Self-template synthesis of mesoporous and biodegradable FeO nanospheres as multifunctional nanoplatform for cancer therapy.

Superparamagnetic FeO nanospheres have demonstrated great potential as important components in nanomedicine for cancer imaging and therapy. One of the major obstacles that impedes their application is the slow degradation of ingested FeO nanospheres, which potentially causes long-term health risks. To tackle this issue, we proposed to fabricate FeO nanospheres with mesoporous structure via a simple self-template etching method. The mesoporous FeO nanospheres not only offered large specific surface area and weak-acidic responsive degradability, but also exhibited T2-weighted magnetic resonance contrast enhancement and magnetic targeting, which made them possible to serve as excellent cancer therapeutic nanoplatform. Both inorganic photothermal therapeutic Au nanoparticles and organic chemotherapeutic doxorubicin hydrochloride were demonstrated to be successfully loaded onto such kind of nanoplatform, and the hybrid nanomedicine demonstrated synergistic photothermal and chemotherapeutic activity for tumor elimination under near infrared irradiation and improved biodegradability in weak acidic tumor microenvironment. We believe that this study paved a simple way for designing multifunctional FeO-based biodegradable nanomedicine.