PMC

Schema for the synthesis of immuno-HAuNS bioconjugates.

(A) Darkfield microscopic images of the perivascular area of tumor slices from A431 tumors of mice injected with C225-HAuNS and IgG-HAuNS. Gold nanoshells were pseudocolored green. Cell nuclei were stained with DAPI (blue). (B) Graph of the particle counts per viewing field under darkfield (×200, n = 5). Data represent means ± SD. *P < 0.01 compared with C225-HAuNS.

Biodistribution of ¹¹¹In-labeled DTPA-C225-HAuNS and DTPA-IgG-HAuNS. Uptake in the liver was significantly higher with ¹¹¹In-DTPA-C225-HAuNS than with ¹¹¹In-DTPA-IgG-HAuNS (P = 0.001). Tumor uptake was higher with ¹¹¹In-DTPA-C225-HAuNS than with ¹¹¹In-DTPA-IgG-HAuNS, but the difference was not statistically significant (P = 0.08). The data are expressed as means of percentage of injected dose per gram of tissue (%ID/g) ± standard derivation (n = 4).

Selective binding of anti-EGFR-conjugated HAuNS to A431 cells. A431 cells were seeded onto a 96-well plate and incubated with C225-HAuNS (7.3 × 10¹⁰ particles/mL), IgG-HAuNS (7.3 × 10¹⁰ particles/mL), or C225 (500 μg/mL) plus C225-HAuNS for 30 min at 37°C. Only cells incubated with C225-HAuNS had a strong light-scattering signal. Cells were stained with DAPI for visualization of cell nuclei (blue). Light-scattering images of nanoshells were pseudocolored green. Original magnification: ×630.

(A) Transmission electron micrographs of the plain HAuNS (left) and C225-HAuNS (right) reveal the morphology of hollow gold nanoshells. The images also show the presence of a layer of C225 antibody coating on the shells of HAuNS. (B) Absorption spectra of the HAuNS showing the plasma resonance peak tuned to the NIR region and the blue shift after C225 conjugation. λ_max = 828 nm for HAuNS and λ_max = 810 nm for C225-HAuNS. Scale bar: 50 μm.

(A) Heating of aqueous C225-HAuNS solutions exposed to NIR light centered at 808 nm at 8 W/cm². (B) Cell viability after various treatments. Cells retained normal morphology with no apparent death observed (stained green with calcein CM) when cells were not treated or treated with C225-HAuNS alone, NIR laser alone, or non-targeted IgG-HAuNS plus NIR laser. In contrast, most cells were dead after treatment with C225-HAuNS plus NIR laser. Dead cells were labeled red with ethidium homodimer-1 (EthD-1) Magnification: ×40. (C) Images of untreated viable cells and dead cells treated with C225-HAuNS and NIR laser at higher magnification (×400). The dead cells showed rounded morphology (asterisk) and membrane damage as indicated by positive staining with EthD-1 (arrow, red). DIC, differential interference contrast.