New technology may someday be the preferred method for treating cancer
U.S. Department of Energy's Ames Laboratory scientist, Surya Mallapragada is in charge of research that designs and creates nanoscopic polymers to be used for drug/DNA delivery to patients with cancer or diseases.
Both gene and drug delivery are branches of Materials Science and are useful for sustained delivery, or steady release over a desired period time. The both utilize polymers as a means of transport. To visualize a polymer, imagine an ordinary metal chain. Each chain is made up of the same link, repeated over and over for a necessary length. Polymers are composed of the same configuration of chemicals, called monomers (the links), that are repeated over the necessary length to comprise the polymer (the chain).
Gene delivery involves encasing DNA in a polymer, and wrapping it in a coating suitable to its purpose. In the case of cancer, the coating’s job is to blend the polymer into the bloodstream, and encode itself to be released on contact with cancer. The transmitted DNA then causes the cancer to undergo apoptosis, or programmed cell death.
Drug delivery is very similar, except that, as the name suggests, a drug or a vaccine is placed in the polymer. Since the vaccine is encased in the polymer, it won’t be released all at once, but over a period of time instead. For example, to treat the influenza virus, the polymer is coated with a sugar, which the bloodstream attacks, which releases the drugs to apoptosize the virus. The polymer itself safely dissolves in the bloodstream.
These polymers are adjuvants, or chemical enhancers. The proper adjuvant, when coupled with a vaccine, can speed up, extend, or strengthen the effects of the vaccine being used. Aluminum salts are common adjuvants added in the vaccination against tetanus, diphtheria, and Hepatitis B. Mallapragada’s lab uses the influenza virus as their control to test their polymer’s effectiveness.
The puzzle for her team to solve in this research is how to make the proper polymer to suit the situation. These polymers are responsible for transporting a gene or drug, and residing in the human body without causing damage to any surrounding tissue.
Using polymers for drug delivery has widespread use in everyday life now. Mallapragada says,
“Drug delivery is very common now. There are so many devices for it. That’s what the nicotine patch is. That’s what makes pills like allergy medications last for 24 hours. And there are polymers to speed up the delivery as well as delay it.”
“Polymers are very effective at delivering small molecules, like nicotine. Delivering large molecules like protein and DNA is more difficult. Gene delivery is a newer field, but we are making a lot of progress every year.”
Mallapragada says that 75 percent of the research done for gene delivery is for cancer.
There is a lot of testing that is left to be done to prove the safety of using these materials as a means of sustained delivery to the bloodstream. Drug delivery is commonplace in society today. It is likely that gene therapy will share the same distinction someday, with the help of researchers like Mallapragada.
Here is a newly-made batch of polymers created at the U.S.
Department of Energy's Ames Laboratory to transport genes
and drugs to the human bloodstream to treat cancer and
ISU grad student Justin Adams is doing a cytotoxicology test to determine how well the polymer can blend in a biological environment.
The work done here will help in finding new ways
to combat diseases.