壳聚糖-丝素蛋白-磷酸三钙支架的力学性能及异位成骨能力的研究

摘要

Objective To find a better scaffold material for periodontal tissue engineering by comparing the mechanical properties and osteogenic potentials of the chitosan-silk fibroin (CS-SF) scaffold versus the chitosan-silk fibroin-tricalcium (CS-SF-TCP) scaffold.Methods The 2 sorts of scaffolds were prepared by freezing and lyophilizing techniques.The modulus of compressibility in the 2 scaffolds was determined by a tensile testing machine (INSTRON 5544).Mouse bone marrow stromal cells (BMSCs) were incubated in the 2 scaffolds for 3 days before the complexes were implanted aseptically into the subcutaneous back of nude mice.Four weeks after implantation,specimens were harvested for gross observation,hematoxylin-eosin staining and immunohistochemical staining of type Ⅰ collagen to assess the in vivo osteogenic potentials of the 2 scaffolds.Results The compressive strength of the CS-SF-TCP scaffold [(1.44±0.96) MPa] was significantly higher than that of the CS-SF scaffold [(0.44±0.15) MPa] (P＜0.05).All the implants were covered by a thick membrane by gross observation.HE staining showed beth CS-SF+BMSCs and CS-SF-TCP+BMSCs complexes had massive cellular proliferation and collagen synthesis in the pores of the 2 scaffolds.Expressions of type Ⅰ collagen were observed in the 2 complexes but the expression in the CS-SF-TCP+BMSCs was significantly higher than in the CS-SF+BMSCs (P＜0.05).Conclusion The CS-SF-TCP scaffold is more suitable for periodontal tissue engineering because it possesses better biomechanical performance and a greater osteogenic potential than the CS-SF scaffold.%目的 对壳聚糖-丝素蛋白支架(CS-SF)与壳聚糖-丝素蛋白-磷酸三钙支架(CS-SF-TCP)的力学性能及早期体内成骨能力进行实验研究,以寻求更适合牙周组织工程的支架材料.方法 采用二次冻干技术制备2种支架,用Instron 5544拉伸实验机对该2种支架的压缩模量进行测试,并将2种支架与矿化诱导后的骨髓基质细胞(BMSCs)复合培养3d后无菌条件下移植入裸鼠背部皮下,4周时取出标本行大体观察、苏木精-伊红染色、Ⅰ型胶原免疫组织化学染色,观察2种支架的体内成骨能力.结果 力学性能检测结果显示:CS-SF组与CS-SF-TCP组的抗压强度分别为(0.44±O.15)MPa、(1.44±0.96) MPa.CS-SF-TCP组高于CS-SF组(P＜0.05).早期体内成骨能力结果:肉眼观察取出的植入物均有薄膜包绕.HE染色可见CS-SF+BMSCs与CS-SF-TCP+BMSCs组可见支架中心长入大量的细胞并有胶原样物质生成.免疫组织化学见2组均有不同程度的Ⅰ型胶原阳性表达,CS-SF-TCP+BMSCs组表达要高于CS-SF+BMSCs组(P＜0.05).结论 与CS-SF支架相比,CS-SF-TCP支架有更好的力学性能及诱导BMSCs形成新生的骨组织的能力,更适合于牙周组织工程的支架.