"Nature has been utilizing nanostructures for billion of years. The following two properties, (i) being about the size of typical biological objects and (ii) the possibility of tailoring their properties by changing their size, make nanoparticles attractive for biomedical applications. Using nanoparticles to deliver drugs to tumours offers an attractive possibility to avoid obstacles that occur during conventional systemic drug administration. This NANOPUZZLE project pretends to develop an innovative controlled release methodology, based on hyperthermia and magnetic nanoparticles, as platform for the incorporation of different molecules with different functionalities, to obtain a multifunctional system for cancer treatment and diagnose that leads antitumoral drugs discharge only in the tumoral area. Multifunctional magnetic nanoparticles loaded with a targeting agent (folic acid) and a potent antitumoral drug (doxorubicin) will be prepared. These active molecules will be coupled to the magnetic nanoparticles (MNPs) due to complementary oligonucleotides strands (oligo-zipper). Due to the magnetic properties of these nanomaterials, a local heating induced by an alternating magnetic field, will release the drug in the desired target as a consequence of the DNA denaturation (oligo-unzipping). For this approach, the increase of temperature is only required directly in the nanoparticles and the heating of the surroundings is not needed. For instance, less quantity of nanoparticles and a weaker external magnetic field will be required, avoiding the main inconveniences of conventional hyperthermia treatments. Furthermore, the superparamagnetic properties of these MNPs will also allow their use as contrast agents for tracking and diagnosis by magnetic resonance imaging (MRI)."