Electron microscope image of nanobot moving through dentinal tubule to reach bacterial colony (Credit: Theranautilus)
A team of researchers at the Bengaluru-based Indian Institute of Science (IISc) and a startup incubated by it has come up with a new technique that promises to increase the success rate of root canal treatments substantially.
The root canal treatments involve removing the infected soft tissue inside the tooth, called the pulp, and flushing the tooth with antibiotics or chemicals to kill the bacteria that cause the infection. However, the treatments often fail to altogether remove all the bacteria – especially antibiotic-resistant bacteria such as Enterococcus faecalis. They remain hidden inside microscopic canals in the tooth called dentinal tubules.
In the new study, the researchers have designed nanosized robots, which can be controlled using a device that generates a low-intensity magnetic field. These nanobots were then injected into extracted tooth samples, and the researchers tracked their movement using a microscope.
By tweaking the frequency of the magnetic field, the researchers were able to make the nanobots move at will and penetrate deep inside the dentinal tubules. The nanobots were made of silicon dioxide coated with iron.
“We have also established that we can retrieve them … we can pull them back out of the patient’s teeth,” says Shanmukh Srinivas, a member of the team and Research Associate at the IISc’s Centre for Nano Science and Engineering (CeNSE), IISc. He is a co-founder of the startup named Theranautilus.
A team of researchers at the Bengaluru-based Indian Institute of Science (IISc) and a startup incubated by it has come up with a new technique that promises to increase the success rate of root canal treatments substantially.
The team was also able to manipulate the magnetic field to make the surface of the nanobots generate heat, which can kill the bacteria nearby. “No other technology in the market can do this right now,” says Debayan Dasgupta, his colleague at CeNSE, and co-founder of Theranautilus.
Earlier, scientists have used ultrasound or laser pulses to create shockwaves in the fluid used to flush out bacteria and tissue debris, to improve the efficiency of root canal treatment. But these pulses were found to penetrate only up to 800 micrometers, and their energy also dissipates fast. The nanobots, instead, could penetrate up to 2,000 micrometers. Using heat to kill the bacteria further provides a safer alternative to harsh chemicals or antibiotics, the researchers noted.
The startup Theranautilus is an outcome of several years of work on magnetically controlled nanoparticles carried out in the lab of Ambarish Ghosh, Professor at CeNSE. His group, along with collaborators, has previously shown that such nanoparticles can trap and move objects using light, swim through blood and inside living cells, and stick firmly to cancer cells. “These studies have shown that they are safe to use in biological tissues,” says Dasgupta.
The team has tested their nanobots in mice models and found them to be safe and effective. They are now working on developing a unique medical device that can easily fit inside the mouth and allow the dentist to inject and manipulate the nanobots inside the teeth during root canal treatment.
“We are very close to deploying this technology in a clinical setting, considered futuristic even three years ago,” says Ghosh. The team has published a report on their work in the science journal Advanced Healthcare Materials.
India Science Wire
ISW/SP/IISc/NANOBOT/18/05/2022
