可注射生物玻璃—磷酸钙骨水泥复合生物材料的实验研究

发布时间：2018-04-25 11:06

本文选题：磷酸钙骨水泥 + 生物玻璃　；参考：《第四军医大学》2013年博士论文

【摘要】：我国50岁以上人群中有骨质疏松(Osteoporosis, OP)患者近7000万，每年新发脊柱压缩骨折约181万例。微创椎体成形术(Vertebroplasty, VP)或球囊扩张椎体后凸成形术(Balloon kphoplasty, BKP)是脊柱压缩骨折(Vertebral compression fractures, VCF)的主要外科治疗手段。VP或BKP中所采用的材料大多数为聚甲基丙烯酸甲酯（Polymethylmethacrylate, PMMA）。该材料存在明显缺陷：不可吸收、无生物活性（骨传导、诱导作用等），固化过程中发热明显等。因此，寻找一种能够具有良好流动性、骨传导、骨诱导作用，兼具良好的力学支撑性能及一定降解率的骨修复材料已经成为骨科亟待解决的难题。磷酸钙骨水泥（Calcium phosphate cement, CPC）因其自固化，无类似PMMA的产热效应，可任意塑形，良好的生物相容性、骨传导性及可降解被新生骨替代等特点，具有广阔的临床应用价值。然而，CPC在体内降解缓慢。另外，在一些供血不足区域及伴代谢紊乱的老年病患中，CPC的骨传导作用并不足以达到完全的骨修复效果，因此赋予CPC更高的传导性或诱导性可进一步改善其生物学性能。生物玻璃（Bioactive glass, BG）由于其良好的生物活性和生物相容性倍受关注，生物玻璃与软组织或骨之间存在密切的离子交换，可直接参与人体骨组织的代谢和修复过程，最终可在材料表面形成与人体骨相同的无机矿物成分——碳酸羟基磷灰石，诱导新生骨组织的生长。将其作为可注射型材料组成成分与CPC复合应用于椎体成形或球囊成形术及不规则骨缺损如口腔及颅面部等处的骨缺损填充修复的研究鲜见文献报道。目的：优选最佳的CPC与BG材料复合比，研发出一种体内可吸收、具有良好生物相容性及成骨活性的新型可注射生物复合材料。方法： 1.将CPC与BG以不同质量比混合后，比较其固化时间及可注射性能，筛选出合适的材料复合比； 2.将CPC与BG以选定的材料复合比及固液比混合后，分析其组成成分，微观结构，固化时间，可注射性能，力学强度及体外生物活性特性和降解性等材料学特性； 3.将大鼠成骨细胞(osteoblasts, OB)接种于材料试件表面，观察OB在试件表面粘附、增殖和分化能力； 4.将CPC-BG复合生物材料植入新西兰白兔体内4，12周后，行大体、显微CT（Micro-computed tomography，Micro-CT）分析和组织学观察。结果： 1.随着BG加入的比例增加（10%,20%,30%,40%），CPC-BG复合生物材料的固化时间延长，可注射性能提高。较单纯CPC，CPC-BG组固化时间延长（21min到44min），同时可注射性能显著提高（P 0.05）； 2. CPC-BG复合生物材料的材料学研究中，X射线衍射分析（X-ray diffraction，XRD）结果显示CPC及CPC-BG复合生物材料组主要的衍射峰为沉积的羟基磷灰石（Hydroxyapatite, HAp），随着BG含量从10%升至20%，可出现Ca2SiO4及Ca3SiO5衍射峰，电镜观察发现加入BG后，材料结构更紧密。力学性能方面，固化1天及7天后的材料CPC+20%BG组明显高于单纯CPC组（P 0.05）。体外生物活性实验结果发现，浸泡模拟体液（Simulated body fluid, SBF）后，CPC-BG组表面HA沉积量明显多于CPC。能谱结果（Energy dispersive spectroscopy, EDS）表明，CPC-BG复合材料表面沉积的HA主要由Ca, P及Si组成，而CPC仅含Ca及P元素。体外降解实验发现，加入BG后可提高材料降解性； 3.细胞学实验结果表明，加入BG后，可提高成骨细胞的粘附，增殖及分化。MTT结果显示，8h后，CPC-BG复合材料组与单纯CPC组有统计学差异（P0.05）。随着时间的延长，细胞进一步增殖，在1d，4d及7d时MTT结果显示，CPC-BG组优于CPC组，其中在4d及7d时，CPC-BG组与CPC组有统计学差异（P 0.05）。碱性磷酸酶活性（Alkaline phosphatase, ALP）检测发现，7d时，CPC-BG组与CPC组有统计学差异（P 0.05）； 4.新西兰白兔体内植入实验中，大体，Micro-CT和组织学检测显示，，在4周和12周，所有材料组的体内降解率和新生骨生成量随着时间的延长而增加，其中CPC-BG组材料的体内降解率和新生骨生成量均明显高于CPC组（P 0.05）。结论： 1．CPC-BG（10%,20%）复合生物材料的固化时间及可注射性符合外科手术要求，随着BG的增加，复合生物材料的成分、微观结构发生了改变，可注射性，力学性能进一步提高，同时，体外生物活性及降解率也有了明显的改善； 2．将BG引入CPC中，有利于成骨细胞的粘附、增殖和分化； 3．CPC-BG复合生物材料具有优秀的生物相容性，更高的生物活性、体内降解率和骨生成率，更有利于骨缺损的修复。
[Abstract]:Nearly 70 million patients with osteoporosis ( OP ) in China over the age of 50 years , with about 1.8 million new vertebral compression fractures per year , are the main surgical treatment methods for vertebral compression fractures ( VCF ) . Most of the materials used in VP or BKP are polymethyl methacrylate ( PMMA ) . The material has obvious defects such as non - absorption , no biological activity ( bone conduction , induction action , etc . ) , obvious heat generation during curing , etc . Therefore , it is difficult to find a bone repairing material which can have good fluidity , bone conduction and osteoinductive effect , and has good mechanical support property and certain degradation rate .

Calcium phosphate cement ( CPC ) has broad clinical application value because of its self - curing , non - PMMA - like heat - producing effect , arbitrary shaping , good biocompatibility , bone conductivity and degradable bone replacement .

Because of its good biological activity and biocompatibility , biological glass ( BG ) can be directly involved in metabolism and repair of bone tissue in human body due to its good biological activity and biocompatibility .

Purpose :

A novel injectable biological composite material with good biocompatibility and osteogenic activity is developed .

Method :

1 . after mixing the CPC and the BG at different mass ratios , comparing the curing time and the injectable performance of the CPC and the BG , and screening out a suitable material composite ratio ;

2 . After mixing CPC and BG with the selected material composite ratio and solid - liquid ratio , the components , microstructure , curing time , injectability , mechanical strength and in vitro biological activity and degradability are analyzed .

3 . inoculating rat osteoblasts ( OB ) on the surface of the material test piece , and observing the adhesion , proliferation and differentiation ability of the OB on the surface of the test piece ;

4 . The CPC - BG composite biomaterial was implanted in New Zealand white rabbit for 4 , 12 weeks , and then was analyzed by micro - computed tomography ( Micro - CT ) and histological observation .

Results :

1 . With the increase of BG addition ( 10 % , 20 % , 30 % , 40 % ) , the curing time of CPC - BG composite biomaterial was prolonged , and the injection performance was improved . Compared with CPC , CPC - BG group had prolonged curing time ( 21min to 44min ) , while the injection performance was improved significantly ( P 0.05 ) .

2 . In the material study of CPC - BG composite biomaterial , X - ray diffraction ( XRD ) results show that the main diffraction peaks of CPC and CPC - BG composite biomaterial groups are deposited hydroxyapatite ( CPC ) . As the BG content increases from 10 % to 20 % , the diffraction peaks of Ca2SiO4 and CaSiO5 can be observed , and the material structure is more compact . In terms of mechanical properties , the CPC + 20 % BG group after curing for 1 day and 7 days is obviously higher than that of the pure CPC group ( P 0.05 ) . The results of in vitro bioassay showed that the HA deposition of CPC - BG group was significantly higher than that of CPC after immersion of simulated body fluid ( SBF ) . Energy dispersive spectroscopy ( EDS ) indicated that the HA of CPC - BG composite was mainly composed of Ca , P and Si , while CPC contained only Ca and P elements .

3 . The results showed that the CPC - BG group was superior to CPC group at 1d , 4d and 7d after addition of BG . The results showed that the CPC - BG group was superior to CPC group at 1d , 4d and 7d after 8 h . The results showed that CPC - BG group had statistical difference with CPC group ( P 0.05 ) . There was significant difference between CPC - BG group and CPC group ( P 0.05 ) .

4 . In vivo implantation experiment of New Zealand white rabbits , in general , Micro - CT and histological examination showed that in both 4 and 12 weeks , the in vivo degradation rate and the amount of new bone formation increased with the extension of time , in which the in vivo degradation rate and the amount of bone formation in CPC - BG group were significantly higher than that of CPC group ( P 0.05 ) .

Conclusion :

1 . The curing time and injectability of CPC - BG ( 10 % , 20 % ) composite biomaterial conform to the surgical requirements . With the increase of BG , the composition and microstructure of the composite biomaterial change , the injectability and the mechanical property are further improved , meanwhile , the in vitro bioactivity and degradation rate are obviously improved ;

2 . introducing BG into CPC , which is beneficial to the adhesion , proliferation and differentiation of osteoblasts ;

3 . The CPC - BG composite biomaterial has excellent biocompatibility , higher biological activity , in vivo degradation rate and bone formation rate , and is more favorable for repairing bone defect .

【学位授予单位】：第四军医大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R318.08

【参考文献】