Study Of Primary Culture Of Olfactory Ensheathing Cells And Their Interaction With Spiral Cord Injury Repairing Materials

Recently, Olfactory Ensheathing Cell (OECs) is a powerful treatment tool used for spinal cord injury repair. However, there are also some problems. The main shortcoming of this method is lacking of ideal supporting materials and appropriate scaffold, which leads to a short cell growth time and thus, results in undesirable effect of nerve repair and function reconstruction.Thus, searching for a suitable supporting material for OECs is of highly importance. The materials should be biocompatible, highly cohesive to OECs.What's more; the cells stick to it should be lively and grow continuously.This research compared some methods of separating and purifying OECs, The OECs were isolated and purified from neonatal rat by improved NASH method. OECs were stained by GFAP, P⁷⁵, S-100 immunocytochemistry to identify them. The result indicated that improved NASH method was the most effective method to obtain large amount of OECs and the purity can be as high as 80%. OECs were obtained by this method for following study.In the study, three kinds of materials: PLA, PLGK and PRGD were synthesized. BSA (1mg/mL) was chosen to contact with the three materials respectively, then the adsorptive capacity of the materials was tested in different time during the process of adsorbing BSA with Bradford method and the infrared reflection method. The three materials were incubated with 5% BSA in shaking table for 12h and then were dried. The surfaces of the material were tested by FT-IR and their spectrograms obtained both before and after the action of BSA were compared, then the absorption of BSA was analyzed.The result showed that in the initial 2 hours, PLA had a higher protein adsorptive capacity than the other two materials. However, the amount of protein adsorbed by PRGD was increasing with the time extension and the amount was much higher than the others. This result agreed with spectrograms. A drop of water was dripped on the surface of the three materials. The contact angles of materials were determined through high temperature microscope and the hydrophilicity of materials was compared. The result of water contact angle of PLA was 65.1°, PLGK was 48.9°, PRGD was 43.7°, indicating that PRGD had the best hydrophilicity.After cultivating the purified OECs onto the surface of the three materials, the cell activity was analyzed by detecting OD value through MTT measurement. The adherent rate was calculated, and the growth features on the material surface was examined through scan electron microscope and fluorescence microscope after stained by S-100.The results showed that, the material PRGD could maintain more cells, better cell spreading and better growth condition.In summary, PRGD has good hydrophilicity and protein absorption, PRGD is proved to be excellent in biocompatibility, cellular affinity and proliferation of OECs. Therefore, the PRGD could be used as the scaffold of spinal cord injury repair.