March 13, 2009 A PhD candidate from the Harvard-MIT Division of Health Sciences and Technology (HST) has pioneered some innovative new treatments in the emerging field of nanomedicine that could aid in the fight against cancer. Geoffrey von Maltzahn's polymer-coated gold ‘nano-antennas’ are designed to be injected into the bloodstream to target and destroy cancerous tumors.
Cancer is one of the leading causes of death in our modern society, with over a million people diagnosed every year. Despite the huge amount of money and resources that have been invested into finding effective ways to treat cancer, the complexity of the disease in its many manifestations has meant a cure has been elusive. The most common forms of cancer treatment, such as chemotherapy, are designed to kill the fast-growing cells that form a malignant tumor, but these end up attacking many of the body’s naturally growing cells as well as not being thorough in their attack on cancerous cells.
Von Maltzahn's new method involves injecting nanomaterials, which are materials on the scale of one ten thousandth of a millimeter, into the bloodstream. These tiny gold 'nano-antennas' gradually concentrate at the site of the tumor by infiltrating pores in rapidly growing tumor blood vessels. Near-infrared light can penetrate the surface of the skin, and shining it on these nanoparticles causes them to convert the light energy into heat, heating up the particles and destroying the cancer cells they have conglomerated around. Using this method researchers have been able to target and completely remove one hundred percent of tumors in laboratory mice, without harming any healthy cells surrounding the tumor.
Von Maltzahn has also pioneered a second nanoparticle-based invention designed to utilize a more natural approach to seek and deliver therapeutics to cancer in the body. Looking to the swarming activities of ants, he has designed a simple set of particles that communicate with each other whilst in the body and collaboratively detect and destroy cancers. One particular two-step approach that he has demonstrated involves harmless 'scout' particles that travel around the body with the goal of finding and broadcasting the location of cancer cells. Secondary 'assassin' particles can pick up the broadcast and target the area in question with large and localized doses of therapeutic drugs. Von Maltzahn claims that this method can deliver over 40 times the regular dose to affected areas.
“If such highly-targeted delivery can be achieved clinically, this method would enable doctors to increase the drug dose that is delivered to tumors, increasing its overall efficacy and reducing side-effects,” Von Maltzahn explains. “This concept of engineering systems of nanoparticles that collectively outsmart disease barriers has many potential applications in medicine, from improving regenerative medicines to ultra-sensitive diagnostics.”
All this innovation has not gone unnoticed by the scientific community. Thanks to these inventions, Geoffrey von Maltzahn was awarded the Lemelson-MIT Student Prize for Inventions.
Stephen Saunders
