Biocompatible and biodegradable three-dimensional scaffolds are commonly porous which serve to provide suitable microenvironments for mechanical supporting and optimal cell growth. Silk fibroin (SF) is a natural and biomedical polymer with appropriate and improvable mechanical properties. Making a composite with a bioceramicas reinforcement is a general strategy to prepare a scaffold for hard tissue engineering applications. In the present study, SF was separately combined with titanium dioxide (TiO₂) and fluoridated titanium dioxide nanoparticles (TiO₂-F) as bioceramic reinforcements for bone tissue engineering purposes. At the first step, SF was extracted from Bombyx mori cocoons. Then, TiO₂ nanoparticles were fluoridated by hydrofluoric acid. Afterward, SF/TiO₂ and SF/TiO₂-F nanocomposite scaffolds were prepared by freeze-drying method to obtain a porous microstructure. Both SF/TiO₂ and SF/TiO₂-F scaffolds contained 0, 5, 10, 15 and 20 wt% nanoparticles. To evaluate the efficacy of nanoparticles addition on the mechanical properties of the prepared scaffolds, their compressive properties were assayed. Likewise, the pores morphology and microstructure of the scaffolds were investigated using scanning electron microscopy. In addition, the porosity and density of the scaffolds were measured according to the Archimedes’ principle. Afterward, compressive modulus and microstructure of the prepared scaffolds were evaluated and modeled by Gibson–Ashby’s mechanical models. The results revealed that the compressive modulus predicted by the mechanical model exactly corresponds to the experimental one. The modeling approved the honeycomb structure of the prepared scaffolds which possess interconnected pores.

中文翻译：

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用于骨组织工程的丝素蛋白/ TiO 2和丝素蛋白/氟化TiO 2纳米复合支架的力学建模

具有生物相容性且可生物降解的三维支架通常是多孔的，可为机械支撑和最佳细胞生长提供合适的微环境。丝素蛋白（SF）是一种天然的生物医学聚合物，具有适当且可改善的机械性能。用生物陶瓷增强材料制造复合材料是制备用于硬组织工程应用的支架的一般策略。在本研究中，SF分别与二氧化钛（TiO ₂）和氟化二氧化钛纳米颗粒（TiO ₂ -F）结合用作骨组织工程用途的生物陶瓷增强剂。第一步，从桑蚕茧中提取SF 。然后，TiO ₂纳米颗粒被氢氟酸氟化。然后，通过冷冻干燥法制备了SF / TiO ₂和SF / TiO ₂ -F纳米复合支架，得到了多孔的微观结构。SF / TiO ₂和SF / TiO ₂-F支架包含0、5、10、15和20wt％的纳米颗粒。为了评估纳米颗粒添加对制备的支架的机械性能的功效，测定了它们的压缩性能。同样，使用扫描电子显微镜研究了支架的孔形态和微观结构。另外，根据阿基米德原理测量支架的孔隙率和密度。然后，通过Gibson-Ashby的力学模型对准备好的脚手架的压缩模量和微观结构进行评估和建模。结果表明，力学模型预测的压缩模量与实验值完全吻合。该模型批准了所制备的具有互连孔的支架的蜂窝结构。