Finnish researchers involved in the development of synthetic biomaterials
27.05.2010
An international team has prepared a library of synthetic biomaterials, so-called Janus-molecules, that mimic cell membranes. Self-assembled nanostructures which they call "dendrimersomes" may be broadly useful for delivering cancer drugs safely to the body. The study appeared in Science on 21st May.
The international collaboration led by professor Virgil Percec (University of Pennsylvania, USA) also included Dr. Sami Nummelin from the Department of Applied Physics at Aalto University School of Science and Technology. Their collaboration began already in 2000 when Nummelin was a visiting scholar in professor Percec's research group. Subsequently Percec has visited at TKK (Molecular Materials) and at Jyväskylä Nanoscience Center collaborating with Academy professor Kari Rissanen and Dr. Jarmo Ropponen (currently at VTT, Espoo).
Janus-molecules (Org. Lett. 2004, 6, 2495) are repetitively branched tree-like molecules with hydrophilic and hydrophobic ends. Current research provides the first description of the preparation, structure, self-assembly and mechanical properties of liposomes and other selected complex nano-assemblies made from amphiphilic dendrimers. The so-called dendrimersomes may act as hosts for a variety of guest molecules and could therefore have widespread applications as safe delivery vehicles for drugs, proteins, gene therapy, imaging and diagnostic agents.
Dendrimersomes combine the stability and mechanical strength of "polymersomes" (liposomes made from block copolymers) with the biological function of stabilized phospholipid liposomes. However, this new class of nanomaterial is considerably more stable in time in a large variety of media and temperatures, superior in uniformity of size and easier to prepare and functionalize. According to Nummelin, molecular periphery can be tailored to various applications without affecting their self-assembly.
These dendrimersomes show special promise in nanomedicine since their membrane thickness (5-8 nm) is close of the thickness of natural bilayer membranes.
"This facilitates incorporation of biological materials such as receptors or integral proteins to the dendrimersome", Nummelin describes.
A total of 107 Janus-dendrimers were synthetized. The real breakthrough to commercialize this concept and materials still requires a substantial amount of work and also some luck.
"We will definitely carry on this research with our cross-disciplinary research consortium; we have come this far by combining the professional knowledge of chemists, biologists, and physicists", Nummelin concludes.
Further information:
Dr. Sami Nummelin
Molecular Materials, Department of Applied Physics
sami.nummelin [at] tkk [dot] fi, tel: +358 9 470 22537 or +358 50 522 4595
Article in Science:
http://www.sciencemag.org/cgi/content/abstract/328/5981/1009
