If all goes according to plan, more veterinarians will use nanoparticles coated in gold to shrink feline soft tissue tumors and improve other cancer modalities. The process, which injects particles that measure in nanometers into tumors, mimics hyperthermia, and is “an end to a means,” said Kevin Hahn, DVM, PhD, DACVIM.

The value of hyperthermia partnered with radiation and chemotherapy has proven to be effective, but doctors seldom use it because of the messy, time-consuming process, Hahn said. “It makes you feel like you’re back in the Renaissance age,” he said of hyperthermia, which entails sticking probes into a tumor. With nanorice, pets get the benefits of hyperthermia without the bloody mess, added Hahn, who is testing nanorice on at least 10 cats in Texas. “We’re letting technology do the work.”

The first stage of the testing, which began in January 2006, will assess how well nanorice penetrate soft tissue tumors. Nanorice, particles named for Rice University researchers, “will increase the effectiveness of other anti-cancer modalities,” Hahn said. “We know what it’s going to do. [We’re assessing] proper dosing and delivery schemes,” he added.

Inserted through an IV catheter, nanorice – also called auroshells – remain inert until activated by ultrasound. When activated, particles vibrate and create heat, which augments cell damage, Hahn explained. To date, there have been no reported complications with at least seven client-owned cats injected with nanorice.

After nanorice is injected using IV catheters, cats are kept in room temperature conditions to maintain blood vessel size. Twenty-four hours later, the tumor is removed and reviewed for nanorice dispersion. The goal is uniform distribution of the particles so that all portions will have the same elevated temperature once activated by ultrasound, Hahn said.

In the future, Hahn plans to inject auroshells into cats with soft tissue tumors and activate them during radiation therapy. "This will accelerate the shrinkage of the tumor, making surgical removal and the long-term prognosis favorable for the cat," he told NEWStat.