Lu's laboratory specializes in isolating aptamers that bind to specific molecules and converting them into effective sensors and diagnostic agents. His team used an aptamer that binds to nucleolin receptors, which are found in abundance on certain breast cancer cells. The researchers then developed an effective method for attaching the aptamer to a liposome loaded with cisplatin, a drug that effectively kills cancer cells but has troublesome side effects when administered intravenously.
Tests in cells grown in the lab yielded promising results. Four days after they exposed the cells to the new drug-delivery system, 59.5 percent of the breast cancer cells had died, while less than 12 percent of breast cancer cells treated with cisplatin alone had died.
"By labeling a liposome that contains cisplatin with a cancer cell-specific aptamer, we have shown delivery of the drugs to cancer cells without significant damage to regular cells," Lu said, "making it possible to maximize the drug potency while minimizing its side effects."
This approach "integrates the advantages of small molecules and antibodies," said Cheng, who helped pioneer the use of aptamers as targeting molecules for drug delivery. "This is the first study to integrate the aptamers and the liposome."
Another advantage of using aptamers as targeting agents is that they are easily disabled. They readily bind to complementary DNA, which prevents them from interacting with cell receptors.
The new approach will be useful for many applications, Wong said. "What we're really doing here is coming up with a general toolbox to deal with a broad range of cancers."
"You can change aptamers to target a different
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign