BSA-functionalized MnFe2O4 nanoassemblies as a multifunctional platform for chemo-photodynamic therapy with magnetic heating and MRI contrast capabilities

Multifunctional nanoplatforms capable of integrating therapy and imaging functions are of significant interest for cancer research. In this work, we report the synthesis of bovine serum albumin (BSA)-functionalized manganese ferrite nanoassemblies (MnFe 2 O 4 @BSA NAs) as a multifunctional platform for chemo-photodynamic therapy and magnetic functionality. Ethylenediamine-modified MnFe 2 O 4 nanoassemblies were first prepared via a thermal decomposition route and subsequently conjugated with BSA to improve aqueous stability, biocompatibility, and drug-loading capability. The resulting nanoassemblies exhibited well-defined morphology (50–60 nm), good colloidal stability, and superparamagnetic behavior that was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, zeta-potential, DLS and magnetic measurements. The anticancer drug doxorubicin hydrochloride (DOX) and the photosensitizer Rose Bengal (RB) were successfully loaded into MnFe 2 O 4 @BSA NAs, showing high loading efficiency and pH-responsive DOX release. Under visible-light irradiation, RB-loaded MnFe 2 O 4 @BSA NAs generated reactive oxygen species (ROS) through combined photodynamic and photo-Fenton-like processes. In vitro studies using MCF-7 breast cancer cells demonstrated that the combined RB-DOX-loaded MnFe 2 O 4 @BSA NAs exhibited enhanced cytotoxicity under light irradiation compared to individual chemotherapy or photodynamic therapy, indicating a synergistic chemo-photodynamic effect. Moreover, MnFe 2 O 4 @BSA NAs showed good heating efficacy under an AC magnetic field and significant signal reduction on the T 2 -weighted phantom image with transverse relaxivity ( r 2 ) of 123.7 mM −1 s −1 . Overall, this study presents MnFe 2 O 4 @BSA NAs as a multifunctional in-vitro platform integrating drug delivery, photodynamic activity, magnetic heating, and MRI contrast properties, providing a foundation for future image-guided and in vivo therapeutic investigations.