Featured Research

from universities, journals, and other organizations

Transport System Smuggles Medicines Into Brain

Date:
February 16, 2005
Source:
Netherlands Organization For Scientific Research
Summary:
Dutch researcher Corine Visser investigated a new way of transporting medicines into the brain. Her approach made use of an iron transport system located on the blood-brain barrier. The smaller the medicine, the more easily it penetrates the brain.

Dutch researcher Corine Visser investigated a new way of transporting medicines into the brain. Her approach made use of an iron transport system located on the blood-brain barrier. The smaller the medicine, the more easily it penetrates the brain.

Related Articles


A special barrier between the blood and the brain, the so-called blood-brain barrier (BBB), protects the brain from toxic substances. It only lets through important nutrients for the brain such as iron, glucose and oxygen. Visser allowed larger molecules, such as medicines, to pass through the blood-brain barrier by attaching these to the iron-containing protein transferrin. This technique allowed the medicines to 'hitch a lift' and pass unnoticed though the BBB. How much medicine reaches the brain depends on the size of the molecule attached to the transferrin.

Much of the BBB is made up of capillary endothelial cells, the cells which line the walls of blood vessels. In the brain, unlike other parts of the body, these cells are closely packed together. This makes it almost impossible for substances to pass between the cells. Further in the brain, few substances can pass through the endothelial cells.

Transferrin is a protein in the blood that contains two iron atoms. On reaching the BBB it binds to transferrin receptors on the endothelial cells. Once the transferrin has bound to the receptor, a vesicle in the cell completely engulfs it. The transferrin then releases the iron atoms, which are brought to the brain by another protein. A major advantage of this transport system with vesicles is that larger molecules can pass through the BBB. The vesicle has a diameter of about 120 nanometres.

<b>Conjugation</b>

In three stages, Visser investigated how medicines can enter the brain via the transferrin receptor. In the first stage she demonstrated the presence of the receptor in her BBB model by using radioactively-labelled transferrin. She then conjugated an enzyme to the transferrin. With the enzyme attached, the transferrin also bound to the receptor and was taken up in the cells of the BBB.

Finally, Visser attached a tiny fat bubble (liposome) containing small molecules, such as medicines, to the transferrin. She discovered that the transferrin with the liposome attached was also taken up by the cell. However, the cell subsequently broke down the liposomal content, because the liposomes were significantly bigger than the previously linked enzyme. Liposomes have a diameter of 100 nanometres and the enzyme a diameter of 3 to 4 nanometres. Therefore a liposome or a direct conjugation can be chosen, dependent on the intracellular destination of the medicine.

The research was funded by the Netherlands Organisation for Scientific Research.


Story Source:

The above story is based on materials provided by Netherlands Organization For Scientific Research. Note: Materials may be edited for content and length.


Cite This Page:

Netherlands Organization For Scientific Research. "Transport System Smuggles Medicines Into Brain." ScienceDaily. ScienceDaily, 16 February 2005. <www.sciencedaily.com/releases/2005/02/050213135505.htm>.
Netherlands Organization For Scientific Research. (2005, February 16). Transport System Smuggles Medicines Into Brain. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2005/02/050213135505.htm
Netherlands Organization For Scientific Research. "Transport System Smuggles Medicines Into Brain." ScienceDaily. www.sciencedaily.com/releases/2005/02/050213135505.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Nurse Nina Pham Cured of Ebola

Texas Nurse Nina Pham Cured of Ebola

AFP (Oct. 25, 2014) — An American nurse who contracted Ebola while caring for a Liberian patient in Texas has been declared free of the virus and will leave the hospital. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) — The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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