PEGylated dendrimers: a novel mechanism of drug delivery

March 11, 2010

Monash Institute of Pharmaceutical Science (MIPS) researchers, in collaboration with the biotechnology company Starpharma Holdings Ltd have developed a new method to deliver medications that may benefit thousands of patients with particular types of cancer, HIV and lymphatic conditions world-wide.

The Melbourne-based research team has shown how PEGylated Polylysine dendrimers, a new type of nano-sized , can be altered to target either the lymphatic system or the bloodstream.

Lead researcher at MIPS and the Associate Dean of Research, Professor Chris Porter said the discovery has particular implications for the treatment of diseases which are spread via the lymphatics and lymph nodes.

"We are excited by the possibilities that this technology may provide in the improved treatment of particular types of diseases, including metastatic cancer, lymphoma, HIV and metastitial tuberculosis," Professor Porter said.

Dendrimers are precisely defined, synthetic that are approximately 5-10 nanometres in diameter. They are made up of layers of polymer surrounding a central core. The dendrimer surface contains many different sites to which drugs may be attached and also attachment sites for materials such as (PEG) which can be used to modify the way the dendrimer interacts with the body.

PEG can be attached to the dendrimer to 'disguise' it and prevent the body's defence mechanisms from detecting it, thereby slowing the process of breakdown. This allows the delivery system to circulate in the body for an extended time period, maximising the opportunities for the drug to reach the relevant sites.

Professor Porter's group and Starpharma have been investigating dendrimer-based drug delivery systems for some time - but these most recent finding appear to hold particular promise.

The data, published in the , demonstrates that by increasing dendrimer size by increasing the chain length of attached polyethylene glycol (PEG) chains, a dramatic increase in absorption efficiency after subcutaneous injection can be achieved and transported into the lymphatic system. Conversely, a shorter PEG chain was shown to lead to rapid absorption into the blood.

"Our work suggests that careful design of the size and surface characteristics of PEGylated Polylysine dendrimers provides an opportunity to choose whether these delivery systems are absorbed and distributed via the bloodstream or the lymphatic system," Professor Porter said.

"The ability to target therapeutic treatments in this way offers the potential to maximise drug concentrations at sites of action within the lymphatic system - and importantly to minimise concentrations elsewhere, potentially reducing side effects and toxicity. It is still early days, but we're confident the potential for improved patient treatment is significant'.

Explore further: Novel approach to detoxifying cancer drugs

Related Stories

Novel approach to detoxifying cancer drugs

November 7, 2006

Anticancer drugs are often highly toxic when delivered straight, but "wrapping" them inside larger molecules can lessen the side effects as well as make them more effective, according to a new study by researchers at the ...

Single-Dose Drug-Loaded Dendrimer Cures Mice of Colon Cancer

November 13, 2006

In a dramatic demonstration of the power of nanotechnology, a team of investigators has designed a nanoscale, polymeric drug delivery vehicle that when loaded with a widely used anticancer agent cures colon cancer in mice ...

New Nanoparticles for Targeting Tumors

March 27, 2008

As a wide variety of nanoparticles continue to demonstrate their ability to improve the delivery of imaging agents and drugs to tumors, nanoparticle researchers have turned their attention to the challenge of systematically ...

Cancer drug delivery research cuts time from days to hours

July 22, 2008

Researchers at Case Western Reserve University have developed a technique that has the potential to deliver cancer-fighting drugs to diseased areas within hours, as opposed to the two days it currently takes for existing ...

Recommended for you

Rice de-icer gains anti-icing properties

May 23, 2016

Rice University scientists have advanced their graphene-based de-icer to serve a dual purpose. The new material still melts ice from wings and wires when conditions get too cold. But if the air is above 7 degrees Fahrenheit, ...

Nanoscale Trojan horses treat inflammation

May 23, 2016

Nanosized Trojan horses created from a patient's own immune cells have successfully treated inflammation by overcoming the body's complex defense mechanisms, perhaps leading to broader applications for treating diseases characterized ...

Dendrite-proof batteries made possible by Zylon nanofibers

May 17, 2016

(Phys.org)—One of the biggest problems plaguing high-energy, lithium-metal batteries is dendrites, which form when some of the lithium from the electrode begins to branch outside the electrode and into the electrolyte, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.