Evaluation of casein coated iron oxide magnetic nanoparticles

Theranostic systems offer a promising approach for early cancer diagnosis and treatment. Here we report the investigation of Na-caseinate-coated iron oxide magnetic nanoparticles (MNP) for potential use in theranostics. The MNP were synthesized in a continuous flow, coated with Na-caseinate, and crosslinked enzymatically for improved stability and drug loading. To evaluate their magnetic suitability for magnetic particle imaging (MPI) and hyperthermia, we conducted DC magnetization measurements, magnetic particle spectroscopy (MPS), and AC-magnetometry. Results show that Na-caseinate coating has minimal impact on magnetic behavior, with a stable magnetization saturation (Ms) of 109(5) A·m²/kg(Fe) for both coated and uncoated particles. The MPI signal (A3*) decreased by less than 15%, with a slight 2% drop in the A5/A3 ratio. Additionally, Na-caseinate coating improved salt stability without altering magnetic performance, supporting their potential for theranostic applications in drug delivery, MPI, and hyperthermia.