PROCEEDINGS ARTICLE | March 15, 2013
Proc. SPIE. 8596, Reporters, Markers, Dyes, Nanoparticles, and Molecular Probes for Biomedical Applications V
KEYWORDS: Near infrared, Cancer, Nanoparticles, Polymers, Luminescence, Semiconductor lasers, Laser irradiation, Cell death, In vitro testing, Ovarian cancer
Optical nano-materials present a promising platform for targeted molecular imaging of cancer biomarkers and its
photodestruction. Our group is investigating the use of polymeric nanoparticles, loaded with indocyanine green, an FDA-approved
chromophore, as a theranostic agent for targeted intraoperative optical imaging and laser-mediated destruction
of ovarian cancer. These ICG-loaded nanocapsules (ICG-NCs) can be functionalized by covalent attachment of targeting
moieties onto their surface. Here, we investigate ICG-NCs functionalized with anti-HER2 for targeted fluorescence
imaging and laser-mediated destruction of ovarian cancer cells in vitro. ICG-NCs are formed through ionic cross-linking
between polyallylamine hydrochloride chains and sodium phosphate ions followed by diffusion-mediated loading with
ICG. Before functionalization with antibodies, the surface of ICG-NCs is coated with single and double aldehyde
terminated polyethylene glycol (PEG). The monoclonal anti-HER2 is covalently coupled to the PEGylated ICG-NCs
using reductive amination to target the HER2 receptor, a biomarker whose over-expression is associated with increased
risk of cancer progression. We quantify uptake of anti-HER2 conjugated ICG-NCs by ovarian cancer cells using flow
cytometery. The in-vitro laser-mediated destruction of SKOV3 cells incubated with anti-HER2 functionalized ICG-NCs
is performed using an 808 nm diode laser. Cell viability is characterized using the Calcein and Ethidium homodimer-1
assays following laser irradiation. Our results indicate that anti-HER2 functionalized ICG-NCs can be used as theranostic
agents for optical molecular imaging and photodestruction of ovarian cancers in-vitro.