Study On Preparation Of CNPs Microspheres And Reparation Of Peripheral Nervous System Injury

Background:Cerium oxide nanometer oxide（CNPs）is a kind of rare earth element oxide,and has capabilities of clear oxygen free radicals（ROS）,conversion signaling pathways,pass through the blood brain barrier（BBB）and so on.CNPs has a prospect in the treatment of neurodegenerative diseases,but the tissue permeability and fluid retention of CNPs have the effect of biological immune irritancy and other side effects if implantation directly into the living body.At the same time,due to the CNPs coexist of Ce³⁺and Ce⁴⁺transformation,result to produce oxygen vacancy,this feature makes the CNPs has the oxidation resistance.However,it also causes the unprotected CNPs to lose the oxygen vacancy wherever it’s inside and outside of the living body,result to reduce its anti-oxidative stress effect.For the CNPs application optimization,this study try to use PLGA as the microspheres walls,and use the emulsifying dispersion prepared CNPs microsphere samples,create peripheral nervous system injury animal model,make the samples of CNPs microspheres and the control groups implanted into the animal damaged peripheral nervous system（with sciatic nerve as a locus）,this experimental results proves that CNPs microsphere has repair effect of peripheral nervous system injury in animals.Objective:1.CNPs microsphere can repair the injured peripheral nervous system.2.The antioxidation of CNPs is a main reason of CNPs microsphere repairing injured peripheral nervous system.Methods:Preparation of experimental samples:PLGA used as the wall material of microsphere,dissolved in DCM（dichloromethane）,and add CNPs,prepare CNPs microsphere through magnetic agitation,emulsification,filtration,centrifugation and freeze-drying;also prepare blank microspheres;weigh CNPs.Evaluation of cytotoxicity and cellular activity in vitro:With evaluation of cytotoxicity and activity in vitro,the cell OD value was detected by multifunctional enzyme labeling system and cell survival rate and productivity rate were calculated.Animal experiment:With 15 rats to establish the animal model,divided into three groups,the injured nerve myelin with crushed method,implanted with CNPs microspheres,blank microspheres and CNPs samples respectively and corresponding,repeat in the second week of implanted into equal amounts of 3 group samples respectively,extracting animal sciatic nerve and skeletal muscle tissue sampling in the fourth week,take the tissue sample morphology and immunohistochemical testing and finally result analysis.Results:1.The prepared CNPs microsphere is a regular round spherical solid with full shape,smooth surface,no adhesion between microspheres,with good dispersion.2.Compared with blank microspheres,CNPs microspheres had no cytotoxicity,and the cell survival rate was higher in the group with high concentration of CNPs than CNPs.The cell proliferation experiments of CNPs microsphere group,blank microsphere group and CNPs group showed that CNPs microsphere could reduce the cells stimulation of CNPs,and CNPs microsphere with a stronger ability to promote cell proliferation than the blank microsphere group,and the cell productivity rate increased with the increasing concentration of CNPs microsphere.3.Sciatic nerve repair and corresponding skeletal muscle status of rats in CNPs microspheres are better than the others significantly.4.The total superoxide dismutase protein concentration of sciatic nerve tissue of rats in CNPs microspheres are higher than the others.Conclusion:1.CNPs microsphere can repair the injured peripheral nervous system.2.The repair of injured peripheral nervous system by CNPs microsphere may due to its antioxidant property.