Microrobots based on bacteria and biohybrids that will one day fight cancer

Scientists at the Max Planck Institute for Intelligent Systems’ Physical Intelligence Department have merged robotics and biology by equipping E.coli bacteria with artificial parts to create biohybrid Microrobots. As can be seen on Figure 1, first, the team attached nanoliposomes onto each bacterium. These spherical carriers contain a material, ICG (green particles), that melts under near-infrared illumination. In the aqueous center, liposomes contain water-soluble drug molecules (DOX) that are chemotherapeutic.

Researchers attached magnetic nanoparticles as the second component to the bacteria. The iron oxide particles act as a booster for this highly mobile microorganism when exposed to a magnet field. This allows for easier control of the bacteria’s swimming — a design that is better suited to an in-vivo application. The streptavidin-biotin complex that binds the magnetic particles and liposomes to the bacteria is very stable and difficult to break. It was first developed in Nature a few year ago and has been useful in the construction of biohybrid nanorobots.

E. coli are versatile and fast swimmers. They can swim through a wide range of materials, from liquids to viscous tissues. They also possess highly sophisticated sensing abilities. Bacteria is attracted to chemical gradients, such as acidity or low oxygen levels. Both are present near tumor tissue. Bacteria mediated tumor treatment is the process of treating cancer by injecting bacteria near the cancer. The bacteria flow into the area where the cancer is, grow and activate the patient’s immune system. Since more than a hundred years, bacteria-mediated tumor therapy is a popular therapeutic method.

Source:
https://phys.org/news/2022-07-bacteria-based-biohybrid-microrobots-mission-day.html