Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Jagged graphene can slice into cell membranes

 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.	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.

Credit: Kane lab/Brown University

Abstract:
A collaboration of biologists, engineers, and material scientists at Brown University has found that jagged edges of graphene can easily pierce cell membranes, allowing graphene to enter the cell and disrupt normal function. Understanding the mechanical forces of nanotoxicity should help engineers design safer materials at the nanoscale.

Jagged graphene can slice into cell membranes

Providence, RI | Posted on July 10th, 2013

Researchers from Brown University have shown how tiny graphene microsheets ultra-thin materials with a number of commercial applications could be big trouble for human cells.

The research shows that sharp corners and jagged protrusions along the edges of graphene sheets can easily pierce cell membranes. After the membrane is pierced, an entire graphene sheet can be pulled inside the cell where it may disrupt normal function. The new insight may be helpful in finding ways to minimize the potential toxicity of graphene, said Agnes Kane, chair of the Department of Pathology and Laboratory Medicine at Brown and one of the study's authors.

"At a fundamental level, we want understand the features of these materials that are responsible for how they interact with cells," Kane said. "If there's some feature that is responsible for its toxicity, then maybe the engineers can engineer it out."

The findings were published online July 9 in Proceedings of the National Academy of Sciences.

Discovered about a decade ago, graphene is a sheet of carbon just one atom thick. It is incredibly strong despite being so thin and has remarkable electronic, mechanical, and photonic properties. Commercial applications in small electronic devices, solar cells, batteries and even medical devices are just around the corner. But not much is known about what effect these materials might have if they get inside the body either during the manufacturing process or during a product's lifecycle.

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

These latest findings come from an ongoing collaboration between biologists, engineers, and material scientists at Brown aimed at understanding the toxic potential of a wide variety of nanomaterials. Their work on graphene started with some seemingly contradictory findings.

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 said. "That allows us to better interpret the biological impacts of these materials. It's really a wonderful collaboration."

From here, the researchers will look in more detail into what happens once a graphene sheet gets inside the cell. But Kane says this initial study provides an important start in understanding the potential for graphene toxicity.

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

Other contributors to the study were Brown graduate students Yinfeng Li (now a professor at Shanghai Jiao Tong University), Hongyan Yuan, and Megan Creighton. The research was supported by the National Science Foundation (grants CMMI-1028530 and CBET-1132446) and the Superfund Research Program of the National Institute of Environmental Health Sciences (grant P42 ES013660).

####

For more information, please click here

Contacts:
Kevin Stacey

401-863-3766

Copyright © Brown University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Iranian Researchers Planning to Produce Edible Insulin January 28th, 2015

Nanoparticles that deliver oligonucleotide drugs into cells described in Nucleic Acid Therapeutics January 28th, 2015

'Bulletproof' battery: Kevlar membrane for safer, thinner lithium rechargeables January 28th, 2015

Spider electro-combs its sticky nano-filaments January 28th, 2015

Graphene

Researchers Make Magnetic Graphene: UC Riverside research could lead to new multi-functional electronic devices January 27th, 2015

Fullerex launches 2015 edition of the Bulk Graphene Pricing Report January 26th, 2015

GS7 Graphene Sensor maybe Solution in Fight Against Cancer January 25th, 2015

Nanosensor Used for Simultaneous Determination of Effective Tea Components January 24th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Nanoscale Mirrored Cavities Amplify, Connect Quantum Memories: Advance could lead to quantum computing and the secure transfer of information over long-distance fiber optic networks January 28th, 2015

Detecting chemical weapons with a color-changing film January 28th, 2015

'Bulletproof' battery: Kevlar membrane for safer, thinner lithium rechargeables January 28th, 2015

Researchers Make Magnetic Graphene: UC Riverside research could lead to new multi-functional electronic devices January 27th, 2015

Discoveries

Detecting chemical weapons with a color-changing film January 28th, 2015

Joint international research project leads to a breakthrough in terahertz spectroscopy January 28th, 2015

Iranian Researchers Planning to Produce Edible Insulin January 28th, 2015

Nanoparticles that deliver oligonucleotide drugs into cells described in Nucleic Acid Therapeutics January 28th, 2015

Announcements

Iranian Researchers Planning to Produce Edible Insulin January 28th, 2015

Nanoparticles that deliver oligonucleotide drugs into cells described in Nucleic Acid Therapeutics January 28th, 2015

'Bulletproof' battery: Kevlar membrane for safer, thinner lithium rechargeables January 28th, 2015

Spider electro-combs its sticky nano-filaments January 28th, 2015

Safety-Nanoparticles/Risk management

A spoonful of sugar in silver nanoparticles to regulate their toxicity January 21st, 2015

Nutrition, Safety Key To Consumer Acceptance of Nanotech, Genetic Modification In Foods December 2nd, 2014

Sustainable Nanotechnologies Project November 20th, 2014

A gut reaction November 19th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE