One of the most common cause of deaths are various tumor diseases. Tumor cells often appears to be not vulnerable for some drugs. That is why developing therapies which includes many diffrent mechanisms of work are very important.In my studies I was trying to synthesize iron oxide extrimelly small rounded shaped particles which could handle three different mechanisms of killing tumor cells. Firstly they have special magnetic properties which, allows us to local incresing temperature thanks to variable magnetic field. So we could in some way „boil“ cells. Secondly I tried to admixture radioactive element. And thirdly I connected the particles with antitumor drug. In my project I was sythesizing those particles and investigated their properties and also how they interact with cells.