Neural Stem Cell-derived Exosomes Loaded Adhesive Hydrogel Promotes Neurological Function And Angiogenesis In Ischemic Stroke Mice

PurposeStroke is a severe disabled disease,and ischemic stroke is the most common type of stroke.The clinical treatment strategy is limited and has a strict time window period.Neural stem cell derived exosomes(NSC-Exo)can promote nerve repair after ischemic stroke.In this study,adhesive hyaluronic acid(HAD)hydrogel controlled released the exosomes for the treatment of ischemic stroke.This is an alternative treatment strategy for exosomes in the treatment of ischemic stroke.MethodsHippocampus neural stem cells(NSCs)of mice were isolated and cultured,and were identified;the medicated plasma of Buyang Huanwu Decoction(MP-BHD)was prepared,and the use of MP-BHD preconditioning NSCs to obtain therapeutic exosomes(Exos).Exos were identified by transmitting electron microscope,nanoparticle tracking analysis and WB.The differential expression of Exo miRNA was detected by high-throughput sequencing.Adhesive HAD hydrogel was prepared through conventional hydrogel methods.The material properties of HAD were identified by mechanic experiments.Scanning electron microscope was use to observe micro-form of Exos.After the establishment of mouse middle cerebral arterial occlusion(MCAO)model,PBS,Exo,HAD and HAD-Exo were stereotactically inj ected into ischemic junctional area of MCAO models;the neurological function improvement of mice was evaluated by behavioral experiments.The promotion of the infarct volume of MCAO model were assessed by laser speckle image system(LSIS)and MRI;Immunofluorescence staining was used to detect of newborn vascular-related cells in the brain tissue.ResultsThe isolated cells were identified as NSC in vitro;the exosome production preconditioned by MP-BHD increased by 4-5 times.The high-throughput sequencing showed that Exo contained neural related miRNA expression profiles.Material experiments showed that HAD had the properties of hydrogel and Exo could be adhere to the HAD micro-structure surface.The in vitro experiments showed that HAD-Exo controlled released.Exos were maintained for more than 14 days in the brain.The hydrolysis rate was negatively related to the release rate of the Exos in vitro.Behavioral experiments showed that the neurological function of the HAD-Exo group had improved the most significantly.The LSIS and MRI showed the most significant improvement of intracranial vascular and infarction volume in the HADExo group.ConclusionsThe NSCs derived exosomes preconditioned by MP-BHD in HAD hydrogel.HAD-Exo could promote cell proliferation,angiogenesis and anti-inflammation,and improve cerebral infarct volume and neurological function recovery.HAD hydrogel as a delivery scaffold is suitable for controlled release of exosomes in the ischemic area.The HAD-Exo complex treatment strategy decreased the frequency of medication,and optimized the application process of ischemic stroke.