Platelet-membrane-coated nanoparticles enable safe and targeted thrombolysis with preserved neurovascular integrity.

Recombinant tissue-type plasminogen activator (rtPA) is the only FDA-approved thrombolytic agent for acute ischemic stroke, yet its clinical utility is constrained by a narrow therapeutic time window, rapid clearance, and hemorrhagic transformation risk. Here, we developed a biomimetic nanothrombolytic comprising rtPA-conjugated, platelet-membrane-coated PLGA nanoparticles loaded with perfluorohexane (PNP-rtPA) to improve thrombus specificity and vascular safety. PNP-rtPA preserved rtPA enzymatic activity, achieved efficient fibrin clot lysis in vitro, and markedly enhanced thrombolysis in an electrical-stimulation-induced carotid thrombosis model. Using a refined proximal photothrombotic middle cerebral artery (MCA) occlusion mouse model that generates stable large-vessel thrombosis, we show that PNP-rtPA restored cerebral blood flow more effectively than free rtPA, reduced infarct volume, improved neurological outcomes, and increased short-term survival. Pharmacokinetic and imaging analyses demonstrated prolonged circulation and enhanced accumulation of PNP-rtPA in the injured cerebrovascular bed. Importantly, PNP-rtPA mitigated blood-brain barrier (BBB) disruption, preserved tight junction and basement membrane integrity, and reduced hemorrhagic transformation and edema. Correspondingly, astrocytic swelling, microglial activation, and systemic cytokine release were attenuated, indicating improved neurovascular protection. Together, these results establish platelet-membrane cloaking and nanoscale rtPA delivery as an effective strategy to reconcile thrombolytic efficacy with vascular safety. PNP-rtPA represents a translatable biomimetic platform for achieving precise and safe thrombolysis in ischemic vascular disease.