Microwave breast tumor sensing and targeting using multiswarm contrast-agent-loaded bacterial nanorobots

Previous work has shown that the directions and speeds of bio-compatible flagellated magnetotactic bacteria (MTB) could be guided along pre-planned paths deep inside the human body through external magnetic fields. Furthermore, a microwave contrast agent such as carbon nanotubes (CNTs) could be loaded onto MTB to alter the dielectric properties of tissues near the agent. Based on these two phenomena, we illustrate how multiple aggregations of MTB released into human breast can be tracked simultaneously and monitored using the differential microwave imaging (DMI) technique. We also present novel strategies to detect and localize a breast cancerous mass through the DMI-trackable bacterial propulsion and steering platform, and use an anatomically realistic breast model as a testbed to verify the feasibility of this breast cancer diagnostic technique.