Smart diagnostic nano-agents for cerebral ischemia

Cerebral ischemia (or ischemic stroke) is undeniably one of the most important life-threatening cerebral disorders. It occurs due to a clot formation in one of the blood arteries supplying the brain, causing a reduction or interruption of the blood flow. To date, the use of thrombolytics like the recombinant tissue plasminogen activator or the use of mechanical thrombectomy are the only two food and drug administration-approved treatments. However, these cannot be applied without first evaluating the beneficial or adverse effects on the patient. Thus, imaging is decisive for identifying the appropriateness of each stroke patient, leading potentially to improved therapeutic outcomes. In this review, we will present a variety of diagnostic nano-agents, and a few theranostic ones, for the assessment of ischemic stroke, highlighting their strengths and weaknesses.