Finally, consider imaging. “If you had a contrast agent to label the cells, that would really improve our ability to decide where to end the surgical margin,” which is extremely important not only for a cure, but also to reduce the impact of what can often be disfiguring procedures, Dr. El-Sayed said.
Explore This Issue
September 2011Key to the realization of these goals is successful targeting. “My day-to-day focus is to figure out how to functionalize the particles so that they can be used in these various biological applications,” Dr. El-Sayed said. Of the possible mechanisms to explore, the epidermal growth factor receptor (EGFR), a target that is over expressed in 90 percent of oral squamous cell carcinomas, seems the best bet. “The nanoparticles will still have to travel through a number of (physiologic) barriers to reach the target,” said Dr. El-Sayed. He’s convinced, however, that nanotechnology in head and neck cancer is not an “if” but a “when.”
We could actually reduce the dose of radiation that we have to give to the patient.”
—Ivan El-Sayed, MD
When Is Now
For recent progress in targeted nanoscale therapy in head and neck cancer, look no further than the Journal of Oral Maxillofacial Surgery. (Ward BB, Dunham T, Majoros IJ, et al. Targeted dendrimer chemotherapy in an animal model for head and neck squamous cell carcinoma [published online ahead of print June 17, 2011].) The article describes a study conducted by Brent Ward, DDS, MD, and colleagues at the University of Michigan in Ann Arbor. Dr. Ward is an assistant professor and fellowship program director at the Michigan Nanotechnology Institute for Medicine and Biological Sciences and the department of oral and maxillofacial surgery at the University of Michigan.
“Whether head and neck surgeons or otolaryngologists or general surgeons, my colleagues all have an interest in limiting toxicity and in organ-sparing therapies,” said Dr. Ward, who thinks the nanotechnology platform being researched at his institute might be just versatile enough to fit the bill.
Dr. Ward is working with a multidisciplinary team of chemists, immunologists, biologists and physicists to develop dendrimers, which are 5 nm-diameter polyamidoamine, spherical constructs (the size of a hemoglobin molecule) that are amenable to multiple targeting moieties. “With this we have the ability to conjugate functional arms,” targeting folic acid receptors, EGFR or molecules sensitive to imaging modalities, for example, he said.
For therapeutics, “the power of this device is that we can look at a tumor, ID the receptors that are available and then target that specific tumor type based on its receptor availability,” he said. Heightened efficacy and reduced toxicity are the results.