Improving Stroke Treatment Using Magnetic Nanoparticle Sensors to Monitor Brain Thrombus Extraction.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Neurology

Background:

• Mechanical thrombectomy (MT) is a key treatment for ischemic stroke, but clot fragmentation and slippage can occur.
• Real-time feedback on clot-stent attachment is needed for complete clot removal during MT.

Purpose of the Study:

• To develop and validate a novel sensing system using antibody-targeted magnetic nanoparticles (NPs) for real-time clot detection during MT.
• To assess the precision of this system in determining clot proximity to the stent retriever.

Main Methods:

• Simulations were performed to model signals from NPs on a clot model under oscillating magnetic fields.
• An in vitro apparatus was constructed to measure signals from NPs using a pickup coil at varying distances and angles.
• Antibody-targeted, 100 nm iron oxide core/shell NPs were used to coat clot models.

Main Results:

• Simulations predicted clot localization within 180 µm, irrespective of pickup coil orientation.
• The experimental system achieved an in vitro distance recovery precision of 41 µm with the coil 1 mm from the clot.
• Rotation-correction formulae were developed to enhance localization accuracy.

Conclusions:

• Magnetic NP sensing offers a safe and real-time method to confirm clot attachment to the stent retriever during MT.
• This technology has the potential to improve the efficacy and safety of mechanical thrombectomy for ischemic stroke.