【作者】 杨耀武；

【导师】 毛天球；

【作者基本信息】 第四军医大学 ， 口腔临床医学， 2004， 博士

【摘要】 由肿瘤切除、创伤和感染造成的颌面骨缺损需要大量的骨移植物修复，自体和同种异体骨应用最多，但都有一定的局限性。开发的人工替代品有生物陶瓷、聚合物、合金以及复合材料等，其中钙磷陶瓷类的HA和β-TCP因具有良好的生物相容性和骨传导性能而得到广泛的研究。煅烧牛骨又称为陶瓷化骨（TBC），是一种具有天然松质骨小梁结构的多孔生物材料，由无机骨矿物质组成。由于经过高温煅烧，材料无免疫原性，无毒性。拥有天然骨传导性，TBC与骨诱导因子如BMPs，骨髓和培养的成骨细胞复合后显示了良好的成骨性能。 鸵鸟松质骨（OCB）是一种新型异种生物材料，文献中很少提及。实验中对OCB进行化学处理后高温煅烧，将其转化为钙磷陶瓷（COB）。进一步用焦磷酸钠液浸泡后再次煅烧至1100℃，将COB中的HA成分转化为HA／β-TCP／NaCaPO₄多相钙磷陶瓷。课题研究了鸵鸟骨转化多相钙磷陶瓷的成分、特性、降解性能和生物相容性，并探索其用于骨组织工程支架材料的可行性。 1．鸵鸟及牛松质骨形态比较及成分测定、抗折强度分析 目的：制备鸵鸟及牛松质骨并比较其结构、成分和抗折强度。方法：新鲜鸵鸟及牛骨经过化学处理后制备出松质骨材料。观察材料表面结构，分析其水分、有机质、及无机物含量，测定其抗折强度。结果：鸵鸟松质骨表 第四军医大学博士学位论文面及孔隙结构与牛松质骨相比有不同特点，与牛松质骨孔隙相比，鸵鸟松质骨孔径大小更不均匀。鸵鸟及牛松质骨水分、有机质及无机物含量分别为（6 .85士0.10）%、（28.75士0.83）%、（64.40士0.78）%和（6.36士0.16）%、 （2979土0.28）%、（63.85士0.35）%。两者的抗折强度分别为（14.18士2.50）MPa和（22.93士3.93）MPa。结论:鸵鸟及牛松质骨在水分、有机质及无机物含量方面接近。鸵鸟松质骨材料具有与牛松质骨不同的孔隙特点，有望成为另一类有价值的异种骨替代材料。2.陶瓷化鸵鸟松质骨支架制备及成分、性能分析目的:制备陶瓷化鸵鸟松质骨支架并分析其成分及性能。方法:鸵鸟松质骨化学处理后高温锻烧，将其转化为钙磷陶瓷。通过大体及扫描电镜观察材料表面结构，测定材料孔隙率、矿物组成、元素比及抗折强度。结果:陶瓷化鸵鸟松质骨是一种多孔钙磷陶瓷材料，主要成分为轻基磷灰石，钙磷元素比为1.613。平均孔隙率为（70.27土6.23）%，多数材料孔隙大小不均匀。平均抗折强度为（l .92士0.63）MPa。结论:陶瓷化鸵鸟松质骨是一种孔隙结构特点与其他异种陶瓷骨不同的钙磷陶瓷材料，其孔隙特点可能对成骨有利。3.将陶瓷化鸵鸟松质骨转化为多相钙磷陶瓷目的:将锻烧鸵鸟松质骨转化为多相钙磷陶瓷并对其性能、成分进行分析。方法:陶瓷化鸵鸟松质骨用不同浓度焦磷酸钠浸泡后高温处理，将陶瓷化鸵鸟松质骨的主要成分经基磷灰石（HA）转化为多相钙磷陶瓷。通过大体及扫描电镜观察材料表面结构，测定材料孔隙率、抗折强度、矿物组成及元素比。结果:部分可降解性陶瓷化鸵鸟松质骨支架是一种多孔钙磷陶瓷材料，主要由HA、p一磷酸三钙（p一TCP）、和磷酸钙钠（NaCaP04）组成。随着焦磷酸钠浓度的增加，HA含量减少，p一TcP和NaCaPO;含量增多。材料平均抗折强度为（l .95士0.46） MPa。材料钙磷元素比值为1.511。平均孔隙率为（60.71士6.9）%，孔隙大小不均匀。结论:通过在高温下与焦磷酸钠作用，陶瓷化鸵鸟松质骨能够被转化为p一TCP旧户了NaCaP04多相钙磷陶瓷，该材料具有独特的天然多孔结构，有可能成为一种新型植骨 第四军医大学博士学位论文材料。4.鸵鸟骨转化多相钙磷陶瓷支架细胞相容性研究目的:评价由鸵鸟松质骨制备的多相钙磷陶瓷支架的细胞相容性。方法:通过理、化方法将锻烧鸵鸟松质骨改性为H刀p一TCP加aCaPO;多相钙磷陶瓷，然后分离兔骨髓基质细胞，体外扩增、诱导后接种于鸵鸟钙磷陶瓷支架。骨髓基质细胞与支架复合培养8天，通过相差显微镜、扫描电镜观察细胞在材料上的勃附、伸展及生长情况。通过细胞计数观察细胞增殖情况。结果:骨髓基质细胞在多相钙磷陶瓷支架表面及孔隙内贴附、伸展、增殖良好。结论:鸵鸟骨转化多相钙磷陶瓷支架具有良好的细胞相容性。5.鸵鸟骨转化多相钙磷陶瓷生物相容性研究目的:评价新型材料鸵鸟骨转化多相钙磷陶瓷支架的生物相容性。方法:通过理、化方法将锻烧鸵鸟松质骨改性为H刀p一TCPfNacaPO;多相钙磷陶瓷，然后进行溶血试验、凝血试验、热源试验、急性毒性试验及肌肉植入试验。结果:材料无溶血现象，不影响凝血功能。动物实验发现材料不引起阳性热源反应及急性毒性。肌肉植入试验显示纤维组织能够长入材料内部，材料对肌肉无刺激。部分标本出现轻微的炎性反应，与材料部分降解有关。结论:多相钙磷陶瓷支架具有良好的生物相容性。6.鸵鸟骨转化多相钙磷陶瓷支架肌内降解性能研究目的:观察两种不同比例H刀p一TCP加aCaPO4的多相钙磷陶瓷降解情况。方法:通过理、化方法将锻烧鸵鸟松质骨转化为H刀p一TcP/N acaPo;多相钙磷陶瓷。通过不同剂量焦磷酸钠处理得到不同比例HA/p一TcP/NaCaP0更多还原

【Abstract】 Large amounts of bone graft are frequently used to reconstruct the maxillofacial bone defects resulting from tumor resection, trauma, infection. Autograft and allograft bone are often used, but each has its limitations. To avoid the potential risk, artificial substitutes including bioceramics, polymers, alloys, and composite biomaterials have been studied. Among them calcium phosphate ceramics, e.g. hydroxyapatite(HA) and beta-tricalcium phosphate(P-TCP) have been extensively studied because their good biocompatible and osteoconductive properties. Sintered bovine bone, or true bone ceramic(TBC) is a porous biomaterial with a natural trabecular structure like that of cancellous bone and is composed of inorganic bone material. Because it is formed by sintering at a high temperature, TBC is not immunogenic, and no cytotoxicity is observed. Augmentation of the natural osteoconductivity of TBC with osteoinductive agents such as bone morphogenetic proteins (BMPs), bone marrow, and cultured osteoblasts has yielded promising osteogenic properties.Ostrich cancellous bone(OCB) is a kind of new xenogenic biomaterial which is rarely mentioned by other literatures. In our experiments, the OCBwas given a chemical management, then it was calcined to a high temperature and to be transformed to calcium phosphate ceramics(COB). Then the COB blocks were soaked in different concentration of sodium pyrophosphate (Na4P2O7-H2O, NP) solution and heated to 1100C to transform its constitution from HA into HA/p-TCP/NaCaP04 multiphasic calcium phosphate ceramics. In this study, we investigated the components, characterization, degradable ability, Biocompatibility of the multiphasic calcium phosphate ceramic and explored its application as the scaffold in bone tissue engineering.1. Compare of heterogenous ostrich and bovine cancellous bone: configuration, components and bending strengthObjective: To prepare the ostrich and bovine cancellous bone(OCB and BCB) and compare their configuration, components and bending strength . Methods: preparing the ostrich and bovine cancellous bone by chemical management. Then observing the surface configuration and analyzing the component proportion of water, organic and mineral material of the cancellous bone. Determining the bending strength of the material. Results: The OCB had different surface configuration and porosity structure with that of BCB. The pore size of OCB was even more uneven than that of BCB. The component proportion of water, organic and mineral material of the OCB and BCB was separately(6.85+0.10)%, (28.75+0.83)%. (64.40+0.78)% and(6.36+0.16) %, (29.79+0.28) %, (63.85+0.35) %. The average bending strength of OCB and BCB was separately ( 14.18+2.50) Mpa (22.93+3.93) Mpa. Conclusion: Both OCB and BCB had similar component proportion of water, organic , mineral material. The OCB material has different porosity characteristics compared with BCB and it might become another valuable heterogenous bone graft material.2. Preparation of ceramic-like ostrich cancellous bone scaffold andanalysis of its components and characterizationObjective: To prepare the COB scaffold and study its components and characterization. Methods. After the chemical management the OCB was heated to a high temperature and to be transformed to calcium phosphate ceramics. Then observing the surface configuration of the material by SEM and analyzing the following properties of the material: porosity, mineral composition, element ratio and bending strength. Results: The COB was a kind of porous calcium phosphate ceramic composed of hydroxyapatite(HA) and the Ca/P element ratio of COB was 1.613. the average porosity was (70.27+6.23 ) % and the pore size of most material was uneven. The average bending strength of COB was (1 92+0.63 ) MPa. Conclusion: The COB was a king of calcium phosphate ceramic with different porosity characteristics compared with other xenografts, for example, the bovine cancellous bone ceramic. The porosity characteristics of COB maybe make it more benefit to osteogenesis更多还原