丝素蛋白-聚乙烯醇复合凝胶对骨组织工程支架性能的影响

The materials and preparation of tissue-engineered bone scaffolds are crucial for the performance of the scaffolds. Compared with a single polyvinyl alcohol gel, a silk fibroin - polyvinyl alcohol composite gel can not only increase the stress that the scaffold can bear but also improve the toughness of the scaffold. Research has proven that by using a water bath heating method, silk fibroin powder and polyvinyl alcohol grains are mixed and heated in a ratio of 1∶4 to make a silk fibroin - polyvinyl alcohol composite gel. Then it is fully mixed with hydroxyapatite and, based on the low-temperature freeze-drying technology, a test sample is prepared. Compression tests measured a maximum compressive strength of 31.2 MPa and an elastic modulus of 11.07 MPa. The maximum total deformation is lower than that of a single polyvinyl alcohol/hydroxyapatite sample, and it is not prone to fracture and pulverization during compression, with good comprehensive mechanical properties. Electron microscope experiments observed that the pore size of the hydroxyapatite/silk fibroin - polyvinyl alcohol composite sample is 15 - 350 μm, with evenly distributed micropores and good connectivity. When the silk fibroin - polyvinyl alcohol (1∶4) composite gel after water bath heating is mixed with hydroxyapatite in a ratio of 1.5∶1, the 3D-printed composite scaffold has a good shape, no wire expansion, and obvious pores. The hydroxyapatite/silk fibroin - polyvinyl alcohol composite material prepared using this method has mechanical properties and pore size conducive to the repair of bone defects in weight-bearing areas and the growth of bone cells.

组织工程骨支架材料及制备对支架性能影响至关重要。同单一聚乙烯醇凝胶相比,丝素蛋白-聚乙烯醇复合凝胶不仅可以增加支架所承受应力而且可以提高支架韧性。研究证明,使用水浴加热方法,将丝素蛋白粉末与聚乙烯醇晶粒按照1∶4混合加热,制成丝素蛋白-聚乙烯醇复合凝胶。再与羟基磷灰石充分混合,基于低温冷冻干燥技术,制备成试验试样。压缩试验测量最大压缩强度为31.2 MPa,弹性模量为11.07 MPa,最大总变形低于单一聚乙烯醇/羟基磷灰石试样,且压缩时不易发生断裂及粉碎,综合力学性能较好。电镜实验观察得到羟基磷灰石/丝素蛋白-聚乙烯醇复合材料试样孔径为15350μm,微孔分布均匀且连通性较好。水浴加热后的丝素蛋白-聚乙烯醇（1∶4）复合凝胶与羟基磷灰石按照1.5∶1混合时,3D打印复合材料支架成形好,无丝材膨胀,孔隙明显。使用此方法制备的羟基磷灰石/丝素蛋白-聚乙烯醇复合材料,力学性能及孔径大小利于负重部位骨缺损修复及骨细胞的生长。