微弧氧化联合溶胶-凝胶工艺制备钛表面复合生物涂层的研究

目的探讨微弧氧化联合溶胶-凝胶工艺制备钛表面复合生物涂层。方法钛片根据表面处理工艺不同分为5组:对照组,MAO(微弧氧化组),MAO+Sol/gel(微弧氧化+溶胶-凝胶组),MAO+Sol/gel-LowZn(微弧氧化+溶胶-凝胶低锌组),MAO+Sol/gel-HighZn(微弧氧化+溶胶-凝胶高锌组)。利用扫描电镜(SEM)观察涂层表面形貌,X射线能谱分析仪(EDX)和X射线衍射仪(XRD)分析元素分布和成分,测厚仪测量涂层厚度;粗糙度测试仪测量表面粗糙度。结果 SEM下可见MAO组钛表面粗糙多孔,联合溶胶-凝胶处理后,钛表面更加平整紧密,EDX得出MAO+Sol/gel组钙磷元素的质量百分比分别为25.00%和15.49%,MAO+Sol/gel-Low Zn组和MAO+Sol/gel-High Zn组钙、磷、锌元素的质量百分比分别为22.87%、15.01%、1.82%与18.66%、15.60%、7.45%,XRD得出MAO+Sol/gel组、MAO+Sol/gel-Low Zn组和MAO+Sol/gel-High Zn组均可见特征性羟基磷灰石(HA)峰和Ca3(PO4)2峰,MAO+Sol/gel-High Zn组表面涂层厚度最高(10.40±0.49)μm(P<0.05),MAO+Sol/gel组表面粗糙度最高(1.17±0.10)μm(P<0.05)。结论应用微弧氧化联合溶胶-凝胶工艺,可在钛金属表面制备出HA涂层,并通过调节溶胶凝胶中Zn(NO3)2·6H2O的含量,制备出HA和不同含量锌离子的复合生物涂层。经过两种不同工艺联合处理后,钛表面涂层厚度逐渐增加,而粗糙度随着溶胶凝胶中锌离子的增加逐渐降低。     

纯钛表面微弧氧化法制备含钙锌涂层的抗菌性能研究

目的:应用微弧氧化法对纯钛进行表面改性,形成含不同浓度钙离子、锌离子的涂层,探讨涂层对变形链球菌黏附和形态的影响。方法:用微弧氧化法在钛表面制备含不同浓度钙离子、锌离子涂层的5组样品,即低钙组(L-Ca)、高钙组(H-Ca)、低锌组(L-Zn)、中锌组(M-Zn)和高锌组(H-Zn),以未涂层机械抛光组(CP)作为对照组;用贴膜法评价6组钛样品对变形链球菌抗菌性能的影响;以扫描电镜(SEM)观察细菌在样品表面黏附数量和菌体形态的变化。采用SPSS 13.0软件包对数据进行统计学分析。结果:贴膜法实验表明,与CP组相比,L-Ca、H-Ca组抗菌性能无显著差异(P>0.05),含锌组抗菌效果显著(P<0.01),H-Zn组抗菌性显著高于L-Zn组(P<0.05)。扫描电镜观察,含锌组可影响细菌的黏附数量和菌体形态,且与锌的含量有关。结论:微弧氧化法制备的含锌离子涂层可有效抑制变形链球菌的黏附并影响其菌体形态,其具有的抗菌性能随锌含量的升高而增强。     

钛表面载银HA-TCP溶胶凝胶涂层的制备及其抗菌性的研究

目的：用溶胶凝胶法在钛表面制备载银HA-TCP涂层，并观察其抗菌性能。方法：采用溶胶凝胶法将Ag^＋导入HA-TCP溶胶，并在钛表面涂层。用X射线衍射（XRD）和傅立叶变换红外光谱（FTIR）对涂层结构进行表征分析，用X射线能谱（EDS）分析涂层表面元素构成和分布，用扫描电镜（SEM）观察涂层表面形貌。观察涂层对牙龈卟啉单胞菌P.g、具核梭杆菌F.n、伴放线放线杆菌A-a的生长抑制作用，并计算抗菌率。结果：载银HA-TCP溶胶在钛表面涂层均匀，由大量的亚微米及细微的介孔组成。XRD检测出HA、钛、锐钛矿和β-TCP的衍射峰；FTIR分析涂层含有OH^-．PO4^3-及CO3^2-的特征吸收峰。EDS检测发现钙、磷、钛、碳、氧和银在涂层表面的分布。与对照组比较，载银HA-TCP涂层对牙龈卟啉单胞菌P.g、具核梭杆菌F.n、伴放线放线杆菌A.a具有明显的抗菌效果。结论：本试验在钛表面涂覆载银HA-TCP溶胶，使钛植入体获得了具有生物活性及抗菌性的仿生涂层。     

碳磷灰石鸡蛋壳粉作为骨修复材料的初步研究

目的：研制一种新型的碳磷灰石骨修复材料,初步观察其成骨作用。方法：以鸡蛋壳为原料,采用微波法制备不同加热条件下的骨修复材料,利用扫描电镜（SEM）、X射线衍射仪（XRD）、傅立叶红外（FT-IR）和能谱分析（EDXA）手段,表征微波处理前后材料的理化性能。进一步选用新西兰兔制备直径5mm的颅骨全层缺损区,以未经微波处理的鸡蛋壳粉及Bio—Oss作为对照,充填经微波处理后的新型骨修复材料,8周后观察新生骨的生成情况。结果：SEM,XRD,FT-IR和EDXA分析证实：随加热时间延长,材料的微观形态由针状向球状转变,碳磷灰石的特征性波峰也不断增强;研制的新材料含有与人体骨相似的碳、磷和钙成分。动物实验的结果表明,经微波处理的碳磷灰石鸡蛋壳粉充填的缺损区,比未处理组和空白对照组的缺损区有更多的矿化新生骨和较少的未矿化新生骨,接近Bio—Oss的效果。结论：微波加热法能有效地将天然碳酸钙转化为碳磷灰石,该材料有望作为一种潜在的新型骨修复材料。     

釉质仿生矿化模型的研究

目的：构建釉质生物矿化的模型,包括有机基质模板（类釉原蛋白寡肽序列）的建立和无机离子供体（包裹钙磷离子的温度敏感性脂质体）的合成,体外实现类釉质样结构的再矿化。方法：首先通过标准固相法合成所需“类釉原蛋白”寡肽[（Gln?Pro?Ala）4?Thr?Lys?Arg?Glu?Glu?Val?Asp],并用CaCl2溶液诱导其进行自组装;其次采用二棕榈酰磷脂酰胆碱和二肉豆蔻卵磷脂为原料,通过相交融合法分别合成包裹钙、磷离子的温度敏感性脂质体;最后在37℃时,将酸蚀后的牙片浸泡在包裹钙、磷离子的脂质体与寡肽的混悬液中,作为实验组。将酸蚀后的牙片浸泡在包裹钙磷离子的脂质体混悬液中,作为对照组,促进脱矿后的釉质再矿化。矿化后的牙片通过扫描电镜（ SEM）、傅立叶变换红外光谱仪（ FTIR）和X射线衍射仪（ XRD）进行表征。结果：实验组的脱矿釉质表面均匀有序的沉积了一层釉质样的羟基磷灰石晶体（ HA）结构,而对照组只沉积了较少量无序的HA晶体。结论：通过类釉原蛋白寡肽有机矿化模板的建立,以及仿生釉质矿化过程中钙、磷离子的输送,构建了釉质仿生矿化模型,并实现了脱矿釉质表面类釉质样微结构的再生。     

牙种植体纳米含氟羟基磷灰石涂层材料制备实验研究

目的 探讨用溶胶-凝胶法制备出的纳米含氟羟基磷灰石（nFHA）材料用于纯钛表面涂覆的理论依据。方法 本实验于2010年1-5月在中南大学粉末冶金研究院完成。采用溶胶-凝胶法制备nFHA和羟基磷灰石（HA）材料,通过X线衍射（XRD）、透射电镜（TEM）表征其物相组成及颗粒大小,扫描电镜（SEM）观察涂层在纯钛表面形貌。结果 XRD检测结果显示,运用溶胶-凝胶法可制备出nFHA材料,氟离子进入HA晶体中,以nFHA固溶体形式存在。TEM显示,nFHA晶体呈短棒状,粒径大部分在100 nm以下,符合纳米级别。SEM显示,热处理后的nFHA涂层,为多孔形貌,相互形成穿通结构,颗粒均匀分布,无明显裂纹。结论 （1） 采用溶胶-凝胶法可制备出nFHA涂层材料;（2） nFHA较HA在钛基表面涂层可形成更佳的孔隙结构。     

纳米羟基磷灰石-壳聚糖复合材料对细胞粘附的影响

目的：制备纳米羟基磷灰石-壳聚糖（nano hydroxyapatite-chitosan,nHA/CS）复合材料,观察其对成纤维细胞粘附行为的影响.方法：将溶胶-凝胶法制得的纳米羟基磷灰石充分混合于2%壳聚糖乙酸溶液中,冷冻干燥法制备纳米羟基磷灰石-壳聚糖复合材料,并对材料进行X射线衍射分析（XRD）、红外光谱分析（FT-IR）、扫描电镜（SEM）、透射电镜（TEM）检测.将NIH3T3细胞分别接种于复合材料和致密羟基磷灰石（dense hydroxyapatite,HA）表面,细胞计数法计算细胞粘附数量,扫描电镜下观察细胞粘附形态.结果：XRD分析结果表明溶胶-凝胶法制备的HA和nHA的晶体结构符合标准羟基磷灰石的空间6方晶体结构.TEM分析结果显示nHA/CS材料中羟基磷灰石为纳米级粉体.接种5、7、9 d后nHA/CS材料表面的细胞粘附数量高于HA组,差异有显著性（P＜0.05）.扫描电镜下,细胞以多个突起粘附于复合材料表面,并具有良好的伸展状态.结论：与HA相比,nHA/CS材料更有利于成纤维细胞的粘附,生物相容性良好.     

钛表面掺镓羟基磷灰石涂层的合成和性能表征

目的:钛表面制备含镓羟基磷灰石(Ga-HA)涂层并研究其理化性能。方法:溶胶-凝胶法制备Ga-HA,浸润-提拉法制备涂层并煅烧。SEM检测涂层表面形貌,FTIR、XRD分析其基团结构,拉伸试验检测其结合强度,AAS检测镓、钙离子释放浓度。结果:Ga-HA的结晶度高于HA。体外释放实验结果显示煅烧后涂层钙、镓离子释放量减少。讨论:镓的掺入使HA结晶度增强但未改变其主要晶相结构;镓的掺入有助于减缓涂层的降解,为Ga-HA涂层在骨质疏松患者的临床应用提供了基础。     

电化学沉积钙磷涂层和钙磷-壳聚糖涂层的体外降解实验

目的 观察电化学沉积钙磷涂层和钙磷-壳聚糖涂层(electrodeposited calcium phosphate-chitosan coating,ECPC)的体外降解情况.方法 用电化学方法在钛合金表面制备钙磷涂层和ECPC涂层,将破骨细胞分别接种于两种涂层表面(细胞组);无细胞组不加细胞.测量第3、6天上清液的钙离子吸光度.结果 两种涂层表面均可形成破骨细胞吸收陷窝,原始培养液钙离子吸光度(0.183±0.002)均高于各组上清液(P<0.05);钙磷涂层和ECPC涂层第6天细胞组钙离子吸光度[(0.158±0.006)和(0.158±0.02)]高于无细胞组[(0.151±0.003)和(0.156±0.02),P<0.05].结论 钙磷涂层和ECPC涂层在体外均既可被破骨细胞吸收形成陷窝,也可在培养液中溶解.     

六种防龋制剂对牙釉质脱矿作用的研究

目的 比较６种含氟及微量元素的防龋制剂对牙釉质脱钙的影响,观察早期龋形成过程中釉质脱钙与时间的关系。方法 选择牛牙８４颗,分为７组,实验区分别用含有相等氟离子的氟化锶,氟化亚锡氟阳酸铵,氟化锌,氟化镧,氟化钠及去离子水处理,所有样本浸泡于乳酸凝胶中形成人工釉质龋,经过对不同浸泡时间酸蚀酸胶中的钙含量的观测,各组样本４８小时以前釉质脱钙量时间的变化有所不同,４８小时以后酸蚀凝胶中钙含量趋于恒定,结果     

Functionally gradient bonelike hydroxyapatite coating on a titanium metal substrate created by a discharging method in HBSS without organic molecules

PURPOSE: This study evaluated the quality of coatings on titanium surfaces prepared by discharging in Hanks' balanced salt solution without organic molecules (HBSS-). MATERIALS AND METHODS: 10 x 10 x 1.0-mm titanium plates were used as cathodes of a coating device developed in the laboratory and immersed in HBSS-. A piece of platinum foil was used as a counterelectrode. Discharging was maintained at 1 A and 10 V (416 mA/cm2) for periods of 90, 270, and 540 seconds. Crystal phases of the coatings were identified by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). In addition, the surface characterization and Ca/P atomic ratio of the titanium surfaces were determined by x-ray photoelectron spectroscopy (XPS). Furthermore, the surface topography, the thickness of the coatings, and the bonds between coatings and titanium substrates were observed by scanning electron microscopy. RESULTS: The FTIR and XRD studies demonstrated that the deposits on the titanium after 540 seconds of discharging were crystalline hydroxyapatite. In addition, the thickness of the titanium suboxide layer increased during discharging. The XPS studies indicated that after 540 seconds of processing, the mean Ca/P ratio of the coatings on the titanium was 1.71, which is similar to that of human bone. DISCUSSION: In addition, the replacement of sodium ions with calcium ions seemed important for the promotion of crystallization of the coating. Furthermore, the XPS studies demonstrated that the coatings had a gradient function. Scanning electron microscopy showed that adhesion between coatings and the titanium substrate was close. The coatings were approximately 1 microm thick. CONCLUSION: These findings suggest that a very thin crystalline bonelike hydroxyapatite coating with a gradient function could be prepared on a titanium metal substrate in HBSS- by a discharging method.     

Hydroxyapatite coating on a titanium metal substrate by a discharging method in modified artificial body fluid

PURPOSE: The aim of this study was to evaluate the formation of a hydroxyapatite coating on titanium plate by discharging in typical and modified artificial body fluids. MATERIALS AND METHODS: Japanese Industrial Standard Grade 2 titanium plates were used as specimens. Discharging was performed on the specimens in each solution, and the surface topography of each coating was observed with a scanning electron microscope. The Ca/P atomic ratio and surface characterization of each coating were evaluated by x-ray photoelectron spectroscopy, and crystal phases of each coating were analyzed by Fourier transform infrared spectroscopy and x-ray diffraction. RESULTS: Tricalcium phosphate formed on the titanium surface in a 1.5 Ca/P solution with high ion concentrations of calcium (2.5 mmol/L) and phosphorous (1.67 mmol/L). Crystalline HA was formed on the titanium surface in a 1.5 Ca/P solution (Hanks' balanced salt solution without organic molecules) with low ion concentrations of calcium (1.26 mmol/L) and phosphorus (0.83 mmol/L). DISCUSSION: A solution containing organic pH buffer was insufficient to form stable coatings on the titanium surface. Coating properties strongly depended on the Ca/P chemical ratio of the applied solution. A Ca/P ratio of 1.5 was appropriate for preparing a calcium phosphate coating on a titanium surface, whereas a Ca/P ratio of 2.5 was excessively high. CONCLUSION: These findings suggest that Hanks' balanced salt solution without organic molecules is the most suitable solution for forming crystalline hydroxyapatite coatings on titanium surfaces by the discharging method.     

疏水性硅涂层对牙科氧化锆陶瓷的表面改性研究

目的：在牙科氧化锆陶瓷表面制备疏水性硅涂层,为提高其与树脂的粘结耐久性提供理论基础。方法：以正硅酸乙酯（tetraethoxysilane,TEOS）为硅源,甲基三甲氧基硅烷（methyltrimethoxysilane,MTMS）为改性剂,通过溶胶-凝胶法在牙科氧化锆陶瓷表面制备硅涂层。扫描电镜观察涂层形貌,X射线能谱分析仪分析涂层前后陶瓷表面结构变化,红外光谱分析疏水改性前后凝胶的化学结构。通过静态接触角测量评价瓷片润湿性的改变。结果：在牙科氧化锆陶瓷表面制得硅涂层。扫描电镜观察涂层致密平整,红外光谱分析证明改性后溶胶疏水基团的加入。硅涂层处理后的氧化锆表面硅元素明显增加。静态接触角测试表明对照组的接触角高于未改性硅涂层（P〈0.01）,而疏水改性后的硅涂层接触角明显高于对照组和未改性硅涂层组（P〈0.01）。结论：通过溶胶-凝胶法在氧化锆表面制备疏水性硅涂层,可以有效降低氧化锆陶瓷表面亲水性,有望在提高氧化锆-树脂界面抗水解能力的同时,增强粘结耐久性。     

Characterization of hydroxyapatite films obtained by pulsed-laser deposition on Ti and Ti-6AL-4v substrates.

OBJECTIVES: Pulsed-laser deposition (PLD) is a development process to obtain hydroxyapatite (HA) thin film. It is an alternative to hydroxyapatite deposition techniques usually employed to cover orthopaedic or dental titanium implant surfaces. The aim of this study is to find out the characteristic ratio for Ca/P (1.66) deposit on titanium implant with the PLD process. METHODS: In a preliminary study, the coating parameters of pure and highly crystalline HA on Ti or Ti-6Al-4V substrates were verified by analysing the deposit by Rutherford backscattering spectroscopy (RBS). Ablation parameters to reach a stoichiometric hydroxyapatite composition (ideal Ca/P atomic ratio) and to control the growth of crystalline phases were: 575 degrees C for the substrate temperature, 0.4 mbar H2O vapour pressure in the ablation chamber, the target substrate distance was 40 mm and the deposition time was 120 min. In a second part, the film properties were analysed by means of XRD, SEM, AFM. The coating adhesion of the HA to the substrate was determined with a micro scratch tester. RESULTS: The analysed HA thin films showed a perfect crystallized and textured deposit. Sample observation and surface quality analysis demonstrated a surface roughness and adhesion of the films to the substrates compatible with biological applications. SIGNIFICANCE: These results suggest that pulsed-laser deposition is a suitable technique to obtain crystalline and adherent hydroxyapatite films on Ti or Ti-6Al-4V substrates. The quality of the HA deposit with the PLD process could be an interesting option for coating dental implant.     

应用IBAD方法制备纯钛表面多孔TCP／HA涂层材料的微观分析

目的:为了改善钛种植体的生物相容性,对纯钛表面沉积多孔磷酸三钙/羟基磷灰石(Tricalciumphosphate/hydroxyapatite,TCP/HA)复合涂层材料的表面结构和化学成分进行分析,并与沉积羟基磷灰石(Hydroxyapatite,HA)的钛表面进行对比。方法:用离子束辅助沉积方法(Ionbeamassisteddeposition,IBAD)在纯钛表面沉积HA和TCP/HA涂层材料,通过扫描电镜(Scanningelectronmicroscope,SEM)、原子力显微镜(Atomicforcemicroscopy,AFM)、X射线能谱分析(EnergydispersiveX-rayanalysis,EDX)以及X射线衍射(X-raydiffraction,XRD)技术,检测两种涂层材料表面的微观形态和化学成分,并进行比较。结果:SEM和AFM显示TCP/HA涂层材料表面存在多孔结构,表面化学成分分析显示TCP/HA涂层的钙磷比低于HA,XRD证实TCP/HA涂层内同时存在TCP和HA两种化合物。结论:用IBAD方法在纯钛表面成功地沉积了具有多孔结构的TCP/HA复合涂层材料,该涂层材料和基体材料的结合牢固,改善了基体材料的生物相容性,是一种有应用前景的种植体表面涂层材料。     

The role of surface reactions in the dissolution of stoichiometric hydroxyapatite.

Stoichiometric hydroxyapatite was successively equilibrated in 0.1 M KCl under CO₂-free conditions at pH values ranging from 4.90 to 9.94. Following the removal of an irreversible surface which generated excessive Ca and P solution concentrations, the behaviour of the solid was reproducible. This surface of one atom-layer thickness or less was believed to have formed during the preparation of the solid. The molar Ca:P ratio in equilibrium solutions commonly deviated from 1.67 and was a function of pH and previous sample history. The influence of these parameters, surface:solution ratio and ionic strength on the solution Ca:P ratio was attributed to their effect on the relative contribution of surface and bulk dissolution and/or their direct effect on surface composition. With successive equilibration at any given pH, the solution Ca:P ratio reached a limiting value of 1.67 at which stage the hydroxyapatite was considered to possess a surface composition unique for that pH.     

A methodological study for the analysis of apatite-coated dental implants retrieved from humans

The stability of thermally processed hydroxyapatite coatings for oral and orthopedic bioprostheses has been questioned. Information on the chemical changes, which occur with hydroxyapatite biomaterials post-implantation in humans, is lacking. The purpose of this investigation was to begin to examine post-implantation surface changes of hydroxyapatite-coated implants using scanning electron microscopy (SEM), x-ray microanalysis (EDAX), Fourier transform infrared spectroscopy (FTIR), and x-ray diffraction (XRD). Three retrieved dental implant specimens from humans following clinical failure due to peri-implantitis were examined. Unimplanted cylinders served as controls. Clinically, the retrieved specimens were all enveloped by a fibrous tissue capsule with bone present at the apical extent of the implant. SEM analysis showed that the retrieved surfaces were coated with both calcified and proteinaceous deposits. EDAX scans of the retrieved specimens demonstrated evidence of hydroxyapatite coating loss reflected by increasing titanium and aluminum signals. Other foreign ions such as sodium, chloride, sulfur, silica, and magnesium were detected. XRD of the control specimens showed that the samples were predominantly apatite; however, two peaks were detected in the diffraction pattern, which are not characteristic of hydroxyapatite, indicating that small amounts of one or more other crystalline phases were also present. The retrieved specimens showed slightly larger average crystal size relative to the control sample material, and the non-apatite lines were not present. FTIR evaluation of the retrieved specimens revealed the incorporation of carbonate and organic matrix on or into the hydroxyapatite. Narrowing of and increased detail in the phosphate peaks indicated an increase in average crystal size and/or perfection relative to the controls, as did the XRD results. Based on these results, we conclude that chemical changes may occur within the coating, with the incorporation of carbonate and concomitant reduction in hydroxyapatite coating thickness. Thermodynamic dissolution-reprecipitation of the coating itself and subsequent surface insult by bacterial and local inflammatory components may be involved with these changes.