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 Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex

nachricht New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>