Tumor-targeted Gd-doped mesoporous Fe(3)O(4) nanoparticles for T(1)/T(2) MR imaging guided synergistic cancer therapy

In this study, a novel intelligent nanoplatform to integrate multiple imaging and therapeutic functions for targeted cancer theranostics. The nanoplatform, DOX@Gd-MFe(3)O(4) NPs, was constructed Gd-doped mesoporous Fe(3)O(4) nanoparticles following with the doxorubicin (DOX) loading in the mesopores of the NPs. The DOX@Gd-MFe(3)O(4) NPs exhibited good properties in colloidal dispersity, photothermal conversion, NIR triggered drug release, and high T(1)/T(2) relaxicity rate (r(1)=9.64 mM(−1)s(−1), r(2)= 177.71 mM(−1)s(−1)). Benefiting from the high MR contrast, DOX@Gd-MFe(3)O(4) NPs enabled simultaneous T(1)/T(2) dual-modal MR imagining on 4T1 bearing mice in vivo and the MR contrast effect was further strengthened by external magnetic field. In addition, the DOX@Gd-MFe(3)O(4) NPs revealed the strongest inhibition to the growth of 4T1 in vitro and in vivo under NIR irradiation and guidance of external magnetic field. Moreover, biosafety was also validated by in vitro and in vivo tests. Thus, the prepared DOX@Gd-MFe(3)O(4) NPs would provide a promising intelligent nanoplatform for dual-modal MR imagining guided synergistic therapy in cancer theranostics.