How do Nanoparticles Enter Cells?

There is an ovarian cancer drug called DOXIL that is delivered to cells in a nanoparticle made of molecules of fat. But, how does the nanoparticle enter the cell?

According to a recent study that uses computers to model this process, there are mainly 3 ways in which scientists think a nanoparticle can enter the cell: penetration, endocytosis, and semi-endocytosis.

In order to enter a cell, the nanoparticle has to cross the cell membrane, which separates the internal components of the cell from the outside.

Endocytosis and Semi-Endocytosis

Endocytosis-Semiendocytosis

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The Educational Impact of Meeting Real Scientists

The most exciting moments of my pre-college education were from a field trip to the geology department of Augustana College where I was shown around the facilities by Dr. Michael Wolf. He showed me tools that scientists use to experiment with rocks under intense heat and pressure.

Augustana College. Image source.

Augustana College. Image source.

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How Some Nanoparticles are Like Chocolate Chip Cookies

Synthesizing nanoparticles is sometimes a lot like baking cookies. You start with ingredients, mix them together, and put them in the oven. After a few hours, you take them out and admire your hard work. Just like there are lots of different kinds of cookies, there are also many different kinds of nanoparticles. The easiest kind to make is the so-called homogeneous nanoparticle; much like a shortbread cookie, homogeneous nanoparticles are the same all the way through. Like the shortbread cookie, these nanoparticles are very versatile: you can cover them in chocolate (or protein molecules, if we’re talking about a nanoparticle), keep them plain, or use them for any number of other things. They’re not the only kind of cookie, however; my favorite has always been chocolate chip.

There’s another kind of nanoparticle that, like the chocolate chip cookie, is beloved by many because of how different it is than our same-all-the-way-through shortbread cookie example above. These nanoparticles, like chocolate chip cookies, are made up of two parts: 1) the main cookie part, known as the crystal and 2) the chocolate chip part, known as the dopant. The nanoparticle, like the cookie, is mostly crystal, with only a few dopant atoms per particle. If there are too many chocolate chips and not enough cookie to hold the whole thing together, the result is just a mess. But why would we want to add different atoms to our nanoparticle? It’s certainly not for flavor, like the chocolate chips in our cookies are; in this case, it’s so we can “see” the nanoparticles.

1 - chocolate chip cookies and fluorescent nanoparticles

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Slowing the Speed of Light to Zero

For centuries humans have been obsessed with speed. We are constantly pushing the limits for how fast we can make things travel. Currently in modern physics, light is regarded as the fastest thing in the universe and is the basis for Albert Einstein’s theory of special relativity. But what if the light you saw could be slowed down and even stopped? As hard as it is to believe, scientists at Harvard University have done just that!

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Swiss Army Knife of Science – Collaborations & Research Instrumentation

This blog post comes at a time when our center is probing the nano-bio interface (see prior blog entries below) with one of the largest collection of scientific research instrumentation to which I have ever had access. The Center for Sustainable Nanotechnology has researchers at 5 universities across the Midwest as well as the Pacific Northwest National Laboratory in Washington. By working in a multi-institutional team, each center member has direct access to each university’s analytical facilities, as well as the many state-of-the-art instruments housed at Pacific Northwestern National Laboratory. Plus, there’s bound to be at least one, if not more, expert in one of our institutions who knows how to do a particular experiment well.

This is my swiss army knife. Look at all it can do! Super multi-functional, just like our interdisciplinary research center.

This is my swiss army knife. Look at all it can do! Super multi-functional, just like our interdisciplinary research center.

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The Roof Coating that could Reduce Smog

In 2012 around 7 million people died as a result of air pollution exposure according to the World Health Organization. Air Pollution is now the world’s largest single environmental health risk. Reducing air pollution could save lives around the globe and our own buildings could be a solution.

Cairo on a low-smog day. Still lots of smog. Image source.

Cairo on a low-smog day. Still lots of smog. Image source.

The air is a vital part of our environment, which makes air pollution an ever-relevant topic. A typical human inhales 7 to 14 liters of air every minute. One component of pollution is smog. Nitrogen oxides – a product of fuel consumption – react with organic compounds with low boiling points (“volatile organic compounds” or “VOCs”) in the presence of sunlight to create smog. Contrary to popular belief, death as a result of smog is often not a direct result of poisoning by pollutants in the air, but rather, a result increasing susceptibility to diseases. Continue reading

Invisible Remnants of Dead Stuff Hiding in Water

Ready for a little test?  Try to list all of the things you can think of that are found in a river or lake…

NiagaraFalls

Sweet picture of the Niagara River in Niagara Falls, New York.

I’m sure you came up with things like fish, algae, dirt, plants, and many others.  But one thing found in these water bodies that you may not have thought of and that I’m really interested in studying is natural organic matter, or NOM (not to be confused with the sound you make while eating a delicious meal). NOM dissolved in water is hard to detect with the naked eye but can be readily detected using a variety of scientific instruments. A glass of water with and without NOM, for example, would look very similar to the naked eye, with just a slight color change. However, it turns out they differ in some very important ways. Continue reading