Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Controlled and targeted release of drugs

24.01.2013
Nanomedicine
Researchers have discovered a method that allows for the controlled release of an active agent on the basis of a magnetic nanovehicle. The research, conducted as part of the National Research Programme "Smart Materials" (NRP 62), opens up new possibilities for the develop-ment of targeted treatments, which are more efficient and trigger fewer side effects.

Certain drugs are toxic by nature. For example, anti-cancer drugs developed to kill diseased cells also harm healthy ones. To limit the side effects of chemotherapy, it would be a great step forward if it were possible to release a drug only in the affected area of the body. In the context of the National Research Programme "Smart Materials" (NRP 62) - a cooperation between the SNSF and the Commission for Technology and Innovation (CTI) - researchers of ETH Lausanne, the Adolphe Merkle Institute and the University Hospital of Geneva have discovered a method that might represent an important step towards the development of an intelligent drug of this kind. By combining their expert knowledge in the areas of material sciences, biological nanomaterials and medicine, they were able to prove the feasibility of using a nanovehicle to transport drugs and release them in a controlled manner.

This nanocontainer is a liposome, which takes the shape of a vesicle. It has a diameter of 100 to 200 nanometers and is 100 times smaller than a human cell. The membrane of the vesicle is composed of phospholipids and the inside of the vesicle offers room for the drug. On the surface of the liposome, specific molecules help to target malignant cells and to hide the nanocontainer from the immune system, which might otherwise consider it a foreign entity and seek to destroy it. Now the researchers only needed to discover a mechanism to open up the membrane at will.

Nano effect
This is exactly what the researchers succeeded in doing (*). How they did it? By integrating into the liposome membrane superparamagnetic iron oxide nanoparticles (SPION), which only become magnetic in the presence of an external magnetic field. Once they are in the field, the SPION heat up. The heat makes the membrane permeable and the drug is released. Researchers proved the feasibility of such a nanovehicle by releasing in a controlled manner a coloured substance contained in the liposomes. "We can really talk of nanomedicine in this context because, by exploiting superparamagnetism, we are exploiting a quantum effect which only exists at the level of nanoparticles," explains Heinrich Hofmann of the Powder Technology Laboratory of EPFL. SPION are also an excellent contrast agent in magnetic resonance imaging (MRI). A simple MRI shows the location of the SPION and allows for the release of the drug once it has reached the targeted spot.

Designed for medical practice
"To maximise the chances of discovering an effective treatment, we focused on nanocontainers, which would be readily accepted by doctors," adds Heinrich Hofmann. This strategy limits the range of possibilities. Liposomes, which are already used in a number of drugs on the market, are composed of natural phospholipids which can also be found in the membranes of human cells. To open them up, researchers focused on SPION, which had already been the subject of numerous toxicological studies. More efficient materials were ignored because little or nothing was known about their effects on humans. In terms of shape, another important parameter of magnetism, they chose to use only spherical nanoparticles, which are considered safer than fibrous shapes. The intensity and frequency of the magnetic field needed to release the active agent are compatible with human physiology.
The combination of these parameters presented the researchers with another challenge: to reach a temperature sufficiently high to open up the liposomes, they were forced to increase the size of the SPION from 6 to 15 nanometres. The membrane of the vesicles has a thickness of only 4-5 nanometres. Then the masterstroke: the research group of Alke Fink at the Adolphe Merkle Institute was able to regroup the SPION in one part of the membrane (*). This also made MRI detection easier. Before starting in-vivo tests, the researchers aim to study the integration of SPION into the liposome membrane in greater detail.

National Research Programme "Smart Materials" (NRP 62)
NRP 62 is a cooperation programme between the Swiss National Science Foundation (SNSF) and the Commission for Technology and Innovation (CTI). It strives to promote scientific excellence and contribute to the successful industrial exploitation of smart materials and their applications. NRP 62 intends to combine the expertise and resources of various research institutions across Switzerland. The researchers will devise the technologies needed for the development of smart materials and for their application in intelligent systems and structures. NRP 62 consists of 21 projects of use-inspired fundamental research. It has a budget of CHF 11 million and ends in 2015.

(*)Bonnaud Cécile, Vanhecke Dimitri, Demurtas, Davide, Rothen-Rutishauser Barbara and Fink Alke (2013). Spatial SPION localization in liposome membranes. IEEE Transaction on Magnetics : doi 10.1109/TMAG.2012.2219040
(available as a PDF from the SNSF; e-mail: com@snf.ch)

Contact
Prof. Heinrich Hofmann
Laboratoire de technologie des poudres
Ecole polytechnique fédérale de Lausanne
CH-1015 Ecublens
Phone: +41 21 693 36 07
E-mail: heinrich.hofmann@epfl.ch

Prof. Alke Fink
Institut Adolphe Merkle
Université de Fribourg
Rte de l'Ancienne Papeterie
CH-1723 Marly
Phone: +41 26 300 95 01
E-mail: alke.fink@unifr.ch

Communication division | idw
Further information:
http://www.snsf.ch

More articles from Health and Medicine:

nachricht NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures
17.11.2017 | National Institute of Standards and Technology (NIST)

nachricht High speed video recording precisely measures blood cell velocity
15.11.2017 | ITMO University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>