By Lara Updike
A BYU research team has invented a method of treating cancer that has great potential to alleviate the painful side effects of chemotherapy.
The method has been tested on rats and could be used on people in three to five years. It combines two new ideas: plastic carriers that contain the toxic drugs so they can flow through the blood without damaging healthy tissues, and the application of ultrasound to release them at the tumor site.
“The experiment that we did was very promising,” said Jared Nelson, a BYU graduate who tested the method for his master”s thesis. “Some types of models we feel it would be most applicable to are colon cancer, the model we used (in our test), as well as breast cancer and ovarian cancer.”
Chemotherapy and excision (operational removal) are still widely used to treat solid tumors though they sicken and deform patients, Nelson said. Specifically, doxorubicin, the drug used when testing the new method, is known to damage the heart, he said.
“It was very encouraging to see very preliminary data to show that there was some protection to the heart when we compared the drug all by itself to the drug within the carrier,” Nelson said. However, he added, “That part of the study wasn”t extremely exhaustive. I don”t know that we could go as far to conclude that there wasn”t any other damage.”
BYU faculty and students continue studying the method, perfecting the procedure and trying it out on other types of cancer and different animals.
“It works really well on rats, but people are really different from rats,” said William Pitt, BYU professor of chemical engineering, who developed the method with Natalya Rapoport, professor of bioengineering at the University of Utah.
Pitt and Rapoport met at a conference in 1993 and discovered a mutual interest in ultrasound”s potential for delivering drugs – antibiotics at first. In 1997, they began studying the delivery of cancer drugs as well.
Together they developed a microscopic carrier for cancer drugs.
“Dr. Rapoport and I are the only ones in the world using this type of plastic carrier,” Pitt said. “It”s a commercial plastic that we buy, but we”ve used it in a way that no one”s thought of using it before.”
When tiny molecules of the water-soluble plastic are introduced into a test tube because of their chemical structure, they naturally form a sphere around the drug molecule.
The carriers, unless disturbed by ultrasound, flow through the blood without interacting with the surrounding tissue until they are flushed out through the kidneys.
Before they”re flushed out, a doctor can shine ultrasound on a tumor, causing the carriers to break apart and release the doxorubicin.
“We showed that the drug was released only where we shined the ultrasound and not anywhere else,” Pitt said.
The ultrasound is applied from on top of the skin, so there is no pain and no surgery. The ultrasound waves also make the cancer cells more permeable to the drug. After the ultrasound is stopped, the carriers spontaneously reform.
