Carbon nanotubes sucessfully deliver cancer drugs (in mice)

paclitaxel.jpg

“A holy grail in cancer therapy is to deliver high doses of drug molecules to tumor sites for maximum treatment efficacy while minimizing side effects to normal organs,” write Zhuang Liu and colleagues at Stanford University before revealing the results of experiments they have carried out with a material that has the potential to be just such a holy grail.

The material in question is a single-walled carbon nanotube attached to a molecule of paclitaxel, a widely used chemotherapy drug.  This connection is made using a cleavable ester bond that makes the entire molecule water soluble.

Single-walled carbon nanotubes  have the unusual property of tending to pass easily through the walls of the especially leaky blood vessels that form inside tumours. In this way, they end up being concentrated in tumours, carrying their deadly load of paclitaxel. Here the esther bond is cleaved, leaving the drug to do its work.

The result is a tenfold higher concentration of paclitaxel in the tumour than is possible with other means. That’s important because it means cancer can be treated with lower doses of chemotherapy for the body as a whole while ensuring that the tumour itself receives a high dose.

In tests, Liu says the technique works well in mice and the team is duly chuffed:

“To our knowledge, this is the first successful report that carbon nanotubes are used as drug delivery vehicles to achieve in vivo tumor treatment efficacy with mice.”

A similar kind of approach is already being investigated with quantum dots.¬† But there’s an important difference. Carbon nanotubes are pure carbon which is thought to be relatively benign. Quantum dots on the other hand are often made from heavy metals which have potentially serious health implications.

It’s never worth getting your hopes up with these kinds of early results. Nevertheless, it’ll be interesting to see where this work leads.

Ref: arxiv.org/abs/0808.2070: Drug Delivery with Carbon Nanotubes for In Vivo Cancer Treatment

One Response to “Carbon nanotubes sucessfully deliver cancer drugs (in mice)”

  1. Zephir says:

    /*..carbon nanotubes are pure carbon which is thought to be relatively benign.. */

    http://www.theinquirer.net/gb/inquirer/news/2008/05/22/carbon-nanotubes-cause-cancer