Featured Research

from universities, journals, and other organizations

Self-assembled DNA Buckyballs For Drug Delivery

Date:
August 31, 2005
Source:
Cornell University
Summary:
Cornell University researchers have made DNA buckyballs -- tiny geodesic spheres that could be used for drug delivery and as containers for chemical reactions.

A scanning electron microscope photo of a self-assembled DNA buckyball.
Credit: Image courtesy of Cornell University News Service

Now Cornell University researchers have made DNAbuckyballs -- tiny geodesic spheres that could be used for drugdelivery and as containers for chemical reactions.

The term"buckyballs" has been used up to now for tiny spherical assemblies ofcarbon atoms known as Buckminsterfullerenes or just fullerenes. Underthe right conditions, carbon atoms can link up into hexagons andpentagons, which in turn assemble into spherical shapes (technicallytruncated icosahedrons) resembling the geodesic domes designed by thearchitect-engineer Buckminster Fuller. Instead of carbon, the Cornellresearchers are making buckyballs out of a specially prepared, branchedDNA-polystyrene hybrid. The hybrid molecules spontaneouslyself-assemble into hollow balls about 400 nanometers (nm) in diameter.The DNA/polystyrene "rods" forming the structure are each about 15 nmlong. (While still on the nanoscale, the DNA spheres are much largerthan carbon buckyballs, which are typically around 7 nm in diameter.)

About70 percent of the volume of the DNA buckyball is hollow, and the openspaces in the structure allow water to enter. Dan Luo, Cornellassistant professor of biological and environmental engineering inwhose lab the DNA structures were made, suggests that drugs could beencapsulated in buckyballs to be carried into cells, where naturalenzymes would break down the DNA, releasing the drug. They might alsobe used as cages to study chemical reactions on the nanoscale, he says.
Thenanoscale, hollow buckyballs are also the first structures assembledfrom "dendrimerlike DNA." If three strands of artificial DNA arecreated such that portions of each strand are complementary to portionsof another, the three strands will bind to each other over thecomplementary portions, creating a Y-shaped molecule. By joiningseveral Y's in the same way, Luo's research group created moleculeswith several arms, a sort of tree shape (dendri- means tree in Greek).Then they attached polystyrene molecules to the dendrimerlike DNAforming a hybrid molecule called an amphiphile -- a molecule that bothlikes and hates water. DNA is hydrophillic -- attracted to water --while polystyrene is hydrophobic -- water repels it.

Theresearchers expected the amphiphiles to assemble in water into somesort of solid structure arranged so that DNA would have a maximuminteraction with water and polystyrene would avoid water as much aspossible. Other researchers have used other amphiphiles to makespheres, rods and other solids. The hollow buckyballs were anintriguing and serendipitous surprise. A model suggests that onebuckyball consists of about 19,000 amphiphiles, with their water-lovingDNA mostly on the outside of the rods that form the structure. Howthese tens of thousands of molecules were able to self-organize to formsuch an intricate and complex structure is still an open question, theresearchers say. They are seeking collaborators to solve the puzzle.

Luoand Ph.D. graduate students Soong Ho Um, Sang Yeon Kwon and Jong BumLee described DNA buckyballs in an invited talk titled "Self-assemblyof nanobuckyballs from dendrimer-like-DNA-polystyrene amphiphiles"Sunday, Aug. 28, at the 2005 annual meeting of the American ChemicalSociety in Washington, D.C. They reminded the audience that althoughthe geometry of solid truncated icosahedrons was first described byArchimedes on paper more than 2,000 years ago, the skeletal,hollow-faced version of buckyballs had not been envisioned untilLeonardo da Vinci's illustrations in 1494.

Luo added that DNAbuckyballs may turn out to have unusual electronic, photonic andmechanical properties, and that because DNA is easily labeled andmanipulated, his research group's work offers a way to study in detailthe self-assembly process -- a process very important to the futuredevelopment of nanotechnology.


Story Source:

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


Cite This Page:

Cornell University. "Self-assembled DNA Buckyballs For Drug Delivery." ScienceDaily. ScienceDaily, 31 August 2005. <www.sciencedaily.com/releases/2005/08/050829074441.htm>.
Cornell University. (2005, August 31). Self-assembled DNA Buckyballs For Drug Delivery. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2005/08/050829074441.htm
Cornell University. "Self-assembled DNA Buckyballs For Drug Delivery." ScienceDaily. www.sciencedaily.com/releases/2005/08/050829074441.htm (accessed July 28, 2014).

Share This




More Matter & Energy News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Carbon Trap: US Exports Global Warming

The Carbon Trap: US Exports Global Warming

AP (July 28, 2014) AP Investigation: As the Obama administration weans the country off dirty fuels, energy companies are ramping-up overseas coal exports at a heavy price. (July 28) Video provided by AP
Powered by NewsLook.com
Shipping Crates Get New 'lease' On Life

Shipping Crates Get New 'lease' On Life

Reuters - Business Video Online (July 25, 2014) Shipping containers have been piling up as America imports more than it exports. Some university students in Washington D.C. are set to get a first-hand lesson in recycling. Their housing is being built using refashioned shipping containers. Lily Jamali reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
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:
from the past week

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