Among many biomaterials, gelatin methacrylate (GelMA), a photocurable protein, has been widely used in 3D bioprinting process owing to its excellent cellular responses, biocompatibility and biodegradability. However, GelMA still shows a low processability due to the severe temperature dependence of viscosity. To overcome this obstacle, we propose a two-stage temperature control system to effectively control the viscosity of GelMA. To optimize the process conditions, we evaluated the temperature of the cooling system (jacket and stage). Using the established system, three GelMA scaffolds were fabricated in which different concentrations (0, 3 and 10 wt%) of silanated silica particles were embedded. To evaluate the performances of the prepared scaffolds suitable for hard tissue regeneration, we analyzed the physical (viscoelasticity, surface roughness, compressive modulus and wettability) and biological (human mesenchymal stem cells growth, western blotting and osteogenic differentiation) properties. Consequently, the composite scaffold with greater silica contents (10 wt%) showed enhanced physical and biological performances including mechanical strength, cell initial attachment, cell proliferation and osteogenic differentiation compared with those of the controls. Our results indicate that the GelMA/silanated silica composite scaffold can be potentially used for hard tissue regeneration.

中文翻译：

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两级冷却系统辅助硬组织再生的 3D 打印明胶甲基丙烯酸酯 (GelMA)/硅烷化二氧化硅支架

在众多生物材料中，甲基丙烯酸明胶（GelMA）是一种光固化蛋白，由于其优异的细胞反应、生物相容性和生物降解性，已被广泛用于3D生物打印过程。然而，由于粘度对温度的严重依赖性，GelMA 的加工性能仍然很低。为了克服这个障碍，我们提出了一种两级温度控制系统来有效控制 GelMA 的粘度。为了优化工艺条件，我们评估了冷却系统（夹套和平台）的温度。使用已建立的系统，制造了三种 GelMA 支架，其中嵌入了不同浓度（0、3 和 10 wt%）的硅烷化二氧化硅颗粒。为了评估制备的适用于硬组织再生的支架的性能，我们分析了物理（粘弹性、表面粗糙度、压缩模量和润湿性）和生物学（人间充质干细胞生长、蛋白质印迹和成骨分化）特性。因此，与对照组相比，具有更高二氧化硅含量（10 wt%）的复合支架显示出增强的物理和生物学性能，包括机械强度、细胞初始附着、细胞增殖和成骨分化。我们的结果表明，GelMA/硅烷化二氧化硅复合支架可潜在地用于硬组织再生。与对照组相比，具有更高二氧化硅含量（10 wt%）的复合支架显示出增强的物理和生物学性能，包括机械强度、细胞初始附着、细胞增殖和成骨分化。我们的结果表明，GelMA/硅烷化二氧化硅复合支架可潜在地用于硬组织再生。与对照组相比，具有更高二氧化硅含量（10 wt%）的复合支架显示出增强的物理和生物学性能，包括机械强度、细胞初始附着、细胞增殖和成骨分化。我们的结果表明，GelMA/硅烷化二氧化硅复合支架可潜在地用于硬组织再生。