【作者】 王栋；

【导师】 杨辉；

【作者基本信息】 陕西科技大学 ， 生物化工， 2010， 硕士

【摘要】 羟基磷灰石(hydroxyapatite,HAP)是构成骨和牙的主要无机质,其分子中的Ca2+可与含有羧基的氨基酸、蛋白质、有机酸等发生交换反应,因此HAP具有良好的骨传导性能和生物活性,能与骨组织形成牢固的骨性结合,促进骨骼生长,是公认的性能良好的骨修复替代材料。但是单一的HAP材料抗弯强度和抗压强度低,极大地限制了HAP作为人体骨骼替代物的应用范围和使用价值,为了提高材料的力学性能以及加快新骨的形成速度,必须引入其它物质,从而形成多种多样的HAP复合材料。HAP用作人体植入材料时,由于运动、摩擦和松动,其表面易引发感染,影响植入体的寿命,也给患者带来二次手术的痛苦和经济负担。目前解决植入体感染问题较多采用药物包埋植入骨或抗菌药物重组骨的方法,但这些方法都存在着不能高温灭菌、工艺复杂和长期疗效不理想等不足。本课题研究的目的就是合成掺杂抗菌性金属离子的纳米HAP复合材料,使其既具有良好的生物活性和生物相容性,又具有优良的抗抑菌性能和力学性能,提高其作为骨修复材料的综合性能。本文采用共沉淀法制备一种具有抗菌性能的复合材料——载银载铜羟基磷灰石(Ag/Cu/HAP),研究制备Ag/Cu/HAP的影响因素,并讨论Ag+和Cu2+对HAP晶体结构和性能的影响；试验制备了具有优良的抗抑菌性能和力学性能的复合材料——丝素蛋白(SF)和Ag/Cu/HAP的复合材料(SF/Ag/Cu/HAP),并研究影响其制备的因素；检测SF/Ag/Cu/HAP的力学性能,并分别通过自然落菌法和动物细胞培养实验观察其抗菌性和生物相容性。采用X一射线衍射、扫描电镜、傅里叶变换红外光谱分析对得到的HAP复合粉体进行结构表征。结果表明：采用共沉淀法合成Ag/Cu/HAP晶体是可行的,Ag+和Cu2+的载入使Ag/Cu/HAP晶体形貌从针状变为片状,而且晶体尺寸比HAP的要小。反应温度、反应液浓度、pH值和加料顺序对Ag/Cu/HAP晶体的表面形态、结晶度和大小有较大影响,高温烧结使Ag/Cu/HAP晶体形貌由片状变为球状。利用摩尔比为1：2：8的CaCl2-C2H5OH-H2O三元体系作为溶剂可以对丝素纤维进行快速溶解,制得SF蛋白后可以采用共沉淀法一步合成SF/Ag/Cu/HAP晶体,其晶粒尺寸和晶体形貌受反应温度影响较大,HAP和SF的复合比影响HAP之间的交联程度,SF含量越高HAP间的交联度越大。Ag/Cu/HAP和SF/Ag/Cu/HAP均具有强抗菌性,SF/Ag/Cu/HAP复合材料还具有很高的抗压强度和良好的生物相容性。更多还原

【Abstract】 Hydroxyapatite(HAP) is the main inorganic component of the natural bone and tooth.The Ca2+ in HAP can complex with organic substance that contains carboxyl group such as amino acid,protein, organic acid,so HAP has excellent biocompatibility and bioactivity. HAP is considered to be the fantastic substitute material in bone’repair because it can firmly combine with bone tissue and accelerate the growth of bone.But the bending strength and compressive strength of pure HAP material are very low, which largely limit the application of HAP material as the substitute for human body skeleton.Therefore,a composite of HAP and other materials should be prepared to improve the brittleness and osteo-inductivity of HAP.The surface of HAP implant is often infected for the looseness and vibration of the implants,which would not only shorten the life of implant, but also cause pain and economic burden to patients because of the second surgery. Now drug-embedded bone implant and antibiotic recombinant bone are frequently used to avoid infection,but these methods also have their disadvantages such as cannot be sterilized by heating, complexity of process and lack of long-term curative effect. The goal of this study is to synthesize nanosized HAP composites carrying metallic ion whose comprehensive performance of bone-repair materials is improved.The metal containing HAP composites not only have excellent bioactivity and biocompatibility, but also have anti-bacterial function and fantastic mechanical property.In this paper, the HAP carrying Ag+and Cu2+(Ag/Cu/HAP)was prepared by using the co-precipitation method. Factors affecting the preparation of Ag/Cu/HAP were studied, besides,the effects of doped Ag+ and Cu2+ on the microstructure and properties of HAP crystals were also discussed.In addition, a silk-fibroin/Ag/Cu/HAP composite(SF/Ag/Cu/HAP) with excellent anti-bacterial function and mechanical property was prepared. The factors affecting the preparation of silk-fibroin/Ag/Cu/HAP composite was also investigated. The mechanical property of the SF/Ag/Cu/HAP was tested and the anti-bacterial property and biocompatibility of the SF/Ag/Cu/HAP were confirmed through freely fallen bacteria method and animal cell culture experiments.The composition and microstructure of the HAP composite powders were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR).The results were as follows:Ag/Cu/HAP can be synthesized by using the co-precipitation method.The crystal of Ag/Cu/HAP takes platelet shape different from the needle shape of pure HAP because of the effects of doped Ag+ and Cu2+. The crystal size of Ag/Cu/HAP was smaller than that of pure HAP. The temperature, pH, concentration of reaction solution and starting material-feeding sequence could greatly affect the morphology, crystallinity and size of the Ag/Cu/HAP composite.High temperature calcination changes the crystal shape of Ag/Cu/HAP from platelet to globular.The silk fiber can be easily resolved in solution that contains CaCl2, C2H5OH, H2O with the molar ratio of 1:2:8.The silk-fibroin/Ag/Cu/HAP composite was synthesized by using the co-precipitation with one step when the mixture solution of silk fibroin and the starting materials of Ag/Cu/HAP was used as the reaction solution. The crystal size and shape of silk-fibroin/Ag/Cu/HAP composite was greatly affected by reaction temperature. The ratio of HAP to SF in SF/Ag/Cu/HAP composite influences the cross-linking degree of HAP in crystal.The more SF in the crystal,the higher degree of cross-linking of HAP in crystal.Both the Ag/Cu/HAP composite and SF/Ag/Cu/HAP composite have effective anti-bacterial property. Moreover, SF/Ag/Cu/HAP composite has quite good compressive strength and fantastic biocompatibility.更多还原