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Clean Power "Rough edges at the nanoscale: The bottom corner of a piece of graphene penetrates a cell membrane. Mechanical properties — rough edges, sharp corners — can make graphene dangerous to human cells. Scale bar represents two microns."
Image Credit: Kane lab/Brown University

Published on July 15th, 2013 | by James Ayre

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Graphene May Be More Toxic Than Previously Thought, Research Finds — Graphene Can Enter Human Cells And Disrupt Cellular Function

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July 15th, 2013 by
 
Graphene micro-sheets may be considerably more toxic to human cells than was previously thought, according to new research from Brown University. The new research has found that the sharp edges of graphene sheets can easily pierce cell membranes, and then after piercing the membranes, be pulled into the cell where they then disrupt normal cellular functions.

"Rough edges at the nanoscale: The bottom corner of a piece of graphene penetrates a cell membrane. Mechanical properties — rough edges, sharp corners — can make graphene dangerous to human cells. Scale bar represents two microns." Image Credit: Kane lab/Brown University

“Rough edges at the nanoscale: The bottom corner of a piece of graphene penetrates a cell membrane. Mechanical properties — rough edges, sharp corners — can make graphene dangerous to human cells. Scale bar represents two microns.”
Image Credit: Kane lab/Brown University

The researchers think that their work should spur further investigations into the effects that graphene may possibly have on human/animal health, and could perhaps lead to the development of means to minimize any potential toxicity.

“At a fundamental level, we want to understand the features of these materials that are responsible for how they interact with cells,” stated Agnes Kane, chair of the Department of Pathology and Laboratory Medicine at Brown, and study author. “If there’s some feature that is responsible for its toxicity, then maybe the engineers can engineer it out.”

For those that don’t know, graphene is essentially just a sheet of carbon that is only one atom think, but it possesses an incredible number of unique electronic, mechanical, and photonic properties, as well as being incredibly strong. Since it was discovered only relatively recently — about a decade ago — there remains much that is unknown about it though. But even though there are many unknowns, there is still a great deal of interest in the material, especially with regard to electronics, solar energy, batteries, medical devices, etc. The commercial application of the material is expected to be only a couple of years off — so it would be good to know about any potential toxicity. Before this new research, there wasn’t really anything known about what effect graphene might have on the human body, whether with regard to normal exposure via product wear-and-tear or exposure via a working environment — such as during the manufacturing of products containing the material.



“These materials can be inhaled unintentionally, or they may be intentionally injected or implanted as components of new biomedical technologies,” stated Robert Hurt, a professor of engineering and one of the study’s authors. “So we want to understand how they interact with cells once inside the body.”

Brown University explains the research further:

Preliminary research by Kane’s biology group had shown that graphene sheets can indeed enter cells, but it wasn’t clear how they got there. Huajian Gao, professor of engineering, tried to explain those results using powerful computer simulations, but he ran into a problem. His models, which simulate interactions between graphene and cell membranes at the molecular level, suggested that it would be quite rare for a microsheet to pierce a cell. The energy barrier required for a sheet to cut the membrane was simply too high, even when the sheet hit edge first.

The problem turned out to be that those initial simulations assumed a perfectly square piece of graphene. In reality, graphene sheets are rarely so pristine. When graphene is exfoliated, or peeled away from thicker chunks of graphite, the sheets come off in oddly shaped flakes with jagged protrusions called asperities. When Gao reran his simulations with asperities included, the sheets were able to pierce the membrane much more easily.

Annette von dem Bussche, assistant professor of pathology and laboratory medicine, was able to verify the model experimentally. She placed human lung, skin and immune cells in Petri dishes along with graphene microsheets. Electron microscope images confirmed that graphene entered the cells starting at rough edges and corners. The experiments showed that even fairly large graphene sheets of up to 10 micrometers could be completely internalized by a cell.

“The engineers and the material scientists can analyze and describe these materials in great detail,” Kane stated. “That allows us to better interpret the biological impacts of these materials. It’s really a wonderful collaboration.”

The researchers are now planning to follow this work up by investigating in further detail what happens — biologically speaking — when sheets of graphene end up inside of human cells. Kane notes, though, that the work that they have already done provides an important first step with regard to understanding the potential toxicity of graphene.

“This is about the safe design of nanomaterials,” she explained. “They’re man-made materials, so we should be able to be clever and make them safer.”

The new research was just published July 9th in the Proceedings of the National Academy of Sciences.

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About the Author

's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy. You can follow his work on Google+.



  • Chris Stroh

    Wonder if volcanic eruptions or a meteor caused the dinosaurs extinction? Imagine all the sulphuric acid and possible ecosystem toxins that would be created!

  • Chris Stroh

    polymers all the same great useful properties and dangerous to our enviroment! next stop stanene! Maybe they can make a alloy 2d material out of graphene?

  • William S Blade

    ever thought of NOT using man made materials? Nature does it better. I am sorry one day you will learn this even if it takes the death of most of the human race.

    • Moneyispower

      what an ignorant statement.

    • Dusty Gazongas

      yeah, there’s only a bazillion different crystals/plant resins that do everything we could ever need

  • Wayne Williamson

    duh…when/where will any of these creations not be sealed within some kind of containment. From a manufacturing standpoint, its best they are clean rooms without any humans involved…

    Ok, I have to admit when I heard about the carbon nanotubes, graphine, etc that the first thing that entered my mind was asbestos. As long as precautions are taken there shouldn’t be an issue….

    My second thought was that both of these products have been with us for our short(millions of years) of being. That being said, it never hurts to treat the raw materials as dangerous.

  • beernotwar

    Silly graphene industry. Don’t you know you’re supposed to get rich making the stuff first, and once your product is all over the place let the hippies figure out if it’s dangerous. You’ll never get rich following the precautionary principle!

    • http://zacharyshahan.com/ Zachary Shahan

      lol :D nice. :D

  • Jack

    When ordinary pencil lead is used for writing tiny flakes of graphene are spread on the paper. Is there any evidence that this is a health hazard?

    • Lauren

      Possibly, but most likely not. The graphene used in pencil graphite is still several atoms long and wide, even when flaked.The fact that that graphene is able to be reduced to the width of an individual atom via nanotechnology is probably the only reason why toxicity is an issue. The larger pencil graphite probably cannot enter a cell and the body can likely filter it out of the bloodstream successfully, but a cell may not be able to filter out individual graphene atoms.

      • David Fuchs

        You do know that graphene was originally isolated using a pencil and scotch tape.

    • David Fuchs

      I was going to ask the same question. Also who paid for this research? If it was one of the fossil fuel front groups, then this should be taken with a grain of salt, since graphene micro flakes can increase the storage capacity of Li-ion batteries up to 10x. Which basically removes range and cost from the EV automobile equation.

      • Bob_Wallace

        It seems to have been published in the Proceedings of the National Academy of Sciences.

        That’s a pretty prestigious journal with high quality editorial and review standards.

        Like any first finding it should be considered “interesting” but not definitive until it has been verified by further studies. Since the study does raise a health risk issue, it would be wise to be very careful with graphene until we understand it better.

        Remember how Madam Curie learned the hard way?

        • David Fuchs

          “it would be wise to be very careful with graphene until we understand it better.”

          You are correct. Just to be safe I am throwing out all my pencils ……

      • rick solar

        They should take it with a grain of graphene haha

    • zak

      The difference may be that when you write with a graphite-point pencil, the graphite retains its graphene – graphene intermolecular bonding (possibly due to Van der Waals?). The “graphene” as you describe would then have a thickness much larger than what it would be with just one sheet.

    • techandi

      As I understand it:

      A pencil contains graphite, not graphene. Graphene is only a single atom wide. Even those tiny flakes of graphite are not so tiny to be graphene, that needs special techniques to be produced.

      • David Fuchs

        see my comment above scotch tape and a pencil …

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