Fig. 2

Picture of a person with a tumor on one forearm. The patient is weighing 70 kg. The tumor measures 1 cm in diameter, and it weighs 1 g. If the patient were to be treated with general chemotherapy, then 70,000 g of his body are exposed to the drug, intended for only the malignant 1 g. 99,9999 % of the total number of cells in the patient´s body would—in wanton—be exposed to toxicity [except the cells in the central nervous system (CNS)]. With “targeted therapy” the situation could be completely reversed. The following is what the procedure might be: The drug is loaded into a nanoparticle system (e.g. liposomes). The load also includes magnetic particles (e.g. iron based). The vectors are constructed in such a way that they are dissolved by temperatures exceeding +42 °C. The loaded nanoparticles are given i.v. to the patient. A magnet is attached to the skin near the tumor. In some time (hours), the majority of the nanoparticles will have accumulated in the tumor. Employing microwaves, the temperature in the tumor is then elevated to above +42 °C, causing dissolution of the nanoparticles. The active drug is released, exposing the tumor cells to high concentrations of the drug. Normal cells are spared, and side-effects from the bone-marrow, mucous membranes and the skin are avoided. There is a synergistic effect in utilizing hyperthermia to dissolve the vector: Most malignant tumor cells are more susceptible to elevated temperatures than most normal cells. At +43 °C, the majority of malignant cells are lethally injured, whereas most of the normal cells can recover. It all sounds simple. But in reality, there are numerous obstacles and pitfalls on the road. In this publication, we will point to some of them