April 26 (UPI) -- In the near future, the war on plaque could be waged by an army of tiny robots.
Engineers, dentists and biologists at the University of Pennsylvania developed a system of microscopic robots that work catalytically to destroy biofilms.
"Treating biofilms that occur on teeth requires a great deal of manual labor, both on the part of the consumer and the professional," Penn engineer Edward Steager said in a news release. "We hope to improve treatment options as well as reduce the difficulty of care."
Biofilms feature bacteria entangled in protective scaffolding. The scaffolding holds together the bacteria and helps it bind to different types of surfaces, including water pipes, teeth, implants and catheters.
"Existing treatments for biofilms are ineffective because they are incapabale of simultaneously degrading the protective matrix, killing the embedded bacteria, and physically removing the biodegraded products," said Hyun Koo, researcher at Penn's School of Dental Medicine. "These robots can do all three at once very effectively, leaving no trace of biofilm whatsoever."
Prevoiusly, Koo and his colleagues have deployed iron-oxide-containing nanoparticles to destroy biofilm. The nanoparticles catalytically activate hydrogen peroxide to release bacteria-killing free radicals.
By chance, Steager and his colleagues have been using iron-oxide nanoparticles to develop microscopic robotic systems, or microbots.
Together, the two teams of researchers developed a pair of microbot systems to breakup and kill biofilms. Scientists dubbed the systems catalytic antimicrobial robots, or CARs.
The first system features iron-oxide nanoparticles suspended in a solution. When directed to move by a magnetic force, the microbots operate like a snowplow, clearing away the biofilm. The second system features nanoparticles embedded in 3D gel molds. Scientists used the microbot-filled gels to attack biofilms clogging pipes and tubing.
Both CARs effectively destroyed the biofilm scaffolding and killed bacteria. When scientists tested the two systems on plaque-plagued teeth, they microbot systems were able to destroy the biofilms on the surface of the teeth, as well as in the hard to reach crevices between root canals.
"Existing treatments for biofilms are ineffective because they are incapable of simultaneously degrading the protective matrix, killing the embedded bacteria, and physically removing the biodegraded products," said Koo. "These robots can do all three at once very effectively, leaving no trace of biofilm whatsoever."
Researchers described their new microbot technologies this week in the journal Science Robotics.
Steager, Koo and their research partners are currently working to improve their techniques for precisely directing the tiny robots with magnetic forces.
"We think about robots as automated systems that take actions based on actively gathered information," said Steager. "The motion of the robot can be informed by images of the biofilm gathered from microcameras or other modes of medical imaging."