PROCEEDINGS ARTICLE | February 25, 2012
Proc. SPIE. 8233, Reporters, Markers, Dyes, Nanoparticles, and Molecular Probes for Biomedical Applications IV
KEYWORDS: Gold, Near infrared, Laser therapeutics, Cancer, Breast cancer, Tumors, Calibration, Luminescence, Cell death, Receptors
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.
