부산대학교 도서관

背景:课题组前期研究发现,添加硫酸钡可以提高磷酸钙骨水泥的力学性能与显影性能,但伴随磷酸钙降解残存的显影剂难以降解,在植入部位产生的占位效应及破骨效应影响骨修复进程,因此需要开发一种可生物降解的新型显影材料. 目的:探讨生物活性可降解材料多聚磷酸锶的显影能力及其对磷酸钙骨水泥理化性能与成骨效应的影响. 方法:①分别制备磷酸钙骨水泥(CPC)、淀粉改性磷酸钙骨水泥(CPS)与含多聚磷酸锶(占骨水泥粉末的质量分数为20%)淀粉改性磷酸钙骨水泥(20%SrPP-CPN),表征3组骨水泥的理化性能.②将3组骨水泥浸提液分别与大鼠骨髓间充质干细胞共培养,检测细胞增殖、能量代谢与成骨分化能力.③在24只SD大鼠颅顶部两侧各制作直径5 mm的骨缺损,随机分为对照组(不进行任何干预)、CPC组、CPS组与20%SrPP-CPN组进行干预,每组6只.干预4,12周后取材进行相关检测. 结果与结论:①与其他两组骨水泥比较,20%SrPP-CPN的显影能力增强、抗压强度与降解速率升高、固化时间延长,并且20%SrPP-CPN在降解过程中可稳定释放Sr2+.②CCK-8实验显示20%SrPP-CPN不影响骨髓间充质干细胞的增殖;细胞饥饿实验(无血清培养)显示相较于其他两组骨水泥,20%SrPP-CPN可促进骨髓间充质干细胞的增殖;相较于其他两组骨水泥,20%SrPP-CPN可提升骨髓间充质干细胞内ATP浓度.碱性磷酸酶与茜素红染色显示,相较于其他两组骨水泥,20%SrPP-CPN可促进骨髓间充质干细胞的成骨分化.③在大鼠颅骨缺损实验中,Micro-CT扫描、组织学(苏木精-伊红、Masson染色)观察显示相较于CPC组、CPS组,20%SrPP-CPN组骨水泥降解明显,并且大量新生骨组织分散于降解的骨水泥中;免疫组化染色显示相较于CPC组、CPS组,20%SrPP-CPN组缺损处Runx2蛋白表达升高(P＜0.01).④结果表明,20%SrPP-CPN具有良好的显影性能与促成骨性能.
BACKGROUND:Our previous studies found that adding barium sulfate could improve the mechanical and radiopaque properties of calcium phosphate cement.However,with the degradation of calcium phosphate,the remaining radiopaque agent is difficult to degrade,and the space-occupying and osteoclast effects at the implantation site affect the bone repair process.Therefore,it is necessary to develop a new biodegradable radiopaque material. OBJECTIVE:To discuss the radiopaque ability of bioactive degradable material strontium polyphosphate(SrPP)and its impact on the physicochemical properties and osteogenic effect of calcium phosphate cement. METHODS:(1)Calcium phosphate cement(CPC),starch modified calcium phosphate cement(CPS)and starch modified calcium phosphate cement(20%SrPP-CPN)containing SrPP(20%mass fraction of bone cement powder)were prepared respectively,and the physicochemical properties of the three groups of bone cements were characterized.(2)The three groups of bone cement extracts were co-cultured with rat bone marrow mesenchymal stem cells,respectively,to detect cell proliferation,energy metabolism,and osteogenic differentiation.(3)Bone defects with a diameter of 5 mm were made on each side of the top of the skull of 24 SD rats,and they were randomly divided into control group(without any intervention),CPC group,CPS group,and 20%SrPP-CPN group for intervention,with 6 rats in each group.Relevant tests were performed after 4 and 12 weeks of intervention. RESULTS AND CONCLUSION:(1)Compared with the other two groups of bone cement,20%SrPP-CPN had enhanced radiopaque ability,increased compressive strength and degradation rate,and prolonged curing time,and 20%SrPP-CPN could release Sr2+ stably during degradation.(2)CCK-8 assay showed that 20%SrPP-CPN did not affect the proliferation of bone marrow mesenchymal stem cells.Cell starvation test(serum-free culture)showed that 20%SrPP-CPN could promote the proliferation of bone marrow mesenchymal stem cells compared with the other two groups of bone cement.Compared with the other two groups of bone cements,20%SrPP-CPN increased adenosine triphosphate concentration in bone marrow mesenchymal stem cells.Alkaline phosphatase and alizarin red staining showed that 20%SrPP-CPN could promote osteogenic differentiation of bone marrow mesenchymal stem cells compared with the other two groups of bone cement.(3)In the rat skull defect experiment,Micro-CT scanning and histological observation(hematoxylin-eosin and Masson stainings)showed that bone cement in 20%SrPP-CPN group was significantly degraded compared with that in CPC and CPS groups,and a large number of new bone tissues were dispersed in degraded bone cement.Immunohistochemical staining showed that Runx2 protein expression was increased in 20%SrPP-CPN group compared with CPC group and CPS group(P＜0.01).(4)These results show that 20%SrPP-CPN has good radiopaque ability and osteogenic properties.