Developing adequate biomaterials to engineer cell-scaffold interactions has become a promising way for physically regulating the biological behaviors of cells in the field of tissue engineering. Biopolymeric hydrogels have shown great merits as cellular scaffolds due to their biocompatible and biodegradable characteristics. In particular, the advent of atomic force microscopy (AFM) provides a powerful tool for characterizing native specimens at the micro/nanoscale, but utilizing AFM to investigate the detailed structures and properties of hydrogel scaffolds has been still scarce. In this paper, hybrid natural biopolymers are used to form hydrogel scaffolds which exhibit tunable structural and mechanical properties characterized by AFM peak force tapping imaging, and the applications of the formed hydrogel scaffolds in tissue engineering are studied. AFM morphological images showed that the cross-linking reactions of sodium alginate and gum arabic via calcium cations yielded the porous hydrogel scaffolds. By altering the component ratios, AFM mechanical images showed that the porous and mechanical properties (Young's modulus and adhesion force) of the hydrogel scaffolds were tunable. Next, the nanoscale structural and mechanical dynamics of the fabricated hydrogel scaffolds during the degradation process were revealed by AFM peak force tapping imaging. The experimental results on three different types of cells showed that the fabricated hydrogel scaffolds facilitate the formation of cellular spheroids. The research provides a novel idea to design tunable hydrogel scaffolds based on AFM characterizations for investigating cell-scaffold interactions, which will have potential impacts on tissue engineering.

中文翻译：

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基于组织工程学的基于原子力显微镜表征的可调杂化生物聚合物水凝胶支架。

开发足够的生物材料来工程化细胞-支架相互作用已经成为在组织工程领域中物理调节细胞生物学行为的有前途的方法。由于其生物相容性和可生物降解的特性，生物聚合物水凝胶已显示出作为细胞支架的巨大优势。特别是，原子力显微镜（AFM）的出现提供了一种强大的工具，可用于在微米/纳米尺度上表征天然标本，但仍缺乏利用AFM来研究水凝胶支架的详细结构和特性的方法。在本文中，杂种天然生物聚合物被用于形成水凝胶支架，该支架表现出以AFM峰值力攻丝成像为特征的可调节的结构和机械性能，研究了形成的水凝胶支架在组织工程中的应用。AFM形态学图像表明，藻酸钠和阿拉伯胶通过钙阳离子的交联反应产生了多孔水凝胶支架。通过改变组分比率，AFM机械图像显示水凝胶支架的多孔和机械性能（杨氏模量和粘附力）是可调的。接下来，通过AFM峰值力攻丝成像揭示了在降解过程中所制备的水凝胶支架的纳米级结构和力学动力学。在三种不同类型的细胞上的实验结果表明，所制备的水凝胶支架可促进细胞球体的形成。