Immune Cell-Based Microrobots for Remote Magnetic Actuation, Antitumor Activity, and Medical Imaging

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Oncology

Background:

• Clinical translation of medical microrobots necessitates integrated design for tracking, actuation, and imaging.
• Macrophage-based microrobot designs often overlook crucial parameters like actuation and imaging integration.
• Existing approaches lack comprehensive integration of essential functionalities for effective microrobot deployment.

Purpose of the Study:

• To develop novel macrophage-based microrobots with integrated magnetic steering, medical imaging, and antitumor capabilities.
• To demonstrate the feasibility of wireless magnetic actuation and real-time imaging of these microrobots.
• To evaluate the efficacy of these microrobots in targeting and reducing tumor viability.

Main Methods:

• Engineered living macrophage-based microrobots by combining macrophages with magnetic Janus particles (FePt nanofilm coated) and bacterial lipopolysaccharides.
• Utilized magnetic resonance imaging (MRI) and optoacoustic imaging (OAI) for microrobot visualization in phantoms and ex vivo tissues.
• Demonstrated wireless magnetic actuation and real-time OAI tracking under static and flow conditions.
• Investigated microrobot steering toward urinary bladder tumor spheroids and assessed their antitumor effects.

Main Results:

• Successfully created macrophage-based microrobots with combined wireless magnetic actuation, tracking, and antitumor functions.
• Visualized microrobots using MRI and OAI in simulated and ex vivo environments.
• Achieved real-time magnetic actuation and imaging under various conditions, including physiological flow.
• Demonstrated significant reduction in tumor spheroid viability upon targeted delivery of microrobots.

Conclusions:

• The study presents a proof-of-concept for integrating macrophage-based microrobots with clinical imaging modalities for cancer therapy.
• The developed microrobots offer a promising platform for targeted cancer intervention and can be adapted for diverse medical applications.
• This approach overcomes previous design limitations by integrating essential parameters for effective microrobot-based medical treatments.