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

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Nanoscale view of energy storage January 16th, 2017

Seeing the quantum future... literally: What if big data could help you see the future and prevent your mobile phone from breaking before it happened? January 16th, 2017

NUS researchers achieve major breakthrough in flexible electronics: New classes of printable electrically conducting polymer materials make better electrodes for plastic electronics and advanced semiconductor devices January 14th, 2017

Imaging

Distinguishing truth under the surface: electrostatic or mechanic December 31st, 2016

Nanoscale 'conversations' create complex, multi-layered structures: New technique leverages controlled interactions across surfaces to create self-assembled materials with unprecedented complexity December 22nd, 2016

Safe and inexpensive hydrogen production as a future energy source: Osaka University researchers develop efficient 'green' hydrogen production system that operates at room temperature in air December 21st, 2016

First use of graphene to detect cancer cells: System able to detect activity level of single interfaced cell December 20th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Nanoscale view of energy storage January 16th, 2017

Chemistry on the edge: Experiments at Berkeley Lab confirm that structural defects at the periphery are key in catalyst function January 13th, 2017

Deciphering the beetle exoskeleton with nanomechanics: Understanding exoskeletons could lead to new, improved artificial materials January 12th, 2017

New laser based on unusual physics phenomenon could improve telecommunications, computing January 12th, 2017

Nanomedicine

New active filaments mimic biology to transport nano-cargo: A new design for a fully biocompatible motility engine transports colloidal particles faster than diffusion with active filaments January 11th, 2017

Keystone Nano Announces FDA Approval Of Investigational New Drug Application For Ceramide NanoLiposome For The Improved Treatment Of Cancer January 10th, 2017

Captured on video: DNA nanotubes build a bridge between 2 molecular posts: Research may lead to new lines of direct communication with cells January 9th, 2017

Arrowhead Provides Response to New Minority Shareholder Announcement January 7th, 2017

Sensors

Nanoscale Modifications can be used to Engineer Electrical Contacts for Nanodevices January 13th, 2017

Researchers create practical and versatile microscopic optomechanical device: Trapping light and mechanical waves within a tiny bullseye, design could enable more sensitive motion detection January 11th, 2017

STMicroelectronics Peps Up Booming Social-Fitness Scene with Smart Motion Sensors for Better Accuracy, Longer Battery Life, and Faster Time to Market January 2nd, 2017

Advance in intense pulsed light sintering opens door to improved electronics manufacturing December 23rd, 2016

Discoveries

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Nanoscale view of energy storage January 16th, 2017

Seeing the quantum future... literally: What if big data could help you see the future and prevent your mobile phone from breaking before it happened? January 16th, 2017

NUS researchers achieve major breakthrough in flexible electronics: New classes of printable electrically conducting polymer materials make better electrodes for plastic electronics and advanced semiconductor devices January 14th, 2017

Announcements

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Nanoscale view of energy storage January 16th, 2017

Seeing the quantum future... literally: What if big data could help you see the future and prevent your mobile phone from breaking before it happened? January 16th, 2017

NUS researchers achieve major breakthrough in flexible electronics: New classes of printable electrically conducting polymer materials make better electrodes for plastic electronics and advanced semiconductor devices January 14th, 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