Tiny sponges built the size of viruses and encapsulated with chemicals that link specifically to tumor cells were used to deliver cancer drugs in a new study undertaken at Vanderbilt University. And the researcher leading the work says that the nanosponge approach proved three to five times better at reducing tumor activity when compared to the direct injection of therapeutics in a recent animal study.
"We call the material nanosponge, but it is really more like a three-dimensional network or scaffold," says Eva Harth, assistant professor of chemistry at Vanderbilt. "The backbone is a long length of polyester. It is mixed in solution with small molecules called cross-linkers that act like tiny grappling hooks to fasten different parts of the polymer together. The net effect is to form spherically shaped particles filled with cavities where drug molecules can be stored. The polyester is biodegradable, so it breaks down gradually in the body. As it does, it releases the drug it is carrying in a predictable fashion."
Harth's nanosponges are 50 nanometers in size, she explains, a tiny size that is essential in improving the delivery of therapeutics. In the animal study, Harth reported success in reducing tumor activity in mouse models for breast cancer and glioma. The nanosponge was loaded with paclitaxel, a well known chemotherapy drug. And now she plans to start toxicity studies as well as a new animal study to see if the new approach can trigger tumor shrinkage.
The Department of Defense, National Science Foundation and National Institutes of Health have all helped fund the work at Vanderbilt.
- here's the story from Vanderbilt University