Physiologically Adaptive Soft Millirobot for Atraumatic Endovascular Therapy.

Area of Science:

• Biomedical Engineering
• Interventional Medicine
• Robotics

Background:

• Localized drug delivery to the vascular endothelium is crucial for managing arterial and venous diseases.
• Current methods face challenges in atraumatic navigation and effective drug deposition under blood flow.

Purpose of the Study:

• To introduce EndoBot, a soft, untethered millirobot for atraumatic endoluminal navigation and localized drug delivery.
• To evaluate EndoBot's ability to interact with vasculature adaptively and deliver therapeutic agents safely.

Main Methods:

• EndoBot utilizes mechanically adaptive surface crawling for locomotion in diverse vasculature.
• Testing involved phantom vessels, ex vivo human umbilical veins, and an in vivo rat inferior vena cava model.
• Wireless deployment/retrieval via vascular sheaths and magnetic manipulation under fluoroscopic guidance were employed.

Main Results:

• EndoBot demonstrated stable, surface-conformal locomotion under physiological flow conditions without causing vessel injury.
• Low radial contact pressures (<1 kPa) ensured atraumatic interaction with the endothelium.
• Successful endoluminal painting strategy for flow-resistant drug depot transfer was achieved, confirmed by blood compatibility tests.

Conclusions:

• EndoBot provides a translationally viable platform for localized endothelial drug delivery, preserving vessel integrity.
• This technology paves the way for novel preventive and maintenance-oriented endovascular therapies.
• EndoBot addresses a critical unmet need in interventional medicine for vascular disease management.