Physiologically Adaptive Soft Millirobot for Atraumatic, Image-Guided Endovascular Therapy.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Vascular Medicine

Background:

• Current vascular interventions like drug-eluting stents often cause endothelial damage, leading to restenosis and thrombosis.
• Localized drug delivery to the vascular endothelium is crucial for managing arterial and venous diseases effectively.

Purpose of the Study:

• To introduce EndoBot, a soft, untethered millirobot for atraumatic endovascular drug delivery.
• To demonstrate EndoBot's ability to navigate and deliver drugs without compromising vessel integrity.

Main Methods:

• Magnetically actuated corkscrew propulsion and surface crawling for low-pressure navigation.
• Feasibility testing in phantom models, ex vivo human veins, and in vivo rat models under fluoroscopic guidance.
• Novel endoluminal painting technique for uniform drug depot deposition.

Main Results:

• EndoBot achieved stable, atraumatic navigation in various vascular models, preserving endothelial integrity.
• The robot maintained position and delivered drugs effectively under challenging flow conditions and vessel irregularities.
• Blood compatibility tests showed no increased coagulation or significant hemolysis.

Conclusions:

• EndoBot represents a translationally viable platform for localized, atraumatic endovascular drug delivery.
• This technology has the potential to enhance preventive interventions for early-stage vascular disease and adjunctive therapies for advanced conditions.