image: SCAMT Lab, ITMO University
A group of Russian scientists have synthesized manganese-zinc ferrite nanoparticles that can potentially be used in cancer treatment. Due to their unique magnetic properties, the particles can serve as deactivators of affected cells while having almost no negative impact on healthy tissues. The results have been published in the Journal of Sol-Gel Science and Technology.
One of the most important global goals in today's medicine is finding ways to combat cancer. Currently, there are several kinds of treatments with differing effectiveness and various side effects. In most cases, the treatment causes harmful impact not only to cancer cells but also the adjacent healthy tissues or the body at large.
Magnetic fluid hyperthermia is a promising method that can help alleviate the side effects of cancer treatment. This method involves introducing a magnetic nanoparticles-containing sol into a tumor followed by its exposure to a variable magnetic field. This causes the heating of the nanoparticles and leads to the deactivation of cancer cells. However, the majority of the materials used for this purpose are toxic to the body. What is more, the particles continue to heat up to relatively high temperatures, which entails serious damage to healthy tissues.
These problems could be solved by the application of special nanoparticles which can change their magnetic properties depending on the temperature. In physics, there is such a notion as the Curie temperature (also known as the Curie point), which is the temperature at which a sharp decrease in magnetization is observed.
"When the Curie temperature is reached, a ferromagnetic changes into a paramagnetic, consequently the particles cease to be as susceptible to the magnetic field and their further heating stops," explains Vasilii Balanov, a Master's student at ITMO University and one of the research's authors. "When the temperature drops back again, the particles resume their heating. Essentially, we observe a self-management of temperature in a narrow range. If we select a composition that experiences such a transition at the temperature we need, then it could prove effective for magnetic fluid hyperthermia."
Choosing the material, the scientists opted for ferrites - compounds of iron oxide (III)Fe2O3 with oxides of other metals. Generally, thanks to their properties, these materials are widely applied in computer technologies, but, as it turned out, they can also be used for medical purposes.
"We took the particles with the general formula Zn(x)Mn(1-x)Fe2O4, in which zinc and manganese are selected in a certain proportion," expounds Vasilii Balanov. "They don't have a toxic effect on the body, and with the right ratio of manganese and zinc we were able to achieve a Curie temperature in the range of 40-60 degrees Celsius. This temperature allows us to deactivate cancer cells, concurrently, the short-term thermal contact is relatively harmless to healthy tissues."
As of now, the scientists have already synthesized the nanoparticles and studied their magnetic properties. The experiments confirmed that the material doesn't heat up above 60 degrees Celsius when exposed to a variable magnetic field. Coming next will be the experiments on living cells and, if these are successful, on animals.