Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Synthetic Capsules Made of Natural Building Blocks

23.03.2009
Block copolymer vesicles from protein and sugar components

The basis of all life forms are vesicles: membrane-enclosed, liquid-filled “bubbles” made of lipids, proteins, and carbohydrates.

Cells, which are separated from the surrounding medium by their cell membrane, are really just big vesicles. Small vesicles play a critical role in the intracellular transport of biomolecules.

Synthetic vesicles, such as liposomes and polymersomes, made of lipids and polymers respectively, are used to transport active ingredients in products such as cosmetic or pharmaceutical formulations. They also have potential as microreactors intended to mimic the behavior of living cells.

This would be more successful if the vesicles were made of natural components. As reported in the journal Angewandte Chemie, researchers working with Sébastien Lecommandoux and Christophe Schatz at the University of Bordeaux (France) have now attached together blocks of sugar molecule chains (polysaccharides) and protein chains (polypeptides) in a linear fashion. In water, these block copolymers spontaneously form vesicles.

The researchers used dextran, a polymer made of glucose building blocks, and poly(benzyl L-glutamate) (PBLG), a biocompatible polypeptide. By using a series of reactions referred to as “click” chemistry, they attached these molecules to each other blockwise. The advantages of this method are the mild reaction conditions, the nearly quantitative yield, and the fact that other functional side groups on the reactants do not interfere with the reaction.

In this way, the scientists produced block copolymers that combine a polypeptide (protein-like) block and a sugar block. The hydrophobic (water-repellant) polypeptide adopts a helical conformation and in aqueous environments prefers to be side-to-side with those like itself. This results in membrane-like layers that close in on themselves to form spherical vesicles. On both sides of the synthetic membrane, the hydrophilic (water-friendly) dextran chains coil up into a stabilizing “corona”. Electron microscope images reveal membranes that are about 21 nm thick surrounding vesicles of a very uniform size (about 45 nm radius).

The researchers would like to use their simple, versatile synthetic strategy to make other synthetic glycopeptides that could be used as model compounds for the exploration of cellular sugar structures (glycomics). The vesicles could also form the basis for a new generation of drug and gene transporters, because their sugar corona binds well to glycoproteins on the surfaces of living cells. The vesicles are also similar to the hulls of viruses and are a first step toward mimicking virus morphology.

Author: Sébastien Lecommandoux, Université de Bordeaux, Pessac (France), http://recherche.enscpb.fr/lcpo/fr/fichier%20html/perso_lecommandoux-fr.htm

Title: Polysaccharide-block-polypeptide Copolymer Vesicles: Towards Synthetic Viral Capsids

Angewandte Chemie International Edition 2009, 48, No. 14, 2572–2575, doi: 10.1002/anie.200805895

Sébastien Lecommandoux | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://recherche.enscpb.fr/lcpo/fr/fichier%20html/perso_lecommandoux-fr.htm

More articles from Life Sciences:

nachricht One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie

nachricht The dark side of cichlid fish: from cannibal to caregiver
20.04.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>