Tag Archives: titanium dioxide

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/

Micromotors Deliver Oral Vaccines

Researchers are working on new generations of oral vaccines for infectious diseases. But to be effective, oral vaccines must survive digestion and reach immune cells within the intestinal wall. As a step in this direction, UC San Diego nanoengineering researchers have developed oral vaccines powered by micromotors that target the mucus layer of the intestine.

The work appears in the ACS journal Nano Letters. It’s a collaboration between the labs of nanoengineering professors Joseph Wang and Liangfang Zhang at the UC San Diego Jacobs School of Engineering.

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The lack of needles is one reason oral vaccines are attractive. Another reason: oral vaccines can generate a broad immune response by stimulating immune cells within the mucus layer of the intestine to produce a special class of antibody called immunoglobulin A (IgA). The NanoLetters paper documents the team’s efforts to use magnesium particles as tiny motors to deliver an oral vaccine against the bacterial pathogen Staphylococcus aureus. When coated over most of their surfaces with titanium dioxide, magnesium microparticles use water as fuel to generate hydrogen bubbles that power their propulsion.

To develop the oral vaccine, the researchers coated magnesium micromotors with red blood cell membranes that displayed the Staphylococcal α-toxin, along with a layer of chitosan to help them stick to the intestinal mucus. Then, they added an enteric coating that protects drugs from the acidic conditions of the stomach.

The micromotors safely passed through the stomach to the intestine, at which point the enteric coating dissolved, activating the motors. Imaging of mice that had been given the vaccine showed that the micromotors accumulated in the intestinal wall much better than non-motorized particles. The micromotors also stimulated the production of about ten times more IgA antibodies against the Staphylococcal α-toxin than the static particles.

Source: http://jacobsschool.ucsd.edu/

A stamp-sized nanofilm stores more data than 200 DVDs

Ninety percent of the world’s data has been created in the last two years, with a massive 2.5 quintillion bytes generated every single day. As you might suspect, this causes some challenges when it comes to storage. While one option is to gradually turn every square inch of free land into giant data centers, researchers from the  Center for Advanced Optoelectronic Functional Material Research, Northeast Normal University (China) may have come up with a more elegant solution. In a potential breakthrough, they have developed a new nanofilm80 times thinner than a human hair — that is able to store large amounts of data holographically. A single 10-by-10 cm piece of this film could archive more than 1,000 times the amount of data found on a DVD. By our count, that means around 8.5 TB of data. This data can also be retrieved incredibly quickly, at speeds of up to 1GB per second: The equivalent of 20 times the reading speed of modern flash memory.

In the journal Optical Materials Express, the researchers detail the fabrication process of the new film. This involves using a laser to write information onto silver nanoparticles on a titanium dioxide (titania) semiconductor film. This stores the data in the form of 3D holograms, thereby allowing it to be compressed into smaller spaces than regular optical systems.

That’s exciting enough, but what really makes the work promising is the fact that the data is stored in a way that is stable. Previous attempts at creating films for holographic data storage have proven less resilient than alternate storage methods since they can be wiped by exposure to ultraviolet light. That makes them less-than-viable options for long-term information storage. The creators of this new film, however, have shown that it has a high stability even in the presence of such light. This environmental stability means that the device could be used outside — or even conceivably in harsher radiation conditions like outer space.

Going forward, the researchers aim to test their new film by putting it through its paces outdoors. Should all go according to plan, it won’t be too long before this is available on the market. We might be willing to throw down a few bucks on Kickstarter for a piece!

Source: https://www.osapublishing.org
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