Targeted Delivery Of Edaravone By Nanoliposome For The Treatment Of Ischemic Stroke

Objective: To prepare nanoliposomes for the targeted delivery of edaravone in the treatment of focal cerebral ischemia/reperfusion injury in rats.Methods: Edaravone loaded liposomes were prepared by film dispersion method.The morphology,particle size and zeta potential of the liposomes were characterized by transmission electron microscopy(TEM)and dynamic light scattering(DLS).In vitro glucose deficiency and hypoxia/reperfusion(OGD/R)injury model was established by using mouse neuroblastoma(N2a)cells.MTT and flow cytometry were used to detect the effects of EDV-LIP on the survival rate and apoptosis of N2 a cells.Focal ischemia/reperfusion injury rat model was established by using middle cerebral artery occlusion(MCAO).Fluorescent labeled liposomes were injected intravenously and main organs of rats were sacrificed and then the distribution and metabolism of liposomes in MCAO rats were observed by in vivo imaging system.The histopathological changes of heart,liver,spleen,lung and kidney were observed by hematoxylin eosin staining.MCAO rats were divided into 5 groups: sham operation group(Sham),phosphate buffer injection group(PBS),liposome injection group(LIP),edaravone injection group(EDV)and edaravone loaded liposomes injection group(EDV-LIP)intravenously.To evaluate the therapeutic effect of edaravone loaded liposomes on cerebral ischemia/reperfusion injury in rats,the changes of body weight,neurological function score,retention time on the rod,brain water content and cerebral infarct volume were recorded.Results: Edaravone loaded liposomes prepared in this study had good dispersity and uniform sphere-like morphology with the size of ～100 nm.Toxicity tests in vitro and in vivo showed that the liposomes had no obvious toxicity to cells and animals.Fluorescence labeled liposomes were injected into MCAO rats intravenously.Fluorescence imaging performed at different time points after injection manifested that the liposomes could reach the brain of MCAO rats after injection and concentrated in the ischemic region,and the concentration increased as time prolongs.Neurological function score and rod test results demonstrated that edaravone loaded liposome significantly improved the behavior of rats compared with PBS group.TTC staining results proved that the volume of cerebral infarction in EDV-LIP group was effectively reduced compared with PBS group on the1 st and 3rd days after drug injection.Immunohistochemical staining results declared that edaravone loaded liposomes could significantly improve the changes of neuron cell size,and lessen neuron cells loss.Conclusions: The nanoliposomes prepared in this study have suitable size,favourable dispersibility and good biocompatibility.After vein injection,they can be enriched in the lesion of ischemic injury in the brain of MCAO rats.The injection of edaravone loaded liposomes into MCAO rats could improve the behavior,reduce the cerebral edema,and effectively reduce the cerebral ischemic infarction volume and neuronal loss.These results indicate that these nanoliposomes have great potential in the treatment of ischemic stroke.