Tag Archives: Nanoparticle

Nanoparticles in contrast agent “see” blood vessels better

Interactions of nanoparticles with biological ...

Interactions of nanoparticles with biological molecules are facilitated by ligands on nanoparticle surfaces. (Photo credit: Wikipedia)

Wouldn’t it be nice if doctors didn’t have to use invasive tests such as heart catheterization to tell if any of your arteries are clogged? Heart caths are not fun – and they carry their own set of risks.

I’m happy to say they’re working on it. Just saw this report on an NIH-funded study using nanoparticles as part of a contrast agent to help doctors visualize the state of your blood vessels much more accurately. A Temple University bioengineer has developed a method for “linking polyphenols, which are very strong antioxidants, to polymers that can self-assemble into nanoparticles.”

The coolest part is that the polymers on the outside get destroyed when they come in contact with arterial plaques (the stuff that can block circulation and cause strokes or heart attacks). Then the contrast agent, including its antioxidants, is released when the polymers dissolve.

The study is two years long. If this works, it could save a lot of people a lot of suffering. Read more here.

P.S. Not biomed but still cool. Engineers have found a way to recycle those ubiquitous plastic grocery bags into practical nanomaterials.

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Nanoparticles can damage plant DNA

We eat radishes. "Radish Roll" (Photo credit: ulterior epicure)

It’s not good news, but it’s also not unexpected. Recent experiments with adding engineered nanoparticles to plants’ diets determined that the plants started gradually shriveling up and dying.

Specifically, the plants being experimented with were radishes and two ryegrass ground covers that grazing animals commonly eat.  Researchers at National Institute of Standards and Technology (NIST) and the University of Massachusetts Amherst (UMass) wanted to learn:

…whether nanosizing cupric oxide [a reactive chemical that removes electrons from other compounds] made the generation and accumulation of DNA lesions more or less likely in plants. If the former, the researchers also wanted to find out if nanosizing had any substantial effects on plant growth and health.

They found out. The radishes absorbed twice as much cupric oxide and developed twice as many DNA lesions when the mineral came in smaller nanoparticles versus those bigger than 100 nanometers. And the results on the radish seedlings were definitively destructive.

Although the DNA of the two ryegrasses was not as dramatically affected, in all three plant species, growth of both roots and shoots was significantly stunted. Next up for these researchers will be similar testing with “titanium dioxide nanoparticles — such as those used in many sunscreens — on rice plants.”

This report’s conclusions stick strictly to the science and don’t project anything about how the effects of this experiment might apply to human beings being injected or otherwise treated with medicines or protocols involving nano-sized particles. It’s reassuring, at least, to know that high-level researchers are working to test the safety of nanoparticles for living systems. Let’s hope this series of experiments is the first of many that will lead to new, strict standards for nano-sized development.

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Mouse studies say nanoparticle-delivered drugs can be targeted

dick mouse

Image via Wikipedia

Reports are all over the Internet about a recent study using nanoparticles as additions to vaccines that target lymph nodes. The study has found that, at least in mice, these nano-loaded treatments can boost antibody- and immune responses against lethal infections. The Duke University team that did the study says their loaded nanoparticles closely mimic the structure and actions of mast cells—those little guys that naturally help us fight infection. They say the fact that they can load the particles with different combinations of cytokines means they can steer the direction of the immune response.

Sounds very promising indeed. My first thought was, this is in mice. How well does mouse research translate into human treatments? First, I learned that the mouse has 99% of the same genes as we humans. Then, too, scientists already have a huge selection of sophisticated tools¬† for working with mice. Plus, the mouse’s tiny size makes it affordable for large studies.

Then I learned that lots of research studies conducted with mice have not translated at all well to humans. A global cross-discipline (academia, industry, clinical) group convened last year to discuss the whole mouse-as-model issue and came to some conclusions. The most significant of these, for our purposes here, seems to be that mice studies have been successfully translated mostly to validate drug targets and to determine safe and effective doses of combination treatments in humans. Read the entire (slightly windblown) mouse model conference report here.

Another example of successfully using nanoparticles as targeted carriers is in treating prostate cancer in mice. Tumors

Nanoparticle Characterization
Image by EMSL via Flickr

shrank significantly, and treated mice survived much longer than untreated, and longer, too, than even those treated with the same drug but not delivered with the targeted nano carrier. And in this study they aimed to have the targeted drugs bypass both healthy tissue and the immune system. It’s wonderful that such precision is possible.

But meanwhile, because I regularly research information about the very long time—often decades—it takes for asbestos exposure to show up as deadly disease in human beings, I continue to worry about the long-term effects of manufactured nanoparticles being injected into living creatures. I sincerely hope scientists are planning long-term followup studies of mice treated with nanoparticle-boosted drugs and vaccines. Before we head towards human clinical studies, let’s make sure the mice didn’t get saved to live another day and then die of complications from having nanomaterials delivered directly into their bodies.

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Nanoparticles: Magnetized in the fight to stop cancer from spreading

Most deaths from cancer come after the primary tumor has been treated—usually with some combination of surgery and chemo or radiation—when stray cancer cells from the tumor escape and spread to other parts of the body (metastasis).

Italiano: traduzione italiana di :File:Cancer ...

Image via Wikipedia

Since not all cells from cancer tumors behave the same way or have the same DNA, researchers have been looking for a way to study single cells. The problem was separating them. Now this new nanoparticle approach uses magnets to detect whether cells are growing, dividing or dying. It spins the cells in a magnetic field where each type rotates at a different speed. Larger, dying or dividing cells rotate more slowly and in specific patterns. so they can be separated into a group of single cells. Thus the researcher can focus on investigating the behavior of those particular cells.

One of the big promises of this approach is that scientists may now be able to test drugs on just the cells themselves instead of on the entire human organism—thus avoiding some of the worst side effects for patients. And, instead of throwing everything they have at the patient in hopes of affecting the disease, doctors can work with the cells and then with greater confidence prescribe medicine they’ve been able to test as working best for this individual person.

What a blessing for cancer patients this will be.

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