异亮氨酸-赖氨酸-缬氨酸-丙氨酸-缬氨酸多肽纳米纤维对神经干细胞生物学行为的影响

Self-assembly of IKVAV nanofiber and its effect on neural stem cells

目的制备异亮氨酸-赖氨酸-缬氨酸-丙氨酸-缬氨酸(IKVAV)多肽材料并检测其对神经干细胞(NSC)的生物学行为的影响。方法合成IKVAV多肽两亲性分子,进行自组装,用透射电镜(TEM)检测。培养NSC,加入IKVAV,用CCK-8检测吸光度(A值)显示NSC活性。同时检测IKVAV对NSC黏附、分化和轴突生长的影响。结果成功合成IKVAV并自组装成为凝胶,TEM显示为纳米纤维,直径7～8 nm,长度可达到数百纳米。当IKVAV浓度为20 mg/L和60 mg/ L时,A值有明显增加,和对照组相比差异有统计学意义(P＜0．01)。加入IKVAV后,神经球黏附率由4%上升到96%,神经球分化率由6%上升到100%,向神经元分化的比率由4．5%提高到5．6%,同时促进神经轴突生长。结论IKVAV可形成纳米纤维,并且具有良好的神经生物活性,是一种优良的神经生物材料。

Objective To synthesize bioactive IKVAVpeptide biomaterial and self-assemble it in vitro,and investigate its effect on neural stem cells （NSC）. Methods IKVAV-PA was synthesized and purified. Cell culture media with divalent cation or HCl were added to IKVAV-PA solution to induce self- assembly. The assembled material was tested with transmission electron microscope （TEM）. NSC were cultured and added with IKVAV. CCK-8 kit was used to test the biocompatibility and bioactivity. The adhesion,differentiation and neurite extension of NSC were also tested after IKVAV added. Results IKVAV-PA was synthesized successfully. IKVAV-PA could be self-assembled to produce a gel. TEM showed the self-assembled material was nanofibers with diameter of 7-8 nm and length of hundreds nanometers.When 20 mg/L or 60 mg/L IKVAV was added, NSC could have better bioactivity. Absorbance of them was increased （P 〈 0.01 ）, the adherence rate increased from 4 % to 96 % , and differentiation rate promoted from 6% to 100%. The percentage of neurons differentiated from NSC also changed from 4.5 % to 5.6 %. The cell extensions were longer when IKVAV was added. Conclusion IKVAV-PA can self-assemble to nanofiber gel, and this new biomaterial has good biocompatibility and neural bioactivity.