A team of engineers in collaboration with dentists at the University of Pennsylvania have developed microscopic robots to clean surfaces, such as a person's teeth, of bacterial biofilms. Biofilms are sticky conglomerations of bacteria and can be found on both organic and inorganic objects. They are very difficult to remove normally as the sticky matrix acts as a defense against antimicrobial agents.
“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,” says Hyun Koo team co-lead at the University of Pennsylvania's School of Dental Medicine. “These robots can do all three at once very effectively, leaving no trace of biofilm whatsoever.”
From the University of Pennsylvania article: "Together, the cross-school team designed, optimized, and tested two types of robotic systems, which the group calls catalytic antimicrobial robots, or CARs, capable of degrading and removing biofilms. The first involves suspending iron-oxide nanoparticles in a solution, which can then be directed by magnets to remove biofilms on a surface in a plow-like manner. The second platform entails embedding the nanoparticles into gel molds in three-dimensional shapes. These were used to target and destroy biofilms clogging enclosed tubes.
Both types of CARs effectively killed bacteria, broke down the matrix that surrounds them, and removed the debris with high precision. After testing the robots on biofilms growing on either a flat glass surface or enclosed glass tubes, the researchers tried out a more clinically relevant application: Removing biofilm from hard-to-reach parts of a human tooth.
The CARs were able to degrade and remove bacterial biofilms not just from a tooth surface but from one of the most difficult-to-access parts of a tooth, the isthmus, a narrow corridor between root canals where biofilms commonly grow."
Read more about the teeth cleaning robots that combat bacterial buildup at University of Pennsylvania.