Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chasing tiny vehicles

22.07.2009
Microscope shows how nanoferries invade cells

Nanoparticles are just billionths of a millimeter in size. Exhibiting novel and often surprising properties, they are finding their way into an endless stream of equally innovative products.

In medical therapies, for example, tiny nanovehicles could one day ferry drugs or even genes into cells. So far, the only way of testing these approaches has been to wait for the desired effect to show – the activation of a transported gene inside a cell for example.

Under the direction of LMU Munich physicochemist Professor Christoph Bräuchle, a research group cooperating with Dr. Christian Plank of the Technische Universität München (TUM) has now used a highly sensitive microscopic technique to pursue individual nanoparticles as they make their way into target cells – in real-time and at high spatial and temporal resolution. They tested magnetic nanoparticles that could be used, among other things, in cancer therapy. This approach should also allow a better understanding of existing nanovectors as well as the development of new systems, as reported in the current cover story of the Journal of Controlled Release. (Journal of Controlled Release, 20 July 2009)

Nanoparticles are so small that many barriers in the body simply can't stop them. They can also use the bloodstream to reach any part of the body. Researchers and doctors alike hope that these tiny vehicles will one day be put to work in therapies carrying drugs directly to the seat of a disease. "Even genes can be transported this way," says Plank. "That means we could be seeing new breakthroughs in gene therapy soon, which has seen more than its fair share of setbacks. After all, lacking most are functional transporters." Such vehicles or vectors have been developed mainly from viruses until now. But even deactivated viruses can sometimes trigger unwanted side-effects. Nanoferries, on the other hand, have been tailored to deliver genes or drugs directly to the target without side-effects.

For such a targeted delivery, however, nanoferries need a kind of search mechanism to guide them to where their cargo is needed. Magnetic particles have already been tried in cancer therapies: They have been administered by infusion and then directed – via magnetic fields – to a tumor whose cells they should invade directly. But until now, is has been impossible to observe nanoparticles along their route, especially into living tumor cells. It is a prerequisite, though, for therapeutic approval and the definition of functional doses to know the exact path of these carriers and the efficiency of their transport and uptake by cancer cells.

So far, only the appearance or absence of the desired therapeutic effect would tell whether an approach was even promising or not. "It's like a black box," Bräuchle says. "You put something in at one end, then wait and see if anything comes out at the other end. What happens in between is anyone's guess." Now, his workgroup has employed highly sensitive single-molecule fluorescence microscopy to follow the nanoferries on their voyage. This highly sensitive method works by tagging individual particles with a dye that acts like a "molecular lamp" to light up the particle's path into the cell.

"Thus, we have traced magnetic lipoplex nanoparticles and made movies of their transport," reports Anna Sauer, first author of the study. "We were able to watch the particles in real-time and at high temporal and spatial resolution as they made their way into the cells." In doing so, the research team could even define separate phases: how the particles reached the cell membrane, came to rest there and then ultimately – enclosed in a membrane vesicle – invaded the cells. The vesicles move randomly, often downright erratically inside the cell, until a so-called motor protein binds them and quickly transports them towards the cell nucleus – the ultimate target for the gene.

The research team is now in a position to characterize and describe in great detail the individual steps along this path. "Our new approach has also revealed bottlenecks in nanoferry transport," Bräuchle reports. "We saw, for example, that the magnetic field can only direct particles outside cells. But, contrary to expectations, it did not facilitate entry into cells. Thanks to these new insights, existing nanoferries can be suitably optimized in future, and even new systems developed."

The work was performed in the scope of the clusters of excellence NIM and CiPSM.

Publication: "Dynamics of magnetic lipoplexes studied by single particle tracking in living cells"
A.M. Sauer, K.G. de Bruin, N. Ruthardt, O. Mykhaylyk, C. Plank, C. Bräuchle,
Journal of Controlled Release, 20 July 2009
Contact:
Professor Christoph Bräuchle
Department of Chemistry and Biochemistry of Ludwig-Maximilians-Universität (LMU) Munich
Tel.: +49 (0) 89 / 2180 - 77547
Fax: +49 (0) 89 / 2180 - 77548
E-Mail: christoph.braeuchle@cup.uni-muenchen.de

Christoph Braeuchle | EurekAlert!
Further information:
http://www.uni-muenchen.de
http://www.cup.uni-muenchen.de/pc/braeuchle/

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>