Scientists find tiny nanorobots could reduce size of bladder tumors

By Imogen Howse via SWNS

Tiny nanorobots have been used to reduce the size of bladder tumors in a breakthrough that could help treatment of the disease.

Bladder cancer has one of the highest incidence rates in the world, ranking as the fourth most common tumor in men.

Fortunately, it has a relatively low mortality rate, but nearly half of all tumors resurface within five years.

This means patients require ongoing monitoring, and often receive treatment via direct drug administration into the bladder.

While survival rates following this method are good, it scores poorly when it comes to therapeutic effectiveness.

This results in patients making frequent hospital trips and receiving many repeat treatments, thereby making bladder cancer one of the most expensive cancers to treat.

However, researchers have now found a promising alternative which could treat patients for longer, meaning less hospital trips and lower hospital bills.

Scientists from the Institute for Bioengineering of Catalonia (IBEC), the Institute for Research in Biomedicine (IRB Barcelona), and the Autonomous University of Barcelona (UAB) have discovered that nanorobots can be used to directly target tumors.

These tiny nanomachines carry an enzyme called urease on their surface, which reacts with urea found in urine and enables them to self-propel through the bladder.

Then, using a system which scans the different layers of the bladder and provides a 3D reconstruction, the nanorobot is able to observe the entire organ and deliver therapeutic agents directly to a patient’s tumor.

This improves upon previous treatments whereby a patient would have to change position every half hour to ensure a drug reaches all walls of the bladder.

Published in the journal Nature Nanotechnology, the treatment delivered is radioactive iodine – a radioisotope commonly used for the localized treatment of tumors.

Studies on mice found that bladder tumors were reduced by 90 percent through a single dose of urea-powered nanorobots.

Samuel Sánchez, research professor at IBEC and the study’s lead author, said: “With a single dose, we observed a 90 percent decrease in tumor volume.

“This is significantly more efficient given that patients with this type of tumor typically have six to 14 hospital appointments with current treatments.

“Such a treatment approach would enhance efficiency, reduce the length of hospitalization, and lower treatment costs.”

Explaining the system the nanomachine uses to observe the bladder, co-author Julien Colombelli, leader of the Advanced Digital Microscopy platform at IRB Barcelona, said: “The innovative optical system that we have developed enabled us to eliminate the light reflected by the tumor itself.

“This allowed us to identify and locate nanoparticles throughout the organ without prior labeling at an unprecedented resolution.

“We observed that the nanorobots not only reached the tumor but also entered it, thereby enhancing the action of the radiopharmaceutical.”

It was initially unclear why the nanorobots were able to enter the tumors, but the researchers ultimately determined that the nanoparticles were able to break down the extracellular matrix of the tumor by their self-propelling chemical reaction.

“This phenomenon favored greater tumor penetration and was beneficial in achieving preferential accumulation in the tumor," said doctoral student Serra Casablancas, co-author of the study.

The team also believe that this form of treatment may generate less adverse side effects for patients, with study co-leader Dr. Jordi Llop explaining: “The localized administration of the nanorobots carrying the radioisotope reduces the probability of generating adverse effects, and the high accumulation in the tumor tissue favors the radiotherapeutic effect."

It is hoped that this discovery will open the door to the use of nanorobots in this context, paving the way for more innovative bladder cancer treatments.