Adaptive Control of Nanomotor Swarms for Magnetic-Field-Programmed Cancer Cell Destruction

Abstract

Magnetic nanomotors (MNMs), powered by a magnetic field, are ideal platforms to achieve versatile biomedical applications in a collective and spatio­temporal fashion. Although the programmable swarm of MNMs that mimics the highly ordered behaviors of living creatures has been extensively studied at the microscale, it is of vital importance to manipulate MNM swarms at the nanoscale for on-demand tasks at the cellular level. In this work, a Cy5-tagged caspase-3-specific peptide-modified MNM is designed, and the adaptive control behaviors of MNM swarms are revealed in lysosomes to induce the cancer cell apoptosis under a rotating magnetic field (RMF). A magneto-programmed vortex is predicted to occur with swarms under RMF by the finite element method model and verified in vitro. According to the dynamic model and numerical simulation, the critical rotating frequency under which MNMs are out of step is strongly correlated to their assembling and swarming properties. The adaptivity of swarms maximizes the synchronous rotation to achieve an optimal energy conversion rate. The frequency-adapted controllability of MNM swarms for cancer cell apoptosis is observed in real time in vitro and in vivo. This work provides theoretical and experimental insights to adaptively control MNM swarms for cancer treatment.

An Engineered Bacteria-Hybrid Microrobot with the Magnetothermal Bioswitch for Remotely Collective Perception and Imaging-Guided Cancer Treatment

“…The change was caused by the fluidic drag beyond the maximal available magnetic torque, which led to the loss of synchronization between the microrobots and RMF. The inherent shape of the bacteria has a low p -value ( p = 2.66, aspect ratio) (Figure S12), which allowed to locomote efficiently under a wide range of driving frequency . In the x – y plane, the engineered bacteria-hybrid microrobots could precisely sense the changes of the rotating magnetic field direction (RMF, 20 mT, 2 Hz) and the trajectory could be planned (Figure m, Movie S1).…”

“…The inherent shape of the bacteria has a low p-value (p = 2.66, aspect ratio) (Figure S12), which allowed to locomote efficiently under a wide range of driving frequency. 62 In the x−y plane, the engineered bacteriahybrid microrobots could precisely sense the changes of the rotating magnetic field direction (RMF, 20 mT, 2 Hz) and the trajectory could be planned (Figure 2m, Movie S1). Due to the limited capabilities of a single microrobot, the collective capabilities of microrobots can provide effective treatment at the biological level.…”

Mechanical stimuli-driven cancer therapeutics

“…7b and c). 71,81,82 The nanocubes were designed to be either simply internalized or to target mitochondria for effective cancer therapy. With their interparticle dipolar interactions and geometrical flat surface, exposure to the RMF helped to assemble the magnetic nanocubes into a rod-like morphology.…”

Sensing of Fluidic Features Using Colloidal Microswarms

“…Microswarms can serve as the potential candidate to realize the task . They have the capability of actively moving into confined environments and performing different behaviors actuated by tailored external fields. − Different colloidal microswarms have been reported, such as snake-like swarms, aster-like swarms, and vortex-like swarms . As the collective behaviors of interacting agents in swarms are influenced by the fluidic conditions, the features of motion, patterns, and behaviors of swarms will be changed accordingly.…”