【作者】 蔡日强；

【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】 生物材料羟基磷灰石(HAP)的化学组成和结构与人体骨骼和牙齿的主要无机成分类似,具有良好的骨传导性、生物相容性和生物活性,适宜做骨取代物,广泛应用于矫形外科领域和硬组织修复。为了防止HAP修复材料植入体内时发生感染,并改善HAP力学性能上的缺陷,研究合成掺杂抗菌HAP和羟基磷灰石／丝素蛋白复合材料(HAP/SF)。本试验采用水热合成法制备具有良好抗菌性能的载银载镧羟基磷灰石(Ag/La/HAP)和载银载镧羟基磷灰石／丝素蛋白复合材料(Ag/La/HAP/SF)。考察反应原料和浓度、水热反应时间和温度、pH值控制剂尿素的加量、模板剂山梨醇对晶体生长、晶体化学组成、晶体尺寸大小和形貌以及稳定性的影响,采用XRD、FTIR、SEM和TEM等分析检测方法对掺杂抗菌HAP和Ag/La/HAP/SF复合材料进行结构性能表征,并采用最小抑菌浓度法(MIC)检测掺杂抗菌HAP的抗菌性能,通过Ⅰ型胶原酶消化法培养成骨细胞反映HAP材料的生物相容性。结果表明制备HAP的较好原料为0.1mol/L的CaCl2溶液与等浓度的(NH4)2HPO4溶液,按1g/160ml反应液的比例加入尿素控制pH值,并加入山梨醇作为模板剂,在120℃下水热反应2h以上可以得到结晶良好、晶型稳固、纯度高的HAP晶体,并具有独特的板条状形貌,且为强度较高的单晶体,过度延长反应时间对得到板条状HAP晶体不利。银离子(Ag+)具有很强的抗菌性能,镧离子(La3+)则可以细化晶体并提高晶体的稳定性,这两种离子在水热反应体系中都可以通过共沉淀和离子交换进入HAP当中形成掺杂HAP,载银的关键在于控制反应体系pH值由合成HAP初期的10-11下降至7-8,尿素作为HAP水热反应体系中的pH值控制剂可以实现,载镧则可以在广泛的碱性条件下实现。蚕丝由0.5%的Na2CO3溶液按浴比1：50脱胶后,采用三元溶齐(CaCl2、C2H5OH和H2O的摩尔比为1：2：8)溶解丝素蛋白纤维得到丝素蛋白的盐溶液,经透析脱盐得到丝素蛋白溶液(SF),丝素蛋白溶液直接加入水热反应体系中一步合成得到不同复合比例的羟基磷灰石／丝素蛋白(HAP/SF)复合材料。制备的HAP/SF复合材料形貌以板条状为主,还出现了独特的针棒状和晶须,能够显著提高HAP的力学性能,SF所占复合比例的提升将使HAP/SF复合材料容易交联团聚。由抑菌性试验测得Ag/La/HAP对大肠杆菌和金黄色葡萄球菌的最小抑菌浓度为30.32ppm, I型胶原酶消化法在Ag/La/HAP和HAP/SF复合材料压片表面培养的成骨细胞生长良好,也表明所制备的掺杂抗菌HAP和HAP/SF复合材料具有良好的生物相容性。更多还原

【Abstract】 Hydroxyapatite (HAP) has the similar chemical composition and structure to human bones and teeth in major inorganic components. HAP is widely used as bone substitute materials in the field of orthopedic surgery and hard tissue repair due to its good bone conductivity, biocompatibility and biological activity. A problem, however, is that they create an acidic environment at the implant site that induces an inflammatory response.To enhance the mechanical strength and to prevent infection of HAP implants a silver and lanthanum doped hydroxyapatite/silk fibroin composite materials (Ag/La/HAP/SF) composite was synthesized by hydrothermal synthesis method. Silk fibroin fiber was dissolved in the mix solution of ternary solvent (CaCl2, C2H5OH and H2O molar ratio of 1:2:8). After desalination by dialysis it become silk fibroin solution (SF sols) which was directly added into the reaction system to synthesize a different ratio of HAP/SF fibroin composite materials. According to the ratio of urea mass to reaction solution system, 1g/160ml urea was added in reaction solution to control pH value. Sorbitol as a template agent was also used:The phase composition and morphology of HAP and Ag/La/HAP/SF composites were observed using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR). The effects of the concentration of starting reactants, reaction time and temperature, pH value, the amount of urea used, the pH control agents, the template agent of sorbitol on the growth, chemical composition, size and morphology as well as the stability of obtained crystal, were investigated. The antibacterial properties of doped antibacterial HAP were detected using the minimum inhibitory concentration method (MIC). The bioactivity and biocompatibility of the metal-ions-doped HAP material were observed through cell culture method of osteoblasts from a mouse.The results show that, the better starting materials for preparation of HAP are 0.1mol/L of CaCl2 solution and (NH4)2HPO4 solution. A single HAP crystal with high purity and a unique sheet morphology was obtained by hydrothermal method at 120℃, reacted for 2h. Over-extension of reaction time was not good for formation of the sheet morphology HAP. Silver ions (Ag+) has a strong anti-bacterial properties and lanthanum ions (La3+) can refine and improve the crystal stability of crystal. These two ions in the hydrothermal reaction system can be adopted by co-precipitation and ion exchange into the HAP. The control of pH value is very important for synthesis of Ag-doped HAP. The pH value in reaction system was changed from the starting value 10-11 down to 7-8. Urea was a good agent to control pH value of synthesis solution. We can dope La in HAP crystal under a wide range of alkaline conditions.The sheet HAP/SF composites were composed of many unique needle bars and whiskers, which can significantly improve the mechanical properties of HAP. The increase of SF in composite enhance the cross links between HAP crystal and SF. The MIC testing results showed that Ag/La/HAP has efficient antibacterial properties against to Escherichia coli and Staphylococcus aureus and the MIC is 30.32ppm. The osteoblast cells grew well on the Ag/La/HAP and HAP/SF composite surface showed that the prepared doped antibacterial HAP and HAP/SF composite material having a good biocompatibility.更多还原