June 26, 2006 Coated Virus Nanoparticles Boost MRI Signals Virus
particles, with their well-characterized nanoscale structures
and ease of large-scale production, have become a popular tool
for cancer nanotechnology researchers (click here for earlier
stories) aiming to develop targeted antitumor therapies. A new
study, published in the journal Nano Letters, adds to this
growing toolbox with the demonstration that a bacterial virus,
known as a bacteriophage, can be turned into a powerful magnetic
resonance imaging (MRI) agent. Kent Kirshenbaum, Ph.D., and
colleagues at New York University School of Medicine, used the
outer coat of the bacteriophage virus, known as MS2, as their
base nanoparticle. This protein shell, which the investigators
mass-produced in a genetically engineered strain of E. coli,
contains 180 identical proteins that self-assemble into a
27.4-nanometer-diameter particle. Using a fluorescent dye as a
marker, the investigators then determined that there are 1,080
identical chemically reactive