An international team with the participation of researchers from the Higher Council for Scientific Research (CSIC) has developed carbon nanocapsules that are activated with radiation to reduce the proliferation and growth of cancer tumors. This finding, tested in mice and published in the journal ACS Nano, could be used in both biomedical imaging and cancer radiation therapy.
These are nanocapsules with stable samarium atoms that are irradiated with neutrons to achieve high levels of radioactivity that destroy tumor cells and thus reduce the growth and proliferation of tumors. In nanomedicine, one of the most promising treatments includes the use of radioactive nanoparticles administered intravenously to cope with tumors.
The nanocapsules have been tested in experiments with mice. The results have showed reduction in some of the tumors, prevention of their proliferation and reduction of the growth rate. “There are still more studies to calculate the optimal doses and side effects, but the existing results are very promising,” said Gerard Tobías Rossell , a researcher at the Institute of Materials Science (ICMAB-CSIC) .
The high radiation achieved allows the nanocapsules to be used for radiation therapy against cancer, and not only for biomedical imaging studies, as until now.
Biomedical imaging requires lower radioactivity (used to detect nanocapsules within the body), but radiation therapy, on the other hand, requires higher radiation to destroy the cancer cells that form tumors locally. The great radioactivity achieved in this study also allows the administered dose to be much lower than with other treatments.
The nanocapsules are formed by carbon nanotubes, that is, by graphene sheets rolled and sealed by the tips. “These nanocapsules are waterproof, since the graphene wall does not allow the radioactive atoms inside to spread throughout the rest of the body,” said Tobias.
The atoms inside are samarium (samarium chloride), already used in hospitals as palliative for bone metastases. When the nanocapsules are prepared, the atoms are not radioactive. Only after being irradiated with neutrons, isotopes 152, stable, become isotopes 153, radioactive, and useful for cancer treatment.
Stable and easy to handle nanocapsules
The fact of working with non-radioactive particles has multiple advantages: on the one hand, it allows the entire process of filling the tubes and subsequent processing in any laboratory, since the use of radioactive facilities is not required.
The generation of radioactive waste and the exposure of these products to researchers are also reduced. In addition, it allows alleviating the time limitation imposed by the use of radioactive elements, since these require generally much faster handling. The nanocapsules can be stored without any special requirement until the day of use.
The study was carried out by an international team of researchers from ICMAB-CSIC and the Catalan Institute of Nanoscience and Nanotechnology (ICN2) , and also from different centers in the United Kingdom, France, Greece, the Czech Republic and Italy, and the company Cis Bio International, within the European RADDEL project (RADioactivity DELivery).