Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Making Cancer Cells Visible

Abstract:
Tumor proteases change the magnetic properties of nanoparticles

Making Cancer Cells Visible

Posted on May 08, 2006

Wouldn’t it be nice if we could detect tumors and their metastases as easily as we find broken bones with X-rays? A team of scientists headed by S. Bhatia in Boston (USA) has been working on this problem. They have found a way to make a tumor-specific protease visible by using Fe3O4 nanoparticles and magnetic resonance imaging (MRI).

Organic tissue is mostly made of water and fat, substances that contain many protons (positively charged hydrogen ions or hydrogen nuclei). These have an intrinsic angular momentum, known as spin, and thus a magnetic moment. In a magnetic field, they line up and rotate with a certain frequency that is proportional to the strength of the external field. If electromagnetic waves with the same frequency (resonance) are beamed in, they disturb the orientation of the protons in the external material field. When the electromagnetic wave is switched off, the protons flip back to their original position, which causes them to give off an electromagnetic signal of their own. This can be detected and gives information about the proton density and the chemical environment in the region being studied. These data allow for the computation of a 3D image that depicts the different tissues in the body.

How can this be used to detect mutated cells with the best possible resolution and high confidence? The Boston researchers used nanoparticles of Fe3O4 whose magnetic properties change when they aggregate into large multimeric complexes.

Two biomolecules that bind to each other with high affinity, biotin and neutravidin, act as a “glue” to hold the Fe3O4 particles together. Half of the nanoparticles are coated with biotin, the other half with neutravidin. Long polyethylene glycol (PEG) chains are coupled to these biomolecules in order to keep the particles from interacting with each other. The anchor for the PEG chains is a peptide that contains a segment that can be cleaved by a tumor-specific enzyme, matrix metalloproteinase-2 (MMP-2).

MMP-2 is mostly found in the immediate area around growing tumor cells, meaning that the PEG chains are only cleaved from the Fe3O4nanoparticles when they are near a tumor. This then allows the biotin–neutrovidin glue to do its job—the Fe3O4 particles aggregate and the tumor becomes visible in the MRI image.

####


Author: Sangeeta N. Bhatia, Massachusetts Institute of Technology, Cambridge (USA), lmrt.mit.edu/personnel/sangeeta.asp

Title: Proteolytic Actuation of Nanoparticle Self-Assembly

Angewandte Chemie International Edition, 2006, 45, No. 19, 3161–3165, doi: 10.1002/anie.200600259

Contact:
Editorial office:
angewandte@wiley-vch.de

or David Greenberg (US)
dgreenbe@wiley.com

or Julia Lampam (UK)
jlampam@wiley.co.uk

Copyright © Angewandte Chemie

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

Nanomedicine

Arrowhead Pharmaceuticals Begins Dosing in Phase 1 Study of ARO-APOC3 for Treatment of Hypertriglyceridemia March 11th, 2019

New optical imaging system could be deployed to find tiny tumors: Near-infrared technology pinpoints fluorescent probes deep within living tissue; may be used to detect cancer earlier March 8th, 2019

Computer-designed vaccine elicits potent antibodies against RSV: The nanoparticle platform for this respiratory syncytial virus study will be applied to vaccine research on flu, HIV, and more; Seattle startup Icosavax will advance related clinical trials March 8th, 2019

CEA-Leti Breakthrough Opens Path to New Vaccine for HIV: Lipidots Platform Strengthens Immune Response to Protein That Is Key to HIV Vaccine; Results Presented in Nature Publishing Group’s npj Vaccines February 27th, 2019

Materials/Metamaterials

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Now made in Japan – Asian battery manufacturers welcome highly conductive nanotube additive March 7th, 2019

Can a flowing liquid-like material maintain its structural order like crystals? February 27th, 2019

Super-light, super-insulating ceramic aerogel keeps the hottest temperatures at bay February 17th, 2019

Announcements

New method to reduce uranium concentration in contaminated water March 18th, 2019

Review of the recent advances of 2D nanomaterials in Lit-ion batteries March 15th, 2019

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project