Nano-scale drug delivery for chemotherapy

Going smaller would yield better results, especially when it comes to the fight against cancer drugs.Duke bio-engineering from the University to have a simple and inexpensive for loading anti-drug payloads Cancer in the development of nano-scale delivery vehicles in animal models have shown that this new nanoformulations tumors can be removed after a single treatment. After tax relief of the drug to the tumor, the delivery vehicle breaks down into harmless by-products significantly reduced toxicity to the recipient.

Nano-delivery systems are increasingly attractive to researchers because of their ability to obtain efficiently in tumors. For the damaged blood vessels of tumors are more porous and permeable than normal vessels could easily enter the nanoformulations and accumulate in tumor cells. This means that a higher dose of the drug is given, to increase the anticancer capabilities while reducing side effects associated with systemic chemotherapy

"When used to deliver anti-cancer drugs in our models is that the new formulation of four times the maximum tolerated dose of the same drug itself, and it induces almost complete regression after injection, said Ashutosh Chilkoti, Theo Pilkington Professor of Biomedical Engineering at Duke's Pratt School of Engineering. "The free drug had little effect on the reduction of tumors and prolong survival of animals.

The experimental results Chilkoti were published early online in the journal Nature Materials.

"Equally important, we believe, is the new method, which we said in point to create these drugs," Chilkoti. "Unlike other approaches, we can produce large quantities of simple and inexpensive, and we believe that the new approach could theoretically be used to improve the effectiveness of existing cancer drugs. "

Of central importance for the new method, such as drugs "attached" to its delivery system polypeptides and if a drug is dissolved in water.

The delivery system uses the bacterium Escherichia coli (E. coli) that have been genetically modified to produce a polypeptide known as artificial chimeric polypeptide. Since E. coli is often used to produce proteins is a simple and reliable for the production of specific polypeptides in high yield.

If one of these chimeric polypeptides connected, the drug takes the features that drugs alone do not possess. Most drugs do not dissolve in water, its capacity limits are supported by the cells. But since he is bound to a nanoparticle, the drug soluble.

"If these two elements are combined in a container to collect spontaneously, even in a water-soluble nanoparticles," said Chilkoti. "In addition, self-assembly consistently and reliably in a size of 50 nanometers, or making it ideal for cancer therapy. Because of many chemotherapeutic agents are insoluble, we believe that this new approach might work for them too. "

Recent experiments involving doxorubicin, a drug widely used to treat blood cancers, breast, ovaries and other organs. The researchers injected mice with tumors subcutaneously or with the chimeric polypeptide doxorubicin in combination with doxorubicin alone or implanted.

The mice treated with doxorubicin alone had a mean tumor size 25 times larger than the new ones are treated with the combination. The average survival time of mice treated with doxorubicin was 27 days compared to more than 66 days for mice, the new formulation.

The Duke researchers are now planning to test the new combination of different types of cancer and tumors growing in various organs. You may also try the combination of these chimeric polypeptides with other insoluble drugs and to test their effectiveness against tumors.