Targeted delivery of extracellular matrix protected against neurologic defects after focal ischemia reperfusion in rats.

Ischemic stroke is one of the leading causes of morbidity and mortality worldwide and characterized by defective angiogenesis. The functional sequences (RGDs, GRGDSPASSPISC) derived from fibronectin have been confirmed to augment angiogenesis in vivo and in vitro. However, delivery of peptides into the brain parenchyma has been hampered by the presence of the blood-brain barrier (BBB). We fused RGDs with penetratin (Antp) derived from Drosophila antennapedia homeodomain protein to improve the penetration of peptides through BBB into ischemic hemisphere. We found Antp-RGDs successfully not only penetrate the SH-SY5Y cells but also penetrated through BBB into ischemic hemisphere by intraperitoneal injection. In addition, application of Antp-RGDs to the focal cerebral ischemic reperfusion injury in rats resulted in the reduction of cerebral ischemic volume and the improvement of neurologic score according to the 21-point score. We further demonstrated that activation of phosphorylation-extracellular-signal related kinase 1/2 (p-ERK 1/2) and upregulation of gene VEGF resulted from post-treatment with Antp-RGDs 2 hours after reperfusion onset might at least partly contribute to the benefic changes after focal cerebral ischemic reperfusion injury in rats. Our data suggested that Antp-RGDs may serve as an attractive therapeutic intervention for treating ischemic stroke.