Navigation Links
Chasing tiny vehicles
Date:7/20/2009

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 Bruchle, a research group cooperating with Dr. Christian Plank of the Technische Universitt Mnchen (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," Bruchle 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," Bruchle 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."


'/>"/>

Contact: Professor Christoph Braeuchle
christoph.braeuchle@cup.uni-muenchen.de
49-892-180-77547
Ludwig-Maximilians-Universitt Mnchen
Source:Eurekalert

Related biology news :

1. Let the cat keep chasing the mouse
2. Healing wounds with lasers, vehicles that drive themselves, other cutting-edge optics
3. Unmanned aerial vehicles mark robotic first for British Antarctic Survey
4. RAND paper finds diesel, hybrid vehicles can provide more societal benefits than gas-powered autos
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/21/2016)... VANCOUVER, British Columbia , June 21, 2016 ... been appointed to the new role of principal ... has been named the director of customer development. ... , NuData,s chief technical officer. The moves reflect ... development teams in response to high customer demand ...
(Date:6/15/2016)... ALBANY, New York , June 15, 2016 ... published a new market report titled "Gesture Recognition Market ... Trends and Forecast, 2016 - 2024". According to the ... at USD 11.60 billion in 2015 and is ... and reach USD 48.56 billion by 2024.  ...
(Date:6/7/2016)... -- Syngrafii Inc. and San Antonio Credit Union (SACU) ... Syngrafii,s patented LongPen™ eSignature "Wet" solution into SACU,s ... in greater convenience for SACU members and operational ... document workflow and compliance requirements. Logo ... Highlights: ...
Breaking Biology News(10 mins):
(Date:11/30/2016)... 2016 /PRNewswire/ - Portage Biotech Inc. ("Portage" or "the ... excited to announce the formation of EyGen, Ltd. ... ophthalmology assets through proof of concept. EyGen,s lead ... Portage Pharmaceuticals Limited and being developed for topical ... anterior segment diseases. This agent has the potential ...
(Date:11/30/2016)...  The Allen Institute for Cell Science has ... available collection of gene edited, fluorescently tagged human ... structures with unprecedented clarity. Distributed through the Coriell ... a crucial first step toward visualizing the dynamic ... human cells healthy and what goes wrong in ...
(Date:11/30/2016)... , Nov. 30, 2016  Tempus, a technology ... care, and Penn,s Abramson Cancer Center have partnered ... positive response to immunotherapy treatment based on next ... As part of a research collaboration, Tempus will ... melanoma cancer patient data to Penn. Utilizing next-generation ...
(Date:11/30/2016)... , 30. November 2016   ... hat heute die Unterzeichnung einer Reihe von ... zufolge wird Evotec AG Screeningleistungen für Mercks ... bereitstellen. Der Zugriff auf diese Bibliotheken in ... eröffnet einen schnelleren Weg zur Ermittlung und ...
Breaking Biology Technology: