Abstract
Nanotheranostics integrates diagnostic and therapeutic functions within a single plat-form, representing a compelling strategy for personalized cancer therapy. Magnetic iron oxide nanoparticles are intrinsic suitable for imaging and hyperthermia. However, insuf-ficient colloidal stability in physiologic environment as well as a lack in surface function-ality often limit their application in biomedicine. In this work, we address these limitations by developing drug-loaded polymeric magnetic nanohybrids (pMNHs) stabilized by nu-cleobase-functionalized copolymers that serve as both stabilizing agents and drug carri-ers. Hydrophilic copolymers were synthesized via RAFT polymerization and functional-ized with cytosine and guanine. MNPs were prepared by continuous micromixer-assisted co-precipitation, followed by copolymer self-assembly to form stable pMNHs. Physico-chemical and magnetic characterization assessed their suitability for magnetic resonance imaging (MRI), magnetic particle imaging (MPI), and therapeutic magnetic hyperthermia. Polymer stabilization largely preserved magnetic performance, reducing the magnetic par-ticle spectroscopy (MPS)-derived A3* by 22% while changing A5/A3 by < 1%, and enhanced salt stability without further impairing the magnetic response. Following successful dox-orubicin (Dox) loading, the pMNHs showed evidence of cellular uptake while maintain-ing approximately 90% viability in HeLa cells across the tested Dox concentration range of 0.2–20 µM. Radiofrequency exposure induced a Dox-characteristic spectral change with-out substantially affecting the magnetic response, providing preliminary evidence for ex-ternally triggered Dox release. These findings establish nucleobase-functionalized pMNHs as effective platforms for cancer theranostics.