To avoid large open surgery using scaffold transplants, small‐sized cell carriers are employed to repair complexly shaped tissue defects. However, most cell carriers show poor cell adherences and viability. Therefore, polyhydroxyalkanoate (PHA), a natural biopolymer, is used to prepare highly open porous microspheres (OPMs) of 300–360 µm in diameter, combining the advantages of microspheres and scaffolds to serve as injectable carriers harboring proliferating stem cells. In addition to the convenient injection to a defected tissue, and in contrast to poor performances of OPMs made of polylactides (PLA OPMs) and traditional less porous hollow microspheres (PHA HMs), PHA OPMs present suitable surface pores of 10–60 µm and interconnected passages with an average size of 8.8 µm, leading to a high in vitro cell adhesion of 93.4%, continuous proliferation for 10 d and improved differentiation of human bone marrow mesenchymal stem cells (hMSCs). PHA OPMs also support stronger osteoblast‐regeneration compared with traditional PHA HMs, PLA OPMs, commercial hyaluronic acid hydrogels, and carrier‐free hMSCs in an ectopic bone‐formation mouse model. PHA OPMs protect cells against stresses during injection, allowing more living cells to proliferate and migrate to damaged tissues. They function like a micro‐Noah's Ark to safely transport cells to a defect tissue.

中文翻译：

---

细胞微方舟：高度开放的多孔聚羟基链烷酸酯微球作为组织再生的可注射支架

为了避免使用支架移植的大型开放手术，采用小型细胞载体修复形状复杂的组织缺损。但是，大多数细胞载体显示出较差的细胞粘附性和生存能力。因此，聚羟基链烷酸酯（PHA）是一种天然生物聚合物，可用于制备直径为300-360 µm的高度开放的多孔微球（OPM），结合了微球和支架的优势，可作为具有增殖干细胞的可注射载体。除了可以方便地注射到有缺陷的组织上，并且与由聚丙交酯（PLA OPM）和传统的多孔性较低的空心微球（PHA HM）制成的OPM的性能较差相比，PHA OPM的表面孔隙为10–60 µm，并且相互连接平均大小为8.8 µm的传代细胞，导致体外细胞粘附率高达93.4％，连续增殖10 d并改善了人骨髓间充质干细胞（hMSCs）的分化。在异位骨形成小鼠模型中，与传统的PHA HM，PLA OPM，商业透明质酸水凝胶和无载体hMSC相比，PHA OPM还支持更强的成骨细胞再生。PHA OPM保护细胞免受注射过程中的压力，使更多的活细胞增殖并迁移至受损组织。它们的作用就像微型诺亚方舟，可将细胞安全地运输到缺损组织。PHA OPM保护细胞免受注射过程中的压力，使更多的活细胞增殖并迁移至受损组织。它们的作用就像微型诺亚方舟，可将细胞安全地运输到缺损组织。PHA OPM保护细胞免受注射过程中的压力，使更多的活细胞增殖并迁移至受损组织。它们的作用就像微型诺亚方舟，可将细胞安全地运输到缺损组织。