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 'Y' a protein unicorn might matter in glaucoma
23.10.2017 | Georgia Institute of Technology

nachricht Microfluidics probe 'cholesterol' of the oil industry
23.10.2017 | Rice University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>