Nanoparticles in Prosthetics & Bionics

During my time in the Marine Corps I met several people that lost limbs in the war. I made the decision to leave the service to get my degree. Inspired by my fellow soldiers, my ultimate goal is to start a company making prosthetics and bionic limbs, hopefully making their lives a little bit easier.

Flight into Iraq

Flight into Iraq

One problem with prosthetics is that they can only be worn for a short period of time. This is partly due to discomfort issues. However, a more serious concern is infection. Our bodies sweat and move constantly, so there is an increased risk of irritation and subsequent infection with long-term prosthetic use.

Several products have been created and tested that help reduce infections caused by implantable medical devices. Some of these products use silver nanoparticles. As we’ve discussed before on this blog (entry 1, entry 2), silver nanoparticles fight microbes by slowly releasing silver ions that are toxic to bacteria and other microbial pests. The surface of implantable medical devices can be coated with silver nanoparticles, and the slow release of silver ions helps keep the area of implantation free of infection.

Perhaps one day prosthetic materials coated with silver nanoparticles will be widely available (perhaps made by my company!). While I have only been conducting nanoparticle research through the Research Experiences for Veterans program for about two months, I have learned a tremendous amount about some of the exciting advances in nanotechnology. This is just a glimpse into my first exciting idea, and I’m sure to have more as my technical experience grows.

Liposuction and Gold Nanoparticles

Scientists have discovered that tiny particles of gold injected into fat tissues can offer a new and potentially safer way to carry out liposuction procedures. Liposuction by definition is the process of removing excess fat found underneath the skin by suction. Although liposuction has a reputation as a low risk cosmetic surgery, this procedure is not without its problems. One of the primary problems stems from the fact that fat is not an isolated feature of the body. Simply put, nerves and other closely located tissues may be removed along with the fat. Recent research shows that gold nanoparticles may be the solution to this problem. Problems associated with liposuction deserve some attention, as this is one of the most commonly performed cosmetic surgeries and people ranging from ages twelve to eighty-seven have had this procedure.

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Our Hidden Bacterial Friends Keep Us All Alive – Shewanella oneidensis

While the word “bacteria” conjures images of human illness and death for many people, the vast majority of bacteria in the world allow for the healthy functioning of humans and ecosystems. The way they do this ranges from breaking down food in animals’ digestive systems (yes, even ours) to cycling life-giving chemical elements from things like sediment and rocks back into living food chains. Today I will be discussing only one aspect of only one of our hidden little friends—Shewanella oneidensis’ power to mobilize the critical element iron for use by other organisms. Without Shewanella, you and I and most other life on earth would have a big problem on our hands.

Bacteria help make this possible. Image source

Bacteria help make this possible. Image source

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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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