Doxorubicin (DOX) as one of the main chemotherapies used in breast cancer in the form of many dosage forms such as encapsulation within pegylated liposomes and by injection. Both dosage forms have several side effects, most importantly dilated cardiomyopathy, erythema, acral erythema, and others. Also, DOX acquires resistance in dose-dependent manner by time. Consequently, there is an urgent need for novel approaches and strategies to improve current chemotherapeutic agents' delivery systems including DOX. Nanoparticles (NPs) have found their way in almost all aspects of biomedical applications within the last two decades, such as medical diagnostics, imaging, and drug/gene delivery systems. Mesoporous silica NPs are of great interest as an efficient drug/gene delivery system due to their unique properties. In the same context, magnetic nanoparticles contributed significantly to biomedicine, for their apparent features emerging at the nanoscale. Core/shell nanoparticles have potential characteristics as they incorporate the multiple merits of the used nanoparticles. Herein, we have developed multifunctional iron oxide/mesoporous silica/amino; core/shell (M/silica/Amino), by sonochemical method, loaded with DOX as a Drug Delivery System (DDS) for breast cancer treatment.