Nanoparticles accumulate in ischemic core and penumbra region even when cerebral perfusion is reduced

► Nanoparticles accumulated in ischemic region in ischemic state. ► Accumulation was observed before obvious cerebral cell death was evident. ► Injected nanoparticles leaked into brain parenchyma only in ischemic region. ► Liposomal drug delivery system is potentially applicable to ischemic stroke therapy.