Development of intelligent theragonostic bacteria-based biomedical microrobot

We proposed new concepts on the development of intelligent biomedical microrobot using flagellated bacteria Salmonella typhimurium which has various properties such as micro-actuators, micro-sensors, treatment and diagnosis of solid tumors. We fabricated a bacteria-based microrobot using attenuated Salmonella typhimurium for medical applications. In addition, for motility enhancement of microrobots, we regulated the bacteria selective attachment on microbead surfaces using the patterning methods through the submerged property of microbeads on agarose gel. Firstly, we fabricated bacteria-based microrobots using polystyrene (PS) microbeads which are treated with anti-bacterial adherent factors, such as O2 plasma or bovine serum albumin. The selective bacteria-attached PS microbead groups using O2 plasma or BSA are showed higher motility than untreated whole bacteria-attached PS microbead groups. Secondly, we fabricated bacteria-based microrobots using biocompatible materials, poly(ethylene glycol) (PEG). We regulate the bacteria selective attachment on PEG microbead surfaces using bacteria adhesion materials, poly-L-lysine (PLL). Similar with the bacteria-based microrobots using PS microbeads, the selective bacteria-attached PEG microbeads group through the PLL selective coating showed higher motility than PLL-uncoated and whole PLL-coated PEG microbeads groups. Therefore, we expected that the proposed fabrication methods of the bacteria-based microrobots could have the following characteristics such as the high efficiency using flagellated bacteria, the enhanced motility using the bacteria selective patterning, and the potential applicability to human body using the biocompatible materials.