FDA Prepares for Nanomedicine Revolution
Atomic-Scale Nanoparticles Promise New Era in Medicine
What Is Nanomedicine? continued...
"Just a few decades ago, a computer used to be the size of a room," says Marth. "Now everyone has a laptop. It's the same thing in biology. We are seeing the miniaturization of biology, which will rapidly change the way we do research and develop drugs."
By allowing scientists to take such a close look at biological processes, nanotechnology offers new tools to understand what causes disease. We've been able to learn a lot by cracking the DNA code. But genetics doesn't tell us all the biology we need to know.
"We have not been able to answer all of the questions about a lot of important diseases -- grievous diseases such as diabetes, cardiovascular disease, diseases of aging, cancer. All these diseases have some genetic underpinning, but the genetic role is partial," says Marth. "What nanomedicine is able to do is to begin to identify and interrogate those processes which are outside our genetic inheritance."
That's only part of the story. Nanotechnology also offers powerful new tools to treat disease.
The FDA already has approved two cancer drugs based on nanotechnology: Abraxane and Doxil, which package cancer drugs into nanoscale lipid droplets and allow higher chemotherapy doses with fewer side effects.
Second-generation drugs of this type will carry nanoparticles on their surfaces that not only target the drugs to cancer cells, but also allow them to penetrate deep into tumors. The FDA has given the green light to clinical trials of Cornell dots -- nanoscale silicon cages that carry nanoparticles to tumor cells.
Marth says that nanomedicine will speed the discovery of biomarkers that identify diseased cells. Once these biomarkers are found, they can be used to bind therapeutic nanoparticles only to the cells that need them, leaving normal cells alone.
Bao's team is pioneering another approach: using nanoparticles to repair genetic mutations. Their first target will be the mutation that causes sickle cell disease.
"We are trying to develop nanodevices to fix this mutation," Bao says. "We use a nanoscissors -- technically a zinc finger nuclease -- to cut the DNA at a pre-described location. At the same time, we supply a piece of DNA that has no mutation. In repairing the DNA cut, the cell actually uses the template we supply."