Study on the treatment of ischemic stroke rats with two-dimensional graphite carbon nitride nanosheets loaded with Senkyunolide I
Objective:To investigate the therapeutic effect of two-dimensional graphite phase carbon nitride(g-C3N4)nanosheets loaded with Senkyunolide I(SEI)on ischemic stroke rats.Methods:The layered g-C3N4 was formed by thermal reaction of melamine,and the thin layer g-C3N4 nanosheets were obtained and characterized af-ter thermal stripping and acid peeling.SEI was loaded onto g-C3N4 nanosheets,the SEI in the supernatant was de-termined by UV-vis absorption spectrum,the mass ratio of SEI loaded with g-C3N4 was calculated,and the drug release of SEI-g-C3N4 composite nanosheets was determined at 1 h,3 h,6h,12 h,24 h and 48 h.The SD rats with middle cerebral artery occlusion(MCAO)were injected with SEI-g-C3N4 composite nanosheets 48 h before the establishment of the model.Neurobehavioral score was performed 24 h after the establishment of the model.After the score,the samples were stained with TTC,TUNEL and HE,respectively.Results:Through the charac-terization experiment,the prepared g-C3N4 nanosheets had the advantages of small size(about 100 nm),large spe-cific surface area,good dispersion and positive surface charge(33.3 mV).The results of UV-vis absorption spec-tra showed that g-C3N4 had successfully loaded SEI and the mass ratio of SEI/g-C3N4 was 15.06.The drug release results showed that the release rate of SEI was close to 50%at 24 h.The neurological function score of MCAO group was significantly higher than that of sham group(P<0.0001),indicating that the modeling was successful.Compared with MCAO group,the neurological function score of MCAO+SEI group was decreased(P>0.05),and that of MCAO+SEI-g-C3N4 group was decreased(P<0.001).Compared with MCAO+SEI group,the neuro-logical function score of MCAO+SEI-g-C3N4 group was decreased(P<0.01).The results of TTC staining showed that compared with sham group,the cerebral infarction size of MCAO group was increased significantly(P<0.0001);compared with MCAO group,the cerebral infarction size of MCAO+SEI group was decreased(P<0.0001),and that of MCAO+SEI-g-C3N4 group was decreased significantly(P<0.0001).Compared with MCAO+SEI group,the cerebral infarction size of MCAO+SEI-g-C3N4 group was decreased(P<0.001).The results of TUNEL staining showed that the apoptosis rate of MCAO group was higher than that of sham group(P<0.0001),indicating that the modeling was successful,that of MCAO+SEI-g-C3N4 group was higher than that of sham group(P>0.05),and that of MCAO+SEI-g-C3N4 group was lower than that of MCAO group(P<0.001).The results of in vivo biosafety experiment showed that compared with sham group,there was no significant dif-ference in body weight between SEI group and SEI-g-C3N4 group,and no obvious pathological changes in corti-cal brain structure and cell morphology.Conclusion:The SEI-g-C3N4 composite nanosheets with good biosafety are successfully prepared,and they can reduce the cerebral infarction size,inhibit apoptosis,reduce the pathologi-cal changes of brain tissue,and improve the neurobehavioral function of MCAO rats,indicating that SEI-g-C3N4 composite nanosheets can be used in the treatment of ischemic stroke rats.