Efficient In Vitro Labeling of Human Prostate Cancer Cells with Superparamagnetic Iron Oxide Nanoparticles

The purpose of this study was to investigate the feasibility and optimization of protocols using superparamagnetic iron oxide (SPIO) nanoparticles to label human prostate cancer cell lines PC3 in vitro. The PC3 cells were labeled with different concentrations (28-252 mu g Fe/mL) of SPIO and increasing incubation time (6-24 hours), in the presence or absence of a transfection agent poly-l-lysine (PLL). The cell labeling efficiency was analyzed by Prussian blue stain method. The cellular viability was evaluated using trypan blue dye exclusion test. The signal intensity change of the labeled cells was assessed with magnetic resonance imaging (MRI). The results demonstrated that the iron oxide uptake by PC3 cells was dependent on dose and time. The PLL significantly increased the iron load of cells (p < 0.01). A final concentration of SPIO nanoparticles of 42-126 mu g/mL with 12-24 hours incubation times could be sufficient to label PC3 cells for cellular MRI without impairment of cell viability. This technology may allow for further study into the mechanisms underlying prostate cancer progression as well as permit the real-time imaging of the effectiveness of cancer therapies in vivo.