Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Mini-beacon design a major development for smart drug delivery

Abstract:
A nanoscopic beacon used by Melbourne researchers will help to enhance the design of smart gene and drug delivery systems.

Mini-beacon design a major development for smart drug delivery

August 02, 2005

A team from the University of Melbourne’s Department of Chemical and Biomolecular Engineering has used a molecular beacon made from single DNA strands to measure how easily DNA (e.g. genes) can pass through the wall of drug delivery particles.

Federation Fellow Professor Frank Caruso, who heads the Centre for Nanoscience and Nanotechnology, says, “The past number of years has seen major advances in the design of ‘molecular vehicles’ – particles that can be filled with a medicine or new genes. The vehicles then ferry their contents to the site in the body where they are needed.”

“One of the major roadblocks that we have encountered in designing these molecular transport systems is how to get the vehicle contents out of their container once they reach the site where they are needed.”

In order to achieve this effectively, the researchers need to know how big the pores in the vehicle’s membranes are and how easily the contents can pass through them. This has proved quite difficult.

Dr. Angus Johnston who works with Professor Caruso says, “Scientists designing these drug-delivery vehicles need to be able to measure the very small number of molecules which pass through the membrane. Normally, we could label the molecules, so we can see them as they pass through. The problem with this is that adding a label alters the size, so the ability to pass through the pore will change when the label is removed.”

Dr. Johnston and Professor Caruso have developed a clever technique that overcomes this problem which allows scientists to rapidly and accurately determine the permeability of DNA through films.

The beacons the researchers used are single DNA strands which have a light-emitting molecule (a fluorophore) at one end and a quencher at the other. A fluorophore is simply a molecule that emits light and a quencher is a molecule that stops the fluorophore from emitting light.

The DNA strand self assembles so that the two end segments pair up, forming a loop in the centre – much like the shape of a round-bottomed flask. This is the closed molecular beacon.

When the beacon is closed the fluorophore on one end of the DNA strand is close to the “quencher” on the other end, which stops the fluorophore from giving off light.

To determine the permeability of the capsule, the molecular beacons are placed inside the delivery vehicle. If DNA passes through the capsule wall, the beacon opens and the fluorophore emits light. So when DNA passes through the capsule, the beacon is switched ‘on.’ If no DNA passes through the capsule, the beacon remains switched off.

The researchers used this technique with different length strands of DNA and were able to use the beacons to successfully determine whether or not the strands were able to pass through the membrane.

Professor Caruso says, “We hope to now use the technique in the design of intelligent drug-delivery systems which can transport medicine to target locations and release the contents in a controlled way.”

The research was recently published in the Journal of the American Chemical Society and highlighted in the July 15 Issue of the journal Science. This research was funded by the Australian Research Council.

####

Contact:
Elaine Mulcahy
Media Promotions Officer
emulcahy@unimelb.edu.au
Tel: 61 3 8344 0181
Mob: 0421 641 506

Frank Caruso
Chemical and Biomolecular Engineering
(03) 8344 3461
fcaruso@unimelb.edu.au

Angus Johnston
Chemical and Biomolecular Engineering
(03) 8344 9833
0409 863 255
angusj@unimelb.edu.au

Copyright © University of Melbourne

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Self Assembly

Building a smart cardiac patch: 'Bionic' cardiac patch could one day monitor and respond to cardiac problems June 28th, 2016

Self-assembling icosahedral protein designed: Self-assembling icosahedral protein designed June 22nd, 2016

DNA shaping up to be ideal framework for rationally designed nanostructures: Shaped DNA frames that precisely link nanoparticles into different structures offer a platform for designing functional nanomaterials June 14th, 2016

Automating DNA origami opens door to many new uses: Like 3-D printing did for larger objects, method makes it easy to build nanoparticles out of DNA May 30th, 2016

Nanomedicine

A drop of water as a model for the interplay of adhesion and stiction June 30th, 2016

How cancer cells spread and squeeze through tiny blood vessels (video) June 30th, 2016

Building a smart cardiac patch: 'Bionic' cardiac patch could one day monitor and respond to cardiac problems June 28th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Sensors

Researchers discover new chemical sensing technique: Technique allows sharper detail -- and more information -- with near infrared light June 24th, 2016

Artificial synapse rivals biological ones in energy consumption June 21st, 2016

A new form of hybrid photodetectors with quantum dots and graphene June 19th, 2016

Drum beats from a one atom thick graphite membrane June 15th, 2016

Discoveries

A drop of water as a model for the interplay of adhesion and stiction June 30th, 2016

No need in supercomputers: Russian scientists suggest a PC to solve complex problems tens of times faster than with massive supercomputers June 30th, 2016

Surprising qualities of insulator ring surfaces: Surface phenomena in ring-shaped topological insulators are just as controllable as those in spheres made of the same material June 30th, 2016

How cancer cells spread and squeeze through tiny blood vessels (video) June 30th, 2016

Announcements

A drop of water as a model for the interplay of adhesion and stiction June 30th, 2016

No need in supercomputers: Russian scientists suggest a PC to solve complex problems tens of times faster than with massive supercomputers June 30th, 2016

Surprising qualities of insulator ring surfaces: Surface phenomena in ring-shaped topological insulators are just as controllable as those in spheres made of the same material June 30th, 2016

How cancer cells spread and squeeze through tiny blood vessels (video) June 30th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic