  Purpose: Pulsed-laser irradiation of light-absorbing gold nanoparticles
(AuNPs) attached to cells transiently increases cell membrane permeability for
targeted molecule delivery. Here, we targeted EGFR on the ovarian carcinoma
cell line OVCAR-3 with AuNPs. In order to optimize membrane permeability and to
demonstrate molecule delivery into adherent OVCAR-3 cells, we systematically
investigated different experimental conditions. Materials and methods: AuNPs
(30 nm) were functionalized by conjugation of the antibody cetuximab against
EGFR. Selective binding of the particles was demonstrated by silver staining,
multiphoton imaging, and fluorescence-lifetime imaging. After laser
irradiation, membrane permeability of OVCAR-3 cells was studied under different
conditions of AuNP concentration, cell-incubation medium, and cell - AuNP
incubation time. Membrane permeability and cell viability were evaluated by
flow cytometry, measuring propidium iodide and fluorescein isothiocyanate -
dextran uptake. Results: Adherently growing OVCAR-3 cells can be effectively
targeted with EGFR-AuNP. Laser irradiation led to successful permeabilization,
and 150 kDa dextran was successfully delivered into cells with about 70%
efficiency. Conclusion: Antibody-targeted and laser-irradiated AuNPs can be
used to deliver molecules into adherent cells. Efficacy depends not only on
laser parameters but also on AuNP:cell ratio, cell-incubation medium, and cell
- AuNP incubation time.
