Tag Archives: nanoparticles

How To Recycle Greenhouse Gases into Fuel and Hydrogen

Scientists have taken a major step toward a circular carbon economy by developing a long-lasting, economical catalyst that recycles greenhouse gases into ingredients that can be used in fuel, hydrogen gas, and other chemicals. The results could be revolutionary in the effort to reverse global warming, according to the researchers. The study was published in Science.

Newly developed catalyst that recycles greenhouse gases into ingredients that can be used in fuel, hydrogen gas and other chemicals

We set out to develop an effective catalyst that can convert large amounts of the greenhouse gases carbon dioxide and methane without failure,” said Cafer T. Yavuz, paper author and associate professor of chemical and biomolecular engineering and of chemistry at KAIST (Korea).

The catalyst, made from inexpensive and abundant nickel, magnesium, and molybdenum, initiates and speeds up the rate of reaction that converts carbon dioxide and methane into hydrogen gas. It can work efficiently for more than a month.

This conversion is called ‘dry reforming’, where harmful gases, such as carbon dioxide, are processed to produce more useful chemicals that could be refined for use in fuel, plastics, or even pharmaceuticals. It is an effective process, but it previously required rare and expensive metals such as platinum and rhodium to induce a brief and inefficient chemical reaction.

Other researchers had previously proposed nickel as a more economical solution, but carbon byproducts would build up and the surface nanoparticles would bind together on the cheaper metal, fundamentally changing the composition and geometry of the catalyst and rendering it useless.

The difficulty arises from the lack of control on scores of active sites over the bulky catalysts surfaces because any refinement procedures attempted also change the nature of the catalyst itself,” Yavuz said.

The researchers produced nickel-molybdenum nanoparticles under a reductive environment in the presence of a single crystalline magnesium oxide. As the ingredients were heated under reactive gas, the nanoparticles moved on the pristine crystal surface seeking anchoring points. The resulting activated catalyst sealed its own high-energy active sites and permanently fixed the location of the nanoparticles — meaning that the nickel-based catalyst will not have a carbon build up, nor will the surface particles bind to one another.

It took us almost a year to understand the underlying mechanism,” said first author Youngdong Song, a graduate student in the Department of Chemical and Biomolecular Engineering at KAIST. “Once we studied all the chemical events in detail, we were shocked.”

The researchers dubbed the catalyst Nanocatalysts on Single Crystal Edges (NOSCE). The magnesium-oxide nanopowder comes from a finely structured form of magnesium oxide, where the molecules bind continuously to the edge. There are no breaks or defects in the surface, allowing for uniform and predictable reactions.

Our study solves a number of challenges the catalyst community faces,” Yavuz said. “We believe the NOSCE mechanism will improve other inefficient catalytic reactions and provide even further savings of greenhouse gas emissions.

Source: https://news.kaist.ac.kr/

Nanoparticles Act As Immunotherapy Agents

University of Wisconsin–Madison researchers have developed nanoparticles that, in the lab, can activate immune responses to cancer cells. If they are shown to work as well in the body as they do in the lab, the nanoparticles might provide an effective and more affordable way to fight cancer.

They are cheaper to produce and easier to engineer than the antibodies that underlie current immunotherapies, which as drugs cost tens of thousands of dollars a month.

The nanoparticles were made of sections of the T cell protein PD-1 (in blue) attached to a branched core called a dendrimer (in gray). The branches in the core of the nanoparticle allowed many chunks of the PD-1 protein to bind to the nanoparticle, increasing its effectiveness.

Immunotherapy basically boosts the patient’s own immune system to fight against cancer cells better,” says Seungpyo Hong, a professor in the UW–Madison School of Pharmacy. “The antibodies that are used right now are large, they’re expensive, they’re hard to engineer, and they don’t always show the highest level of efficacy either. So we wanted to explore other ways to activate the immune system.

Hong and postdoctoral associate Woo-jin Jeong led the study, published online Jan. 2 in the Journal of the American Chemical Society, with collaborators at the University of Illinois at Chicago. It’s the first demonstration that nanoparticles can act as immunotherapy agents.

More research is needed to understand their effectiveness in the body, but Hong has applied for a patent on the new nanoparticles and is now testing them in animal models.

In tests against lab-grown strains of cancer, the nanoparticles boosted production of the immune stimulating protein interleukin-2 by T cells, one kind of immune cell in the body, by about 50 percent compared to no treatment. They were just as effective as antibodies. The nanoparticles were also able to improve the effectiveness of the chemotherapy drug doxorubicin in similar tests.

Normally, T cells produce a protein named PD-1 that acts like an off switch for immune responses. This “checkpoint” helps keep T cells from improperly attacking healthy cells.

Source: https://news.wisc.edu/

How To Address Global Warming

Harvesting sunlight, researchers of the Center for Integrated Nanostructure Physics, within the Institute for Basic Science (IBS, South Korea) published in Materials Today a new strategy to transform carbon dioxide (CO2) into oxygen (O2) and pure carbon monoxide (CO) without side-products in water. This artificial photosynthesis method could bring new solutions to environmental pollution and global warming.

While, in green plants, photosynthesis fixes CO2 into sugars, the artificial photosynthesis reported in this study can convert CO2 into oxygen and pure CO as output. The latter can then be employed for a broad range of applications in electronics, semiconductor, pharmaceutical, and chemical industries. The key is to find the right high-performance photocatalyst to help the photosynthesis take place by absorbing light, convert CO2, and ensuring an efficient flow of electrons, which is essential for the entire system.

Titanium oxide (TiO2) is a well-known photocatalyst. It has already attracted significant attention in the fields of solar energy conversion and environmental protection due to its high reactivity, low toxicity, chemical stability, and low cost. While conventional TiO2 can absorb only UV light, the IBS research team reported previously two different types of blue-colored TiO2 (or “blue titania”) nanoparticles that could absorb visible light.

For the efficient artificial photosynthesis for the conversion of CO2 into oxygen and pure CO, IBS researchers aimed to improve the performance of these nanoparticles. The resulted  hybrid nanoparticles showed about 200 times higher performance than nanoparticles made of TiO2 alone and TiO2/WO3 without silver.

Source: https://www.ibs.re.kr/

Turning Light Energy Into Heat To Fight Disease

An emerging technology involving tiny particles that absorb light and turn it into localized heat sources shows great promise in several fields, including medicine. For example, photothermal therapy, a new type of cancer treatment, involves aiming infrared laser light onto nanoparticles near the treatment site. Localized heating in these systems must be carefully controlled since living tissue is delicate. Serious burns and tissue damage can result if unwanted heating occurs in the wrong place. The ability to monitor temperature increases is crucial in developing this technology. Several approaches have been tried, but all of them have drawbacks of various kinds, including the need to insert probes or inject additional materials.

In this week’s issue of APL Photonics,, scientists report the development of a new method to measure temperatures in these systems using a form of light known as terahertz radiation. The study involved suspensions of gold nanorods of various sizes in water in small cuvettes, which were illuminated by a laser focused on a small spot within the cuvette. The tiny gold rods absorbed the laser light and converted it to heat that spread through the water by convection.

 

We are able to map out the temperature distribution by scanning the cuvette with terahertz radiation, producing a thermal image,” co-author Junliang Dong said.

The study also looked at the way the temperature varied over time. “Using a mathematical model, we are able to calculate the efficiency by which the gold nanorod suspensions converted infrared light to heat,” said co-author Holger Breitenborn.

The smallest gold particles, which had a diameter of 10 nanometers, converted laser light to heat with the highest efficiency, approximately 90%. This value is similar to previous reports for these gold particles, indicating the measurements using terahertz radiation were accurate. Although the smaller gold rods had the highest light-to-heat conversion efficiency, the largest rods — those with a diameter of 50 nanometers — displayed the largest molar heating rate. This quantity has been recently introduced to help evaluate the use of nanoparticles in biomedical settings.

By combining measurements of temperature transients in time and thermal images in space at terahertz frequencies, we have developed a noncontact and noninvasive technique for characterizing these nanoparticles,” co-author Roberto Morandotti said. This work offers an appealing alternative to invasive methods and holds promise for biomedical applications.

Source:  https://aip.scitation.org/
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Bacteria Becomes Resistant When Exposed To Li-Ion Nanoparticles

Over the last two decades, nanotechnology has improved many of the products we use every day from microelectronics to sunscreens. Nanoparticles (particles that are just a few hundred atoms in size) are ending up in the environment by the ton, but scientists are still unclear about the long-term effects of these super-small nanoparticles. In a first-of-its-kind study, researchers have shown that nanoparticles may have a bigger impact on the environment than previously thought.

Researchers from the National Science Foundation Center for Sustainable Nanotechnology, led by scientists at the University of Minnesota, found that a common, non-disease-causing bacteria found in the environment, called Shewanella oneidensis MR-1, developed rapid resistance when repeatedly exposed to nanoparticles used in making lithium ion batteries, the rechargeable batteries used in portable electronics and electric vehicles. Resistance is when the bacteria can survive at higher and higher quantities of the materials, which means that the fundamental biochemistry and biology of the bacteria is changing.

At many times throughout history, materials and chemicals like asbestos or DDT have not been tested thoroughly and have caused big problems in our environment,” said Erin Carlson, a University of Minnesota chemistry associate professor in the University’s College of Science and Engineering and the lead author of the study. “We don’t know that these results are that dire, but this study is a warning sign that we need to be careful with all of these new materials, and that they could dramatically change what’s happening in our environment.”

Carlson said the results of this study are unusual because typically when we talk about bacterial resistance it is because we’ve been treating the bacteria with antibiotics. The bacteria become resistant because we are trying to kill them, she said. In this case, the nanoparticles used in lithium ion batteries were never made to kill bacteria.

The research is published in Chemical Science, a peer-reviewed journal of the Royal Society of Chemistry.

Source: https://twin-cities.umn.edu/

Converting CO2 To Valuable Resources

Enzymes use cascade reactions to produce complex molecules from comparatively simple raw materials. Researchers have now copied this principle.

An international research team has used nanoparticles to convert carbon dioxide into valuable raw materials. Scientists at RUB in Germany and the University of New South Wales in Australia have adopted the principle from enzymes that produce complex molecules in multi-step reactions. The team transferred this mechanism to metallic nanoparticles, also known as nanozymes. The chemists used carbon dioxide to produce ethanol and propanol, which are common raw materials for the chemical industry.

The team led by Professor Wolfgang Schuhmann from the Center for Electrochemistry in Bochum and Professor Corina Andronescu from the University of Duisburg-Essen, together with the Australian team led by Professor Justin Gooding and Professor Richard Tilley, reported in the Journal of the American Chemical Society on 25 August 2019.

Transferring the cascade reactions of the enzymes to catalytically active nanoparticles could be a decisive step in the design of catalysts,” says Wolfgang Schuhmann.

 

Source: https://news.rub.de/

 

CRISPR Halts Growth of Breast Cancer

Triple-negative breast cancer (TNBC), lacking estrogen, progesterone and HER2 receptors, has the highest mortality rate of all breast cancers. It more frequently strikes women under age 50, African American women, and women carrying a BRCA1 gene mutation. The highly aggressive, frequently metastatic cancer is in urgent need of more effective targeted therapeutics.

A new tumor-targeted CRISPR gene editing system, encapsulated in a nanogel and injected into the body, could offer a genetic treatment, suggest researchers at Boston Children’s Hospital. In a proof-of-principle study, conducted in human tumor cells and live, tumor-bearing mice, the CRISPR system effectively halted the growth of TNBC while sparing normal cells. Peng Guo, PhD,Marsha Moses, PhD and their colleagues have reported the findings in the journal PNAS.

To date, a lack of effective delivery systems has limited the translation of CRISPR gene editing into therapies. One method uses a virus to deliver CRISPR, but the virus cannot carry large payloads and potentially can cause side effects if it “infectscells other than those targeted. Another method packages the CRISPR tools inside a cationic polymer or lipid nanoparticles. But these elements can be toxic to cells, and the body often traps or breaks down the nanoparticles before they reach their destination.

The new approach encapsulates the CRISPR editing system inside a soft “nanolipogel” made up of a nontoxic double layer of fatty molecules and a hydrogel. Antibodies attached to the gel’s surface then guide the CRISPR nanoparticles to the tumor site. (The antibodies are designed to recognize and target ICAM-1, a therapeutic target for TNBC discovered by the Moses Lab in 2014.)

Because the particles are soft and flexible, they can enter cells more efficiently than their stiffer counterparts. Stiffer nanoparticles tend to get trapped by the cell’s ingestion machinery, while the soft particles fused with the tumor cell membrane and delivered their CRISPR payloads directly inside the cell, the researchers found.

Using a soft particle allows us to penetrate the tumor better, without side effects, and with bigger cargo,” says Guo, the study’s first author. “Our system can substantially increase tumor delivery of CRISPR.”

Source: http://discoveries.childrenshospital.org

Magnetic Nanoclusters Kill Hard-To-Reach Tumors

Researchers at Oregon State University have developed an improved technique for using magnetic nanoclusters to kill hard-to-reach tumorsMagnetic nanoparticles – tiny pieces of matter as small as one-billionth of a meter – have shown anti-cancer promise for tumors easily accessible by syringe, allowing the particles to be injected directly into the cancerous growth. Once injected into the tumor, the nanoparticles are exposed to an alternating magnetic field, or AMF. This field causes the nanoparticles to reach temperatures in excess of 100 degrees Fahrenheit, which causes the cancer cells to die. But for some cancer types such as prostate cancer, or the ovarian cancer used in the Oregon State study, direct injection is difficult. In those types of cases, a “systemicdelivery method – intravenous injection, or injection into the abdominal cavity – would be easier and more effective.

The challenge for researchers has been finding the right kind of nanoparticles – ones that, when administered systemically in clinically appropriate doses, accumulate in the tumor well enough to allow the AMF to heat cancer cells to death.

Olena Taratula and Oleh Taratula of the OSU College of Pharmacy tackled the problem by developing nanoclusters, multiatom collections of nanoparticles, with enhanced heating efficiency. The nanoclusters are hexagon-shaped iron oxide nanoparticles doped with cobalt and manganese and loaded into biodegradable nanocarriers.

There had been many attempts to develop nanoparticles that could be administered systemically in safe doses and still allow for hot enough temperatures inside the tumor,” said Olena Taratula, associate professor of pharmaceutical sciences. “Our new nanoplatform is a milestone for treating difficult-to-access tumors with magnetic hyperthermia. This is a proof of concept, and the nanoclusters could potentially be optimized for even greater heating efficiency.”

Findings were published in ACS Nano.

Source: https://today.oregonstate.edu/

Microwave Stimulated Nanoparticles To Fight Efficiently Cancer

A physicist at The University of Texas at Arlington (UTA) has proposed a new concept for treating cancer cells. In a recently published paper in the journal Nanomedicine: Nanotechnology, Biology and Medicine, UTA physics Professor Wei Chen and a team of international collaborators advanced the idea of using titanium dioxide (TiO2) nanoparticles stimulated by microwaves to trigger the death of cancer cells without damaging the normal cells around them.

The method is called microwave-induced radical therapy, which the team refers to as microdynamic therapy, or MDT. The use of TiO2 nanoparticles activated by light and ultrasound in cancer treatments has been studied extensively, but this marks the first time researchers have shown that the nanoparticles can be effectively activated by microwaves for cancer cell destruction—potentially opening new doors to treatment for patients fighting the disease. Chen said the new therapy centers on reactive oxygen species, or ROS, which are a natural byproduct of the body’s metabolism of oxygen. ROS help kill toxins in the body, but can also be damaging to cells if they reach a critical level. TiO2 enters cells and produces ROS, which are able to damage plasma membranes, mitochondria and DNA, causing cell death.

Cancer cells are characterized by a higher steady-state saturation of ROS than normal, healthy cells,” Chen said. “This new therapy allows us to exploit that by raising the saturation of ROS in cancer cells to a critical level that triggers cell death without pushing the normal cells to that same threshold.

The pilot study for this new treatment concept builds upon Chen’s expertise in the use of nanoparticles to combat cancer.

Chen’s collaborators hail from the Guangdong Academy of Medical Sciences and Beihang University. The team conducted experiments that demonstrate the nanoparticles can significantly suppress the growth of osteosarcomas under microwave irradiation.

While TiO2 and low-power microwave irradiation alone did not effectively kill cancer cells, the combination of the two proved successful in creating a toxic effect for the tumor cells. Microwave ablation therapy has already proven to be an effective treatment against bone cancer, obtaining better results than MDT. However, MDT has applications for combatting other types of cancer, not just the osteosarcomas used for this pilot case.

Using light to activate ROS—as is seen in photodynamic therapy—can be challenging for the treatment of tumors deeply located within the body; in contrast, microwaves lend the ability to create deeper penetration that propagates through all types of tissues and non-metallic materials.

This new discovery is exciting because it potentially creates new avenues for treating cancer patients without causing debilitating side effects,” Chen said. “This targeted, localized method allows us to keep healthy cells intact so patients are better equipped to battle the disease.

Source: https://www.uta.edu/

Gold Nanoparticles Ship With Efficiency CRISPR Cargo

Forget UPS and FedEx: Tiny golden delivery trucks created at Fred Hutchinson Cancer Research Center can ship CRISPR into human blood stem cells, offering a potential way to treat diseases like HIV and sickle cell anemia. And the researchers behind those trucks have even bigger distribution dreams. Gene therapy — the editing of our DNA to treat disease — is a clinical reality today, but only in a handful of rich countries. Fred Hutch scientists think their new CRISPR courier could help deliver gene therapy to patients around the world.

A new paper published in Nature Materials describes how the scientists loaded CRISPR onto spherical gold nanoparticles. These tiny shuttles then deposited the gene-editing tool into blood stem cells donated by healthy individuals and isolated in test tubes, where CRISPR altered genes related to HIV and certain blood disorders.   It is the first time that nanoparticles have successfully ferried CRISPR into blood stem cells to edit DNA, the researchers said. And it’s a promising step toward addressing CRISPR’s critical delivery problems. The first of these problems has vexed the field since the gene-editing technique was discovered. Scientists need to deliver CRISPR into the right spot in a cell. That is proving tricky enough. DNA represents the body’s crown jewels, and CRISPR must sneak past all sorts of security systems to gain access.

And then CRISPR must go global. Gene editing could benefit millions of people worldwide. But as the treatment process stands right now, the vast majority won’t. That process depends almost entirely on highly engineered viruses made in high-tech, multimillion-dollar facilities.
The researchers think their golden nanoparticles can solve both problems. As efficient couriers, they could reduce the need for engineered viruses and specialized research centers. And that could help make these emerging, high-tech treatments accessible and affordable, said senior scientist Dr. Jennifer Adair of Fred Hutch.

Gene therapy has a lot of potential across many diseases, but the process we have right now is just not feasible in every place in the world,” Adair said. “We want to end up delivering gene therapy in a syringe. This gold nanoparticle represents the first possibility we have to do that for blood stem cells.”

Source: https://www.fredhutch.org/