Effect of Chitosan on Motility of Bacteria-Driven Liposomal Microrobots

This study proposes a prototype of bacteria-based microrobots using chitosan-coated liposomes attached to a Salmonella enteritidis bacterial strain. The attachment of the liposome and the bacteria is performed by interaction between the positive charge surface of the liposomes and the gram-negative bacteria. The liposomes are fabricated using hydration method to obtain the average diameter of 10 um and they are coated with chitosan. The chitosan coating is shown to have effect on motility of the microrobots. First, the bacteria cannot attach to chitosan-uncoated liposomes, but they can easily adhere to the chitosan-coated liposomes. Second, when the concentration of chitosan increases from 0.1% to 0.5%, average velocity of the microrobots increases from 1.20±0.12 um/s to 3.25±0.35 um/s. However, when chitosan concentration increases to 1% the average velocity of the microrobots slightly decreases from 3.25±0.35 um/s to 3.17±0.33 um/s, respectively. The study suggests that using chitosan coating can be a potential method for further development of therapeutic bacteria-based liposomal microrobots.