Widely used in biomedical applications due to their superparamagnetic properties and biocompatibility. Commonly employed in targeted drug delivery, where magnetic guidance allows precise accumulation of therapeutics at disease sites, such as tumors. Serve as contrast agents in magnetic resonance imaging (MRI), enhancing image clarity by improving T2 relaxation of water protons. Applied in magnetic hyperthermia treatment, where alternating magnetic fields generate localized heat to destroy cancer cells. Also utilized in bioseparation processes, enabling efficient isolation of biomolecules like DNA, proteins, or specific cells through magnetic separation techniques. Their PEG coating enhances colloidal stability in physiological environments and reduces opsonization, prolonging circulation time in vivo. Additionally, used in environmental applications for removal of heavy metals and organic pollutants from water via magnetic adsorption and easy recovery.