Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Tracking Tumor-Targeting Nanoparticles in the Body

The behavior of targeted quantum dots (Qdots) across three different tumor models using intravital microscopy with submicrometer resolution is described. As in the figure, the differences in extravasation between tumor types are shown and the kinetics are quatnified. Further, by demonstrating similarity in Qdot binding to tumor blood vessels across different tumor types, this work suggests several advantages implicit in vascular targeting compared with tumor cell targeting.
The behavior of targeted quantum dots (Qdots) across three different tumor models using intravital microscopy with submicrometer resolution is described. As in the figure, the differences in extravasation between tumor types are shown and the kinetics are quatnified. Further, by demonstrating similarity in Qdot binding to tumor blood vessels across different tumor types, this work suggests several advantages implicit in vascular targeting compared with tumor cell targeting.

Abstract:
Though targeted nanoparticle-based imaging agents and therapeutics for diagnosing and treating cancer are making their way to and through the clinical trials process, researchers still do not have a good understanding of how nanoparticles reach tumors and how they then bind to and enter the targeted tumor. To overcome that knowledge deficit, two teams of investigators, both part of the Alliance for Nanotechnology in Cancer have undertaken studies aiming to track nanoparticles as they move through living animals.

Tracking Tumor-Targeting Nanoparticles in the Body

Bethesda, MD | Posted on October 27th, 2010

In one study, a team of investigators at Stanford University used quantum dots to study how nanoparticles travel through tumor blood vessels in living test subjects, bind to molecular targets on the surface of those blood vessels, and then travel out of the blood stream and into the tumor itself. Sanjiv Sam Gambhir, co-director of one of nine National Cancer Institute (NCI) Centers of Cancer Nanotechnology Excellence, led this study. He and his colleagues published their findings in the journal Small. In a second study, published in the journal ACS Nano, Alliance investigators Dong Shin, Mostafa El-Sayed, and Shuming Nie of Emory University and the Georgia Institute of Technology used targeted gold nanocrystals to study both active and passive targeting of tumors.

In the Stanford study, Dr. Gambhir and his collaborators exploited the capabilities of intravital microscopy, a technique that enables researchers to see brightly fluorescent markers through a living animal's skin in real time. In this series of experiments, the Stanford team examined nanoparticle trafficking in mice in which a variety of different types of tumors were allowed to grow in the animals' ears. For the fluorescent marker, the investigators used a near-infrared emitting quantum dot linked to RGD, a molecule known to bind tightly to a protein found on the surface of blood vessels surrounding tumors.

To their surprise, the researchers found that regardless of the type of tumor studied, nanoparticle binding only occurred when aggregates of particles - not single particles - were able to tether themselves to multiple, discreet sites within a tumor. The researchers were not able to detect any significant binding when they repeated these experiments using quantum dots lacking the RGD targeting molecule. The investigators also found that binding rates and binding patterns were consistent across all tumor types, a reassuring finding given the natural heterogeneity that characterizes human cancers.

While binding ability appears to be independent of tumor type, the same cannot be said for extravasation, i.e., the transit of a nanoparticle out of the blood stream and into a tumor. The researchers noted in their paper that it is likely that nanoparticle shape and size will play a critical role in determining how a given nanoparticle will extravasate into each particular type of tumor.

Meanwhile, the Emory-Georgia Tech team used rod-shaped gold nanocrystals linked to tumor-targeting peptides to explore the delivery mechanisms that enable nanoparticles to accumulate in tumors. The investigators used gold nanoparticles so that they could quantify the number of nanoparticles reaching tumors and other tissues. Gold does not occur naturally in mammals, so any gold detected in a given tumor or tissue using the highly sensitive and accurate technique known as elemental mass spectrometry would had to have come from gold nanoparticles.

To conduct their experiments, the investigators created three formulations by attaching one of three tumor-targeting molecules to the surface of the gold nanorods. They then injected the nanoparticles into animals bearing implanted human tumors, allowed the nanoparticles to circulate through the body, and measured the amount of gold that accumulated in the implanted tumors and other tissues. The researchers also repeated this experiment using untargeted gold nanoparticles. The results were surprising in that the targeting molecules only marginally increased the amount of gold that accumulated in tumors.

The investigators concluded that gold nanoparticles designed to be used in photothermal anticancer therapy should be injected directly into tumors rather than via intravenous administration in order to achieve the greatest concentration of gold in tumors. They also noted in their paper that these experiments suggest that target binding is not the rate limiting step for nanoparticle delivery, but rather that transport out of the blood stream and into tumors is the major barrier to nanoparticle accumulation in tumors.

The work using intravital microscopy, which is detailed in a paper titled, "Dynamic Visualization of RGD-Quantum Dot Binding to Tumor Neovasculature and Extravasation in Multiple Living Mouse Models Using Intravital Microscopy," was supported in part by the NCI Alliance for Nanotechnology in Cancer, a comprehensive initiative designed to accelerate the application of nanotechnology to the prevention, diagnosis, and treatment of cancer. An abstract of this paper is available at the journal's website.

View Abstract at dx.doi.org/doi:10.1002/smll.201001022

The work using gold nanocrystals, which is detailed in a paper titled, "A Reexamination of Active and Passive Tumor Targeting by Using Rod-Shaped Gold Nanocrystals and Covalently Targeted Peptide Ligands," was also supported in part by the NCI Alliance for Nanotechnology in Cancer. An abstract of this paper is available at the journal's website.

View abstract at pubs.acs.org/doi/abs/10.1021/nn102055s

####

About NCI Alliance for Nanotechnology in Cancer
To help meet the goal of reducing the burden of cancer, the National Cancer Institute (NCI), part of the National Institutes of Health, is engaged in efforts to harness the power of nanotechnology to radically change the way we diagnose, treat and prevent cancer.

The NCI Alliance for Nanotechnology in Cancer is a comprehensive, systematized initiative encompassing the public and private sectors, designed to accelerate the application of the best capabilities of nanotechnology to cancer.

Currently, scientists are limited in their ability to turn promising molecular discoveries into benefits for cancer patients. Nanotechnology can provide the technical power and tools that will enable those developing new diagnostics, therapeutics, and preventives to keep pace with today’s explosion in knowledge.

For more information, please click here

Copyright © NCI Alliance for Nanotechnology in Cancer

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

Automating DNA origami opens door to many new uses: Like 3-D printing did for larger objects, method makes it easy to build nanoparticles out of DNA May 30th, 2016

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Harnessing solar and wind energy in one device could power the 'Internet of Things' May 26th, 2016

Thermal modification of wood and a complex study of its properties by magnetic resonance May 26th, 2016

Academic/Education

Graphene: Progress, not quantum leaps May 23rd, 2016

Smithsonian Science Education Center and National Space Society Team Up for Next-Generation Space Education Program "Enterprise In Space" May 11th, 2016

The University of Colorado Boulder, USA, combines Raman spectroscopy and nanoindentation for improved materials characterisation May 9th, 2016

Albertan Science Lab Opens in India May 7th, 2016

Nanomedicine

Automating DNA origami opens door to many new uses: Like 3-D printing did for larger objects, method makes it easy to build nanoparticles out of DNA May 30th, 2016

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Supercrystals with new architecture can enhance drug synthesis May 24th, 2016

Announcements

Automating DNA origami opens door to many new uses: Like 3-D printing did for larger objects, method makes it easy to build nanoparticles out of DNA May 30th, 2016

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Doubling down on Schrödinger's cat May 27th, 2016

Quantum Dots/Rods

Supercrystals with new architecture can enhance drug synthesis May 24th, 2016

ORNL demonstrates large-scale technique to produce quantum dots May 21st, 2016

First single-enzyme method to produce quantum dots revealed: Biological manufacturing process, pioneered by three Lehigh University engineers, produces equivalent quantum dots to those made chemically--but in a much greener, cheaper way May 9th, 2016

Superfast light source made from artificial atom April 28th, 2016

Nanobiotechnology

Automating DNA origami opens door to many new uses: Like 3-D printing did for larger objects, method makes it easy to build nanoparticles out of DNA May 30th, 2016

Simple attraction: Researchers control protein release from nanoparticles without encapsulation: U of T Engineering discovery stands to improve reliability and fabrication process for treatments to conditions such as spinal cord damage and stroke May 28th, 2016

Scientists illuminate a hidden regulator in gene transcription: New super-resolution technique visualizes important role of short-lived enzyme clusters May 27th, 2016

Supercrystals with new architecture can enhance drug synthesis May 24th, 2016

Research partnerships

Finding a new formula for concrete: Researchers look to bones and shells as blueprints for stronger, more durable concrete May 26th, 2016

The next generation of carbon monoxide nanosensors May 26th, 2016

Revealing the nature of magnetic interactions in manganese oxide: New technique for probing local magnetic interactions confirms 'superexchange' model that explains how the material gets its long-range magnetic order May 25th, 2016

Light can 'heal' defects in new solar cell materials: Defects in some new electronic materials can be removed by making ions move under illumination May 24th, 2016

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







Car Brands
Buy website traffic