Magnetic nanoplatform incorporating a molecular thermometer. A new tool for local hyperthermia

Resumen del trabajo presentado a la 11th International Conference on the Scientific and Clinical Applications of Magnetics Carriers, celebrada en Vancouver (Canada) del 31 de mayo al 4 de junio de 2016.-- et al.Magnetic hyperthemia has already been approved for therapy of cancer and other diseases. The treatment involves a direct injection of nanoparticles into the tumor and the application of an alternating magnetic field until temperature at the borders of the tumor is reaching 43 °C. As the heating power of magnetic nanoparticles is moderate, the amount nanoparticles to be injected for this purpose is very high and that means a long process until the nanoparticles are cleared from the body. On the other hand cell experiments indicate that cell dead can be produced without are increase of the cell temperature. This is suggesting that the development of local intracellular hyperthermia involving a smaller number of particles would be very possible. In order to make this strategy effective an adequate monitoring of the nanoheaters local temperature will be required. In order to investigate this pint we have developed a magnetic nanoplafform that incorporates a luminescent molecular thermometer. The thermometer is based on the luminescence emission of two lanthanide complexes with organic ligands that are located on the surface of the magnetic nucleus and in the interior of the hydrophobic part of an amphiphilic copolymer. One of the lanthanides emits with a constant intensity while the intensity of emission of the other decreases with the temperature, thus the ratio of emission intensities gives the absolute temperature on the surface of the nanoparticle beater. The thermometer shows a line sensitive (5.8%K at 296 K), low uncertainly (0.5K), high reproducibility (>99.5%), and fast time magnetic field reveal the existence of an important temperature gradient between nanoheaters and irreversible intracellular damage in tumor cells leading to cell death without having to increase the temperature of the whole tumor mass. A proof of concept of temperature mapping has been realized on cells that were incubated with the nanoparticles.Peer Reviewe