悬浮液等离子喷涂制备氟代羟基磷灰石生物涂层

主要以氟代羟基磷灰石(FHA)悬浮液为原料,采用悬浮液等离子喷涂技术,在钛基体表面制备了FHA涂层。通过XRD,SEM,FT-IR以及XPS等测试手段,对不同喷涂功率制备的FHA涂层进行表征,并测试其性能。结果表明,粉体及制备的涂层主要晶相为HA,但是粉体进入等离子火焰形成涂层的过程中发生分解,生成α-磷酸钙(α-TCP),β-磷酸钙(β-TCP),以及磷酸四钙(TTCP)等分解产物。XPS结果证明F离子成功取代了OH基团进入HA晶格中,导致FHA涂层的抗溶解性明显提高。电化学实验结果表明,随着喷涂功率的增加,涂层的抗腐蚀性能提高。     

钛生物种植体表面羟基磷灰石生成技术发展现状

总结了现有钛生物种植体表面羟基磷灰石生成技术及其优缺点;并针对钛生物种植体表面羟基磷灰石涂层在制备过程中存在的界面结合强度低、涂层内的残余应力以及膜层中羟基磷灰石(HA)的分布密度等问题,进行归纳总结。     

表面涂覆含氟羟基磷灰石和缺钙羟基磷灰石的镁合金体外降解行为(英文)

通过电化学沉积方法,在生物降解镁合金表面覆盖含氟羟基磷灰石(FHA)涂层和缺钙羟基磷灰石(CDHA)涂层。采用X射线衍射、傅立叶变换红外光谱、透射电子显微镜、扫描电子显微镜和能量色散X射线光谱研究涂层特性。结果表明:涂覆纳米FHA涂层的样品具有垂直于样品表面的纳米针状结构,比涂覆CDHA涂层样品的结构更致密和更均匀。纳米FHA涂层比纳米CDHA涂层具有更小的晶粒尺寸,分别为65 nm和95 nm。然而,CDHA涂层比FHA涂层更厚,厚度分别为19μm和15μm。通过极化、浸泡和析氢实验研究的腐蚀行为表明:纳米FHA涂层和纳米CDHA涂层显著降低腐蚀速率并引起钝化。纳米FHA和纳米CDHA涂层可以加速骨状磷灰石层的形成,相比未覆盖的镁合金可以显著减少溶出速率。纳米FHA涂层能对镁合金提供有效的防护并具有更高的腐蚀性能。因此,覆盖纳米FHA涂层的镁合金在整形外科领域具有良好的应用前景。     

医用镁合金表面激光重熔羟基磷灰石涂层

为提高医用镁合金的表面耐蚀性和生物相容性,采用等离子喷涂和激光重熔复合技术在镁合金表面制备羟基磷灰石(HA)生物涂层。研究结果表明,所制备的羟基磷灰石涂层为短杆状堆积结构,主要由HA和β-TCP相组成;涂层的弹性模量约为50 GPa,较已临床应用的医用金属材料显著降低,显微硬度约为455 HV,具有较好的耐磨性。涂层在模拟体液中具有很好的耐蚀性,在腐蚀12 d后涂层表面形貌仍然较完整,无腐蚀孔洞出现。钙磷沉积实验结果表明,涂层表面形成一层新的生物磷灰石层,表明涂层具有较好的骨诱导性。     

钛表面仿生制备Si-HA涂层的热力学分析

通过计算室温下含硅过饱和钙磷沉积液（SSCPS）中可能形成的各沉积相的过饱和度，对仿生制备含硅羟基磷灰石（Si—HA）的热力学条件进行了分析。结果表明：羟基磷灰石（HA）过饱和度最大；且当pH〈8时，硅不具备以偏硅酸盐形式存在的热力学条件，从而表明SSCPS具备仿生制备Si—HA涂层的热力学可能性。在SSCPS中通过浸泡，在钛表面仿生制备了Si—HA涂层，其Si含量在0．14at％～1．14at％，实验验证了热力学分析的正确性：还跟踪了仿生沉积过程pH值变化。     

羟基磷灰石生物活性梯度涂层材料的界面特点

用透射电子显微镜对钛合金基体等离子喷涂羟基磷灰石 (HA)生物活性梯度涂层的界面进行了观察与分析。结果表明 :经热处理后生物活性梯度涂层的结晶程度明显提高 ,涂层中存在HA晶体、β Ca3(PO4 ) 2 晶体以及中间相CaTiO3 晶体。涂层和基体的界面结合为冶金化学结合 ,HA涂层和基体Ti间存在过渡相ZrO2 ,过渡相ZrO2 的存在有利于提高涂层和基体之间的界面结合力。     

热处理对微束等离子喷涂羟基磷灰石涂层的影响

羟基磷灰石由于其良好的生物活性,被广泛的用作医用植入体的表面涂层材料.采用微束等离子喷涂(Microplasma Spraying,MPS)I艺在Ti-6Al-4V基体上制备羟基磷灰石涂层,通过扫描电镜(SEM)、X射线衍射(XRD)和傅里叶红外光谱(FTIR)分析了热处理对涂层相组成和表面形貌的影响规律.研究表明:微束等离子喷涂制备的羟基磷灰石涂层在经过热处理后结晶度提高,并且非晶相和杂质相转化成为HA结晶相.同时,羟基和磷酸根的完整性得到了恢复.过高的热处理温度易引起涂层裂纹等缺陷的增加,也容易造成羟基脱离造成HA分解.合理的热处理温度范围为600～700℃,保温时间为3 h.     

钛合金表面声电沉积/碱热处理法制备HA涂层研究

为了使钛合金(Ti-6Al-4V)具有生物活性,可在其表面施加生物活性羟基磷灰石(HA)涂层.对比了声电沉积法和碱热处理法实验结果,采用扫描电镜(SEM)、X射线衍射仪(XRD)、电子能谱(EDS)、傅立叶红外透射光谱(FTIR)以及划痕测试等进行了分析.结果表明,直接采用声电沉积法在钛合金表面制备的羟基磷灰石涂层,经热处理后存在龟裂剥落现象;通过碱热处理法,对钛合金基体表面进行预处理,然后,借助声电沉积法,在钛金属表面沉积了透钙磷石涂层,经热碱液处理转变成的羟基磷灰石涂层,涂层完整,未出现剥落.经进一步高温烧结处理,所制涂层仍呈片状形貌,其由部分含钠的羟基磷灰石组成,而且HA涂层破坏的临界载荷未烧结前的4.365 N提高至烧结后的8.175N.     

医用镁合金等离子喷涂羟基磷灰石涂层研究

为了提高医用镁合金的表面耐蚀性和生物相容性,采用等离子喷涂技术在镁合金表面制备羟基磷灰石(HA)涂层.研究结果表明,镁合金表面所制备的HA涂层与基体结合牢固,界面无裂纹、气孔等缺陷.相组成为生物相容性较好的HA和少量的Ca3(PO4)2(TCP),显微组织具有层状特征,涂层表面存在一些有利于骨长人的孔隙.涂层的弹性模量约为19.825 GPa,接近骨的弹性模量,涂层表面硬度为300～350 HV.腐蚀试验和钙磷沉积试验结果表明HA涂层具有较好的耐蚀性和骨诱导性.     

钛合金表面激光熔覆制备含氟羟基磷灰石涂层

从工艺特点出发,对钛合金表面激光熔覆制备含氟羟基磷灰石(FHA)涂层的几个关键问题进行分析,提出了相应的工艺要求,并对涂层的性能表征方法进行了探讨,最后指出保证FHA涂层的力学性能的同时保证涂层的生物性能要求是激光熔覆成功用于FHA制备的关键,也是未来研究的重点所在。     

Electrophoretic deposition of titanium/silicon-substituted hydroxyapatite composite coating and its interaction with bovine serum albumin

Silicon-substituted hydroxyapatite (Ca10(PO4)6-x(SiO4)x(OH)2-x, Si-HA) composite coatings on a bioactive titanium substrate were prepared by electrophoretic deposition technique with the addition of triethanolamine (TEA) to enhance the ionization degree of Si-HA suspension. The surface structure was characterized by XRD, SEM, XRF, EDS and FTIR. The bond strength of the coating was investigated. The results show that the depositing thickness and the images of Si-HA coating can be changed with the variation of deposition time. The XRD spectra of Ti/Si-HA coatings show the characteristic diffraction peaks of HA, and the incorporation of silicon changes the lattice parameter of the crystal. The FTIR spectra shows that the most notable effect of silicon substitution is the decrease of intensities of -OH and PO43- groups with the silicon contents increasing. XRD and EDS element analyses present that the content of silicon in the coating increases with increasing silicon concentration in the suspension. The bioactive TiO2 coating formed may improve the bond strength of the coatings. The interaction of Ti/Si-HA coating with BSA is much greater than that of Ti/HA coating, suggesting that the incorporation of silicon in HA is significant to improve the bioactive performance of HA.     

悬浮液等离子喷涂制备FHA/CS复合涂层

目的 采用悬浮液等离子喷涂技术（SPS）在纯钛表面制备氟代羟基磷灰石/硅酸钙（FHA/CS）生物复合涂层。方法 利用X射线衍射仪（XRD）、傅里叶红外光谱仪（FT-IR）、扫描电子显微镜（SEM）及能谱仪（EDS）对复合涂层的物相组成、组织结构和显微形貌进行分析。通过动电位极化测试和体外生物活性测试,分析复合涂层在模拟体液（SBF）中的腐蚀行为和类骨磷灰石形成能力。通过电感耦合等离子体光谱仪（ICP）分析涂层中Ca2+的释放行为,评估复合涂层的化学稳定性。采用划痕法表征涂层的结合强度。结果 SPS制备的复合涂层具有粗糙的表面和层片堆叠结构。涂层中FHA和CS两相分布均匀,结晶性良好。复合涂层临界载荷达到111.43 N,比单一FHA涂层提高62.5%。与纯钛相比,涂层样品具有较高的腐蚀电位（Ecorr）和较低的腐蚀电流密度（Jcorr）。在SBF溶液中浸泡3天,涂层样品表面被类骨磷灰石完全覆盖。ICP结果表明,复合涂层中Ca2+释放速率低于单一CS涂层。结论 通过SPS在纯钛表面制备的FHA/CS复合涂层具有良好的生物活性、耐腐蚀性能和与基体的结合强度,复合涂层中FHA组分的存在有利于提高涂层的化学稳定性。     

Thermal spraying of functionally graded calcium phosphate coatings for biomedical implants

Biomedical requirements in a prosthesis are often complex and diverse in nature. Biomaterials for implants have to display a wide range of adaptability to suit the various stages of the bio-integration process of any foreign material into the human body. Often, a combination of materials is needed. The preparation of a functionally graded bioceramic coating composed of essentially calcium phosphate compounds is explored. The coating is graded in accordance to adhesive strength, bioactivity, and bioresorbability. The bond coat on the Ti-6Al-4V stub is deposited with a particle range of the hydroxyapatite (HA) that will provide a high adhesive strength and bioactivity but have poor bioresorption properties. The top coat, however, is composed of predominantly α-tricalcium phosphate (α-TCP) that is highly bioresorbable. This arrangement has the propensity of allowing accelerated bio-integration of the coating by the body tissues as the top layer is rapidly resorbed, leaving the more bioactive intermediate layer to facilitate the much needed bioactive properties for proper osteoconduction. The processing steps and problems are highlighted, as well as the results of post-spray heat treatment.     

Microstructure and in vitro bioactivity of laser-cladded bioceramic coating on titanium alloy in a simulated body fluid

In order to obtain bioactivity on the surface of titanium alloy, the bioceramic coating on Ti–6Al–4V was designed and fabricated by laser cladding. The microstructure and bioactivity of laser-cladded bioceramic coating were investigated in vitro via soaking in a simulated body fluid (SBF). The results indicated that the laser-cladded bioceramic coating was metallurgically bonded to the substrate and contained such bioactive phases as hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP). A bone-like apatite layer was spontaneously formed on the surface of laser-cladded coating merely soaked in SBF for 7 days. And the appearance of flake-like and cotton-like morphology, which is the characteristic morphology of apatite, offered an advantageous condition for osseo-connection. The formation ability of apatite was remarkably accelerated on the surface of laser-cladded bioceramic coating compared with the untreated titanium alloy substrate.     

多孔ZrO2/HA医用钛合金微弧氧化复合陶瓷膜层生物力学性能研究

为了获得具有生物力学性能的陶瓷膜层材料并满足临床医学上的需要。以Ti6Al4V钛合金为基体材料,通过微弧氧化工艺方法在电解液中制备氧化锆和羟基磷灰石复合陶瓷膜层材料。利用能谱分析仪和扫描电镜分析膜层结构特点。建立并改进了多孔性膜层力学性能数学模型,利用理论计算与实验测试相结合的方法对膜层相关生物力学性能进行了研究。实验结果表明,氧化锆/羟基磷灰石医用钛合金复合陶瓷能够取得比单一的羟基磷灰石陶瓷膜层更好的生物力学性能。生物陶瓷力学性能与孔隙率及生成的新相有关,通过实验与理论模型相结合的方法能够更好的对生物陶瓷膜层力学性能进行研究,所建立数学模型科学合理,具有一定理论意义。     

Fabrication and Characterization of Suspension Plasma-Sprayed Fluoridated Hydroxyapatite Coatings for Biomedical Applications

Fluoridated hydroxyapatite (FHA) coatings were prepared on a Ti substrate using a suspension plasma spraying technique. The crystalline phases and chemical compositions of the coatings were characterized using x-ray diffraction, Fourier transform infrared spectroscopy, and x-ray photoelectron spectroscopy. The analysis confirmed that the coating consisted of an FHA phase. The corrosion behavior in simulated body fluid was studied using potentiodynamic polarization tests, and the results indicated that the FHA coating greatly enhanced the corrosion resistance of the Ti substrate. The chemical stability of the FHA coatings was assessed by evaluating the release of Ca²⁺ ions. The results indicated that the substitution of fluorine into the hydroxyapatite (HA) structure had a positive effect on the dissolution resistance of the HA. The antibacterial activity was investigated using a surface-plating method; the results revealed that the antibacterial activity of the FHA coating was greater than that of the pure HA coatings. During cell culture tests, the FHA coating did not exhibit cytotoxicity toward the osteoblast cell line, and the cell proliferation was comparable with that of the HA coatings. The antibacterial activity and cell culture results suggested that the plasma-sprayed FHA coating possesses good antibacterial qualities, but is biocompatible with osteoblasts. The promising features of the FHA coating render it suitable for orthopedic and dental applications.     

生物活性多孔钽支架的构建及其初步生物学评价

表面生物活性涂层构建是提升金属内植物骨整合能力的有效途径,本研究利用电化学沉积技术在多孔钽支架表面构建生物活性羟基磷灰石(HA)涂层。通过接触角和比表面积测试发现,HA涂层的构建显著提升了多孔钽表面亲水性,并增加了其比表面积。利用模拟体液浸泡试验评估支架生物活性,发现仅浸泡3天后,多孔钽支架表面就已被类骨磷灰石沉积所覆盖。建成骨细胞培养模型,通过激光共聚焦观察及细胞增殖测试发现,所有支架均具有良好的细胞相容性。并且,细胞共培养5天后,HA涂层化多孔钽支架表面细胞的增殖率分别是未改性材料组和空白对照组的1.1和1.4倍,呈现了更大的促细胞增殖潜力。本研究中所制备的生物活性多孔钽支架具备快速诱导类骨磷灰石沉积能力,能够促进成骨细胞在其表面的贴附和增殖,在骨修复领域具有较大的临床应用前景。     

High-velocity oxyfuel thermal spray coatings for biomedical applications

Plasma spraying is used to produce most commercially available bioceramic coatings for dental implants; however, these coatings still contain some inadequacies. Two types of coatings produced by the high- velocity oxyfuel (HVOF) combustion spray process using commercially available hydroxyapatite (HA) and fluorapatite (FA) powders sprayed onto titanium were characterized to determine whether this relatively new coating process can be applied to bioceramic coatings. Diffuse reflectance Fourier transform infrared (FTIR) spectroscopy, x- ray diffraction (XRD), and scanning electron microscopy (SEM) were used to characterize the composition, microstructure, and morphology of the coatings. The XRD and FTIR techniques revealed an apatitic structure for both HA and FA coatings. However, XRD patterns indicated some loss in crystallinity of the coatings due to the spraying process. Results from FTIR showed a loss in the intensity of the OH^∼ and F^∼ groups due to HVOF spraying; the phosphate groups, however, were still present. Analysis by SEM showed a coating morphology similar to that obtained with plasma spraying, with complete coverage of the titanium substrate. Interfacial SEM studies revealed an excellent coating-to-substrate apposition. These results indicate that with further optimization the HVOF thermal spray process may offer another method for producing bioceramic coatings.     

Preparation and characterization of silicon-substituted hydroxyapatite coating by a biomimetic process on titanium substrate

A biomimetic method has been used to prepare silicon-substituted hydroxyapatite coatings on titanium substrates. The surface structures of the coatings were characterized by X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectroscopy (FTIR). Si substituted hydroxyapatite (Si-HA) coatings with different Si contents were deposited successfully on the titanium substrate by immersing the pretreated titanium substrate into silicon containing supersaturated solutions (SSS) with different SiO₃²⁻ concentrations. The pretreatment of the Ti substrate in a mixed alkaline (NaOH + Ca(OH₂)) followed by a heat treatment produced a 3D porous surface structure with rutile and CaTiO₃ as main phases, which contributed mainly to the fast precipitation and deposition of Si-HA. FTIR results showed that Si in the Si-HA coating existed in the form of SiO₄⁴⁻ groups. The cross-section microstructure was observed by scanning electronic microscopy and the shear strength was tested. The coating was about 5-10 μm in thickness and no interval was observed at the interface between the coating and the substrate. Shear strength testing showed that Si-HA/Ti exhibited higher shear strength than HA/Ti due to the existence of the SiO₄⁴⁻ group in the coating.     

激光熔覆SiO2/La2O3梯度生物陶瓷涂层生物活性研究

目的研究SiO_2含量对钛合金表面激光熔覆梯度生物陶瓷涂层生物活性的影响。方法利用激光熔覆技术,采用梯度成分设计思想,固定涂层中稀土氧化物La_2O_3的添加量,在钛合金TC4表面制备了掺杂不同含量SiO_2的梯度生物陶瓷涂层。采用金相显微镜(OM)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)、噻唑蓝(MTT)及荧光素双醋酸酯(FDA)染色等测试手段,研究了SiO_2含量对激光熔覆制备梯度涂层的组织结构和生物活性的影响。结果 SiO_2在激光熔覆过程中可以降低梯度生物陶瓷涂层的开裂敏感性,并起到细化晶粒的作用。当SiO_2掺杂量为2.5%时,激光熔覆过程中诱导合成的HA+CaTiO_3数量最大;当SiO_2掺杂量为7.5%时,模拟体液(SBF)实验表明,涂层的矿化沉积能力最强。MTT测试表明,SiO_2掺杂量为7.5%的涂层细胞增殖数量的OD值最大,细胞能够紧贴涂层表面生长。FDA染色分析表明,SiO_2掺杂量为7.5%的涂层上细胞数量最多,且分布均匀。结论 SiO_2掺杂量深刻影响着生物活性陶瓷相HA和Ca_2SiO_4数量,进而影响生物陶瓷涂层的生物活性。SiO_2掺杂量为7.5%的涂层具有最佳的生物相容性及生物活性。