The surface of superparamagnetic iron oxide nanoparticles (SPIO) with different molecular weight of poly(ethylene glycol) (PEG) and folic acid (FA) were synthesized. The SPIO-PEG-FA nanoparticles are well-dispersed and have good stability in various pH solutions. The lack of hysterestis and remanence at ambient temperatures is characteristic of superparamagnetic materials for SPIO-PEG-FA. The uptake by macrophage for SPIO-PEG-FA is lower than that of Feridex I.V. even at higher concentration. Internalization of SPIO-PEG-FA in targeted cells (KB cells) was observed by flow-cytometric analysis and in vitro MR imaging. The intensity change of positive KB cell tumor (-20 to 25%) is significantly lower than that of negative HT-1080 cell tumor from precontrast to postcontrast images of the tumor by in vivo MR imaging. These preliminary results demonstrated that SPIO-PEG-FA have the ability to target folate receptor.
- Contrast agent
- Superparamagnetic iron oxide nanoparticles