Tag: nanoparticles (page 1 of 2)

nano virus detectors

 

Nanoparticles, shown in blue, can detect a certain form of plant virus (in pink), and distinguish it from other types.

Science News has a blurb about using nanoparticles to detect viruses.:

Current methods to identify viruses do so using natural molecules such as antibodies, which can be expensive and unstable. Synthetic nanomaterials could be more stable and cheaper if they can be designed to recognize and bind viruses as effectively as antibodies do.

Patrick Shahgaldian at the University of Applied Sciences and Arts Northwestern Switzerland and colleagues bound several turnip yellow mosaic viruses — plant viruses with a common shape — to the surface of silica nanoparticles. Then the team grew a layer of organosilanes — molecules containing carbon-silicon bonds — that surrounded the viruses.

After the researchers detached the viruses, the organosilane layer had imprints that not only matched the viruses’ shape but also were able to recognize them chemically. The nanoparticles successfully bound the template viruses while largely ignoring another similarly shaped one.

The original research appears in Nature Communications.

nanoparticle HIV test

A new HIV test uses gold nanoparticles to determine the presence of the HIV biomarker p24. In the presence of the biomarker the particles clump and turn blue. Otherwise, the particles produce a red color. The test is more sensitive and a lot cheaper than other tests. From Popular Science:

To detect the AIDS-causing virus using the new method, researchers add serum from a patient’s blood sample to a solution of gold nanoparticles. If the nanoparticles come into contact with an HIV biomarker called p24, they clump together into an irregular pattern that turns the mixture blue–indicating a positive test result. If p24 is absent, the gold nanoparticles separate into ball shapes, and the mixture turns red, signaling a negative result.
Lead investigator Molly Stevens said the test could be altered to detect other diseases, including malaria, sepsis, prostate cancer, tuberculosis, and leishmaniasis

Also check out the original publication in Nature Nanotechnology.

magnets kill cancer

In a study recently published in Nature scientists use magnets to kill cancer. To do this, the researchers introduced zinc doped iron nanoparticles which they conjugated to an antibody for the protein death receptor 4 into a culture of colon cancer cells (DLD-1). When a magnetic field is subsequently applied the nanoparticles cause the cells containing them to enter into an apoptotic cycle and die. From Science News:

In the past, scientists have explored killing cancer using tiny iron-containing nanoparticles that latch onto malignant cells and heat up when exposed to a magnetic field. In the new work, a bit of protein guides each nanoparticle to death receptor 4, an aptly named handle on the outside of a cell that acts as a molecular doomsday switch. Exposing the cells to a magnetic field makes the nanoparticles clump together. This clumping pulls together the three molecular prongs that make up the switch, activating it and triggering a process that leads to the cell’s demise.

The scientists from Yonsei University in South Korea tried the approach with a dish of colon cancer cells. Within 24 hours, more than half of the cells exposed to the magnetic field were dead, the team reports online October 7 in Nature Materials.

“They’ve identified a major opportunity for magnetic nanoparticles,” says bioengineer Andrew MacKay of the University of Southern California. “This might be a new way to do really targeted therapeutics.”

Figuring out how to target only particular cells is an ongoing problem, though. Death receptor 4 sits on normal cells too, which can also be destroyed via remote-controlled magnetism. When the researchers tested their approach on developing zebra fish, the tails of the exposed fish developed a kink where cells were killed off in a particular area.

Exciting stuff. Scientists still don’t know if this can be developed into a meaningful therapy. Many cells in the body contain death receptor 4 including healthy cells and they would also be effected by this treatment. More work needs to be done to improve selective delivery of these nanoparticles to cancer cells. They are currently exploring other targets that may improve the nanoparticles’ selectivity.

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