Biochemists have created radioactive nanorobots that can destroy bladder tumors
Bladder cancer is one of the most common cancers. It ranks fourth among the most common tumors in men. Despite the relatively high survival rate, remission in patients lasts a short time. Nearly half of bladder tumor forms give recurrence within five years of recovery.
Patients require constant medical check-ups and repeated courses of medication, which puts a significant financial strain on the health care system. This type of cancer is one of the most expensive to treat, which usually involves direct injection of immunotherapy and/or chemotherapy drugs into the bladder.
Current treatments have side effects and do not always conclusively defeat bladder cancer, as evidenced by the statistics on the number of cases of the disease returning. A promising alternative to such treatment is nanorobots (nanoparticles) that can deliver active substances directly to the tumor. Of particular interest are nanomachines that can move independently in the body.
Such "biological devices" created a group of Spanish biochemists from the Institute of Bioengineering of Catalonia, the Institute of Biomedicine of Barcelona and the Autonomous University of Barcelona. The scientists described it in a paper published in the journal Nature Nanotechnology.
Nanorobots are silicon porous spherical structures with a diameter of 450 nanometers, containing an artificial radioactive isotope of iodine - iodine-131. This isotope is used by physicians to destroy cancer cells in certain types of tumors. The surface of the biomachines is covered with various components, including gold nanoparticles and molecules of urease - an enzyme that breaks down urea to form ammonia and carbon dioxide.
The latter plays the role of the "engine" of the nanomachine. The enzyme interacts with the urea molecules, which make the tiny machines move. The nanorobots then deliver their contents directly to the cancer cells, where the drug accumulates. As a result, the therapeutic effect is distributed evenly throughout the bladder, whereas this is a big problem for existing anti-tumor drugs.
Spanish biochemists tested their technology on laboratory mice, which were first injected with bladder cancer cell cultures, and after some time - nanorobots. Observations of the rodents, which included positron emission tomography and tissue micrographs, showed that the nanoparticles were constantly moving around the mice's bladder and actively penetrating the tumors.
"With a single dose of nanoparticles, we achieved a 90 percent reduction in tumor volume in the rodents. Important to note: without apparent harm to the rest of the animals' bodies. Usually, patients with this type of cancer require six to 14 treatments to achieve a positive effect. Simply put, our nanorobots could revolutionize the treatment of bladder cancer, reducing the length of hospitalization and lowering treatment costs. But human trials are needed first," said Samuel Sanchez, one of the authors of the paper.
Why do nanoparticles penetrate cancer cells? According to the researchers, it is due to the structure of neoplasms inside the bladder - spongy and loose, which makes it easier for nanorobots to penetrate their thickness.
The Spanish scientists' next step is to understand whether cancer recurrence will occur in rodents after nanoparticle treatment.