Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Flares on the Move

12.01.2011
Nanoparticle test kit shows how nanoparticles of different size disperse in tumor tissue

Nanoparticles play a significant role in the development of future diagnostic and therapeutic techniques for tumors, for example as transporters for drugs or as contrast agents. Absorption and dispersion of nanoparticles in tumor tissue depend strongly on particle size.

In order to systematically study this, scientists at the Massachusetts Institute of Technology (MIT, Cambridge, USA) and Harvard Medical School (Boston, USA) have now produced a set of fluorescent nanoparticles of various diameters between 10 and 150 nm. As the team led by Moungi G. Bawendi and Daniel G. Nocera reports in the journal Angewandte Chemie, they were able to use these to simultaneously follow the dispersion of particles of different sizes through mouse tumors in real time.

In order for nanoparticle-based biomedical techniques to work, the nanoparticles must be of optimal size. For studies, it is thus desirable to simultaneously observe the behavior of particles of different size in the same tumor in vivo. This requires chemically comparable particles of various sizes, each size group consisting of particles of uniform size and composition. Additionally, it must be possible to simultaneously detect and differentiate the various particles. Also, they must be biocompatible, and may not form aggregates or adsorb proteins. This complex challenge has now been met.

The researchers developed a set of nanoparticles in various sizes, which can be detected by means of fluorescing quantum dots. Quantum dots are semiconducting structures at the boundary between macroscopic solid bodies and the quantum-mechanical nano-world. By selectively producing quantum dots of different sizes, it is possible to obtain quantum dots that fluoresce at different defined wavelengths, which allows them to be simultaneously detected and differentiated.

To produce nanoparticles in different size classes, the scientists coated cadmium selenide/cadmium sulfide quantum dots with polymer ligands such as silicon dioxide and polyethylene glycol. They attained particles larger than 100 nm in diameter by attaching quantum dots to prefabricated silicon dioxide particles and then coating them with polyethylene glycol. For each size class they selected quantum dots that give off light of a different wavelength.

The researchers intravenously injected a mixture of particles with diameters of 12, 60, and 125 nm into mice with cancer. Fluorescence microscopy was used to follow the particles’ entry into the tumor tissue in vivo. Whereas the 12 nm particles easily passed from the blood vessels into the tissue and rapidly spread out, the 60 nm particles passed through the walls of the vein but stayed within 10 µm of the vessel wall, unable to pass farther into the tissue. The 125 nm particles essentially did not pass through the walls of the blood vessels at all.

Author: Moungi G. Bawendi, Daniel G. Nocera, Massachusetts Institute of Technology, Cambridge (USA), http://web.mit.edu/chemistry/www/faculty/nocera.html

Title: A Nanoparticle Size Series for In Vivo Fluorescence Imaging

Angewandte Chemie International Edition 2010, 49, No. 46, 8649–8652, Permalink to the article: http://dx.doi.org/10.1002/anie.201003142

Moungi G. Bawendi | Angewandte Chemie
Further information:
http://web.mit.edu/chemistry/www/faculty/nocera.html
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>