Featured Research

from universities, journals, and other organizations

Nanomedicine : 'Russian doll' polymer vesicles mimic cell structure

Date:
January 31, 2012
Source:
Centre National de la Recherche Scientifique (CNRS)
Summary:
Nanomedicine faces two main challenges: controlling the synthesis of extremely small vectors containing one or several active ingredients and releasing these agents in the right place at the right time, in controlled forms and doses. Researchers have just recently encapsulated nanovesicles within slightly larger vesicles. This "Russian doll" structure mimics the organization of cell compartments. Reproducing it is a first major step towards triggering controlled reactions within the structure of the cell. This work is already opening up new possibilities in terms of multiple encapsulation,compartmentalized reactors and the administration of vectors via new delivery routes (e.g. oral absorption).

Diagram showing the external polymersomes labeled with a green fluorophore encapsulating the internal polymersomes labeled with a red fluorophore, together with a spinning disk confocal microscopy image.
Credit: © Organic Polymer Chemistry Laboratory (CNRS/ Bordeaux 1 University/ Polytechnic Institute of Bordeaux)

Nanomedicine faces two main challenges: controlling the synthesis of extremely small vectors containing one or several active ingredients and releasing these agents in the right place at the right time, in controlled forms and doses. Researchers from the Organic Polymer Chemistry Laboratory (CNRS/ Bordeaux 1 University/ Institut Polytechnique de Bordeaux) have recently encapsulated nanovesicles within slightly larger vesicles. This "Russian doll" structure mimics the organization of cell compartments. Reproducing it is a first major step towards triggering controlled reactions within the structure of the cell. This work is already opening up new possibilities in terms of multiple encapsulation,compartmentalized reactors and the administration of vectors via new delivery routes (e.g. oral absorption).

Related Articles


These results are published on 27 January 2012, in Angewandte Chemie International Edition.

The principal nanovectors for drug delivery to have been studied so far are lipid vesicles or "liposomes." Analogs of these vectors based on polymers and known as "polymersomes" were discovered about 10 years ago. They have several advantages over liposomes: they are more stable and impermeable, they are more easily "functionalized" and "modulated" (it is possible, for example, to synthesize heat-sensitive polymers or polymers that recognize particular types of cells, such as tumor cells in particular). Over the last 10 years, the team coordinated by Sébastien Lecommandoux has been developing "intelligent" polymersomes from polypeptides whose properties and structures are analogous to those of viruses.

The researchers are now taking this biological mimicry and inspiration further, by encapsulating polymersomes within each other. This compartmentalization mimics the structure of cells, which are themselves composed of compartments (small internal organelles1, where thousands of interactions and reactions take place everyday) and a viscoelastic cytoplasm, providing the cell with a degree of mechanical stability. However, forming such encapsulated polymersomes in a controlled manner is no mean feat.

The scientists managed to do so through the use of a novel emulsion/centrifugation method that was quick, easy, required few reagents and proved highly effective. The team then used imaging with fluorescent markers to demonstrate the formation of structures in which polymersomes were encapsulated within each other. Controlling this compartmentalization makes it possible to envisage the encapsulation of several compounds (inside multiple internal polymersomes) within a single vector. This is what the researchers then went on to demonstrate: they encapsulated two different populations of internal polymersomes within a single larger polymersome. Their findings indicate that it should be possible to incorporate a much larger number of different vesicles within the vector. This is very promising for combined vectorization, in oncology for example, where the possibility of delivering different active ingredients (some of which may otherwise be incompatible) via a single vector would be a major advantage.

These novel structures could also be used as compartmentalized reactors, in catalysis or for biomedical applications. The researchers encapsulated three different fluorescent molecules2 (used as "model active ingredient molecules") in the three compartments comprised in these structures: the external polymersome membrane, the aqueous cavity of the external polymersome and the internal polymersome membrane3. Thus, it is now plausible to encapsulate different reagents in the various compartments of the polymersomes or to trigger different cascade reactions at will in these polymersomes.

In addition to providing improved protection for the encapsulated active ingredients, this packaging approach also facilitates control and allows a more precise modulation of the permeability properties of the vesicles. The researchers modeled this in an experiment involving the in-vitro release of an anticancer agent, doxorubicin (DOX), incorporated in internal encapsulated polymersomes. DOX was released about twice as rapidly from classical nanopolymersomes than from such polymersomes encapsulated within a larger external polymersome.

The researchers are the first to have achieved this type of multiple, controlled encapsulation in compartmentalized vesicles, especially polymers, that also mimic the cytoskeleton, thus reproducing the structure of the cell in its entirety4. The next step will be to use this system to trigger controlled chemical reactions in attoliter volumes (10-18 liters), in a confined environment.


Story Source:

The above story is based on materials provided by Centre National de la Recherche Scientifique (CNRS). Note: Materials may be edited for content and length.


Journal Reference:

  1. Maïté Marguet, Lise Edembe, Sébastien Lecommandoux. Polymersomes in Polymersomes: Multiple Loading and Permeability Control. Angewandte Chemie International Edition, 2012; 51 (5): 1173 DOI: 10.1002/anie.201106410

Cite This Page:

Centre National de la Recherche Scientifique (CNRS). "Nanomedicine : 'Russian doll' polymer vesicles mimic cell structure." ScienceDaily. ScienceDaily, 31 January 2012. <www.sciencedaily.com/releases/2012/01/120131092737.htm>.
Centre National de la Recherche Scientifique (CNRS). (2012, January 31). Nanomedicine : 'Russian doll' polymer vesicles mimic cell structure. ScienceDaily. Retrieved October 30, 2014 from www.sciencedaily.com/releases/2012/01/120131092737.htm
Centre National de la Recherche Scientifique (CNRS). "Nanomedicine : 'Russian doll' polymer vesicles mimic cell structure." ScienceDaily. www.sciencedaily.com/releases/2012/01/120131092737.htm (accessed October 30, 2014).

Share This



More Matter & Energy News

Thursday, October 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Reuters - Innovations Video Online (Oct. 29, 2014) — A Swedish amputee who became the first person to ever receive a brain controlled prosthetic arm is able to manipulate and handle delicate objects with an unprecedented level of dexterity. The device is connected directly to his bone, nerves and muscles, giving him the ability to control it with his thoughts. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Robots Get Funky on the Dance Floor

Robots Get Funky on the Dance Floor

AP (Oct. 29, 2014) — Dancing, spinning and fighting robots are showing off their agility at "Robocomp" in Krakow. (Oct. 29) Video provided by AP
Powered by NewsLook.com
Saharan Solar Project to Power Europe

Saharan Solar Project to Power Europe

Reuters - Business Video Online (Oct. 29, 2014) — A solar energy project in the Tunisian Sahara aims to generate enough clean energy by 2018 to power two million European homes. Matt Stock reports. Video provided by Reuters
Powered by NewsLook.com
Lowe's Testing Robot Sales Assistants in California Store

Lowe's Testing Robot Sales Assistants in California Store

Buzz60 (Oct. 29, 2014) — Lowe’s is testing out what it’s describing as a robotic shopping assistant in one of its Orchard Supply Hardware Stores in California. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins