Scientists use calcium salts to deliver drugs in radionuclide therapy of lung cancer
Scientists from the Laboratory for Molecular Genetic Research at the Lobachevsky University Hospital, the School of Physics and Engineering at ITMO University and the Granov Russian Research Center of Radiology & Surgical Technologies (Saint Petersburg) have developed a new method for delivering radiopharmaceuticals to tumours during cancer treatment.
The carrier substance used to deliver the radioactive particles was calcium carbonate, which helps the drug to accumulate in the tumour while causing minimal damage to healthy tissues. The researchers used the carbonate shell to transport the radioisotope Lutetium (Lu). The radiopharmaceutical had the best effect when combined with chemotherapy.
"We have developed a simple and effective technique for 'packaging' radionuclides into calcium carbonate particles. It allows fast and technologically efficient 'assembly' of hollow capsules and coated drug particles. The surface of calcium carbonate particles can be modified with organic additives and molecular carriers, which increases the stability of these carriers in biological fluids," said Daria Kuznetsova, Head of the Laboratory for Molecular Genetic Research at the UNN University Hospital.
Researchers conducted experiments on mice with lung cancer metastases, administering intravenous doses of radiotherapy to the laboratory animals. A single dose of radionuclide therapy suppressed tumour development and reduced the size of the metastases, while leaving healthy organs and tissues unaffected.
"Ideally, the therapeutic particles should accumulate in the target organ, and their excessive amount should be quickly eliminated from the body. We have used micron-sized particles that selectively accumulate in the lungs due to their size alone. Targeting antibodies and other targeted delivery agents are not needed. After intravenous injection, the microparticles were concentrated in the lungs and remained there for 10-15 days," explains Daria Kuznetsova.
Furthermore, combining radiotherapy with chemotherapy using the common drug cisplatin (CDDP) increased the survival rate of laboratory animals by 20%. According to the researchers, this approach to the treatment of metastatic tumours, combined with improvements in the accuracy and safety of nuclear medicine techniques, will make it possible to successfully treat patients with metastatic cancer when radiotherapy and surgery have no effect.
The research is being carried out as part of a grant from the Russian Science Foundation "Development of a combined treatment for breast cancer using targeted radionuclide therapy combined with immunotherapy" (National Research University ITMO). The results of the study have been published in the Journal of Controlled Release, an international medical journal that publishes high-quality research articles in the broad field of delivery science and technology.
