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.

In Vitro Immersion Behavior of Cold Sprayed Hydroxyapatite/Titanium Composite Coatings

In previous study, dense and homogenous 20wt% HAP/Ti composite coatings were successfully deposited on Ti substrates by cold gas dynamic spray technique. The results revealed that the phase composition of the HAP in the deposit is identical to that of the precursor powder and the bonding strength of the deposit is comparable/better to that of the plasma sprayed HAP. A relatively higher corrosion current of HAP/Ti composite than that of pure Ti coating in simulated body fluid indicates a good bioactivity for composite coating. In the present study, in vitro immersion test is carried out for various period of time and the formation of apatite layer on surface of composite coating proves the good bioactivity of the composite coating further. The cold sprayed HAP/Ti composite can be anticipated to be a promising load-bearing implant material for biomedical applications.

Surface and interface analysis of HAP/TiO2 composite films on Ti6Al4V

The composite films constituted of hydroxyapatite (HAP) submicron particles embedded in the gel composed of the titania nanoparticles were prepared on commercial Ti6Al4V plates with titania buffer layer obtained by a spin-coating technique. The films were annealed in air at 450 ℃, 550 ℃ and 650 ℃, respectively. The phase formation, surface morphology, andinterfacial microstructure of the films were investigated by X-ray diffraction(XRD),Fourier transform infrared spectroscopy (FT-IR), field emission-scanning electron microscopy(FE-SEM) and energy dispersive X-ray (EDS) analysis. The results show that the as-prepared films are all well-crystallized, dense,homogeneous, and there was a close interfacial bond between the film and the substrate. The results of adhesion test indicate that there is a good bonding strength between the film and the substrate. The bone-like apatite formation on the surface of the films after immersion in acellular simulatedbody fluid(SBF) validated their bioactivities.

Mechanical properties of TiO_2-hydroxyapatite nanostructured coatings on Ti-6Al-4V substrates by APS method

TiO2-hydroxyapatite （HA） nanostructured coatings were produced by atmospheric plasma spray method. The effects of starting powder composition and grain size on their mechanical properties were investigated. The microstructure and morphology were characterized by X-ray diffraction and scanning electron microscopy （SEM）. It is found that the coating with 10% HA has the best mechanical properties. Based on Rietveld refinement method, the mean grain size of the as-received powder （212 nm） extensively decreases to 66.4 nm after 20 h of high-energy ball milling. In spite of grain growth, the deposited coatings maintain their nanostructures with the mean grain size of 112 nm. SEM images show that there is a lower porosity in the coating with a higher HA content. Optical microscopy images show that uniform thickness is obtained for all the coatings.

An in-vitro Investigation of Iron-Containing Hydroxyapatite/Titanium Composites

The in-vitro biological behavior of a newly-developed iron-containing hydroxyapatite/titanium（HA/Ti） composite was investigated by immersing the composites in the simulated body fluid（SBF） for up to 5 weeks.The addition of iron was observed to have a significant influence on the in-vitro biological behavior of the composites.The obtained results revealed that the stability of the composites in the physiological solution was markedly improved.The solubility decreased in the order of pure HA,HA/5（Ti-33Fe）,and HA/15（Ti33Fe）.Precipitation occurred on the surface of HA/5（Ti-33Fe） composite,showing a good combination of physiostability with bioactivity,while HA/15（Ti-33Fe） composite exhibited superior physiostability since there was no obvious change on the surface of HA/15（Ti-33Fe）.

HAP／HDPE／UHMWPE复合材料的制备和表征

通过化学共沉淀-水热合成法制备纳米级羟基磷灰石(HAP),再用自制模具制备HAP/高密度聚乙烯(HDPE)/超高相对分子质量聚乙烯(UHMWPE)复合材料。通过扫描电镜观察、X射线衍射分析、热重分析、燃烧实验以及力学性能测试,研究HAP/HDPE/UHMWE复合材料的微观结构和力学性能。研究结果表明:通过口模挤出可使HDPE分子链在应力作用下伸直取向,大量平行于长轴且紧密排列的微纤维形成。UHMWPE的加入可以改善材料的微观结构,增加材料的串晶互锁结构。而HAP和聚乙烯之间只是机械地混合在一起,呈层状结构,HAP被聚乙烯组分紧紧包裹在一起,且在同一样品中HAP含量比较均匀;随着HAP含量增加,拉伸强度和抗弯强度下降,分别从170.7 MPa和160.8 MPa下降到99.2 MPa和94.3 MPa,而弹性模量有所增加,从4.9 GPa上升到5.9 GPa。

电化学方法在钛表面制备Co-YSZ/HAp纳米复合涂层

采用复合电沉积和电泳沉积两步法在钛基体上制备了Co-YSZ/HAp纳米复合涂层,与只采用电泳沉积法在钛基体上制备纳米HAp单一涂层进行了比较研究.采用场发射扫描电镜、X射线衍射和能量散射谱对复合涂层的微观形貌,纳米HAp外层表面形貌,晶相,复合涂层的断面形貌及元素组成分布进行分析研究.通过粘结-拉伸实验测定了涂层与基体的结合强度,结果表明,Co-YSZ/HAp纳米复合涂层与钛基体的结合强度明显高于纳米HAp单一涂层与钛基体的结合强度,说明复合涂层具有更好的力学性能.

纳米HAP改性PMMA骨水泥力学性能的研究

PMMA骨水泥存在力学强度及弹性模量不高、聚合温度、生物相容性有待进一步改进等问题。本文利用水热法合成了纳米HAP粉体,研究HAP粉体对PMMA基骨水泥改性方法及其对力学性能、微观结构的影响。结果表明,当HAP含量在5-10%时,骨水泥的拉伸强度、弹性模量、硬度、冲击韧性等性能均有一定程度的提高。通过粉体的表面改性,界面结合性能得到改善。

氧化石墨烯/羟基磷灰石复合涂层对RAW264.7巨噬细胞免疫活性的影响

背景:纯钛种植体植入机体后存在骨融合失败或者种植体周围感染等问题,因此对钛种植体表面进行改良已成研究的热门话题。巨噬细胞是机体应对外界刺激的一道免疫防线,任何生物材料植入体内后的相关免疫反应均与巨噬细胞相关。目的:采用电化学沉积法在纯钛片表面制备氧化石墨烯/羟基磷灰石复合涂层,分析涂层的表面特征及对RAW264.7巨噬细胞生长、极化的影响。方法:采用电化学沉积法在纯钛片表面分别制备单纯氧化石墨烯涂层、氧化石墨烯/羟基磷灰石复合涂层,表征涂层的物理性能。将纯钛片(空白组)、沉积单纯氧化石墨烯涂层的钛片(对照组)、沉积氧化石墨烯/羟基磷灰石复合涂层的钛片(实验组)分别与RAW264.7巨噬细胞共培养,采用CCK-8法、DAPI染色检测细胞增殖,扫描电镜观察细胞在钛片表面的黏附,流式细胞仪检测细胞极化表型。结果与结论:(1)扫描电镜下可见纯钛片有定向划痕与少量点状凹陷;沉积单纯氧化石墨烯涂层后,钛片表面可见较多裂纹沟壑和大小不均匀的颗粒状物,以及氧化石墨烯特征的褶皱样结构;沉积复合涂层后,钛片表面较光滑,可见团状颗粒,颗粒大小较为均匀。沉积复合涂层钛片的水接触接角小于纯钛片、沉积单纯氧化石墨烯涂层的钛片(P <0.05)。(2)CCK-8检测与DAPI染色显示,相较于空白组、对照组,实验组细胞增殖更快。扫描电镜下可见RAW264.7细胞均黏附于3组钛片表面,随着培养时间的延长细胞形态发生改变,由圆形向梭形转变,至培养7 d时,空白组细胞伸出的伪足短而少,对照组细胞伸出长而多的伪足,实验组细胞伸出短而多的伪足,并且实验组细胞整体饱满度最优。流式细胞仪检测显示,实验组细胞更高比例向抗炎方向M2型极化。(3)结果表明,氧化石墨烯/羟基磷灰石复合涂层具有良好的理化性能及生物学性能。

Antibacterial hydroxyapatite coatings on titanium dental implants

Titanium and its alloys are often used as substrates for dental implants due to their excellent mechanical properties and good biocompatibility.However,their ability to bind to neighboring bone is limited due to the lack of biological activity.At the same time,they show poor antibacterial ability which can easily cause bacterial infection and chronic inflammation,eventually resulting in implant failure.The preparation of composite hydroxyapatite coatings with antibacterial ability can effectively figure out these concerns.In this review,the research status and development trends of antibacterial hydroxyapatite coatings constructed on titanium and its alloys are analyzed and reviewed.This review may provide valuable reference for the preparation and application of high-performance and multi-functional dental implant coatings in the future.

间接3D打印制备Ti/HAp复合材料的结构与性能

采用离子掺杂改性的方式制备不同铷(Rb)含量的羟基磷灰石(Rb-Hydroxyapatite,Rb-HAp)粉末,然后用间接3D打印法制备Ti/Rb-HAp复合材料,对该材料的形貌和物相组成进行分析,测定材料的力学性能,并通过体外细胞培养和细胞增殖与分化实验,研究材料的生物学性能。结果表明:Ti/Rb-HAp复合材料的孔隙率较高,多孔结构有利于新骨组织向内生长和体液的传输。Rb的加入可提高Ti/HAp复合材料的抗弯强度和抗压强度,并且抗压强度随Rb含量增加而小幅提高。与纯Ti相比,Ti/Rb-HAp复合材料可促进MG-63细胞的增殖和ALP活性,具有良好的细胞相容性。浸泡在模拟体液中,Ti/Rb-HAp复合材料表面形成致密的磷灰石层,表明该材料具有优异的生物活性。

Effect of different sol-gel synthesis processes on microstructural and morphological characteristics of hydroxyapatite-bioactive glass composite nanopowders

The aim of this work was to study the influence of the different synthesis processes on microstructural and morphological characteristics and distribution of hydroxyapatite-bioactive glass(HAp-BG)composite nanopowders obtained by sol-gel method.HAp-BG composite nanopowders with 20 wt%bioactive glass were prepared using a sol-gel method via four routes:(I)mixing the prepared HAp solution with BG solution before aging time;(II)mixing the prepared BG solution with the prepared HAp gel after gelation;(III)mixing the calcined BG nanopowders with the prepared HAp solution;and(IV)mixing the two prepared calcined nanopowders by mechanochemical activation.The prepared nanopowders were evaluated and studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectrometer(EDS),Fourier transform infrared(FTIR),transmission electron diffraction(TEM)and Brunauer-Emmet-Teller(BET)method to investigate the phase structure,microstructure and morphology,functional groups,and the size and distribution of nanopowders.Results indicated that morphology,crystallinity,crystallite size and specific surface area(SSA)of the powders are highly correspondent to the process and type of synthesis method.These findings suggest that the modified sol-gel derived HAp-BG composite nanopowders are expected to efficiently provide a possibility to produce a good candidate to use for fabrication of a bulk nanostructured HAp-BG composite for bone tissue engineering.

La(NO_(3))_(3)掺杂对TC4微弧氧化/水热复合涂层显微结构和耐磨性的影响

作为生物医用材料,TC4钛合金在骨组织再修复领域中临床使用量很大,中国每年的消耗量约为百万件以上。但TC4钛合金耐磨性低、生物活性差等问题严重制约其工程应用领域的扩展。为此,采用微弧氧化/水热合成复合技术在TC4表面制备微弧氧化/水热复合涂层,研究水热合成液中La(NO_(3))_(3)掺杂量对TC4钛合金微弧氧化/水热涂层的相组成、微观形貌、显微硬度、耐磨性等参数的影响作用。利用XRD、SEM、显微硬度计、摩擦磨损试验机等手段对TC4钛合金微弧氧化/水热涂层进行表征。研究结果表明:TC4钛合金微弧氧化/水热涂层相组成主要由锐钛矿型TiO_(2)和羟基磷灰石组成。经过水热处理后合成液中La^(3+)进入到复合涂层中,参与涂层反应。随着La(NO_(3))3掺杂量增加,获得的复合涂层中羟基磷灰石相含量先增加后降低。当La(NO_(3))_(3)掺杂量超过24 mmol/L时,涂层表面变得更为光滑。TC4钛合金微弧氧化/水热涂层的显微硬度先降低后增加,且其摩擦系数先增大后减小。当La(NO_(3))_(3)掺杂量达到24 mmol/L时,涂层的显微硬度达到最小值,约为271.8 HV9.8 N;涂层摩擦系数达到最大值,约为0.8~0.9。

钛合金羟基磷灰石骨植入复合材料的研究进展

钛及钛合金因具有高强度、低模量、优异的耐腐蚀性以及良好的生物相容性等优点,被广泛应用于生物医学领域,尤其是作为硬组织替换材料。然而,钛合金属于生物惰性材料,植入人体后难以与人骨实现良好的骨整合。以羟基磷灰石为代表的生物活性陶瓷能够诱导类骨磷灰石沉积和细胞攀附,但不能用于高承载部位。因此,为了改善植入体的生物活性,开发新型钛合金羟基磷灰石复合材料成为骨植入材料的研究热点。采用表面涂层法在钛合金表面制备羟基磷灰石涂层,能够显著改善基体的生物活性,但是存在两者结合强度不高、涂层易产生裂纹等缺点,需要从涂层成分、结构梯度化以及后处理等方面进行改进。粉末冶金技术能够使生物活性陶瓷与金属基体间实现冶金结合,却难以对材料组分分布和结构特征进行精确控制和调整。自然骨为由内部多孔松质骨和表面致密皮质骨组成的梯度结构,采用传统粉末冶金技术制备的骨科假体很难达到这一要求。增材制造技术可以个性化定制植入体,其逐层堆积的成形方式在梯度复合材料制备方面具有极大优势。近年来,研究人员尝试采用增材制造技术来实现植入体的成分复合化和结构梯度化,进一步调控其力学性能和生物学性能。本文总结了钛合金羟基磷灰石复合材料的研究现状,指出了目前研究中存在的问题,并进一步讨论了解决策略,最后提出了一种基于微滴喷射技术的钛合金羟基磷灰石多维梯度复合材料的增材制造方案,以期为开发功能复合的新型生物材料提供参考。

The optimized preparation of HA/L-TiO2/D-TiO2 composite coating on porous titanium and its effect on the behavior osteoblasts

Various surface bioactivation technology has been confirmed to improve the osteogenic ability of porous titanium(pTi)implants effectively.In this study,a three-layered composite coating,i.e.outer layer of hydroxyapatite(HA),middle layer of loose titanium dioxide(L-TiO2)and inner layer of dense TiO2(D-TiO2),was fabricated on pTi by a combined processing procedure of pickling,alkali heat(AH),anodic oxidation(AO),electrochemical deposition(ED)and hydrothermal treatment(HT).After soaking in simulated body fluid for 48 h,the surface of the AHAOEDHT-treated pTi was completely covered by a homogeneous apatite layer.Using MC3T3-E1 pro-osteoblasts as cell model,the cell culture revealed that both the pTi without surface treatment and the AHAOEDHT sample could support the attachment,growth and proliferation of the cells.Compared to the pTi sample,the AHAOEDHT one induced higher expressions of osteogenesis-related genes in the cells,including alkaline phosphatase,Type I collagen,osteopontin,osteoclast inhibitor,osteocalcin and zinc finger structure transcription factor.As thus,besides the good corrosion resistance,the HA/L-TiO2/D-TiO2-coated pTi had good osteogenic activity,showing good potential in practical application for bone defect repair.

羟基磷灰石及其复合涂层的研究现状

钛及其合金金属有良好的机械性能,羟基磷灰石是有优异生物性能的活性陶瓷,因而羟基磷灰石/钛(HA/Ti)复合涂层结合二者优势性能被广泛应用于人体骨组织和牙齿的修复中,以提高材料的医用价值。该文采用冷喷涂、等离子喷涂、磁控溅射、激光熔覆、溶胶-凝胶、电化学沉积等其他技术制备HA/Ti复合粒子,并适当掺入其他金属合金,完善性能,探究其实验后的涂层特征、表面形态对力学性能和生物性能的影响。

Biomechanical evaluation of different hydroxyapatite coatings on titanium for keratoprosthesis

Stable tissue integration is important to keratoprosthesis （KPro）. The aim of this study was to evaluate the tissue bonding ability of hydroxyapatite （HAp）-coated titanium KPro. The samples were divided into three groups： test groups （IBAD group and AD group） and Ti control. The coated samples had a HAp layer created by ion beam assisted deposition （IBAD） or aerosol deposition （AD）. The surface characteristics were analyzed with SEM, AFM, and XRD. The samples were surgically inserted into the muscles of rabbits. Eight weeks after healing, the attachment to the tissue was tested with a universal test device. The three samples exhibited distinctive surface morphology. The force to remove the HAp implants from the muscles was significantly greater than that of Ti group （P〈0.01）, with the AD samples requiring the greatest force （P〈0.01）. After removal, SEM showed that the tissue was firmly attached to the surface of AD samples. Photomicrographs of the peri-implant muscles showed a layer of aligned fibrous tissue without severe inflammation. The AD samples had more fibroblasts. Results indicate that because of enhanced mechanical adhesion of soft tissue to the implants, HAp-coated Ti by AD is a suitable KPro skirt material.

丝素蛋白/羟基磷灰石复合材料的制备及性能表征

为了改善羟基磷灰石(HAP)的脆性和新骨诱导性,采用共沉淀法合成HAP,盐溶法制备丝素蛋白(SF),在胶体状态下将HAP和SF复合得到了SF/HAP复合材料。采用扫描电镜(SEM)、X射线衍射(XRD),傅立叶红外光谱(FIR)对复合材料结构和化学组成进行了分析,在模拟体液中检验了复合材料的生物活性,并对其抗压强度进行了测定。结果表明:HAP与SF在纳米尺度进行了复合,复合材料中SF主要以β-折叠构象存在,酰胺Ⅴ红外特征峰消失,β-折叠构象的其他峰发生了移动,表明HAP与SF间存在化学结合;模拟体液中浸泡18天后,复合材料表面形成了片层状的HAP;与纯的HAP晶体比较,复合材料结构稳定,具有较好生物活性和骨诱导性,其抗压强度可达63 MPa,可望成为理想的骨组织替换和工程支架材料。

羟基磷灰石/钛网状复合材料的制备及其性能

以Ca(OH)2和H3PO4为反应物,通过溶胶-凝胶法制备了羟基磷灰石(HA)粉体;用机械混合法制备了TiH2包覆HA的粉体;用热压法制备了纯HA陶瓷材料及HA/Ti复合材料.XRD相分析结果表明:通过溶胶-凝胶法制备的HA粉体,经过900℃煅烧2 h后,粉体的主晶相为HA,有少量的CaO;HA/TiH2包覆粉末经1 050℃热压后,复合材料中的主要相是HA和Ti,同时出现了Ca2P2O7和Ca3(PO4)2相.1 050℃热压的HA/25%Ti(体积分数)复合材料的断裂韧性为2.4 MPa.m-1/2,抗弯强度为54 MPa,均高于纯HA材料.显微组织的观察表明金属钛在材料中呈网状分布,网状分布的金属相能够通过裂纹桥接机制阻止HA基体中的裂纹的扩展.

Ti/HA生物复合材料的研究进展

钛系医用合金虽然生物相容性较好,在医学领域得到推广应用,但其主要问题是生物活性及耐磨性不理想,容易被磨损或粘住。钛合金和羟基磷灰石(HA)的复合成为生物医用材料的研究热点。综述了近年来Ti/HA生物复合材料的常用制备方法及优缺点,总结了Ti/HA复合材料的研究现状及存在的问题。另外,指出了钛掺杂HA不仅可解决有害的涂层-金属界面层的问题,而且具有杀菌的功效。