Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Batten Down the Hatches Against HIV

22.02.2007
Carbon nanotubes transport gene therapy drug into T-cells known to block HIV from entering cells in vitro

A promising approach to gene therapy involves short DNA fragments (interfering RNA) that bind to specific genes and block their “translation” into the corresponding, disease-related protein. A stumbling block has been the efficient and targeted delivery of RNA into the cells. Researchers led by Hongjie Dai at Stanford University have chosen to use carbon nanotubes as their “means of transport”.

This has allowed them to successfully introduce RNA fragments that “switch off” the genes for special HIV-specific receptors and co-receptors on the cells’ surface into human T-cells and primary blood cells. This leaves few “entry hatches” for the HIV viruses. The researchers report in the journal Angewandte Chemie that this allows for much better silencing effect to the cells than current transport systems based on liposomes.

T-cells are one of the types of white blood cells important for a good immune defense; they detect and destroy virus-affected cells. However, they themselves are among the targets attacked by HIV. In order to enter into a T-cell, the virus must first dock to a receptor known as CD4. Also involved is the co-receptor CXCR4. The use of short interfering RNA strands allows the CD4 and CXCR4 genes of the T-cell to be shut off. The T-cell then strops producing these receptors and the virus cannot find any points of attack on the surface of the cell. This could significantly slow down an HIV infection, as previous work have shown.

... more about:
»HIV »Nanotubes »RNA »T-cell »receptor

But how to get the RNA fragments into the T-cells? The shells of nonpathogenic viruses can be used to smuggle genetic material into cells, but this is dangerous in therapeutic applications because they can trigger allergies. Liposomes, tiny bubbles of fat, are safe but have proven to be ineffective for use in T-cells. Dai and his co-workers have tested a new transport system: carbon nanotubes are known for their abilities to be absorbed by cells and to smuggle other molecules in at the same time. The researchers attached phospholipids—molecules from which cell membranes are also made—to chains of polyethylene glycol. The phospholipids nestle securely onto the outer wall of the carbon nanotubes while the polyethylene glycol chains protrude into the surrounding solution. The required RNA molecules were fastened to the ends of these chains. Once inside the cell, the RNA could easily be split off by means of a sulfur–sulfur bridge.

Author: Hongjie Dai, Stanford University (USA), http://www.stanford.edu/dept/chemistry/faculty/dai/

Title: siRNA Delivery into Human T Cells and Primary Cells with Carbon-Nanotube Transporters

Angewandte Chemie International Edition 2007, 46, No. 12, doi: 10.1002/anie.200604295

Hongjie Dai | Angewandte Chemie
Further information:
http://pressroom.angewandte.org.
http://www.stanford.edu/dept/chemistry/faculty/dai/

Further reports about: HIV Nanotubes RNA T-cell receptor

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>