Functionalized magnetonanoparticles for MRI diagnosis and localization in epilepsy

Area of Science:

• Neuroscience
• Biomedical Engineering
• Nanotechnology

Background:

• Epilepsy diagnosis and monitoring remain challenging, particularly in identifying specific epileptogenic regions.
• Current imaging techniques may lack the specificity or sensitivity to precisely localize seizure foci.
• Developing noninvasive tools to visualize the blood-brain barrier (BBB) and target specific brain tissues is crucial for neurological disease management.

Purpose of the Study:

• To develop nonradioactive magnetonanoparticles (MNP) capable of crossing the BBB.
• To target and concentrate MNP in epileptogenic tissues in animal models of temporal lobe epilepsy.
• To visualize these targeted tissues using magnetic resonance imaging (MRI).

Main Methods:

• Nonradioactive alpha methyl tryptophan (AMT) was attached to iron oxide and dextran-based MNP.
• A rodent model of temporal lobe epilepsy was induced using kainic acid.
• AMT-MNP or plain MNP were administered intravenously, and MRI was performed before and after injection. Intracranial EEGs were used to confirm epileptogenicity in chronic models.

Main Results:

• AMT-MNP successfully crossed the BBB, with intraparenchymal uptake visualized by MRI.
• In acute epilepsy models, AMT-MNP localized to both hippocampi, while plain MNP showed only unilateral changes.
• In chronic epilepsy models, AMT-MNP uptake correlated with seizure occurrence and accurately reflected epileptogenic regions identified by EEG.

Conclusions:

• Nonradioactive AMT-MNP can effectively cross the BBB and pinpoint epileptogenic brain regions.
• This MNP-MRI approach offers a potentially accurate, safe, and cost-effective method for imaging localized cerebral functions.
• The MNP-MRI strategy can be adapted for various bioactive molecules to image normal and abnormal brain activity.