Stem cells with mineralized materials have been used for bone regeneration; however, engineering the complex vascularized structure of the natural bone remains a challenge. Here, we developed platelet-derived growth factor (PDGF) and bio-mineral coated fibers which were then assembled with human adipose-derived stem cells (hADSCs) to form spheroids as building blocks for vascularized bone regeneration. The PDGF incorporated within the spheroid increased the proliferation of hADSCs, which was characterized by Ki-67 staining and DNA contents. Furthermore, the PDGF enhanced not only osteogenic differentiation, but also endothelial differentiation of hADSCs; the cells within the spheroids showed significantly greater gene expression by 2.46 ± 0.14 fold for osteocalcin (OCN) and by 12.85 ± 3.36 fold for von Willebrand factor (vWF) than those without PDGF. Finally, at two months following transplantation of PDGF-incorporated spheroids onto in vivo mouse calvarial defect, the regenerated bone area (42.48 ± 10.84%) was significantly enhanced and the greatest number of capillaries and arterioles with indication of transplanted hADSCs were observed. Moreover, millimeter-scale in vitro tissue prepared by fused assembly of the spheroids exhibited greater mRNA expression-associated to endothelial lineage. Taken together, these findings indicate that stem cell spheroids incorporating PDGF and bio-minerals could be used as a module for successful vascularized bone regeneration.

具有矿物质的干细胞已用于骨骼再生。然而，工程化天然骨骼的复杂血管化结构仍然是一个挑战。在这里，我们开发了血小板衍生的生长因子（PDGF）和生物矿物质涂层的纤维，然后将其与人脂肪衍生的干细胞（hADSCs）组装在一起，形成球体作为血管化骨再生的基础。掺入球状体中的PDGF可增加hADSC的增殖，其特征在于Ki-67染色和DNA含量。而且，PDGF不仅增强了hADSC的成骨分化，而且还增强了内皮分化。骨钙素（OCN）的球体细胞显示的基因表达明显提高了2.46±0.14倍，而12.85±3倍。von Willebrand因子（vWF）的含量是无PDGF的36倍。最后，在将PDGF结合的球体移植到两个月后在体内小鼠颅盖缺损中，再生的骨面积（42.48±10.84％）显着增强，并观察到最大数量的毛细血管和小动脉，提示有移植的hADSC。此外，通过球体的融合组装制备的毫米级体外组织显示出与内皮谱系相关的更大的mRNA表达。综上所述，这些发现表明，结合了PDGF和生物矿物质的干细胞球体可以用作成功进行血管化骨再生的模块。