Using three-dimensional (3D) bone engineering to fabricate bone segments is a better choice for repairing bone defects than using autologous bone. However, biomaterials for bone engineering are burdened with some clinical safety concerns. In this study, we layered commonly found clinical materials, hemostatic gelatin sponges, in a novel manner to create a 3D scaffold for bone engineering purposes. We further examined the comparable benefits of our design with both closed- and open-bottom holders. Cells in stacked layer disc systems were examined after a week of growth and differentiation. Osteoblasts in the outer layers of both closed- and open-bottom holder systems displayed gradually increased alkaline phosphatase (ALP) activity but decreased osteopontin (OPN) expression. Further, cell proliferation assays and LIVE/DEAD staining revealed decreased viable cell counts in the top layer with increased incubation time. However, while layered disc systems with closed-bottom holders underwent differentiation, they kept more differentiated cells alive within the gelatin sponge disc scaffold after 28 d of culturing. Whether cells were inoculated into the top, middle, or bottom portions of the layered disc stack, osteoblasts showed a preference for migrating to the top layer, in keeping with the oxygen and nutrients gradients. Regarding practical application, this study offers valuable information to promote the use of hemostatic gelatin sponges for bone engineering.

中文翻译：

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用于3D骨组织工程的临床明胶海绵上成骨细胞的细胞迁移。

与使用自体骨骼相比，使用三维（3D）骨骼工程制造骨骼段是修复骨骼缺陷的更好选择。然而，用于骨工程的生物材料承受了一些临床安全性问题。在这项研究中，我们以一种新颖的方式对常用的临床材料止血明胶海绵进行了分层，以创建用于骨骼工程目的的3D支架。我们进一步研究了封闭式和开放式刀架在设计上的可比性。经过一周的生长和分化后，检查了叠层碟片系统中的细胞。封闭和开放底部支架系统的外层中的成骨细胞显示出逐渐增加的碱性磷酸酶（ALP）活性，但降低了骨桥蛋白（OPN）的表达。进一步，细胞增殖测定和LIVE / DEAD染色显示，随着孵育时间的增加，顶层中的活细胞数减少。然而，虽然具有封闭底部支架的分层盘系统经历分化，但在培养28天后，它们使更多的分化细胞在明胶海绵盘支架中保持存活。无论是将细胞接种到分层圆盘堆的顶部，中间还是底部，成骨细胞都倾向于迁移到顶层，以保持氧气和养分的梯度。关于实际应用，这项研究提供了宝贵的信息，以促进止血明胶海绵在骨工程中的应用。培养28天后，他们在明胶海绵盘支架中保留了更多分化细胞。无论是将细胞接种到分层圆盘堆的顶部，中间还是底部，成骨细胞都倾向于迁移到顶层，以保持氧气和养分的梯度。关于实际应用，这项研究提供了宝贵的信息，以促进止血明胶海绵在骨工程中的应用。培养28天后，他们在明胶海绵盘支架中保留了更多分化细胞。无论是将细胞接种到分层圆盘堆的顶部，中间还是底部，成骨细胞都倾向于迁移到顶层，以保持氧气和养分的梯度。关于实际应用，这项研究提供了宝贵的信息，以促进止血明胶海绵在骨工程中的应用。