Swarming Multifunctional Heater–Thermometer Nanorobots for Precise Feedback Hyperthermia Delivery

Abstract

Micro-/nanorobots (MNRs) are envisioned to act as "motile-targeting" platforms for biomedical tasks due to their ability to propel and navigate in challenging, hard-to-reach biological environments. However, it remains a great challenge for current swarming MNRs to accurately report and regulate therapeutic doses during disease treatment. Here we present the development of swarming multifunctional heater−thermometer nanorobots (HT-NRs) and their application in precise feedback photothermal hyperthermia delivery. The HT-NRs are designed as photothermal-responsive photonic nanochains consisting of magnetic Fe 3 O 4 nanoparticles arranged periodically in one dimension and encapsulated in a temperatureresponsive hydrogel shell. The HT-NRs exhibit energetic and controllable swarming motions under a rotating magnetic field, while simultaneously functioning as motile nanoheaters and nanothermometers, utilizing their photothermal conversion and (photo)thermal-responsive structural color changes (photothermochromism). Consequently, the HT-NRs can be quickly deployed to a remote target area (e.g., a superficial tumor lesion) using their collective motion and selectively eliminate diseased cells in a specific targeted region by utilizing their self-reporting photothermochromism as visual feedback for precisely regulating external light irradiation. This work may inspire the development of intelligent multifunctional theranostic micro-/nanorobots and their practical applications in precise disease treatment.

Magnetic Microrobot Swarms with Polymeric Hands Catching Bacteria and Microplastics in Water

“…When not externally energized by a magnetic field, these magnetic particles are dispersed and display Brownian motion in water. By applying an external rotating magnetic field (ranging from 3 to 5 mT), the individual beads, initially well dispersed in water, align with the applied field, attracting each other along their magnetic dipoles. , This leads to their self-organization into compact planes due to mutual magnetic interactions at the single-bead level. The precise control over the assembly of these beads effectively counteracts the formation of uncontrolled large aggregates, a common hindrance resulting from magnetic interactions in magnetite or maghemite microrobotic entities …”

Enzymatic micro/nanomotors in biomedicine: from single motors to swarms

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Synthesis of Controllable Superparamagnetic Nano Fe3O4 Based on Reduction Method for Colloidal Clusters of Magnetically Responsive Photonic Crystals

“…On the other hand, superparamagnetic nano Fe 3 O 4 in biomedicine, with its stable material property and good biocompatibility, can serve as magnetic fluid assisted hyperthermia and is expected to become an effective treatment method for cancer [5,6]. Therefore, this monodisperse superparamagnetic nanoparticle is widely used in the fields of color display [7,8], anti-counterfeiting [9,10], sensors [11,12], and biomedicine [13,14].…”