Biomaterial mediated bone regeneration is an attractive strategy for bone defect treatment. Organic/inorganic composites have been well established as effective bone graft. Here, the bone regenerative effect of the composites made from tannic acid (TA) modified hydroxyapatite (HA) (THA) or TA & silver nanoparticles (Ag NPs) modified HA (Ag-THA) and polyurethane (PU) was evaluated on critical-sized calvarial defects in rats. The in vivo study indicates that PU/THA and PU/Ag-THA scaffolds exhibited acceptable biocompatibility and induced significantly enhanced bone mineral densities comparing with the blank control (CON) group as well as PU/HA group. The inclusion of TA on HA brought the composites with enhanced osteogenesis and angiogenesis, evidenced by osteocalcin (OCN) and vascular endothelial growth factor (VEGF) immunohistochemical staining. Tartrate resistant acid phosphatase (TRAP) staining showed high osteoclast activity along with osteogenesis, especially in PU/THA and PU/Ag-THA groups. However, further introduction of Ag NPs on HA depressed the angiogenesis of the composites, leading to even lower VEGF expression than that of CON group. This study once more proved that THA can serve as a better bone composite component that pure HA and can promote osteogenesis and angiogenesis. While, the introduction of antimicrobial Ag NPs on HA need to be controlled in some extent not to affect the angiogenesis of the composites.

生物材料介导的骨再生是骨缺损治疗的一种有吸引力的策略。有机/无机复合材料已被证实是有效的骨移植物。在这里，对由单宁酸（TA）改性羟基磷灰石（HA）（THA）或TA＆银纳米颗粒（Ag NPs）改性HA（Ag-THA）和聚氨酯（PU）制成的复合材料的骨再生效果进行了关键-评估。大鼠颅骨大小缺损。体内研究表明，与空白对照组（CON）组和PU/HA组相比，PU/THA和PU/Ag-THA支架表现出可接受的生物相容性，并诱导显着提高的骨矿物质密度。骨钙素 (OCN) 和血管内皮生长因子 (VEGF) 免疫组织化学染色证明，在 HA 上添加 TA 可以增强复合材料的成骨和血管生成能力。抗酒石酸酸性磷酸酶 (TRAP) 染色显示破骨细胞活性高，同时骨生成，特别是在 PU/THA 和 PU/Ag-THA 组中。然而，在HA上进一步引入Ag NPs抑制了复合材料的血管生成，导致VEGF表达比CON组更低。本研究再次证明THA可以作为比纯HA更好的骨复合材料成分，并能促进成骨和血管生成。同时，需要在一定程度上控制HA上抗菌Ag NPs的引入，以免影响复合材料的血管生成。