Magnetic T-Budbots made from tea plants kill and clean biofilms

Biofilms – microbial communities that form slimy layers on surfaces – are difficult to treat and remove, often because the microbes release molecules that block the entry of antibiotics and other therapies.

Now, researchers reporting in ACS Applied Materials & Interfaces have made magnetically propelled microbots derived from tea buds, which they call "T-Budbots," that can dislodge biofilms, release an antibiotic to kill bacteria, and clean away the debris.

Dipankar Bandyopadhyay and colleagues wanted to develop biocompatible microbots that could be controlled with magnets to destroy biofilms and then scrub away the mess. The team chose Camellia sinensis tea buds as the raw material for their microbots because the buds are porous, non-toxic, inexpensive and biodegradable. Tea buds also contain polyphenols, which have antimicrobial properties.

The researchers ground some tea buds and isolated porous microparticles. Then, they coated the microparticles' surfaces with magnetite nanoparticles so that they could be controlled by a magnet. Finally, the antibiotic ciprofloxacin was embedded within the porous structures. The researchers showed that the T-Budbots released the antibiotic primarily under acidic conditions, which occur in bacterial infections.