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.

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 July 28, 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 July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) 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