Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Premium Vectors' for the Life Sciences: Magnetic Nanoparticles

05.03.2012
Positively charged star polymers containing a magnetic core are particularly suitable as DNA-delivery vectors.
They show extremely high gene transfer efficiency and afterwards enable the quick and simple separation of the transfected cells from the transfection pool. A research team from the University of Bayreuth reports this result in the current online edition of "Biomacromolecules".

Only five months ago a research team from the University of Bayreuth reported a discovery that was internationally acknowledged. The scientists led by Prof. Dr. Ruth Freitag (Process Biotechnology) and Prof. Dr. Axel Müller (Macromolecular Chemistry II) developed large star-shaped polymers that are promising vectors in genetic engineering. Most importantly, the new polymers were capable of introducing genes into a large variety of living cells, including non-dividing and differentiated cells, i.e. cells that up to now typically require viruses for efficient genetic modification. In chemical terms, these molecules can be described as PDMAEMA stars.

Now the Bayreuth team reports a related discovery in the current online edition of "Biomacromolecules". As the team specifies, similar PDMAEMA stars can be constructed with a magnetic core and then combine the ability for efficient transfection with the potential for easy separation of the transfected from the non-transfected cells. This research success stems from an intensive interdisciplinary cooperation of long standing. The magnetic PDMAEMA stars were produced in the Bayreuth polymer chemistry laboratories. Tests in the Biotechnology group then demonstrated that the novel agents may very well constitute 'premium vectors' for the genetic modification of cells.

Biotechnological advantages: high transfection efficiency,
quick and simple isolation of transfected cells

Like the PDMAEMA stars previously tested, the magnetic PDMAEMA stars are also capable of efficiently introducing genetic information, i.e. DNA molecules, into living cells, a process called transfection. "When we transfected cells of a cell line originating from the Chinese hamster (CHO cells), we consistently observed transfection efficiencies that largely exceed those we previously obtained using poly(ethylenimine) (PEI)", explains Prof. Dr. Ruth Freitag. Linear PEI has until now been regarded as the 'gold standard' in cell transfection and is therefore used in genetic engineering processes worldwide.

The new vectors have another advantage in addition to their unusual efficiency. The PDMAEMA stars retain their magnetic properties when they are within the cells. For this reason, the transfected cells can be separated from all other cells in a very simple manner: a standard strong magnet is sufficient to extract specifically the cells that have taken up the DNA from those that have not. This makes the magnetic PDMAEMA stars the ideal tool to extract successfully transfected cells from the general transfection pool, and thereby prepare in pure form, a genetically modified cell population, be it to introduce a new gene, compensate for a missing gene, to substitute a defect genes or to ameliorate the consequences of such aberrations.

Star-shaped giant molecules containing a magnetic core,
synthesis using modern polymer chemistry techniques

How are the magnetic PDMAEMA stars produced? Spherical nanoparticles are the starting point of this process. They belong to the class of iron oxides and have magnetic qualities. Initiator molecules are attached to the surface of such a particle, forming the starting points for the star-shaped structure. Each initiator starts the polymerisation of a long PDMAEMA chain, an 'arm'. This process (called "grafting from") makes the spherical nanoparticle the centre of a large star-shaped molecule. When it is finished, the star-shaped molecule has on average 46 of these chain-like arms. Each arm contains nearly 600 repeating molecule groups.

Patent registration

On account of the high application potential for the life sciences, the magnetic PDMAEMA stars have been registered as a patent in the name of the University of Bayreuth by the Bavarian Patent Alliance (BayPAT, the central patent and marketing agency of the Bavarian universities). The Innovation Advisory Service of Bayreuth University, in particular Dr. Andreas Kokott und Dr. Heinz-Walter Ludwigs, made a major contribution to the preparation for the patent registration.

Publication:

Alexander P. Majewski, Anja Schallon, Valérie Jérôme, Ruth Freitag, Axel H. E. Müller, and Holger Schmalz,
Dual-Responsive Magnetic Core-Shell Nanoparticles for Non-Viral Gene Delivery and Cell Separation,
in: Biomacromolecules, Publication Date (Web): Feb 1, 2012
DOI: 10.1021/bm2017756
For suitability of PDMAEMA stars in genetic therapy see also:
http://www.uni-bayreuth.de/blick-in-die-forschung/31-2011.pdf
Contact for further information:
Prof. Dr. Ruth Freitag
Department of Process Biotechnology
University of Bayreuth
95440 Bayreuth, Germany
Tel.: +49 (0)921 55-7371
Email: ruth.freitag@uni-bayreuth.de
Prof. Dr. Axel Müller
Department of Macromolecular Chemistry II
University of Bayreuth
95440 Bayreuth, Germany
Tel.: +49 (0)921 55-3399
Email: axel.mueller@uni-bayreuth.de

Christian Wißler | Universität Bayreuth
Further information:
http://www.uni-bayreuth.de

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

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

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>