Multifunctional γ-Fe2O3/ZIF-8 Composite for Combined Magnetic Hyperthermia and 177Lu/161Tb Radionuclide Therapy

Abstract

γ-Fe2O3/ZIF-8(B) hybrid nanostructures were engineered as multifunctional theranostic platforms capable of integrating magnetic hyperthermia and dual-radionuclide therapy using 177Lu and 161Tb. The composites were synthesized through a seed-mediated growth route, while two ZIF-8 fabrication pathways (HDS-assisted and methanolic) were evaluated to optimize structural and radiochemical performance. The resulting γ-Fe2O3/ZIF-8(B) composites retained superparamagnetic behavior and exhibited high specific loss power (SLP), confirming their efficiency under alternating magnetic fields. Radiolabeling yields exceeded 95% under mild conditions, and the labeled hybrids demonstrated >90% stability over 14 days. FT-IR and DFT analyses revealed that radiolanthanides coordinate primarily with imidazolate nitrogen atoms at surface or defect sites, forming stable inner-sphere complexes. Electrostatic potential mapping identified nucleophilic regions within ZIF-8 pores that promote strong electrostatic interactions with Lu3+ and Tb3+ ions. These results demonstrate a scalable and modular strategy for constructing multifunctional nanoplatforms that combine magnetic hyperthermia and stable radionuclide incorporation within a single architecture.