A Triple-Targeted Rutin-Based Self-Assembled Delivery Vector for Treating Ischemic Stroke by Vascular Normalization and Anti-Inflammation via ACE2/Ang1-7 Signaling

Changes in the cerebral microenvironment caused by acute ischemic stroke-reperfusion are the main obstacle to the recovery of neurological function and an important cause of stroke recurrence after thrombolytic therapy. The intracerebral microenvironment after ischemia-reperfusion reduces the neuroplasticity of the penumbra and ultimately leads to permanent neurological damage. To overcome this challenge, we developed a triple-targeted self-assembled nanodelivery system, which combines the neuroprotective drug rutin with hyaluronic acid through esterification to form a conjugate, and then connected SS-31, a small peptide that can penetrate the blood brain barrier and target mitochondria. Brain targeting, CD44-mediated endocytosis, hyaluronidase 1-mediated degradation, and the acidic environment synergistically promoted the enrichment of nanoparticles and drug release in the injured area. Results demonstrate that rutin has a high affinity for ACE2 receptors on the cell membrane and can directly activate ACE2/Ang1-7 signaling, maintain neuroinflammation, and promote penumbra angiogenesis and normal neovascularization. Importantly, this delivery system enhanced the overall plasticity of the injured area and significantly reduced neurological damage after stroke. The relevant mechanism was expounded from the aspects of behavior, histology, and molecular cytology. All results suggest that our delivery system may be an effective and safe strategy for the treatment of acute ischemic stroke-reperfusion injury.