Used in targeted drug delivery systems where the magnetic core allows guidance to specific sites in the body under external magnetic fields, while PEG coating improves biocompatibility and prolongs circulation time. Employed in magnetic resonance imaging (MRI) as contrast agents due to strong superparamagnetic properties enhancing image clarity. Applied in bioseparation processes to isolate cells, proteins, or nucleic acids thanks to easy magnetic separation and reduced non-specific binding from PEG layer. Utilized in hyperthermia treatment for cancer, where alternating magnetic fields generate localized heat to destroy tumor cells. Also used in environmental applications such as removal of heavy metals and organic pollutants from water through magnetic separation after adsorption.