U.K. researchers enhance tracking for stem cell injections   One
of the challenges with testing stem cells as treatments is that
they are hard to track in the body, to clearly determine if
they've survived implantation, reached where they were supposed
to go or strayed somewhere else. University of Liverpool
researchers in the U.K. believe that they've solved the problem,
and their breakthrough study is published in the journal ACS
Nano.  A partial solution is already in use. According to the
researchers, the scientists use superparamagnetic iron oxide
nanoparticles (SPION) to tag the cells when injecting them into
a patient, and then MRI scans pick them up, creating some way to
track the cells to see if they reach their goal. But the body's
cells can degrade the SPIONs and make it harder for them to be
tracked, the researchers explain.  The Liverpool scientists'
solution includes developing ways to visualize SPIONs in the
cells before they enter the body. That way, the idea is to both
track where they go wit