil, in a study supported by FAPESP and published in July 2017 in Nature Communications.

“These polluting nanoparticles are so tiny that they behave like gas molecules. When inhaled, they can penetrate the respiratory system’s defensive barriers and reach the pulmonary alveoli, so that potentially toxic substances enter the bloodstream and may increase the incidence of respiratory and cardiovascular problems,” said Paulo Artaxo, Full Professor at the University of São Paulo’s Physics Institute (IF-USP) and a co-author of the study.

Levels of ultrafine particulate matter in the atmosphere are neither monitored nor regulated by environmental agencies not only in Brazil but practically anywhere in the world, according to Artaxo. The São Paulo State Environmental Corporation (CETESB), for example, routinely monitors only solid particles with diameters of 10,000 nm (PM10) and 2,500 nm (PM2.5) – as well as other gaseous pollutants such as ozone (O3), carbon monoxide (CO) and nitrogen dioxide (NO2).

“Between 75% and 80% of the mass of the nanoparticles we measured in this study corresponds to organic compounds emitted by motor vehicles – carbon in different chemical forms. What these compounds are exactly and how they affect health are questions that require further research,” Artaxo said.

He added that a consensus is forming in the United States and Europe based on recent research indicating that these emissions are a potential health hazard and should be regulated. Several US states, such as California, have laws requiring a 20%-30% ethanol blend in gasoline, which also helps reduce emissions of ultrafine particulate matter.

Methodology

The data analyzed in the study were collected during the period of January-May 2011, when ethanol prices fluctuated sharply compared with gasoline prices, owing to macroeconomic factors such as variations in the international price of sugar (Brazilian ethanol is made from sugarcane).

Collection was performed at the top of a ten-story building belonging to IF-USP in the western part of São Paulo City. According to Artaxo, the site was chosen because it is relatively distant from the main traffic thoroughfares so that the aerosols there are “older” in the sense that they have already interacted with other substances present in the atmosphere.

“Generally speaking, the pollution we inhale every day at home or at work isn’t what comes out of vehicular exhaust pipes but particles already processed in the atmosphere,” he explained. “For this reason, we chose a site that isn’t directly impacted by primary vehicle emissions.”

The study was conducted during Joel Ferreira de Brito’s postdoctoral research, which Artaxo supervised. The model used to analyze the data was developed by Brazilian economist Alberto Salvo, a professor at the National University of Singapore and first author of the article. Franz Geiger, a chemist at Northwestern University in the US, also collaborated.

“We adapted a sophisticated statistical model originally developed for economic analysis and used here for the first time to analyze the chemistry of atmospheric nanoparticles,” Artaxo said. “The main strength of this tool is that it can work with a large number of variables, such as the presence or absence of rainfall, wind direction, traffic intensity, and levels of ozone, carbon monoxide and other pollutants.”

Analyses were performed before, during and after a sharp fluctuation in ethanol prices leading consumers to switch motor fuels in São Paulo City. While no significant changes were detected in levels of inhalable fine particulate matter (PM2.5 and PM10), the study proved in a real, day-to-day situation that choosing ethanol reduces emissions of ultrafine particles. To date, this phenomenon had only been observed in the laboratory.

“These results reinforce the need for public policies to encourage the use of biofuels, as they clearly show that the public lose in health what they save at the pump when opting for gasoline,” Artaxo said.

In São Paulo, a city with 7 million motor vehicles and the largest urban fleet of flexible-fuel cars, it would be feasible to run all buses on biofuel. “We have the technology for this in Brazil – and at a competitive price,” he said.

The fact that the city’s bus fleet still depends on diesel, Artaxo warned, creates an even worse health hazard in the shape of emissions of black carbon, one of the main components of soot and a pollutant that contributes to global warming. Alongside electricity generation, the transportation sector is the largest emitter of pollutants produced by the burning of fossil fuels.

For Artaxo, incentives for electric, hybrid or biofuel vehicles are vital to reduce greenhouse gas emissions. “By incentivizing biofuels, we could solve several problems at once,” he said. “We could combat climate change, reduce harm to health and foster advances in automotive technology by offering a stimulus for auto makers to develop more economical and efficient cars fueled by ethanol.”

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

Reduced ultrafine particle levels in São Paulo’s atmosphere during shifts from gasoline to ethanol use by Alberto Salvo, Joel Brito, Paulo Artaxo, & Franz M. Geiger. Nature Communications 8, Article number: 77 (2017) doi:10.1038/s41467-017-00041-5 Published online: 18 July 2017

This paper is open access.

Faster diagnostics with nanoparticles and magnetic phenomenon discovered 170 years ago

A Jan. 19, 2017 news item on ScienceDaily announces some new research from the University of Central Florida (UCF),

A UCF researcher has combined cutting-edge nanoscience with a magnetic phenomenon discovered more than 170 years ago to create a method for speedy medical tests.

The discovery, if commercialized, could lead to faster test results for HIV, Lyme disease, syphilis, rotavirus and other infectious conditions.

“I see no reason why a variation of this technique couldn’t be in every hospital throughout the world,” said Shawn Putnam, an assistant professor in the University of Central Florida’s College of Engineering & Computer Science.

A Jan. 19, 2017 UCF news release by Mark Schlueb, which originated the news item,  provides more technical detail,

At the core of the research recently published in the academic journal Small are nanoparticles – tiny particles that are one-billionth of a meter. Putnam’s team coated nanoparticles with the antibody to BSA, or bovine serum albumin, which is commonly used as the basis of a variety of diagnostic tests.

By mixing the nanoparticles in a test solution – such as one used for a blood test – the BSA proteins preferentially bind with the antibodies that coat the nanoparticles, like a lock and key.

That reaction was already well known. But Putnam’s team came up with a novel way of measuring the quantity of proteins present. He used nanoparticles with an iron core and applied a magnetic field to the solution, causing the particles to align in a particular formation. As proteins bind to the antibody-coated particles, the rotation of the particles becomes sluggish, which is easy to detect with laser optics.

The interaction of a magnetic field and light is known as Faraday rotation, a principle discovered by scientist Michael Faraday in 1845. Putnam adapted it for biological use.

“It’s an old theory, but no one has actually applied this aspect of it,” he said.

Other antigens and their unique antibodies could be substituted for the BSA protein used in the research, allowing medical tests for a wide array of infectious diseases.

The proof of concept shows the method could be used to produce biochemical immunology test results in as little as 15 minutes, compared to several hours for ELISA, or enzyme-linked immunosorbent assay, which is currently a standard approach for biomolecule detection.

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

High-Throughput, Protein-Targeted Biomolecular Detection Using Frequency-Domain Faraday Rotation Spectroscopy by Richard J. Murdock, Shawn A. Putnam, Soumen Das, Ankur Gupta, Elyse D. Z. Chase, and Sudipta Seal. Small DOI: 10.1002/smll.201602862 Version of Record online: 16 JAN 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Nanoparticles can activate viruses lying dormant in lung cells

The nanoparticles in question are from combustion engines, which means that we are exposed to them. One other note, the testing has not been done on humans but rather on cells. From a Jan. 16, 2017 news item on ScienceDaily,

Nanoparticles from combustion engines can activate viruses that are dormant in in lung tissue cells. This is the result of a study by researchers of Helmholtz Zentrum München, a partner in the German Center for Lung Research (DZL), which has now been published in the journal Particle and Fibre Toxicology.

To evade the immune system, some viruses hide in cells of their host and persist there. In medical terminology, this state is referred to as a latent infection. If the immune system becomes weakened or if certain conditions change, the viruses become active again, begin to proliferate and destroy the host cell. A team of scientists led by Dr. Tobias Stöger of the Institute of Lung Biology and Prof. Dr. Heiko Adler, deputy head of the research unit Lung Repair and Regeneration at Helmholtz Zentrum München, now report that nanoparticles can also trigger this process.

A Jan. 16, 2017 Helmholtz Zentrum München press release (also on EurekAlert), which originated the news item, provides more detail,

“From previous model studies we already knew that the inhalation of nanoparticles has an inflammatory effect and alters the immune system,” said study leader Stöger. Together with his colleagues Heiko Adler and Prof. Dr. Philippe Schmitt-Kopplin, he showed that “an exposure to nanoparticles can reactivate latent herpes viruses in the lung.”

Specifically, the scientists tested the influence of nanoparticles typically generated by fossil fuel combustion in an experimental model for a particular herpes virus infection. They detected a significant increase in viral proteins, which are only produced with active virus proliferation. “Metabolic and gene expression analyses also revealed patterns resembling acute infection,” said Philippe Schmitt-Kopplin, head of the research unit Analytical BioGeoChemistry (BGC). Moreover, further experiments with human cells demonstrated that Epstein-Barr viruses are also ‘awakened’ when they come into contact with the nanoparticles.

Potential approach for chronic lung diseases

In further studies, the research team would like to test whether the results can also be transferred to humans. “Many people carry herpes viruses, and patients with idiopathic pulmonary fibrosis are particularly affected,” said Heiko Adler. “If the results are confirmed in humans, it would be important to investigate the molecular process of the reactivation of latent herpes viruses induced by particle inhalation. Then we could try to influence this pathway therapeutically.”

Special cell culture models shall therefore elucidate the exact mechanism of virus reactivation by nanoparticles. “In addition,” Stöger said, ”in long-term studies we would like to investigate to what extent  repeated nanoparticle exposure with corresponding virus reactivation leads to chronic inflammatory and remodeling processes in the lung.”

Further Information

Background:
In 2015 another group at the Helmholtz Zentrum München demonstrated how the Epstein-Barr virus  hides in human cells. In March 2016 researchers also showed that microRNAs silence immune alarm signals of cells infected with the Epstein-Barr virus.

Original Publication:
Sattler, C. et al. (2016): Nanoparticle exposure reactivates latent herpesvirus and restores a signature of acute infection. Particle and Fibre Toxicology, DOI 10.1186/s12989-016-0181-1

Here’s a link to and a citation for the paper on investigating latent herpes virus,

Nanoparticle exposure reactivates latent herpesvirus and restores a signature of acute infection by Christine Sattler, Franco Moritz, Shanze Chen, Beatrix Steer, David Kutschke, Martin Irmler, Johannes Beckers, Oliver Eickelberg, Philippe Schmitt-Kopplin, Heiko Adler. Particle and Fibre Toxicology201714:2 DOI: 10.1186/s12989-016-0181-1 Published: 10 January 2017

©  The Author(s). 2017

This paper is open access and, so too, is the 2016 paper.

Going underground to observe atoms in a bid for better batteries

A Jan. 16, 2017 news item on ScienceDaily describes what lengths researchers at Stanford University (US) will go to in pursuit of their goals,

In a lab 18 feet below the Engineering Quad of Stanford University, researchers in the Dionne lab camped out with one of the most advanced microscopes in the world to capture an unimaginably small reaction.

The lab members conducted arduous experiments — sometimes requiring a continuous 30 hours of work — to capture real-time, dynamic visualizations of atoms that could someday help our phone batteries last longer and our electric vehicles go farther on a single charge.

Toiling underground in the tunneled labs, they recorded atoms moving in and out of nanoparticles less than 100 nanometers in size, with a resolution approaching 1 nanometer.

A Jan. 16, 2017 Stanford University news release (also on EurekAlert) by Taylor Kubota, which originated the news item, provides more detail,

“The ability to directly visualize reactions in real time with such high resolution will allow us to explore many unanswered questions in the chemical and physical sciences,” said Jen Dionne, associate professor of materials science and engineering at Stanford and senior author of the paper detailing this work, published Jan. 16 [2017] in Nature Communications. “While the experiments are not easy, they would not be possible without the remarkable advances in electron microscopy from the past decade.”

Their experiments focused on hydrogen moving into palladium, a class of reactions known as an intercalation-driven phase transition. This reaction is physically analogous to how ions flow through a battery or fuel cell during charging and discharging. Observing this process in real time provides insight into why nanoparticles make better electrodes than bulk materials and fits into Dionne’s larger interest in energy storage devices that can charge faster, hold more energy and stave off permanent failure.

Technical complexity and ghosts

For these experiments, the Dionne lab created palladium nanocubes, a form of nanoparticle, that ranged in size from about 15 to 80 nanometers, and then placed them in a hydrogen gas environment within an electron microscope. The researchers knew that hydrogen would change both the dimensions of the lattice and the electronic properties of the nanoparticle. They thought that, with the appropriate microscope lens and aperture configuration, techniques called scanning transmission electron microscopy and electron energy loss spectroscopy might show hydrogen uptake in real time.

After months of trial and error, the results were extremely detailed, real-time videos of the changes in the particle as hydrogen was introduced. The entire process was so complicated and novel that the first time it worked, the lab didn’t even have the video software running, leading them to capture their first movie success on a smartphone.

Following these videos, they examined the nanocubes during intermediate stages of hydrogenation using a second technique in the microscope, called dark-field imaging, which relies on scattered electrons. In order to pause the hydrogenation process, the researchers plunged the nanocubes into an ice bath of liquid nitrogen mid-reaction, dropping their temperature to 100 degrees Kelvin (-280 F). These dark-field images served as a way to check that the application of the electron beam hadn’t influenced the previous observations and allowed the researchers to see detailed structural changes during the reaction.

“With the average experiment spanning about 24 hours at this low temperature, we faced many instrument problems and called Ai Leen Koh [co-author and research scientist at Stanford’s Nano Shared Facilities] at the weirdest hours of the night,” recalled Fariah Hayee, co-lead author of the study and graduate student in the Dionne lab. “We even encountered a ‘ghost-of-the-joystick problem,’ where the joystick seemed to move the sample uncontrollably for some time.”

While most electron microscopes operate with the specimen held in a vacuum, the microscope used for this research has the advanced ability to allow the researchers to introduce liquids or gases to their specimen.

“We benefit tremendously from having access to one of the best microscope facilities in the world,” said Tarun Narayan, co-lead author of this study and recent doctoral graduate from the Dionne lab. “Without these specific tools, we wouldn’t be able to introduce hydrogen gas or cool down our samples enough to see these processes take place.”

Pushing out imperfections

Aside from being a widely applicable proof of concept for this suite of visualization techniques, watching the atoms move provides greater validation for the high hopes many scientists have for nanoparticle energy storage technologies.

The researchers saw the atoms move in through the corners of the nanocube and observed the formation of various imperfections within the particle as hydrogen moved within it. This sounds like an argument against the promise of nanoparticles but that’s because it’s not the whole story.

“The nanoparticle has the ability to self-heal,” said Dionne. “When you first introduce hydrogen, the particle deforms and loses its perfect crystallinity. But once the particle has absorbed as much hydrogen as it can, it transforms itself back to a perfect crystal again.”

The researchers describe this as imperfections being “pushed out” of the nanoparticle. This ability of the nanocube to self-heal makes it more durable, a key property needed for energy storage materials that can sustain many charge and discharge cycles.

Looking toward the future

As the efficiency of renewable energy generation increases, the need for higher quality energy storage is more pressing than ever. It’s likely that the future of storage will rely on new chemistries and the findings of this research, including the microscopy techniques the researchers refined along the way, will apply to nearly any solution in those categories.

For its part, the Dionne lab has many directions it can go from here. The team could look at a variety of material compositions, or compare how the sizes and shapes of nanoparticles affect the way they work, and, soon, take advantage of new upgrades to their microscope to study light-driven reactions. At present, Hayee has moved on to experimenting with nanorods, which have more surface area for the ions to move through, promising potentially even faster kinetics.

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

Direct visualization of hydrogen absorption dynamics in individual palladium nanoparticles by Tarun C. Narayan, Fariah Hayee, Andrea Baldi, Ai Leen Koh, Robert Sinclair, & Jennifer A. Dionne. Nature Communications 8, Article number: 14020 (2017) doi:10.1038/ncomms14020 Published online: 16 January 2017

This paper is open access.

Investigating nanoparticles and their environmental impact for industry?

It seems the Center for the Environmental Implications of Nanotechnology (CEINT) at Duke University (North Carolina, US) is making an adjustment to its focus and opening the door to industry, as well as, government research. It has for some years (my first post about the CEINT at Duke University is an Aug. 15, 2011 post about its mesocosms) been focused on examining the impact of nanoparticles (also called nanomaterials) on plant life and aquatic systems. This Jan. 9, 2017 US National Science Foundation (NSF) news release (h/t Jan. 9, 2017 Nanotechnology Now news item) provides a general description of the work,

We can’t see them, but nanomaterials, both natural and manmade, are literally everywhere, from our personal care products to our building materials–we’re even eating and drinking them.

At the NSF-funded Center for Environmental Implications of Nanotechnology (CEINT), headquartered at Duke University, scientists and engineers are researching how some of these nanoscale materials affect living things. One of CEINT’s main goals is to develop tools that can help assess possible risks to human health and the environment. A key aspect of this research happens in mesocosms, which are outdoor experiments that simulate the natural environment – in this case, wetlands. These simulated wetlands in Duke Forest serve as a testbed for exploring how nanomaterials move through an ecosystem and impact living things.

CEINT is a collaborative effort bringing together researchers from Duke, Carnegie Mellon University, Howard University, Virginia Tech, University of Kentucky, Stanford University, and Baylor University. CEINT academic collaborations include on-going activities coordinated with faculty at Clemson, North Carolina State and North Carolina Central universities, with researchers at the National Institute of Standards and Technology and the Environmental Protection Agency labs, and with key international partners.

The research in this episode was supported by NSF award #1266252, Center for the Environmental Implications of NanoTechnology.

The mention of industry is in this video by O’Brien and Kellan, which describes CEINT’s latest work ,

Somewhat similar in approach although without a direction reference to industry, Canada’s Experimental Lakes Area (ELA) is being used as a test site for silver nanoparticles. Here’s more from the Distilling Science at the Experimental Lakes Area: Nanosilver project page,

Water researchers are interested in nanotechnology, and one of its most commonplace applications: nanosilver. Today these tiny particles with anti-microbial properties are being used in a wide range of consumer products. The problem with nanoparticles is that we don’t fully understand what happens when they are released into the environment.

The research at the IISD-ELA [International Institute for Sustainable Development Experimental Lakes Area] will look at the impacts of nanosilver on ecosystems. What happens when it gets into the food chain? And how does it affect plants and animals?

Here’s a video describing the Nanosilver project at the ELA,

You may have noticed a certain tone to the video and it is due to some political shenanigans, which are described in this Aug. 8, 2016 article by Bartley Kives for the Canadian Broadcasting Corporation’s (CBC) online news.