Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Nanowires Deliver Biochemical Payloads to One Cell Among Many

Arrow points to nanowire placed on cell surface. (Image: Levchenko Lab)
Arrow points to nanowire placed on cell surface. (Image: Levchenko Lab)

Abstract:
Imagine being able to drop a toothpick on the head of one particular person standing among 100,000 people in a sports stadium. It sounds impossible, yet this degree of precision at the cellular level has been demonstrated by researchers affiliated with The Johns Hopkins University Institute for NanoBioTechnology. Their study was published online in June in Nature Nanotechnology.

Nanowires Deliver Biochemical Payloads to One Cell Among Many

Baltimore, MD | Posted on July 7th, 2010

The team used precise electrical fields as "tweezers" to guide and place gold nanowires, each about one-two hundredth the size of a cell, on predetermined spots, each on a single cell. Molecules coating the surfaces of the nanowires then triggered a biochemical cascade of actions only in the cell where the wire touched, without affecting other cells nearby. The researchers say this technique could lead to better ways of studying individual cells or even cell parts, and eventually could produce novel methods of delivering medication.

Indeed, the techniques not relying on this new nanowire-based technology either are not very precise, leading to stimulation of multiple cells, or require complex biochemical alterations of the cells. With the new technique the researchers can, for instance, target cells that have cancer properties (higher cell division rate or abnormal morphology), while sparing their healthy neighbors.

"One of the biggest challenges in cell biology is the ability to manipulate the cell environment in as precise a way as possible," said principal investigator Andre Levchenko, an associate professor of biomedical engineering in Johns Hopkins' Whiting School of Engineering. In previous studies, Levchenko has used lab-on-a-chip or microfluidic devices to manipulate cell behavior. But, he said, lab-on-a-chip methods are not as precise as researchers would like them to be. "In microfluidic chips, if you alter the cell environment, it affects all the cells at the same time," he said.

Such is not the case with the gold nanowires, which are metallic cylinders a few hundred nanometers or smaller in diameter. Just as the unsuspecting sports spectator would feel only a light touch from a toothpick being dropped on the head, the cell reacts only to the molecules released from the nanowire in one very precise place where the wire touches the cell's surface.

With contributions from Chia-Ling Chien, a professor of physics and astronomy in the Krieger School of Arts and Sciences, and Robert Cammarata, a professor of materials science and engineering in the Whiting School, the team developed nanowires coated with a molecule called tumor necrosis factor-alpha (TNF?), a substance released by pathogen-gobbling macrophages, commonly called white blood cells. Under certain cellular conditions, the presence of TNF? triggers cells to switch on genes that help fight infection, but TNF? also is capable of blocking tumor growth and halting viral replication.

Exposure to too much TNF?, however, causes an organism to go into a potentially lethal state called septic shock, Levchenko said. Fortunately, TNF? stays put once it is released from the wire to the cell surface, and because the effect of TNF? is localized, the tiny bit delivered by the wire is enough to trigger the desired cellular response. Much the same thing happens when TNF? is excreted by a white blood cell.

Additionally, the coating of TNF? gives the nanowire a negative charge, making the wire easier to maneuver via the two perpendicular electrical fields of the "tweezer" device, a technique developed by Donglei Fan as part of her Johns Hopkins doctoral research in materials science and engineering. "The electric tweezers were initially developed to assemble, transport and rotate nanowires in solution," Cammarata said. "Donglei then showed how to use the tweezers to produce patterned nanowire arrays as well as construct nanomotors and nano-oscillators. This new work with Dr. Levchenko's group demonstrates just how extremely versatile a technique it is."

To test the system, the team cultured cervical cancer cells in a dish. Then, using electrical fields perpendicular to one another, they were able to zap the nanowires into a pre-set spot and plop them down in a precise location. "In this way, we can predetermine the path that the wires will travel and deliver a molecular payload to a single cell among many, and even to a specific part of the cell," Levchenko said.

During the course of this study, the team also established that the desired effect generated by the nanowire-delivered TNF? was similar to that experienced by a cell in a living organism.

The team members envision many possibilities for this method of subcellular molecule delivery. "For example, there are many other ways to trigger the release of the molecule from the wires: photo release, chemical release, temperature release. Furthermore, one could attach many molecules to the nanowires at the same time," Levchenko said. He added that the nanowires can be made much smaller, but said that for this study the wires were made large enough to see with optical microscopy.

Ultimately, Levchenko sees the nanowires becoming a useful tool for basic research. "With these wires, we are trying to mimic the way that cells talk to each other," he said. "They could be a wonderful tool that could be used in fundamental or applied research." Drug delivery applications could be much further off. However, Levchenko said, "If the wires retain their negative charge, electrical fields could be used to manipulate and maneuver their position in the living tissue."

The lead author for this Nature Nanotechnology article was Fan, a former postdoctoral fellow in the departments of materials science and engineering and in physics and astronomy. Additional authors included Zhizhong Yin, a former postdoctoral fellow in the Department of Biomedical Engineering; Raymond Cheong, a doctoral student in the Department of Biomedical Engineering; and Frank Q. Zhu, a former doctoral student in the Department of Physics and Astronomy. The research was funded by the National Science Foundation and the National Institutes of Health.

####

About Johns Hopkins University Institute for NanoBioTechnology
The Institute for NanoBioTechnology at Johns Hopkins University brings together 212 researchers from: Bloomberg School of Public Health, Krieger School of Arts and Sciences, School of Medicine, Applied Physics Laboratory, and Whiting School of Engineering to create new knowledge and new technologies at the interface of nanoscience and medicine.

For more information, please click here

Contacts:
For media inquiries contact
Mary Spiro

410 516-4802

Copyright © Johns Hopkins University Institute for NanoBioTechnology

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

The Hydrogen-Fuel cell will revolutionize the economy of the world: New non-platinum and nanosized catalyst for polymer electrolyte fuel cell June 29th, 2015

June 29th, 2015

Efforts to Use Smart Nanocarriers to Cure Leukemia Yield Promising Results June 29th, 2015

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Govt.-Legislation/Regulation/Funding/Policy

X-rays and electrons join forces to map catalytic reactions in real-time: New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions June 29th, 2015

Graphene breakthrough as Bosch creates magnetic sensor 100 times more sensitive than silicon equivalent June 28th, 2015

The peaks and valleys of silicon: Team of USC Viterbi School of Engineering Researchers introduce new layered semiconducting materials as silicon alternative June 27th, 2015

Building a better semiconductor: Research led by Michigan State University could someday lead to the development of new and improved semiconductors June 27th, 2015

Possible Futures

Harris & Harris Group Portfolio Company D-Wave Systems Announces 1,000 Qubit Processor and is Discussed in the Economist June 23rd, 2015

Global Nanoclays Market Analysis, Size, Growth, Trends And Segment Forecasts, 2015 To 2022: Grand View Research, Inc June 15th, 2015

Healthcare Nanotechnology (Nanomedicine) Market Size To 2020 June 5th, 2015

Environmental Issues to Hamper Growth of Global Nanocomposites Market June 4th, 2015

Academic/Education

Rice University boots up powerful microscopes: New electron microscopes will capture images at subnanometer resolution June 29th, 2015

Six top Catalan research centres constitute ‘The Barcelona Institute of Science and Technology’ to pursue a joint scientific endeavour June 27th, 2015

Lancaster University revolutionary quantum technology research receives funding boost June 22nd, 2015

Deben reports on how the University of Portsmouth use in situ µXCT compressive testing to help answer how materials respond to complex loading conditions June 17th, 2015

Nanomedicine

Efforts to Use Smart Nanocarriers to Cure Leukemia Yield Promising Results June 29th, 2015

Chivalrous Knight Does Pro Bono June 27th, 2015

Green Chemistry Methods Used in Iran to Produce Zinc Oxide Nanoparticles June 27th, 2015

Targeted nanoparticles can overcome drug resistance in trypanosomes: A high-tech approach to combat sleeping sickness and potentially other neglected diseases June 26th, 2015

Announcements

The Hydrogen-Fuel cell will revolutionize the economy of the world: New non-platinum and nanosized catalyst for polymer electrolyte fuel cell June 29th, 2015

June 29th, 2015

Efforts to Use Smart Nanocarriers to Cure Leukemia Yield Promising Results June 29th, 2015

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Nanobiotechnology

Nanometric sensor designed to detect herbicides can help diagnose multiple sclerosis June 23rd, 2015

Newly-Developed Biosensor in Iran Detects Cocaine Addiction June 23rd, 2015

Researchers first to show that Saharan silver ants can control electromagnetic waves over an extremely broad range of the electromagnetic spectrum—findings may lead to biologically inspired coatings for passive radiative cooling of objects June 19th, 2015

Cellulose from wood can be printed in 3-D June 17th, 2015

Research partnerships

June 29th, 2015

Graphene breakthrough as Bosch creates magnetic sensor 100 times more sensitive than silicon equivalent June 28th, 2015

The peaks and valleys of silicon: Team of USC Viterbi School of Engineering Researchers introduce new layered semiconducting materials as silicon alternative June 27th, 2015

Building a better semiconductor: Research led by Michigan State University could someday lead to the development of new and improved semiconductors June 27th, 2015

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