The effectiveness of magnetic nanoparticles in various applications is enhanced through the use of suitable coatings. In addition to providing increased stability of the nanoparticles in different solvents or media, many of these coatings are designed to incorporate tailored functional moieties which yield magnetically responsive systems. In this work, magnetic iron oxide nanoparticles coated with citric acid, that show differences in their stability, magnetic properties and heating characteristics have been synthesized by the co-precipitation method. The nanoparticles obtained were further functionalized with poly(ethylene glycol) dimethacrylate based polymers using atom transfer radical polymerization. The nanoparticles were characterized using fourier transform infrared, transmission electron microscopy, x-ray diffraction, dynamic light scattering, thermo-gravimetric analysis, vibrational sample magnetometry, and magnetic induction heating.