Activatable MRI-monitoring gene delivery for the theranostic of renal carcinoma

Multifunctional nanocarriers, which can be used for molecular imaging and drug delivery simultaneously, favor the fabrication of theranostic platforms in a less cost- and time-consuming way. Polyethylene glycol (PEG) modified manganese dioxide (MnO2) nanosheets (PEG-MnO2), used as two-dimensional nanomaterials, not only possess the high surface-to-volume ratio necessary for drug delivery but also display a redoxable property in the tumor microenvironment, producing Mn2+ ions for magnetic resonance imaging (MRI). In this study, we constructed a PEG-MnO2-OPN siRNA nanocomplex via a modular streptavidin bridge for the theranostic treatment of renal carcinoma in vitro and in vivo. This strategy of utilizing PEG-MnO2 nanosheets for OPN siRNA delivery showed effective tumor growth inhibition of 786-O tumor-bearing mice, and such a process could be monitored by the activated T-1-weight MRI, illustrating the promising potential of PEG-MnO2 nanosheets for the fabrication of an MRI-based theranostic system.