Featured Research

from universities, journals, and other organizations

Nanotechnology: Bristly Spheres As Capsules for Drugs

Date:
March 9, 2009
Source:
Wiley-Blackwell
Summary:
Researchers have produced amphiphilic hybrid particles made of a water-insoluble inorganic nanoparticle at the core surrounded by a bristle-like layer of hydrophilic polymer chains. The polymer-coated spheres offer a simple method for the controlled production of superstructures, such as vesicles to be used to encapsulate drugs or as contrast agents.

Amphiphilic molecules, which have one water-friendly (hydrophilic) end and one water-repellant (hydrophobic) end, spontaneously aggregate in aqueous solutions to make superstructures like capsules or bilayers. This phenomenon is responsible for the effects of detergents and soaps. Dirt is enclosed in little capsules of surfactant, which makes it water-soluble.

Cell membranes are also based on this principle: they are simply lipid bilayers, an aggregation of lipid molecules that line up with their hydrophobic tails all together and their hydrophilic heads protruding into the aqueous environment.

As reported in the journal Angewandte Chemie, researchers at the Universities of Hamburg and Freiburg (Germany) led by Horst Weller and Stephan Fφrster have now produced amphiphilic hybrid particles made of a water-insoluble inorganic nanoparticle at the core surrounded by a bristle-like layer of hydrophilic polymer chains.

The inorganic nanoparticles are made of cadmium selenide and cadmium sulfide. Polyethylene oxide chains are attached to the nanoparticles through amino groups. The nature of the superstructures formed in aqueous solution depends on how densely the surfaces of the little spheres are covered with the polymer "bristles". If they are densely packed, the hybrid particles remain in solution as individuals, because the bristles repel each other. If the bristles are less dense, dimers and trimers are formed; still sparser bristles result in long wormlike aggregates of many particles that grow into a network through occasional Y-shaped branches.

For the particles to aggregate in this way, the bristles on the surfaces of the inorganic cores have to reorganize significantly: they move aside a little to free up points of contact so the cores can attach to each other. Aggregation then continues until the resulting ensemble of cores is, as a whole, surrounded by a sufficiently dense layer of bristles, which acts as a shield toward additional particles.

Cores with an even smaller number of polymer bristles aggregate into extended curved layers that close themselves off into capsule-shaped vesicles. The walls of the vesicles consist of a monolayer of the bristly particles.

The polymer-coated spheres offer a new, simple method for the controlled production of superstructures. The vesicles could be used to encapsulate drugs, for example, as contrast agents, or as ordered liquid crystalline phases for the production of nanostructured hybrid materials.


Story Source:

The above story is based on materials provided by Wiley-Blackwell. Note: Materials may be edited for content and length.


Journal Reference:

  1. Stephan Fφrster. Micelle and Vesicle Formation of Amphiphilic Nanoparticles. Angewandte Chemie International Edition, DOI: 10.1002/anie.200805158

Cite This Page:

Wiley-Blackwell. "Nanotechnology: Bristly Spheres As Capsules for Drugs." ScienceDaily. ScienceDaily, 9 March 2009. <www.sciencedaily.com/releases/2009/03/090306103639.htm>.
Wiley-Blackwell. (2009, March 9). Nanotechnology: Bristly Spheres As Capsules for Drugs. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2009/03/090306103639.htm
Wiley-Blackwell. "Nanotechnology: Bristly Spheres As Capsules for Drugs." ScienceDaily. www.sciencedaily.com/releases/2009/03/090306103639.htm (accessed October 22, 2014).

Share This



More Matter & Energy News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) — If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) — Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) — British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
China Airlines Swanky New Plane

China Airlines Swanky New Plane

Buzz60 (Oct. 21, 2014) — China Airlines debuted their new Boeing 777, and it's more like a swanky hotel bar than an airplane. Enjoy high-tea, a coffee bar, and a full service bar with cocktails and spirits, and lie-flat in your reclining seats. Sean Dowling (@SeanDowlingTV) has the details. 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