钛基磷酸钙复合涂层的制备及其生物活性评价

发布时间：2019-05-10 04:26

【摘要】：生物材料的化学组成及其表面拓扑结构在调整蛋白质吸附、细胞粘附、铺展、迁移、增殖和分化等生物学行为中起着关键的作用。由于钛及钛合金具有优越的理化性能,其已被广泛应用于各种植入体,例如骨科、牙科及心血管支架等。然而,钛基材表面具有生物惰性,其与周边骨组织形成骨整合的能力较弱,延缓了组织愈合的时间。因此,改善钛植入体表面生物性能具有重要的临床意义。钛基材表面羟基磷灰石(HAP)复合涂层的制备成为了一种重要的表面生物活性改良手段。本课题在钛表面制备了FHAP/ZrO2、Sr FHAP、Sr-Ca-P/明胶、MnHAP和HAP/Ca SiO3复合涂层。采用扫描电子显微镜(SEM)、X-射线衍射仪(XRD)、傅立叶变换红外光谱仪(FTIR)、X-射线光电子能谱仪(EDS)等分析设备,研究了HAP复合涂层的相结构、形貌和膜层成分等特性。对复合涂层的耐生理液腐蚀性、力学性能和细胞相容性进行了评价。主要研究内容和结论如下:采用恒电流沉积法在钛表面制备出掺氟羟基磷灰石/氧化锆(FHAP/Zr O2)复合涂层。氟离子掺杂进入HAP晶体结构,磷灰石的晶粒变小,结晶度增加,涂层为纳米级针状形貌。涂层致密且分布均匀,厚度约为10μm。ZrO2作为缓冲层,很好地缓解了FHAP与Ti之间热膨胀系数的差异,拉力测试结果表明,即便是在生理溶液中浸泡2w以后,FHAP/ZrO2复合涂层仍然具有较好的结合强度。体外溶解实验表明,FHAP/ZrO2复合涂层具有较单相HAP涂层更低的溶解度,即更好的稳定性。极化测试表明FHAP/ZrO2复合涂层具有较HAP强的耐生理液腐蚀性。细胞粘附实验结果表明FHAP/ZrO2复合涂层具有良好的细胞相容性,成骨细胞大量、紧密地粘附其上,形态良好。为了考察氟离子和锶离子的掺杂对涂层特性的影响,采用电沉积法在钛表面制备出锶和氟共掺杂羟基磷灰石(Sr FHAP)复合涂层。复合涂层分布均匀且致密,为纳米级的针状形貌。氟离子和锶离子共掺杂进入HAP晶体结构,氟作为抗溶解元素以维持涂层的长期稳定性,锶作为溶解元素以促进涂层生物活性和细胞相容性。钙离子溶解实验表明,SrFHAP复合涂层在2w内具有良好的生理稳定性。在模拟体液中,SrFHAP复合涂层表现出较纯HAP更强的耐腐蚀性。体外细胞检测中,复合涂层对成骨细胞粘附与增殖的促进效果最好,表明其具有良好细胞相容性。为了考察锶离子和明胶的掺杂对涂层特性的影响,采用电沉积法在钛表面制备了掺锶磷酸钙/明胶(Sr-Ca-P/明胶)复合涂层。锶离子掺杂进入Ca-P晶体结构,明胶与Sr-Ca-P杂化为Sr-Ca-P/明胶复合涂层,涂层整体为多孔状形貌,涂层表面粗糙而不均匀,多孔结构对于成骨细胞的粘附非常有利。Sr2+离子和明胶均匀地掺杂和分散在Ca-P涂层中。涂层的厚度约为10μm,涂层与基材之间无剥离和/或界面处开裂的现象。拉力测试实验表明Sr-Ca-P/明胶复合涂层与基底的结合强度为5.6MPa±1.8MPa,其结合强度较弱。极化测试表明Sr-Ca-P/明胶复合涂层具有较强的耐腐蚀性。成骨细胞在复合涂层表面粘附性良好,MTT实验表明成骨细胞在复合涂层表面的增殖能力较好,则Sr-Ca-P/明胶复合涂层具有较好的细胞相容性。采用电沉积法在钛表面制备出掺锰羟基磷灰石(MnHAP)复合涂层。Ti表面经过热碱浸泡后形成了Na2TiO3薄膜,该膜的存在可以增加MnHAP复合涂层与钛基材之间的结合强度。复合涂层分布均匀且致密,其由针状晶体聚集而成,厚度约为10μm。拉力测试结果表明MnHAP复合涂层与基底的结合强度约为纯HAP涂层的2倍,基本满足国际标准的要求。极化曲线的分析得知,MnHAP复合涂层使得Ti的耐腐蚀性得到较大增强。Mn HAP涂层在模拟体液中能迅速诱导类骨磷灰石成核和生长,表明涂层具有良好的生物活性。细胞在MnHAP复合涂层表面呈现出典型的成骨细胞粘附表型,锰元素的掺杂使得细胞在MnHAP复合涂层表面的增殖活力表现良好,涂层的细胞相容性良好。采用电沉积法在由纳米SiO2、Ca(NO3)2和NH4H2PO4组成的电解液中,在钛表面制备出了HAP/CaSiO3复合涂层。HAP/CaSiO3复合涂层表面由内部致密的纳米级针须状晶体和外表微米级的孔状结构组成,这种多孔结构对于新骨的形成非常有利。X-射线衍射结果表明复合涂层主要包括HAP相和Ca Si O3相。拉力测试结果表明HAP/CaSiO3复合涂层与Ti基底的结合强度为19.1±4.7MPa,这个值已经基本满足了国际标准的要求。极化测试表明HAP/CaSiO3复合涂层具有较强的耐腐蚀性。MC3T3-E1成骨细胞在HAP/Ca SiO3复合涂层表面的增殖能力显著地高于在HAP表面,表明HAP/CaSiO3复合涂层具有较好的细胞相容性。综上所述,本研究采用电沉积法进行多种离子掺杂磷酸钙活性涂层的构建,对磷酸钙复合涂层的电沉积制备技术进行了理论和实验研究。本研究着重考察氟离子,锶离子,锰离子,硅离子和明胶的存在对复合涂层物理性能、化学性能以及生物活性的影响。成骨所需的多种微量元素(如氟、锶、锰、硅等)被成功地引入到Ca-P涂层中,为进一步研究磷酸钙复合涂层在骨缺损修复中的临床应用提供初步的实验依据。
[Abstract]:The chemical composition of biological material and its surface topological structure play a key role in adjusting the biological behavior of protein adsorption, cell adhesion, spreading, migration, proliferation and differentiation. Titanium and titanium alloys have superior physical and chemical properties, which have been widely used in various implants, such as orthopedic, dental, and cardiovascular stents. However, that surface of the titanium base material has a biological inertia, which is weak in the ability of the peripheral bone tissue to form a bone, which delay the time of tissue healing. Therefore, it is of great clinical significance to improve the biological performance of the surface of the titanium implant. The preparation of the hydroxyapatite (HAP) composite coating on the surface of the titanium substrate has become an important means to improve the surface biological activity. FHAP/ ZrO2, Sr FHAP, Sr-Ca-P/ gelatin, MnHAP and HAP/ Ca-SiO3 composite coatings were prepared on the surface of titanium. The phase structure, morphology and composition of the HAP composite coating were studied by means of scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (EDS). The corrosion resistance, mechanical property and cell compatibility of the composite coating were evaluated. The main research contents and conclusions are as follows: a compound coating of a fluorine-doped hydroxyapatite/ oxide-oxide (FHAP/ Zr O2) is prepared on the surface of the titanium by a constant current deposition method. And the crystal grains of the apatite are smaller and the crystallinity is increased, and the coating is a nano-scale needle-like shape. The results show that the FHAP/ ZrO2 composite coating still has good bonding strength even after soaking for 2w in the physiological solution. In vitro dissolution experiments show that the FHAP/ ZrO2 composite coating has lower solubility, that is, better stability, than that of the single-phase HAP coating. The polarization tests show that the FHAP/ ZrO2 composite coating has high corrosion resistance to the HAP. The results of cell adhesion show that the FHAP/ ZrO2 composite coating has good cell compatibility, and the osteoblast is large and closely adhered to it with good morphology. In order to investigate the influence of the doping of fluoride ion and fluoride ion on the properties of the coating, a composite coating of codoped hydroxyapatite (Sr FHAP) was prepared on the surface of titanium by electrodeposition. The composite coating is uniform and dense, and is a nanometer-scale needle-like shape. The fluoride ion and the ionization ions are co-doped into the HAP crystal structure, and fluorine is used as an anti-dissolution element to maintain the long-term stability of the coating, and is used as a dissolution element to promote the bioactivity and the cell compatibility of the coating. The calcium ion dissolution test shows that the SrFHAP composite coating has good physiological stability in 2w. In the simulated body fluid, the SrFHAP composite coating shows stronger corrosion resistance than the pure HAP. In vitro cell detection, the effect of the composite coating on the adhesion and proliferation of the osteoblast is the best, indicating that it has good cell compatibility. In order to investigate the effect of doping on the properties of the coating, a composite coating of calcium-doped calcium phosphate/ gelatin (Sr-Ca-P/ gelatin) was prepared on the surface of titanium by electrodeposition. The Ca-P crystal structure, the gelatin and the Sr-Ca-P are mixed into the Sr-Ca-P/ gelatin composite coating, the whole of the coating is a porous shape, the surface of the coating is rough and uneven, and the adhesion of the porous structure to the osteoblast is very favorable. Sr2 + ions and gelatin are uniformly doped and dispersed in the Ca-P coating. The coating has a thickness of about 10. m u.m, and there is no peeling and/ or cracking at the interface between the coating and the substrate. The tensile test shows that the bonding strength between the Sr-Ca-P/ gelatin composite coating and the substrate is 5.6 MPa and 1.8 MPa, and the bonding strength is weak. The polarization tests show that the Sr-Ca-P/ gelatin composite coating has strong corrosion resistance. The adhesion of the osteoblast to the surface of the composite coating was good, and the MTT assay showed that the proliferation ability of the osteoblast on the surface of the composite coating was good, and the Sr-Ca-P/ gelatin composite coating had better cell compatibility. The composite coating of Mn-doped hydroxyapatite (MnHAP) was prepared by electrodeposition. And the surface of the Ti is soaked by a hot alkali to form a Na2TiO3 thin film, and the bonding strength between the MnHAP composite coating and the titanium substrate can be increased. The composite coating is uniform and dense, which is formed by the aggregation of needle-like crystals with a thickness of about 10. m u.m. The tensile test results show that the bonding strength between the composite coating of the MnHAP and the substrate is about 2 times that of the pure HAP coating, which basically meets the requirements of the international standard. The analysis of the polarization curve shows that the corrosion resistance of the Ti is greatly enhanced by the composite coating of MnHAP. The Mn-HAP coating can rapidly induce the nucleation and growth of the bone-like apatite in the simulated body fluid, indicating that the coating has good biological activity. The cell has a typical osteoblast adhesion phenotype on the surface of the MnHAP composite coating, and the doping of the manganese element makes the proliferation activity of the cell on the surface of the MnHAP composite coating good, and the cell compatibility of the coating is good. HAP/ CaSiO3 composite coatings were prepared on the surface of titanium by electrodeposition in the electrolyte composed of nano-SiO2, Ca (NO3)2 and NH4H2PO4. The surface of the HAP/ CaSiO3 composite coating is composed of an internal dense nano-scale needle-like crystal and an outer micron-sized porous structure, and the porous structure is very favorable for the formation of the new bone. The X-ray diffraction results show that the composite coating mainly includes the HAP phase and the Ca-Si 3 phase. The tensile test results show that the bonding strength between the HAP/ CaSiO3 composite coating and the Ti substrate is 19.1-4.7 MPa, which has basically met the requirements of international standards. The polarization test shows that the HAP/ CaSiO3 composite coating has strong corrosion resistance. The proliferation ability of MC3T3-E1 osteoblast on the surface of HAP/ Ca SiO3 composite coating was significantly higher than on the surface of HAP, indicating that the HAP/ CaSiO3 composite coating had better cell compatibility. In the light of the above, the present study adopts the electrodeposition method to carry out the construction of a plurality of ion-doped calcium phosphate active coatings, and the electrodeposition preparation technology of the calcium phosphate composite coating is theoretically and experimentally studied. The effects of fluoride ion, iron ion, manganese ion, silicon ion and gelatin on the physical properties, chemical properties and biological activity of the composite coatings were studied. The various trace elements (such as fluorine, iron, manganese, silicon, etc.) required for osteogenesis were successfully introduced into the Ca-P coating to provide a preliminary experimental basis for the further study of the clinical application of the calcium phosphate composite coating in the repair of bone defects.
【学位授予单位】：电子科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R318.08

【相似文献】