MedicineWorld.Org
Your gateway to the world of medicine
Home
News
Cancer News
About Us
Cancer
Health Professionals
Patients and public
Contact Us
Disclaimer

Medicineworld.org: Nano-scale drug delivery for chemotherapy

Back to cancer blog Blogs list Cancer blog  


Subscribe To Cancer Blog RSS Feed  RSS content feed What is RSS feed?

Nano-scale drug delivery for chemotherapy




scale delivery vehicles and demonstrated in animal models that this new nanoformulation can eliminate tumors after a single therapy. After delivering the drug to the tumor, the delivery vehicle breaks down into harmless byproducts, markedly decreasing the toxicity for the recipient.

Nano-delivery systems have become increasingly attractive to scientists because of their ability to efficiently get into tumors. Since blood vessels supplying tumors are more porous, or leaky, than normal vessels, the nanoformulation can more easily enter and accumulate within tumor cells. This means that higher doses of the drug can be delivered, increasing its cancer-killing abilities while decreasing the side effects linked to systematic chemotherapy.



Nano-scale drug delivery for chemotherapy
This is Ashutosh Chilkoti from Duke University.

Credit: Duke University Photography


"When used to deliver anti-cancer medications in our models, the new formulation has a four-fold higher maximum tolerated dose than the same drug by itself, and it induced nearly complete tumor regression after one injection," said Ashutosh Chilkoti, Theo Pilkington Professor of Biomedical Engineering at Duke's Pratt School of Engineering. "The free drug had only a modest effect in shrinking tumors or in prolonging animal survival".

The results of Chilkoti's experiments were published early online in the journal Nature Materials
"Just as importantly, we believe, is the novel method we developed to create these drugs," Chilkoti said. "Unlike other approaches, we can produce large quantities simply and inexpensively, and we believe the new method theoretically could be used to improve the effectiveness of other existing cancer drugs".

Central to the new method is how the drug is "attached" to its polypeptide delivery system and whether or not a drug can be dissolved in water.

The delivery system makes use of the bacterium Escherichia coli (E. coli) which has been genetically altered to produce a specific artificial polypeptide known as a chimeric polypeptide. Since E. coli are usually used to produce proteins, it makes for a simple and reliable production plant for these specific polypeptides with high yield.

When attached to one of these chimeric polypeptides, the drug takes on characteristics that the drug alone does not possess. Most drugs do not dissolve in water, which limits their ability to be taken in by cells. But being attached to a nanoparticle makes the drug soluble.

"When these two elements are combined in a container, they spontaneously self-assemble into a water-soluble nanoparticle," Chilkoti said. "They also self-assemble consistently and reliably in a size of 50 nanometers or so that makes them ideal for cancer treatment. Since a number of chemotherapeutic drugs are insoluble, we think that this new approach could work for them as well".

The latest experiments involved doxorubicin, a usually used agent for the therapy of cancers of the blood, breast, ovaries and other organs. The scientists injected mice with tumors implanted under their skin with either the chimeric polypeptide-doxorubicin combination or doxorubicin alone.

The mice treated with doxorubicin alone had an average tumor size 25 times greater than those treated with the new combination. The average survival time for the doxorubicin-treated mice was 27 days, in comparison to more than 66 days for mice getting the new formulation.

The Duke scientists now plan to test the new combination on different types of cancer, as well as tumors growing within different organs. They will also try combining these chimeric polypeptides with other insoluble drugs and test their effectiveness against tumors.


Posted by: Janet    Source




Did you know?
scale delivery vehicles and demonstrated in animal models that this new nanoformulation can eliminate tumors after a single therapy. After delivering the drug to the tumor, the delivery vehicle breaks down into harmless byproducts, markedly decreasing the toxicity for the recipient.

Medicineworld.org: Nano-scale drug delivery for chemotherapy

Main Page| Cancer blog| Cancer blogs list| Lung cancer blog| Colon cancer blog| Prostate cancer blog| Breast cancer blog| Diabetes watch blog| Heart watch blog| Allergy blog| Bladder cancer blog| Cervical cancer blog| Colon cancer news blog| Diabetes news blog| Esophageal cancer blog| Gastric cancer blog| Health news blog| Heart news blog| Infectious disease blog| Kidney watch blog| Lung disease blog| Lung cancer news blog| Mesothelioma blog| Neurology blog| Breast cancer news blog| OBGYN blog| Ophthalmology blog| Ovarian cancer blog| Cancer news blog| Pancreas cancer blog| Pediatrics blog| Prostate cancer news blog| Psychology blog| Research blog| Rheumatology blog| Society news blog| Uterine cancer blog| Weight watch blog|

Copyright statement
The contents of this web page are protected. Legal action may follow for reproduction of materials without permission.