In this study, Superparamagnetic magnetite nanoparticles (SPMNPs) are used in a new way as direct nanocarrier for Doxorubicin hydrochloride (DOX) via the functionalization of their surface with tri-sodium citrate through ligand exchange to conjugate DOX with imine bond to form tri-sodium citrate functionalized magnetite loaded DOX nanoparticles (DOX/Cit-MNPs). The DOX/Cit-MNPs were coated with chitosan to form chitosan coated citrate functionalized magnetite loaded DOX nanoparticles (Cs/DOX/Cit-MNPs) to offer biodegradability and pH-sensitive drug release features. The Fourier transform infrared spectroscopy (FTIR) analysis confirmed functionalization of SPMNPs, DOX-conjugation, and chitosan coating. The trans electron microscopy (TEM) show spherical nanostructures with average size 40 nm for coated nanocarriers. The saturation magnetization value of carrier was 59 emu/g.The in-vitro release of DOX from the chitosan coated tri-sodium citrate functionalized magnetite loaded DOX nanoparticles (Cs/DOX/Cit-MNPs) was studied to be 75% at pH 5.5 and 28.6% at pH 7.4 which proves the pH sensitivity of encapsulated Cs/DOX/Cit-MNPs. The effect of Cs/DOX/Cit-MNPs toward Human Breast Cancer Cell lines (MCF7) was studied and found to be 76% without magnet and 98% with external magnet after 72 h. With increasing DOX concentration and treatment time, the cell inhibition (IR%) of DOX solution and Cs/DOX-Cit-MNPs suspension to all cells is increased. Cs/DOX/Cit-MNPs showed sustained release and good inhibition to cancer cells and offer a protective mode for normal cells (WISH) compared to the free DOX.