Aggregates of Synthetic Microscale Nanorobots versus Swarms of Computer-Controlled Flagellated Bacterial Robots for Target Therapies through the Human Vascular Network

The field of medical nanorobotics exploits nanometer-scale components and phenomena to enable new or at least to enhance existing medical diagnostic and interventional procedures. The best route for such miniature robots to access the various regions inside the human body is certainly the vascular network which is constituted of nearly 100,000 km of blood vessels. The variations in blood vessels diameters from a few millimeters in the arteries, down to ~4 ¿m in the capillaries with respective important variations in blood flow velocities, lead to significant challenges in the development of a robot relying on a singe type of propulsion method while being trackable in the human body. This tracking feasibility in a living body was realized experimentally by integrating magnetic nanoparticles (MNP) capable of creating a net field inhomogeneity that could be detected by magnetic resonance imaging (MRI). In such an environment, dipole-dipole interaction between synthetic microscale nanorobots encapsulating MNP can be used to achieve higher magnetophoretic velocities when subjected to a 3D magnetic gradient force generated by an upgraded MRI platform to allow such aggregated nanorobots to travel in the blood circulatory network. Here, such approach is evaluated against the flagellar propelling thrust force exceeding 4 pN provided by each MC-1 MRI-trackable magnetotactic cells capable of swimming as swarms under computer control in blood vessels. Such artificial and natural approaches are compared with the advantages of each in targeting regions deep in the human body.