Folic acid (FA) has been used for drug targeting to cancer cells since the folate receptor is significantly overexpressed on the surface of human cancer cells [12] and [13]. The folate receptor-mediated drug delivery is based on the conjugation of drug with folic acid, which is internalized by folate receptor-mediated endocytosis. Furthermore, the attachment of drug to folic acid does not normally interferer with the binding of folate for its receptor. Folic acid has been immobilized on superparamagnetic magnetite [14], polymer nanoparticles [15], or incorporated to a dendrimer-based therapeutic nanodevice [16] for tumor cell-selective targeting. In the present study, folic acid was coupled on the surface of TiO2 for the selective binding to cancer cells.