【摘要】 背景:骨缺损修复的临床成功不仅取决于成骨作用,还与血管生成以及抑制骨吸收能力密切相关。因此,开发具有多种功能的生物支架材料尤为重要。目的:通过微量元素掺杂的方式改善传统骨修复材料所存在的力学强度低、促血管能力不强、骨诱导能力不足等多种问题。方法:通过高温烧结法将不同摩尔含量的铕(0%,1%,3%,5%和7%)掺入聚磷酸钙支架中,制备出多孔掺铕聚磷酸钙支架。采用红外光谱、X射线衍射分析、X射线光电子能谱分析、扫描电镜、压汞法和抗压强度测试等分析方法分别对其结构、晶型、元素组成、孔径分布及力学性能等进行表征分析。将各组支架分别与小鼠胚胎成骨细胞前体细胞和人脐静脉内皮细胞共培养,并通过细胞增殖检测、扫描电镜、激光扫描共聚焦显微镜、酶联免疫吸附法等测试对其生物学性能进行综合评估。结果与结论:(1)铕的掺杂并没有改变聚磷酸钙的主链结构及其β晶型,但可将孔径分布稳定在200-400μm内,以利于骨骼长入。(2)与纯聚磷酸钙支架相比,掺铕聚磷酸钙支架的晶粒结合更紧密且排列更有序,材料的机械强度显著提升。(3)掺铕聚磷酸钙支架表面粗糙度有利于细胞的黏附和铺展,可同时促进小鼠胚胎成骨细胞前体细胞和人脐静脉内皮细胞在支架表面的生长和增殖,其中以5%掺铕聚磷酸钙组最明显。(4)掺铕聚磷酸钙支架可明显刺激材料上小鼠胚胎成骨细胞前体细胞分泌碱性磷酸酶与骨桥蛋白,以及人脐静脉内皮细胞分泌血管内皮生长因子与基质金属蛋白酶9,有利于成骨细胞的增殖分化,其中以5%掺铕聚磷酸钙组最明显。(5)5%掺铕聚磷酸钙可显著上调由成骨细胞分泌的骨保护素/核因子κB受体活化因子配体比例,表现出抑制骨溶解的潜力,可起到防治无菌性松动的作用。(6)结果表明,5%掺铕聚磷酸钙支架具有加速血管生成和成骨及抑制骨吸收的潜在性能,是一种有前途的多功能生物材料。更多还原

【Abstract】 BACKGROUND: The clinical success of bone grafts depends not only on osteogenesis, but also on angiogenesis, and the ability to inhibit osteoclast-mediated bone resorption. Therefore, it is particularly important to develop bio-scaffold materials with multiple functions.OBJECTIVE: To improve various problems of traditional bone repair materials, such as low mechanical strength, poor vascular promoting ability, and insufficient osteoinductive ability through the doping of trace elements.METHODS: A series dose of Eu（0%, 1%, 3%, 5% and 7%, molar ratio）was incorporated into calcium polyphosphate scaffolds by high temperature sintering to achieve a multifunctional europium-doped calcium polyphosphate. Infrared spectroscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, scanning electron microscopy, mercury intrusion method and compressive strength test were used to characterize its structure, crystal form, element composition, pore size distribution, and mechanical properties. The europium-doped calcium polyphosphate scaffold was co-cultured with mouse embryonic osteoblast precursor cells and human umbilical vein endothelial cells. Biological performance was evaluated through cell proliferation detection, scanning electron microscope, laser scanning confocal microscope, and enzyme-linked immunosorbent assay.RESULTS AND CONCLUSION:（1）The doping of Eu3+ did not change the main chain structure and crystal form of calcium polyphosphate, but it could stabilize the pore size distribution within 200-400 μm, which was conducive to bone ingrowth.（2）Compared to pure calcium polyphosphate materials, the crystal grains of europium-doped calcium polyphosphate scaffolds were bonded more closely and ranged well-ordered, which were beneficial to improve mechanical strength of materials.（3）The surface roughness of europium-doped calcium polyphosphate scaffolds was conducive to cell adhesion and spreading. Mouse embryonic osteoblast precursor cells and human umbilical vein endothelial cells seeded on europium-doped calcium polyphosphate scaffolds presented better proliferation and migration, especially 5% group.（4）The secretion of four growth factors（alkaline phosphatase and osteopontin, and human umbilical vein endothelial cells secreted vascular endothelial growth factor and matrix metalloproteinase 9）from co-cultured cells seeded on europium-doped calcium polyphosphate scaffolds was enhanced, which was conducive to the proliferation and differentiation of osteoblasts, especially 5% group.（5）5% europiumdoped calcium polyphosphate significantly up-regulated the ratio of osteoprotegerin/nuclear factor kappa B receptor activator ligand from osteoblast so that it had a potential efficacy to inhibit bone resorption, thus acted as an effect of alleviating aseptic loosening.（6）The above results show that the 5%europium-doped calcium polyphosphate scaffold has the potential to accelerate angiogenesis/osteogenesis and inhibit bone resorption, which is a promising multifunctional biomaterial.更多还原