Here, a versatile strategy to engineer smart theranostic nanocarriers is reported. The core/shell nanosystem is composed of a superparamagnetic iron oxide (Fe3−δO4) nanoparticle (NP) core bearing the biocompatible thermo-responsive poly(2-(2-methoxy)ethyl methacrylate-oligo(ethylene glycol methacrylate), P(MEO2MAx-OEGMA100−x) copolymer (where x and 100-x represent the molar fractions of MEO2MA and OEGMA, respectively). Folic acid (FA) is end-conjugated to the P(MEO2MAx-OEGMA100−x) copolymer, leading to Fe3−δO4@P(MEO2MAx-OEGMA100−x)-FA, to facilitate active targeting of NPs to cancer cells. A highly potent hydrophobic anticancer agent doxorubicin (DOX) is incorporated in the thermo-responsive P(MEO2MAx-OEGMAy) brushes via supramolecular interactions to increase its solubility and the assessment of therapeutic potentials. These experiments confirm the magnetic hyperthermia properties of nanocarrier and reveal that only a small amount (10% ± 4%) of DOX is diffused at room temperature, while almost full drug (100%) is released after 52 h at 41 °C. Interestingly, it is found that P(MEO2MA60-OEGMA40) polymers offer to NPs a promising stealth behavior against Human Serum Albumin and Fibrinogen model proteins.