Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Giving transplanted cells a nanotech checkup: Researchers devise a way to safely see whether replacement cells are still alive

Nanosensors (green spheres) are composed of fat and L-arginine molecules, as well as separate indicator molecules that give off MRI-detectable and light signals when cells are alive. Nanosensors are enclosed in a hydrogel membrane along with liver cells (pink). Nutrients and other relatively small molecules (red) are able to travel across the hydrogel membrane to and from the bloodstream.

Credit: Sayo Studios
Nanosensors (green spheres) are composed of fat and L-arginine molecules, as well as separate indicator molecules that give off MRI-detectable and light signals when cells are alive. Nanosensors are enclosed in a hydrogel membrane along with liver cells (pink). Nutrients and other relatively small molecules (red) are able to travel across the hydrogel membrane to and from the bloodstream.

Credit: Sayo Studios

Abstract:
Researchers at Johns Hopkins have devised a way to detect whether cells previously transplanted into a living animal are alive or dead, an innovation they say is likely to speed the development of cell replacement therapies for conditions such as liver failure and type 1 diabetes. As reported in the March issue of Nature Materials, the study used nanoscale pH sensors and magnetic resonance imaging (MRI) machines to tell if liver cells injected into mice survived over time.

Giving transplanted cells a nanotech checkup: Researchers devise a way to safely see whether replacement cells are still alive

Baltimore, MD | Posted on February 5th, 2013

"This technology has the potential to turn the human body into less of a black box and tell us if transplanted cells are still alive," says Mike McMahon, Ph.D., an associate professor of radiology at the Johns Hopkins University School of Medicine who oversaw the study. "That information will be invaluable in fine-tuning therapies."

Regenerative medicine advances depend on reliable means of replacing damaged or missing cells, such as injecting pancreatic cells in people with diabetes whose own cells don't make enough insulin. To protect the transplanted cells from the immune system, while allowing the free flow of nutrients and insulin between the cells and the body, they can be encased in squishy hydrogel membranes before transplantation. But, explains McMahon, "once you put the cells in, you really have no idea how long they survive." Such transplanted cells eventually stop working in most patients, who must resume taking insulin. At that point, physicians can only assume that cells have died, but they don't know when or why, says McMahon.

With that problem in mind, McMahon's group, which specializes in methods of detecting chemical changes, collaborated with the research group headed by Jeff Bulte, Ph.D., the director of cellular imaging at Hopkins' Institute for Cell Engineering. Bulte's group devises ways of tracking implanted cells through the body using MRI. Led by research fellow Kannie Chan, Ph.D., the team devised an extremely tiny, or nanoscale, sensor filled with L-arginine, a nutritional supplement that responds chemically to small changes in acidity (pH) caused by the death of nearby cells. Changes in the acidity would in turn set off changes in sensor molecules embedded in the thin layer of fat that makes up the outside of the nanoparticle, giving off a signal that could be detected by MRI.

To test how these nanosensors would work in a living body, the team loaded them into hydrogel spheres along with liver cells — a potential therapy for patients with liver failure — and another sensor that gives off bioluminescent light only while the cells are alive. The spheres were injected just under the skin of mice. As confirmed by the light signal, the MRI accurately detected where the cells were in the body and what proportion were still alive. (Such light indicators cannot be used to track cells in humans because our bodies are too large for visible signals to get through, but these indicators allowed the team to check whether the MRI nanosensors were working properly in the mice.)

"It was exciting to see that this works so well in a living body," Chan says. The team hopes that because the components of the system — hydrogel membrane, fat molecules, and L-arginine — are safe for humans, adapting their discovery for clinical use will prove relatively straightforward. "This should take a lot of the guesswork out of cell transplantation by letting doctors see whether the cells survive, and if not, when they die," Chan says. "That way they may be able to figure out what's killing the cells, and how to prevent it."

Potential applications of the sensors are not limited to cells inside hydrogel capsules, Bulte notes. "These nanoparticles would work outside capsules, and they could be paired with many different kinds of cells. For example, they may be used to see whether tumor cells are dying in response to chemotherapy," he says.

Other authors on the paper were Guanshu Liu, Xiaolei Song, Heechul Kim, Tao Yu, Dian R. Arifin, Assaf A. Gilad, Justin Hanes, Piotr Walczak and Peter C. M. van Zijl, all of the Johns Hopkins University School of Medicine.

The study was funded by the National Institute of Biomedical Imaging and Bioengineering (grant numbers R01 EB012590, EB015031, EB015032 and EB007825).

####

For more information, please click here

Contacts:
Shawna Williams

410-955-8236

Copyright © Johns Hopkins Medicine

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 Links

The paper can be found here:

New Technique Developed for Tracking Cells in the Body:

Tracking the Elusive Stem Cell:

Jeff Bulte on Tracking Cells Through the Body:

Hopkins Imaging Scientist Earns New NIH 'Eureka' Grant for Exceptional, Unconventional Research:

Related News Press

News and information

Silk could improve sensitivity, flexibility of wearable body sensors August 20th, 2017

The power of perovskite: OIST researchers improve perovskite-based technology in the entire energy cycle, from solar cells harnessing power to LED diodes to light the screens of future electronic devices and other lighting applications August 18th, 2017

Gold nanostars and immunotherapy vaccinate mice against cancer: New treatment cures, vaccinates mouse in small proof-of-concept study August 18th, 2017

Researchers printed graphene-like materials with inkjet August 17th, 2017

Imaging

Industry’s First Dedicated Cryo-DualBeam System Automates Preparation of Frozen, Biological Samples: New Thermo Scientific Aquilos FIB/SEM protects sample integrity and enhances productivity for cryo-electron tomography workflow August 8th, 2017

Thermo Fisher Scientific Advances Cryo-EM Leadership to Drive Structural Biology Discoveries: New Thermo Scientific Krios G3i raises bar for performance, automation and time-to-results Breakthrough Thermo Scientific Glacios provides a cryo-EM entry path for a broader range of res August 8th, 2017

New Quattro Field Emission ESEM Emphasizes Versatility and Ease of Use: Thermo Scientific Quattro ESEM allows materials science researchers to study nanoscale structure in almost any material under a range of environmental conditions August 8th, 2017

Thermo Fisher Scientific’s New Talos F200i S/TEM Delivers Flexible, High-Performance Imaging: New compact S/TEM can be configured to meet specific imaging and analytical requirements for materials characterization in research laboratories August 8th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Researchers printed graphene-like materials with inkjet August 17th, 2017

Freeze-dried foam soaks up carbon dioxide: Rice University scientists lead effort to make novel 3-D material August 16th, 2017

2-faced 2-D material is a first at Rice: Rice University materials scientists create flat sandwich of sulfur, molybdenum and selenium August 14th, 2017

Engineers pioneer platinum shell formation process – and achieve first-ever observation August 11th, 2017

Nanomedicine

Gold nanostars and immunotherapy vaccinate mice against cancer: New treatment cures, vaccinates mouse in small proof-of-concept study August 18th, 2017

Freeze-dried foam soaks up carbon dioxide: Rice University scientists lead effort to make novel 3-D material August 16th, 2017

Gold shines through properties of nano biosensors: Researchers discover that fluorescence in ligand-protected gold nanoclusters is an intrinsic property of the gold particles themselves August 16th, 2017

Two Scientists Receive Grants to Develop New Materials: Chad Mirkin and Monica Olvera de la Cruz recognized by Sherman Fairchild Foundation August 16th, 2017

Sensors

Silk could improve sensitivity, flexibility of wearable body sensors August 20th, 2017

Researchers printed graphene-like materials with inkjet August 17th, 2017

Sensing technology takes a quantum leap with RIT photonics research: Office of Naval Research funds levitated optomechanics project August 10th, 2017

Giant enhancement of electromagnetic waves revealed within small dielectric particles: Scientists have done for the first time direct measurements of giant electromagnetic fields July 8th, 2017

Discoveries

Silk could improve sensitivity, flexibility of wearable body sensors August 20th, 2017

The power of perovskite: OIST researchers improve perovskite-based technology in the entire energy cycle, from solar cells harnessing power to LED diodes to light the screens of future electronic devices and other lighting applications August 18th, 2017

Gold nanostars and immunotherapy vaccinate mice against cancer: New treatment cures, vaccinates mouse in small proof-of-concept study August 18th, 2017

Researchers printed graphene-like materials with inkjet August 17th, 2017

Announcements

Silk could improve sensitivity, flexibility of wearable body sensors August 20th, 2017

The power of perovskite: OIST researchers improve perovskite-based technology in the entire energy cycle, from solar cells harnessing power to LED diodes to light the screens of future electronic devices and other lighting applications August 18th, 2017

Gold nanostars and immunotherapy vaccinate mice against cancer: New treatment cures, vaccinates mouse in small proof-of-concept study August 18th, 2017

Researchers printed graphene-like materials with inkjet August 17th, 2017

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