Nanoparticles Provide Detailed View Inside Living Animals

Apr 18, 2008

Using nanoparticles designed specifically to produce a bright Raman spectroscopic signal, a team of investigators at the Center for Cancer Nanotechnology Excellence Focused on Therapy Response (Stanford CCNE) has shown that it can produce whole-body images in small animals that can reveal the location of tumors and track how these nanoparticles traffic through the body.

This work, the first to use surface-enhanced Raman spectroscopy (SERS) to provide whole-body images in a living animal, was reported in the Proceedings of the National Academy of Sciences of the United States of America.

Sanjiv Gambhir, M.D., Ph.D., principal investigator of the Stanford CCNE, led the team of investigators that used either single-walled carbon nanotubes (SWCNTs) or one of several commercially available silica-coated gold nanoparticles known as Nanoplex biotags, as SERS contrast agents. Each of the Nanoplex biotags produced a unique Raman signal. To detect either of these nanoparticles in animals, the investigators modified a standard Raman microscope to efficiently measure the Raman signal produced from deep inside living animals.

In one experiment, the investigators injected two different Nanoplex biotags into mice and were able to track both particles simultaneously as they moved through the animal. They subsequently repeated this experiment using four different biotags and again were able to track each of the particles based on their unique Raman signals. The researchers also showed that they could detect tumor-targeted SWCNTs at the sites of implanted tumors in live animals.

In a second paper, Dr. Gambhir and his Stanford CCNE colleagues showed that they could use intravital microscopy to study how targeted quantum dot nanoparticles bind to tumor blood vessels in living animals. In this study, published in the journal Nano Letters, the investigators show that the targeted quantum dots, which bind to the avb3 integrin on tumor blood vessels, are not taken up by the targeted tissue.

In addition, the researchers were surprised to find that individual quantum dots were not binding to their target but rather that clumps or aggregates of quantum dots were required for binding to occur. The investigators confirmed these results in a number of model systems and are now trying to construct models to explain this surprising behavior.

This work, which was supported in part by the NCI’s Alliance for Nanotechnology in Cancer, is detailed in two papers. The first paper, “Noninvasive molecular imaging of small living subjects using Raman spectroscopy,” is available at the journal’s Web site.

The second paper, “Real-time intravital imaging of RGD−quantum dot binding to luminal endothelium in mouse tumor neovasculature.” An abstract of this paper is available at the journal’s Web site.

Source: National Cancer Institute

Explore further: Physicists create new nanoparticle for cancer therapy

add to favorites email to friend print save as pdf

Related Stories

Nanoparticles and their orbital positions

Dec 16, 2013

Physicists have developed a "planet-satellite model" to precisely connect and arrange nanoparticles in three-dimensional structures. Inspired by the photosystems of plants and algae, these artificial nanoassemblies ...

Nanomedicines on their way through the body

May 29, 2012

(Phys.org) -- Which pathways do nanomedicines take after they have been swallowed? Scientists find a recirculation pathway of polymeric micelles using multimodal nonlinear optical microscopy.

Recommended for you

Thinnest feasible nano-membrane produced

12 hours ago

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Wiring up carbon-based electronics

15 hours ago

Carbon-based nanostructures such as nanotubes, graphene sheets, and nanoribbons are unique building blocks showing versatile nanomechanical and nanoelectronic properties. These materials which are ordered ...

User comments : 0

More news stories

Thinnest feasible nano-membrane produced

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Wiring up carbon-based electronics

Carbon-based nanostructures such as nanotubes, graphene sheets, and nanoribbons are unique building blocks showing versatile nanomechanical and nanoelectronic properties. These materials which are ordered ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...