Abstract

The bone is a complex and dynamic structure subjected to constant stress and remodeling. Due to the worldwide incidence of bone disorders, tissue scaffolds and engineered bone tissues have emerged as solutions for bone grafting, which require sophisticated scaffolding architectures while keeping high mechanical performance. However, the conjugation of a bone-like scaffold architecture with efficient mechanical properties is still a critical challenge for biomedical applications. In this sense, the present study focused on the modulating the architecture of silk fibroin (SF) scaffolds crosslinked with horseradish peroxidase and mixed with zinc (Zn) and strontium (Sr)-doped β-tricalcium phosphate (ZnSr.TCP) to mimic bone structures. The ZnSr.TCP-SF hydrogels were tuned by programmable ice-templating parameters, and further freeze-dried, in order to obtain 3D scaffolds with controlled pore orientation. The results showed interconnected channels in the ZnSr.TCP-SF scaffolds that mimic the porous network of the native subchondral bone matrix. The architecture of the scaffolds was characterized by microCT, showing tunable pore size according to freezing temperatures (−196 °C: ∼80.2 ± 20.5 µm; −80 °C: ∼73.1 ± 20.5 µm; −20 °C: ∼104.7 ± 33.7 µm). The swelling ratio, weight loss, and rheological properties were also assessed, revealing efficient scaffold integrity and morphology after aqueous immersion. Thus, the ZnSr.TCP-SF scaffolds made of aligned porous structure were developed as affordable candidates for future applications in clinical osteoregeneration and in vitro bone tissue modelling.

摘要

骨骼是一个复杂的动态结构，承受着持续的压力和重塑。由于骨骼疾病的全球发病率，组织支架和工程骨组织已成为骨移植的解决方案，这需要复杂的支架结构同时保持高机械性能。然而，具有高效机械性能的类骨支架结构的结合仍然是生物医学应用的关键挑战。从这个意义上说，本研究的重点是调节与辣根过氧化物酶交联并与锌 (Zn) 和锶 (Sr) 掺杂的 β-磷酸三钙 (ZnSr.TCP) 混合以模拟骨骼的丝素蛋白 (SF) 支架的结构。结构。ZnSr.TCP-SF 水凝胶通过可编程的冰模板参数进行调整，并进一步冷冻干燥，以获得具有受控孔取向的 3D 支架。结果显示 ZnSr.TCP-SF 支架中的互连通道模拟天然软骨下骨基质的多孔网络。支架的结构由 microCT 表征，显示出根据冷冻温度可调的孔径（-196 °C：~80.2 ± 20.5 µm；-80 °C：~73.1 ± 20.5 µm；-20 °C：~104.7 ± 33.7微米）。还评估了溶胀比、重量损失和流变学特性，揭示了水浸后有效的支架完整性和形态。因此，由排列的多孔结构制成的 ZnSr.TCP-SF 支架被开发为未来在临床骨再生和 TCP-SF 支架模拟天然软骨下骨基质的多孔网络。支架的结构由 microCT 表征，显示出根据冷冻温度可调的孔径（-196 °C：~80.2 ± 20.5 µm；-80 °C：~73.1 ± 20.5 µm；-20 °C：~104.7 ± 33.7微米）。还评估了溶胀比、重量损失和流变学特性，揭示了水浸后有效的支架完整性和形态。因此，由排列的多孔结构制成的 ZnSr.TCP-SF 支架被开发为未来在临床骨再生和 TCP-SF 支架模拟天然软骨下骨基质的多孔网络。支架的结构由 microCT 表征，显示出根据冷冻温度可调的孔径（-196 °C：~80.2 ± 20.5 µm；-80 °C：~73.1 ± 20.5 µm；-20 °C：~104.7 ± 33.7微米）。还评估了溶胀比、重量损失和流变学特性，揭示了水浸后有效的支架完整性和形态。因此，由排列的多孔结构制成的 ZnSr.TCP-SF 支架被开发为未来在临床骨再生和 −20 °C：～104.7 ± 33.7 µm）。还评估了溶胀比、重量损失和流变学特性，揭示了水浸后有效的支架完整性和形态。因此，由排列的多孔结构制成的 ZnSr.TCP-SF 支架被开发为未来在临床骨再生和 −20 °C：～104.7 ± 33.7 µm）。还评估了溶胀比、重量损失和流变学特性，揭示了水浸后有效的支架完整性和形态。因此，由排列的多孔结构制成的 ZnSr.TCP-SF 支架被开发为未来在临床骨再生和体外骨组织建模。