The Research Of Zeolitic Imidazolate Framework Loaded With Methylprednisolone Sodium Succinate For The Treatment Of Noise Induced Hearing Loss

PART I The Synthesis of MPSS-loaded Zeolite Imidazolate Framework-8&Zeolite Imidazolate Framework-90 MOFs Nanomaterial capsulesObject:To load Methylprednisolone sodium succinate with ZIF-8&ZIF-90 MOFs nanomaterial.Methods:As a subclass of MOFs,Zeolite Imidazolate Framework can be synthesized by self-assembly of metal ions and imidazole bonds.In this experiment,ZIF-90 and ZIF-8 were synthesized by adjusting the self-assembly of Zn2+with imidazol-2-formaldehyde,and Zn2+with 2-methylimidazoles respectively.MPSS@ZIF-90,FITC@ZIF-90,MPSS@ZIF-8,FITC@ZIF-8 were obtained by adding MPSS or FITC into the precursor.After the synthesis of the corresponding products,we used a number of instruments and technologies including:solid powder X-ray diffraction(PXRD),cold field emission scanning electron microscope and physical adsorption to detect the products.Result:Methylprednisolone sodium succinate and FITC can be successfully loaded into Zeolite Imidazolate Framework-8&Zeolite Imidazolate Framework-90 metal-organic framework nano materials.It can be seen from SEM that the particle size and morphology of MPSS@ZIF-90 and FITC@ZIF-90 are similar to those of ZIF-90 without load.Meanwhile,for ZIF-8,MPSS@ZIF-8 and FITC@ZIF-8 are also similar to ZIF-8 without load,had no influence on the morphology and the particle size of ZIF-8.The N2 adsorption/desorption isotherms show that ZIF-90 and ZIF-8 have abundant micropores,and they are ordered porous structures.Conclusion:ZIF-90 and ZIF-8 nano materials are rich in micropores,and both of them have ordered porous structure.At the same time,methylprednisolone sodium succinate and FITC can be successfully loaded into ZIF-8&ZIF-90 MOFs nano materials,the morphology and structure of ZIF-90 and ZIF-8 have no obvious change after loading MPSS and FITC.PART II The Study on Transport and Transmission of MPSS-loaded Zeolite Imidazolate Framework-8&Zeolite Imidazolate Framework-90 MOFs Nanomaterial Material Capsules in vivoObject:To explore whether the MPSS-loaded Zeolite Imidazolate Framework-8&Zeolite Imidazolate Framework-90 MOFs Nanomaterial Material Capsules can enter the inner ear through the blood-labyrinth barrier of experimental mice and release slowly.Methods:Twenty seven 4-5 week-old male C57BL/6J mice were randomly divided into 9 groups(n=3):the 1st group was given PBS solution as control group,the 2nd group was given FITC@ZIF-90 solution,the 3rd group was given FITC@ZIF-8 solution,all the three groups took photos of FITC signal detection in the isolated inner ear tissue one day after administration;the 4th group was given PBS solution as control group,the 5th group was given FITC@ZIF-90 solution,the 6th group was given FITC@ZIF-8 solution,all the three groups took photos of FITC signal detection in the isolated inner ear tissue 3 days after administration;the 7th group was given PBS solution as control group,the 8th group was given FITC@ZIF-90 solution,the 9th group was given FITC@ZIF-8 solution,all the three groups took photos of FITC signal detection in the isolated inner ear tissue 5 days after administration;All groups were given drug to mice by intraperitoneal injection.After 1,3 and 5 days of administration,the FITC signal image of mouse inner ear was taken.The excitation/emission wavelength of the Small animal in vivo optical imaging system is 490/535 nm.Result:On the 1st,3rd and 5th day after intraperitoneal injection of FITC@ZIF-90 and FITC@ZIF-8,FITC signals were detected in the inner ear tissues of our experimental mice by using Small animal in vivo optical imaging system,which indicated that our ZIF-90 and ZIF-8 MOFs nanomaterials could enter the peripheral blood circulation after intraperitoneal injection and enter the inner ear through the blood-labyrinth barrier,and release the loaded drugs slowly and continuously in the inner ear.Conclusion:MPSS-loaded ZIF-8&ZIF-90 MOFs Nanomaterial Material Capsules can enter the inner ear through the blood labyrinth barrier and release continuously and slowly.PART III The Study of Protective effect of MPSS-loaded Zeolite Imidazolate Framework-8&Zeolite Imidazolate Framework-90 MOFs Nanomaterial Material capsules on noise-induced hearing lossObject:To explore whether the protective effect of MPSS-loaded Zeolite Imidazolate Framework-8&Zeolite Imidazolate Framework-90 MOFs Nanomaterial Material capsules on noise induced hearing loss is better than that of pure methylprednisolone sodium succinate.Methods:Twenty four 4-5 week-old male C57BL/6J mice were randomly divided into four groups:MPSS(methylprednisolone sodium succinate only)group,MPSS@ZIF-90(ZIF-90 loaded MPSS)group,MPSS@ZIF-8(ZIF-8 loaded MPSS)group and Control(PBS)group.The Twenty four C57BL/6J mice of 4-5 weeks old were tested for ABR hearing threshold before drug administration and noise intervention,so as to eliminate the abnormal hearing mice and record the hearing threshold of each frequency of each normal hearing mouse.Then the mice in each group were exposed to 100 dB SPL steady-state white noise for 3 days,3 hours per day.After noise intervention,ABR threshold was detected in each group of mice.The loss of hair cells in the basement membrane of each group of mice was observed.Result:The results of ABR audiometry showed that the hearing threshold of each group of mice before the intervention were the same in click,16 kHz and 24 kHz,and there was no significant difference in 8 kHz and 32 kHz(P>0.05).After administration and noise intervention,the ABR results showed that MPSS group had significant protective effect on click part compared with the control group;MPSS@ZIF-8 group had significant protective effect on click,8 kHz and 16 kHz,but the protective effect was weaker than MPSS@ZIF-90 group;MPSS@ZIF-90 group had significant protective effect on click and 24 kHz and without hearing loss in this two parts,and the hearing loss in 8 kHz,16 kHz and 32 kHz is lower than 5 dB.According to the pictures of the basement membrane of the cochlea taken by confocal microscope,the outer hair cells of the basement membrane in MPSS@ZIF-90 group were almost no loss in the basal turn,middle turn and apical turn.In MPSS@ZIF-8,MPSS and the Control group,the outer hair cells on the basement membrane of the cochlea were mainly scattered absent in basal turn and middle turn,and the outer hair cells of the apical turn were almost intact.Conclusion:In our noise model,MPSS@ZIF-90 has a strong and significant protective effect on the hearing of mice.Compared with the control group,MPSS@ZIF-8 has a certain protective effect,which is slightly better than MPSS group,but significantly worse than MPSS@ZIF-90.PART Ⅳ The Study on Nephrotoxicity of MPSS-loaded Zeolite Imidazolate Framework-8&Zeolite Imidazolate Framework-90 MOFs nanomaterial capsulesObject:To explore the nephrotoxicity of MPSS-loaded Zeolite Imidazolate Framework-8&Zeolite Imidazolate Framework-90 MOFs nanomaterial capsules in miceMethods:Twenty four 4-5 week-old male C57BL/6J mice were selected and randomly divided into 4 groups(n=6):MPSS group,given the MPSS solution by intraperitoneal injection;MPSS@ZIF-90 group,given the MPSS@ZIF-90 solution by intraperitoneal injection;MPSS@ZIF-8 group,given the MPSS@ZIF-8 solution by intraperitoneal injection;PBS solution was given by intraperitoneal injection in the control group.On the 5th day after administration,the serum of mice was collected by enucleation and blood collection,and the changes of renal function(blood CREA,blood UREA,blood UA)were detected.Result:Through the detection and statistical analysis of three indexes,CREA,UREA and UA,of renal function in each group,it was found that there was no significant differences in these three indexes between MPSS@ZIF-90 group,MPSS@ZIF-8 group,MPSS group and control group.Conclusion:MPSS-loaded Zeolite Imidazolate Framework-8&Zeolite Imidazolate Framework-90 MOFs nanomaterial capsules had no definite damage to the renal function of mice.