RxPG News Feed for RxPG News

Medical Research Health Special Topics World
  Home
 
   Health
 Aging
 Asian Health
 Events
 Fitness
 Food & Nutrition
 Happiness
 Men's Health
 Mental Health
 Occupational Health
 Parenting
 Public Health
 Sleep Hygiene
 Women's Health
 
   Healthcare
 Africa
 Australia
 Canada Healthcare
 China Healthcare
 India Healthcare
 New Zealand
 South Africa
 UK
 USA
 World Healthcare
 
   Latest Research
 Aging
 Alternative Medicine
 Anaethesia
 Biochemistry
 Biotechnology
  Drug Delivery
  Nanotechnology
 Cancer
 Cardiology
 Clinical Trials
 Cytology
 Dental
 Dermatology
 Embryology
 Endocrinology
 ENT
 Environment
 Epidemiology
 Gastroenterology
 Genetics
 Gynaecology
 Haematology
 Immunology
 Infectious Diseases
 Medicine
 Metabolism
 Microbiology
 Musculoskeletal
 Nephrology
 Neurosciences
 Obstetrics
 Ophthalmology
 Orthopedics
 Paediatrics
 Pathology
 Pharmacology
 Physiology
 Physiotherapy
 Psychiatry
 Radiology
 Rheumatology
 Sports Medicine
 Surgery
 Toxicology
 Urology
 
   Medical News
 Awards & Prizes
 Epidemics
 Launch
 Opinion
 Professionals
 
   Special Topics
 Ethics
 Euthanasia
 Evolution
 Feature
 Odd Medical News
 Climate

Last Updated: Oct 11, 2012 - 10:22:56 PM
Drug Delivery Channel

subscribe to Drug Delivery newsletter
Latest Research : Biotechnology : Drug Delivery

   EMAIL   |   PRINT
DNA buckyballs for drug delivery created

Aug 29, 2005 - 10:36:00 PM
DNA buckyballs may turn out to have unusual electronic, photonic and mechanical properties, and that because DNA is easily labeled and manipulated, his research group's work offers a way to study in detail the self-assembly process -- a process very important to the future development of nanotechnology.

 
[RxPG] DNA isn't just for storing genetic codes any more. Since DNA can polymerize -- linking many molecules together into larger structures -- scientists have been using it as a nanoscale building material, constructing geometric shapes and even working mechanical devices.

Now Cornell University researchers have made DNA buckyballs -- tiny geodesic spheres that could be used for drug delivery and as containers for chemical reactions.

The term "buckyballs" has been used up to now for tiny spherical assemblies of carbon atoms known as Buckminsterfullerenes or just fullerenes. Under the right conditions, carbon atoms can link up into hexagons and pentagons, which in turn assemble into spherical shapes (technically truncated icosahedrons) resembling the geodesic domes designed by the architect-engineer Buckminster Fuller. Instead of carbon, the Cornell researchers are making buckyballs out of a specially prepared, branched DNA-polystyrene hybrid. The hybrid molecules spontaneously self-assemble into hollow balls about 400 nanometers (nm) in diameter. The DNA/polystyrene "rods" forming the structure are each about 15 nm long. (While still on the nanoscale, the DNA spheres are much larger than carbon buckyballs, which are typically around 7 nm in diameter.)

About 70 percent of the volume of the DNA buckyball is hollow, and the open spaces in the structure allow water to enter. Dan Luo, Cornell assistant professor of biological and environmental engineering in whose lab the DNA structures were made, suggests that drugs could be encapsulated in buckyballs to be carried into cells, where natural enzymes would break down the DNA, releasing the drug. They might also be used as cages to study chemical reactions on the nanoscale, he says.

The nanoscale, hollow buckyballs are also the first structures assembled from "dendrimerlike DNA." If three strands of artificial DNA are created such that portions of each strand are complementary to portions of another, the three strands will bind to each other over the complementary portions, creating a Y-shaped molecule. By joining several Y's in the same way, Luo's research group created molecules with several arms, a sort of tree shape (dendri- means tree in Greek). Then they attached polystyrene molecules to the dendrimerlike DNA forming a hybrid molecule called an amphiphile -- a molecule that both likes and hates water. DNA is hydrophillic -- attracted to water -- while polystyrene is hydrophobic -- water repels it.

The researchers expected the amphiphiles to assemble in water into some sort of solid structure arranged so that DNA would have a maximum interaction with water and polystyrene would avoid water as much as possible. Other researchers have used other amphiphiles to make spheres, rods and other solids. The hollow buckyballs were an intriguing and serendipitous surprise. A model suggests that one buckyball consists of about 19,000 amphiphiles, with their water-loving DNA mostly on the outside of the rods that form the structure. How these tens of thousands of molecules were able to self-organize to form such an intricate and complex structure is still an open question, the researchers say. They are seeking collaborators to solve the puzzle.

DNA buckyballs for drug delivery created
A scanning electron microscope photo of a self-assembled DNA buckyball.


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

Luo added that DNA buckyballs may turn out to have unusual electronic, photonic and mechanical properties, and that because DNA is easily labeled and manipulated, his research group's work offers a way to study in detail the self-assembly process -- a process very important to the future development of nanotechnology.



Publication: Luo and Ph.D. graduate students Soong Ho Um, Sang Yeon Kwon and Jong Bum Lee described DNA buckyballs in an invited talk titled "Self-assembly of nanobuckyballs from dendrimer-like-DNA-polystyrene amphiphiles" Sunday, Aug. 28, at the 2005 annual meeting of the American Chemical Society in Washington, D.C.
On the web: Cornell University 

Advertise in this space for $10 per month. Contact us today.


Related Drug Delivery News


Subscribe to Drug Delivery Newsletter

Enter your email address:


 Feedback
For any corrections of factual information, to contact the editors or to send any medical news or health news press releases, use feedback form

Top of Page

 
Contact us

RxPG Online

Nerve

 

    Full Text RSS

© All rights reserved by RxPG Medical Solutions Private Limited (India)