Preparation and properties of a cerium-containing hydroxyapatite coating on commercially pure titanium by micro-arc oxidation

A porous cerium-containing hydroxyapatite coating on commercially pure titanium was prepared by micro-arc oxidation （MAO） in an electrolytic solution containing calcium acetate, p-glycerol phosphate disodium salt pentahydrate （β-GP）, and cerium nitrate. The thickness, phase, composition morphology, and biocompatibility of the oxide coating were characterized by X-ray diffraction （XRD）, electron probe microanalysis （EPMA）, scanning electron microscopy （SEM） with energy dispersive X-ray spectrometer （EDS）, and cell culture. The thickness of the MAO film is about 15-25 ~tm, and the coating is porous and uneven, without any apparent interface to the titanium substrates. The results of XRD and EDS show that the porous coating is made up of hydroxyapatite （HA） film containing Ce. The favorable osteoblast cell affinity makes the Ce-HA film have a good biocompatibility. The Ce-HA film is expected to have significant medical applications as dental implants and artificial bone joints.

Preparation and performance of coating on rare-earth compounds-immersed magnesium alloy by micro-arc oxidation

A composite ceramic coating containing Y2O3-ZrO2-MgO（YSZ-MgO） was prepared on AZ91D magnesium alloy,which was immersed in Y（NO3）3 aqueous solution as pretreatment,by micro-arc oxidation（MAO） process.The morphology,elemental and phase compositions,corrosion behavior and thermal stability of the coatings were studied by SEM,EDX,XRD,electrochemical corrosion test,high temperature oxidation and thermal shock test.The results show that the coating mainly consists of ZrO2,Y2O3,MgO,Mg2SiO4,and MgF2.Among these compounds,Y2O3 accounts for 26.7% of（Y2O3 ＋ ZrO2）.The thickness of YSZ-MgO coating is smaller than that of ZrO2-MgO coating,but its compactness and surface roughness are better than those of ZrO2-MgO coating.YSZ-MgO coating has a good corrosion resistance,and its corrosion rate in 5% NaCl aqueous solution is lower than that of ZrO2-MgO and only about 8.5% of that of AZ91D magnesium alloy.After oxidation at 410 °C,the mass gain of AZ91D magnesium alloy presents a linear increase with the oxidation time.The YSZ-MgO coating and ZrO2-MgO coating can remarkably decrease the oxidation mass gain.The oxidation mass gain of YSZ-MgO coating is lower than that of ZrO2-MgO coating,especially during a long oxidation period.The thermal shock resistance of YSZ-MgO coating is superior to ZrO2-MgO coating.

Structure and properties of micro-arc calcium phosphate coatings on pure titanium and Ti-40Nb alloy

The microstructure, physical and mechanical, and chemical properties of micro-arc calcium phosphate （CAP） coatings deposited under different process voltages in the range of 150-400 V on the commercially pure titanium （Ti） and Ti-40%Nb （Ti-40Nb） （mass fraction） alloy were investigated by the SEM, TEM, XRD and EDX methods. The coating thickness, roughness, and sizes of structural elements were measured and showed similar linear character depending on the process voltage for the coatings on both substrates. SEM results showed the porous morphology with spherical shape structural elements and rough surface relief of the coatings. XRD and TEM studies exhibited the amorphous structure of the CaP coating. With increasing the process voltage to 300-400 V, the crystalline phases, such as CaHPO4 and β-Ca2P207, were formed onto the coatings. The annealing leads to the formation of complex poly-phase structure with crystalline phases： CaTi4（PO4）6, β-Ca2P2O7, TiP2O7, TiNb（PO4）3, TiO2, NbO2, and Nb2O5. The applied voltage and process duration in the ranges of 200-250 V and 5-10 min, respectively, revealed the coating formed on Ti and Ti-40Nb with optimal properties： thickness of 40-70μm, porosity of 20%-25%, roughness （Ra） of 2.5-5.0 μm, adhesion strength of 15-30 MPa, and Ca/P mole ratio of 0.5-0.7.

Comparative Study of the Effects of Nano ZnO and CuO on the Biodegradation,Biocompatibility,and Antibacterial Properties of Micro-arc Oxidation Coating of Magnesium Alloy

This research systematically examined the degradation,antibacterial effects,and biocompatibility of micro-arc oxidation(MAO)coatings with nano CuO and ZnO on extruded Mg alloys.Both copper(Cu)and Zinc(Zn)possess antibacterial properties.The findings demonstrated that adding ZnO will appreciably reduce the degradation rate of MAO-coating alloy due to the self-sealing micro holes.CuO+MAO coating exhibited excellent antibacterial performance,with an antibacterial rate of over 90%within 6 h co-cultured with Staphylococcus aureus.Similarly,the antibacterial rate of ZnO+MAO coating reached 90%after 12 h co-culture.Cytotoxicity test using MG63 cell indicated that the incorporation of CuO and ZnO did not notably affect the cell viability rate of the coating.Moreover,after 14 days of culture,the CuO+MAO and ZnO+MAO coated samples exhibited higher alkaline phosphatase(ALP)activity than the MAO-coated and uncoated samples,suggesting favorable osteogenic properties.

Preparation of biocompatible structural gradient coatings on pure titanium

In order to overcome the poor osteo-inductive properties of titanium implant, some methods have been used. The efforts to improve implant biocompatibility and durability by applying a hybrid technique of composite oxidation (pre-anodic and micro-arc oxidation) and hydrothermal treatment were described. Pure titanium was used as the substrate material. An oxalic acid was used as the electrolyte for the pre-anodic oxidation. A calcium and phosphate salt solution was acted as the electrolyte of micro-arc oxidation and the common pure water was used for hydrothermal treatment. X-ray diffraction (XRD), and scanning electron microscopy (SEM) have been used to investigate the microstructure and morphology of the coatings. The results show that a compact TiO2 film can be made by pre-anodic oxidation, which is effective as chemical barriers against the in-vivo release of metal ions from the implants. A porous TiO2 coating can be produced by micro-arc oxidation on titanium plate, which is beneficial to bone tissue growth and enhancing anchorage of implant to bone. De-calcium HA can be formed on the coating using hydrothermal treatment, which is similar with the primary component of bone and has a very good osteo-inductivity.The porous gradient titania coating made by the hybrid oxidation and hydrothermal treatment should show good biocompatibility in the environment of the human body.

Comparison of the corrosion behavior of AM60 Mg alloy with and without self-healing coating in atmospheric environment

Coatings on the surface of Mg alloys are inevitably damaged during their practical applications,and corrosion can easily initiate from the damaged areas to accelerate the failure of Mg parts.A dual self-healing coating has already been developed to solve this problem in our previous work.Considering the practical application of this coating,it is necessary to investigate its service behavior in atmospheric environment.Thus,the corrosion behavior of AM60 Mg substrate with and without the self-healing coating was compared in Shenyang industrial atmospheric environment.The results show that the enrichment of sediments and rainwater on the scratch areas can accelerate the corrosion of the exposed Mg substrate.The inhibitors can be released from the damaged coating to inhibit corrosion.The dual self-healing coating shows better inhibition ability to narrow scratches due to the higher inhibitor concentration and less resumption.Also,the coating with wide scratches displays enough inhibition ability as well.The dual self-healing coating is a good alternative for Mg alloy parts in the practical applications.

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。

A first look at the formation of PEO-PDA coatings on 3D titanium

Additive manufacturing has revolutionized implantology by enabling the fabrication of customized,highly porous implants.Surface modifications using electrochemical methods can significantly enhance the bioactivity and biocompatibility of biomaterials,including 3D-printed implants.This study investigates novel coatings on 3D titanium(Ti)samples.Mesh Ti samples were designed and subjected to plasma electrolytic oxidation(PEO)to form a calcium phosphate coating.Subsequently,a layer of polydopamine(PDA)was applied.The electrochemical properties and morphology of the coatings were analyzed.Scanning electron microscopy(SEM)and energy-dispersive X-ray spectroscopy(EDS)revealed well-developed coatings containing calcium phosphates(including hydroxyapatite),titanium dioxide,and polymerized dopamine,suggesting promising bioactive potential.Composite layers incorporating PDA exhibited superior protective properties compared to base PEO coatings.

二甲双胍对微弧氧化羟基磷灰石涂层金属钛表面的糖尿病大鼠BMSCs细胞增殖和成骨分化的影响及机制研究

目的探究二甲双胍(Met)对微弧氧化羟基磷灰石(MAO-HA)涂层金属钛表面的2型糖尿病(T2DM)大鼠骨髓间充质干细胞(BMSCs)细胞增殖和成骨分化的影响及作用机制。方法20只SPF级雄性大鼠随机分为正常组(NC组)、T2DM组、低剂量二甲双胍组(Met-Low组)、高剂量二甲双胍组(Met-High组),每组5只。采用高糖高脂饲料喂养4周联合腹腔注射链脲佐菌素(STA,50 mg/kg)建立T2DM大鼠模型。Met-Low、Met-high组大鼠分别进行二甲双胍150 mg·kg^(-1)·d^(-1)、300 mg·kg^(-1)·d^(-1)灌胃,NC组、T2DM组以等量0.9%氯化钠溶液灌胃。灌胃4周后,处死大鼠并分离股骨、胫骨中的BMSCs。采用电化学法(ELC)和微弧氧化法(MAO)制备羟基磷灰石(HA)涂层金属钛材料。将正常大鼠来源的BMSCs种植于ELC-HA、MAO-HA涂层表面,培养48 h后,扫描电镜观察涂层表面形态及BMSCs在其表面的吸附情况。将不同来源的BMSCs种植于MAO-HA涂层表面,并分为NC组、T2DM组、Met-Low组、Met-High组。培养48 h后,CCK-8、EdU染色检测BMSCs增殖能力;碱性磷酸酶(ALP)染色、茜素红染色检测BMSCs成骨分化能力;Western blot检测细胞增殖相关标志物[增殖细胞核抗原(PCNA)、Ki67]、成骨分化相关标志物[碱性磷酸酶(ALP)、骨钙素(OCN)、骨桥蛋白(OPN)]、Wnt/βcatenin通路相关蛋白[Wnt3a、β连环蛋白(βcatenin)、糖原合酶激酶-3β(GSK-3β)]蛋白水平。结果MAO-HA涂层表面具有均匀粗糙的孔隙,其上BMSCs充分伸展,细胞突起粗大,而ELC-HA涂层表面十分光滑,其上BMSCs皱缩,突起较细。与NC组相比,T2DM组BMSCs细胞存活率、EdU阳性细胞率及成骨分化能力明显降低,BMSCs中PCNA、Ki67、ALP、OCN、OPN、Wnt3a、βcatenin蛋白水平明显降低,GSK-3β蛋白水平明显升高(均P<0.05)。与T2DM组相比,Met-Low组和Met-High组BMSCs细胞存活率、EdU阳性细胞率及成骨分化能力明显升高,BMSCs中PCNA、Ki67、ALP、OCN、OPN、Wnt3a、βcatenin蛋白水平明显升高,GSK-3β蛋白水平明显降低(均P<0.05)。结论二甲双胍能够促进MAO-HA金属钛表面T2DM大鼠BMSCs增殖和成骨分化能力,其可能通过激活Wnt/βcatenin通路发挥作用。

纯钛表面微弧氧化法制备含羟基磷灰石氧化膜的实验研究

应用微弧氧化技术在纯钛表面制备含羟基磷灰石的氧化物膜。在氧化过程中,将钛试件放入含Ca、P电解液中,用直流脉冲电源处理。用扫描电镜(SEM)观察试件的表面和横断面形貌,X射线能谱(EDS)及X射线衍射(XRD)分析其元素成分和晶相结构。结果表明微弧氧化处理后,纯钛表面生成微孔结构的氧化膜,膜层厚度约20μm,由O、Ti、Ca和P四种元素组成。膜层表面有分布不均匀的火山丘状的微孔分布,直径小于5μm。膜层表面的钙磷原子比为1.63,界面处的钙磷原子比为0.51。膜层由金红石型和锐钛矿型二氧化钛及少量结晶相羟基磷灰石组成。微弧氧化技术在纯钛表面生成了内层致密外层多孔的晶相二氧化钛膜,同时含有少量羟基磷灰石,表明该技术在人工种植牙和人工骨关节等领域具有良好的医学应用前景。

微弧氧化法制备含La羟基磷灰石生物活性涂层

采用微弧氧化法在由0.2mol/L乙酸钙、0.02mol/Lβ-甘油磷酸钠及不同含量硝酸镧组成电解液中,于纯钛表面原位生成多孔含La羟基磷灰石生物涂层。用XRD、SEM、EDS、EPMA、细胞培养等方法对膜层的厚度、物相、成分组成、结合强度以及生物相容性进行了研究。结果表明,随电解液中La含量的增加,膜层的厚度减小,膜层中La含量增大,膜层结合强度提高;细胞培养结果表明,膜层有良好的生物相容性。

钛基羟基磷灰石涂层的界面结构及梯度设计

羟基磷灰石是最有发展前途的生物硬组织替代材料之一,临床上采用在钛合金上涂覆HA生物活性涂层,涂基结合及涂基界面的整合是决定HA涂层性能和可靠性的关键因素。评述了钛基羟基磷灰石涂层的界面微观结构,指出界面上存在纳米氧化物薄膜是提高涂层结合强度的关键,并结合纳米多层薄膜和功能梯度膜的优点,提出改善涂基结合强度,发挥羟基磷灰石生物活性涂层的三明治式的梯度设计。

微弧氧化法制备含铈羟基磷灰石生物活性膜层

采用微弧氧化法在含有乙酸钙、β-甘油磷酸钠、硝酸铈的电解液中在纯钛金属表面原位生成了多孔含Ce羟基磷灰石生物涂层。用XRD、SEM、EDS、细胞培养等方法对膜层的厚度、物相、成分组成及生物相容性进行了研究。结果表明膜层粗糙多孔，厚度为15～25μm，与钛基体之间无明显界面；膜层表面主要物相为含Ce的羟基磷灰石；细胞培养结果表明膜层具有良好的生物相容性。

TC11微弧氧化膜制备及其结构性能研究

在Na2SiO3-Na2WO4-NaOH混合电解液中,利用微弧氧化(MAO)技术在TC11合金表面制备了氧化膜。用扫描电镜(SEM),X射线能谱仪(EDS),X射线衍射仪(XRD)对氧化膜微观结构、化学成分、厚度以及相组成进行了分析,采用HVS-1000维氏显微硬度计、MFT-4000划痕试验机、电化学测量系统完成氧化膜理化性能测试。实验结果表明,微弧氧化膜平均厚度达到135μm,分为两层结构,外层疏松,内层致密,氧化膜主要由TiO2、γ-Al2O3、Al2TiO5以及部分非晶SiO2组成,主要元素在断面上呈现梯度分布。氧化膜最高显微硬度是基体的4.7倍,膜与基体结合力>48.50N。电化学极化曲线分析表明,氧化膜在4.5%盐水溶液中比基体的自腐蚀电流密度降低3个数量级,自腐蚀电位正移599mV。

微弧氧化和电泳沉积复合制备羟基磷灰石/TiO_2复合涂层及其生物学特性

采用微弧氧化和电泳沉积复合的方法,在钛样品表面沉积了羟基磷灰石(hydroxyapatite,HA)/TiO2复合涂层。用扫描电子显微镜, 能量散射X射线能谱分析和X射线衍射对复合涂层的表面形貌、形成过程、元素组成及含量变化、相组成进行了观察和分析。通过剪切粘结 实验确定了复合涂层与基体的结合强度,并在高温消毒后,将成骨样细胞MC3T3E1接种于试件表面进行培养以评估HA/TiO2复合涂层 的生物学性能。结果表明:形成的复合涂层由内层致密的TiO2层、中间HA/TiO2混合过渡层和外层HA层构成,其中HA含量呈梯度变化, 使TiO2层逐渐向HA层过渡。HA/TiO2复合涂层和基体间的结合强度约为(19.3±2.5)MPa。通过细胞免疫荧光染色观察到细胞在培养 3h就可附着于复合涂层表面并形成良好的铺展,而且随着培养时间的延长,细胞的形态更加舒展,附着在复合涂层表面的细胞数量亦逐渐增 加,初步表明复合涂层具有较好的生物学和力学性能。

水热处理对钛表面羟基磷灰石合成的影响

对450V微弧氧化后的12个纯钛试样做不同介质、温度和时间的水热处理,借助SEM和XRD对比研究氨水和去离子水作为水热处理介质以及温度和时间参数对钛表面羟基磷灰石合成的影响,探讨了水热处理中HA的形核长大规律。结果表明:以去离子水和氨水作为处理介质分别获得棒状和粒状两种不同形态的HA,氨水处理得到的HA比去离子水处理的细小均匀。随着温度的升高和保温时间的延长,HA晶粒变大。

钛合金经皮植入式假肢骨内固定植入体表面经生物陶瓷改性后与骨整合的研究

通过对钛合金经皮植入式假肢的的骨内固定植入体表面进行生物陶瓷改性,以研究经改性过的植入体与其宿主骨整合的能力。采用羟基磷灰石喷涂和微弧氧化两种生物陶瓷改性工艺,对骨内固定植入体进行改性处理,将改性过的植入体植入山羊后腿胫骨,术后8周取标本行组织学观察,见两种生物陶瓷改性的植入体均可与宿主骨形成严密整合。计算宿主骨组织与植入体整合率,发现经生物陶瓷表面改性的植入体与宿主骨组织整合率显著高于未经生物改性的对照组植入体(p<0.01),而羟基磷灰石喷涂组和微弧氧化组与宿主骨整合率的差别无统计学意义(p>0.05),说明羟基磷灰石和微弧氧化两种陶瓷层都具有很强的诱导骨生成能力,经其表面改性的骨内固定植入体能与宿主骨形成紧密整合。

含La羟基磷灰石生物活性膜层的制备与性能研究(英文)

采用微弧氧化法在含有乙酸钙、β-甘油磷酸钙、硝酸镧的电解液中在纯钛金属表面原位生成了多孔含La羟基磷灰石的生物涂层.用XRD、SEM、EDS、细胞培养等方法对膜层的厚度、物相、成分组成及生物相容性进行了研究.结果表明,膜层粗糙多孔,厚度在15μm左右,与钛基体之间无明显界面;膜层表面主要物相为含La的羟基磷灰石.细胞培养结果表明,膜层有良好的生物相容性.

溶胶-凝胶/微弧氧化复合制备种植体表面HA/TiO_2复合涂层的研究

目的:探讨微弧氧化和溶胶-凝胶复合方法对钛种植体进行表面改性研究,在提高耐磨性、耐腐蚀性的同时,改善材料的生物活性。方法:利用微弧氧化和溶胶-凝胶复合方法在钛种植体表面制备羟基磷灰石(hydroxyapatite)HA/TiO2复合涂层,用扫描电镜(SEM)观察陶瓷膜层的表面形貌,用χ射线衍射(XRD)仪和X射线能谱(EDX)分析膜层的成分和元素分布。并对材料表面粗糙度的变化和涂层结合力进行检测。结果:形成的复合涂层由内层表面多孔的TiO2层和外层的HA层构成。HA/TiO2复合涂层与基体的结合强度约为(30±2.5)N,同时复合涂层提高了材料的表面粗糙度。结论:采用微弧氧化和溶胶-凝胶复合的方法可在钛种植体表面制备HA/TiO2复合涂层,初步研究表明该涂层具有较好的结构和生物活性。

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。