CAT and Cerebral ischemia: After intravenous administration, the PGP-modified and catalase-encapsulating nanoparticles (cl PGP-PEG-DGL/CAT-Aco NPs) were internalized by the circulating neutrophils via endocytosis and micropinocytosis and transported across the BBB to the ischemic subregion; the delivery method could enhance the therapeutic efficiency of neuroprotectant in the middle cerebral artery occlusion (MCAO) mice and extend the therapeutic time window in acute cerebral ischemia [20].