The specific targeting of intracellular proteins or organelles by magnetic nanoparticles (MNPs) is a major challenge in nanomedicine, as most MNPs are internalized by cells through endocytosis and remain trapped inside small intracellular vesicles, limiting their ability to reach intracellular components. Furthermore, this phenomenon limits their heating capacity in magnetic hyperthermia, and therefore their potential for cancer treatment. This study presents a strategy based on an original double functionalization of MNPs, with polyhistidine peptides (PHPs) triggering endosomal escape and antibodies targeting specific cytosolic proteins. Negatively charged γ-Fe