颗粒状水凝胶支架（GHS）是通过将水凝胶微粒（HMP）紧密接触（堆积），然后形成物理和/或化学颗粒间键来制造的。甲基丙烯酰明胶 (GelMA) GHS 最近已成为生物医学应用的一个有前景的平台；然而，人们对物理交联软 GelMA HMP 结构单元的堆积如何影响 GHS 的物理（孔隙微结构和机械/流变特性）和生物（体外和体内）属性知之甚少。在这里，GHS 孔微结构是通过外部（离心）力引起的 GelMA HMP 堆积和变形来设计的，以调节 GHS 机械和流变特性，以及体外和体内的生物反应。增加离心力的大小和持续时间会增加 HMP 变形/填充，降低 GHS 空隙率和中值孔径，并增加 GHS 压缩模量和储能模量。在松散堆积的 GHS 中，MDA-MB-231 人三阴性乳腺癌细胞在 GelMA HMP 表面上扩散并变平，而在高度堆积的 GHS 中，由于空间限制，它们采用拉长的形态。通过在 GHS 中培养未经处理或经肌球蛋白抑制剂处理的细胞，显示了非肌肉肌球蛋白 II 驱动的收缩性对细胞形态的影响。小鼠体内皮下植入证实 GHS 内的内皮细胞、成纤维细胞和巨噬细胞浸润明显较高，且堆积密度较低，这与体外细胞迁移结果一致。这些结果表明，GelMA GHS 的堆积状态可以实现体外细胞反应和体内组织反应的工程化。这项研究是组织工程和再生的 GelMA GHS 微架构标准化和工程化方面向前迈出的重要一步。© 2024 作者。先进医疗保健材料由 Wiley‐VCH GmbH 出版。

Granular hydrogel scaffolds (GHS) are fabricated via placing hydrogel microparticles (HMP) in close contact (packing), followed by physical and/or chemical interparticle bond formation. Gelatin methacryloyl (GelMA) GHS have recently emerged as a promising platform for biomedical applications; however, little is known about how the packing of building blocks, physically crosslinked soft GelMA HMP, affects the physical (pore microarchitecture and mechanical/rheological properties) and biological (in vitro and in vivo) attributes of GHS. Here, the GHS pore microarchitecture is engineered via the external (centrifugal) force-induced packing and deformation of GelMA HMP to regulate GHS mechanical and rheological properties, as well as biological responses in vitro and in vivo. Increasing the magnitude and duration of centrifugal force increases the HMP deformation/packing, decreases GHS void fraction and median pore diameter, and increases GHS compressive and storage moduli. MDA-MB-231 human triple negative breast adenocarcinoma cells spread and flatten on the GelMA HMP surface in loosely packed GHS, whereas they adopt an elongated morphology in highly packed GHS as a result of spatial confinement. Via culturing untreated or blebbistatin-treated cells in GHS, the effect of non-muscle myosin II-driven contractility on cell morphology is shown. In vivo subcutaneous implantation in mice confirms a significantly higher endothelial, fibroblast, and macrophage cell infiltration within the GHS with a lower packing density, which is in accordance with the in vitro cell migration outcome. These results indicate that the packing state of GelMA GHS may enable the engineering of cell response in vitro and tissue response in vivo. This research is a fundamental step forward in standardizing and engineering GelMA GHS microarchitecture for tissue engineering and regeneration.© 2024 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.