A new type of nanoparticle actively seeks out cancer cells, then automatically assembles itself into clumps large enough to clearly show up on MRI scans.
Researchers at Imperial College London created the nanoparticle to increase both the sensitivity and specificity of MRI in detecting small, early-stage tumors. Nicholas J. Long, PhD, the Sir Edward Frankland BP Chair of Inorganic Chemistry, explained the group’s intent:
By improving the sensitivity of an MRI examination, our aim is to help doctors spot something that might be cancerous much more quickly. This would enable patients to receive effective treatment sooner, which would hopefully improve survival rates from cancer.
The nanoparticle is coated with a protein that seeks out tumors. Interaction with the cancerous cells strips off the protein . That causes the nanoparticles to “self-assemble,” aggregating into larger particles that show up well under MRI. Testing in vitro and in mice determined that the combined particles get large enough to do their job but don’t become too big.
“We’re now looking at fine-tuning the size of the final nanoparticle so that it is even smaller but still gives an enhanced MRI image,” said Juan Gallo, PhD, lead author of the article and a research associate in the Imperial College chemistry department. “If it is too small the body will just secrete it out before imaging, but too big and it could be harmful to the body. Getting it just right is really important before moving to a human trial.”
The researchers have additional ambitions, according to Dr. Long: “We would like to improve the design to make it even easier for doctors to spot a tumor and for surgeons to then operate on it. We’re now trying to add an extra optical signal so that the nanoparticle would light up with a luminescent probe once it had found its target, so combined with the better MRI signal it will make it even easier to identify tumors.”
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