Zhang and his team are also learning the surface characteristics of the particles that would help the nanoparticles get past the body's defense system. And by creating particular surface that would bind with certain types of cells, the nanoparticles could be used as magnetic tracers to detect cancers.

Finally, the particles must be chemically stable enough so that they are not quickly broken down inside the body.

Zhang and his team have used magnetic CoFe2O4 spinel ferrite nanoparticles, synthesized by a microemulsion method using sodium dodecyl sulfate as a surfactant to form micelles. There are many other chemical systems that can be used to produce magnetic nanoparticles, so a future goal is extend the understanding to other systems. That would provide additional flexibility and allow the cost of reagents to be factored into the equation.

Potential uses for the magnetic nanoparticles include:

• Delivery of drugs to specific areas of the body. Magnetic nanoparticles containing drugs could be attracted to specific areas of the body by applying a magnetic field. Concentrating the particles in areas requiring treatment would enhance the therapeutic benefits while reducing side effects on other areas of the body.
  
  
• Improving the quality of magnetic resonance imaging. MRI sometimes does not provide enough contrast to enable good understanding of structures such as tumors. Addition of the magnetic particles could improve contrast between structures.
  
  
• Replacement of radioactive materials used as tracers. Radioactive materials are now attached to drugs as tracers. Physicians can then determine
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