Gold nanorods (GNR) with a peak absorption wavelength of 760 nm were prepared using a seed-mediated method. A
novel protocol has been developed to replace hexadecyltrimethylammonium bromide (CTAB) on the surface of GNR
with 16-mercaptohexadecanoic acid (MHDA) and metoxy-poly(ethylene glycol)-thiol (PEG), and the monoclonal
antibodies: HER2 or CD33. The physical chemistry property of the conjugates was monitored through optical and zetapotential
measurements to confirm surface chemistry. The plasmon resonance is kept in the near infrared area, and
changes from strong positive charge for GNR-CTAB to slightly negative for GNR-PEG-mAb conjugates are observed.
The conjugates were investigated for different cells lines: breast cancer cells and human leukemia lines in vivo
applications. These results demonstrate successful tumor accumulation of our modified PEG-MHDA conjugates of GNR
for HER2/neu in both overexpressed breast tumors in nude mice, and for thermolysis of human leukemia cells in vitro.
The conjugates are non-toxic and can be used in pre-clinical applications, as well as molecular and optoacoustic imaging,
and quantitative sensing of biological substrates.
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