OBJECTIVETo study the feasibility of MRI of human colon adenocarcinoma cell line (Lovo) labeled with superparamagnetic iron oxide(SPIO) nanoparticles in vitro.

METHODSLovo cells (5 × 10(5) and 1 × 10(6)) were cultured in medium containing different SPIO nanoparticles (50 microl and 500 microl). Transmission electron microscopy was used to observe cellular ultrastructure and to determine the uptake and distribution of particles in Lovo cells at 1-, 3-, 6-hours. MRI of Lovo cells was performed with T1WI, T2WI sequences. Unlabeled cells were used as controls.

RESULTSUptake of SPIO nanoparticles occurred within 6 hours. On T1 weighted imaging, there was no significant difference in signal intensity between the experimental groups and the control group. On T2 weighted imaging, there was no significant difference in signal intensity between the experimental groups and the control group after culture of 1 h. Signal intensity began to decrease in 1 × 10(6) Lovo cells labeled with 500 microl SPIO nanoparticle after 3 hours culture. Signal intensity decreased in all the experimental groups after 6 hours culture.

CONCLUSIONHuman colon adenocarcinoma cell line (Lovo) can be labeled with SPIO nanoparticles, and the labeled cells can be imaged with MRI equipment.