Gold nanoshells with NIR plasmon resonance can be modified to simultaneously enhance conjugated NIR
fluorescence dyes and T2 contrast of embedded iron-oxide nanoparticles, and molecularly targeted to breast and other
cancers. We calibrated the theranostic performance of magneto-fluorescent nanoshells, and contrasted the performance
of molecularly targeted and untargeted nanoshells for breast cancer therapy, employing MCF-7L and their HER2 overexpressing
derivative MCF-7/HER2-18 breast cancer cells as in vitro model systems. Silica core gold nanoshells with
plasmon resonance on ~810 nm were doped with NIR dye ICG and ~10 nm iron-oxide nanoparticles in a ~20 nm epilayer
of silica. A subset of nanoshells was conjugated to antibodies targeting HER2. Cell viability with varying laser
power levels in presence and absence of bare and HER2-targeted nanoshells was assessed by calcein and propidium
iodide staining. For MCF-7L cells, increasing power resulted in increased cell death (F=5.63, p=0.0018), and bare
nanoshells caused more cell death than HER2-targeted nanoshells or laser treatment alone (F=30.13, p<0.001). For
MCF-7/HER2-18 cells, death was greater with HER2-targeted nanoshells and was independent of laser power. This
study demonstrates the capability of magneto-fluorescent nanocomplexes for imaging and therapy of breast cancer cells,
and the advantages of targeting receptors unique to cancer cells.
|