Hierarchically porous CaCO₃ scaffolds comprised of micro- (diameter = 2.0 ± 0.3 μm) and nano-sized (diameter = 50.4 ± 14.4 nm) pores were fabricated on silicon substrates using a supercritical CO₂-based process. Differentiated human THP-1 monocytes exposed to the CaCO₃ scaffolds produced negligible levels of the inflammatory cytokine tumor necrosis factor-alpha (TNF-α), confirming the lack of immunogenicity of the scaffolds. Extracellular matrix (ECM) proteins, vitronectin and fibronectin, displayed enhanced adsorption to the scaffolds compared to the silicon controls. ECM protein-coated CaCO₃ scaffolds promoted adhesion, growth, and proliferation of osteoblast MC3T3 cells. MC3T3 cells grown on the CaCO₃ scaffolds produced substantially higher levels of transforming growth factor-beta and vascular endothelial growth factor A, which regulate osteoblast differentiation, and exhibited markedly increased alkaline phosphatase activity, a marker of early osteoblast differentiation, compared to controls. Moreover, the CaCO₃ scaffolds stimulated matrix mineralization (calcium deposition), an end point of advanced osteoblast differentiation and an important biomarker for bone tissue formation. Taken together, these results demonstrate the significant potential of the hierarchically porous CaCO₃ scaffolds for bone tissue engineering applications.

中文翻译：

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用于骨组织工程的分层多孔碳酸钙支架

使用超临界CO ₂基工艺在硅基板上制造了由微米级（直径= 2.0±0.3μm）和纳米级（直径= 50.4±14.4 nm）孔组成的多层多孔CaCO ₃支架。暴露于CaCO ₃支架的分化人类THP-1单核细胞产生的炎症细胞因子肿瘤坏死因子-α（TNF-α）的水平可忽略不计，证实了支架缺乏免疫原性。与硅对照组相比，细胞外基质（ECM）蛋白，玻连蛋白和纤连蛋白显示出对支架的增强吸附。ECM蛋白包被的CaCO ₃支架促进成骨细胞MC3T3细胞的粘附，生长和增殖。在CaCO ₃上生长的MC3T3细胞与对照组相比，支架产生了更高水平的调节成骨细胞分化的转化生长因子-β和血管内皮生长因子A，并显着提高了碱性磷酸酶的活性，碱性磷酸酶的活性是成骨细胞早期分化的标志。此外，CaCO ₃支架刺激基质矿化（钙沉积），高级成骨细胞分化的终点和骨组织形成的重要生物标志物。综上所述，这些结果证明了分层多孔CaCO ₃支架在骨组织工程应用中的巨大潜力。