钛表面聚氨酯涂层的生物矿化及其细胞生物学响应

针对当前钛种植体在临床使用中因界面不匹配导致的种植失败问题,从仿生学角度出发,采用提拉法在钛表面涂覆聚氨酯(PU)高分子涂层,并通过过饱和Ca-P溶液浸泡试验在PU表面原位矿化生成了无机沉积物.采用SEM、EDX、IR、XRD、DSC-TG及接触角测定仪等对矿化后PU表面的理化性能进行了表征和分析,并通过细胞培养试验初步考察了MG63细胞在矿化前后PU表面的增殖及生长情况.结果表明,PU表面矿化物是由纳米片状晶体先聚集堆叠形成团簇状微球,然后微球间互相融合生长而形成的,其成分主要是弱结晶的非化学计量的羟基磷灰石晶体,而且矿化后的PU涂层亲水性更佳,更利于MG63细胞的黏附及增殖.     

医用钛金属表面修饰及性能研究

采用先微弧氧化,再沉积羟基磷灰石的方法,对钛表面进行修饰。研究不同羟基磷灰石浓度、水热温度、水热时间、及冷却时间四种工艺条件下,钛表面形貌特征的变化。扫描电镜结果显示,在羟基磷灰石浓度为27.5 g/L、水热8 h,水热温度180°C情况下,钛金属表面羟基磷灰石均匀沉积;冷却时间延长,钛金属表面羟基磷灰石膜层增厚,粗糙度下降。将人永生化角质形成细胞(HACAT)接种于钛金属表面,采用F-actin染色及CCK-8检测观察细胞形态及增殖能力。共聚焦显微镜观察发现HACAT细胞在修饰后钛片表面增殖较快;CCK-8检测表明早期黏附于修饰后钛片表面的细胞较多(P0.05)。该方法可提高医用钛金属表面活性,增强其与组织的结合能力。     

钛表面固定纤维连接蛋白及其体外细胞培养

通过低温等离子聚合的方法,以丙烯酸为单体在钛表面沉积含有羧基的薄膜,以羧基为接入点固定纤维连接蛋白。样品表面用X射线光电子能谱、傅里叶红外光谱仪进行表征。将固定了纤维连接蛋白的样品进行体外细胞培养,所用的细胞为MG63骨瘤细胞,对照样为纯钛。结果表明, 钛表面聚丙烯酸薄膜能有效地固定纤维连接蛋白,并且固定纤维连接蛋白的样品能促进骨瘤细胞的生长和黏附,具有更高的成骨活性。      

浮法玻璃的铝诱导表面织构研究

本文采用铝诱导表面织构方法,在浮法玻璃表面成功地制备了陷光结构:采用快速辐射加热法对蒸镀约200nm厚Al膜的浮法玻璃基片进行了一定时间的热处理,然后分别经H3PO4和HF/HNO3的混合溶液腐蚀.借助扫描电镜(SEM)、紫外可见分光光度计研究了热处理和HF/HNO3混合溶液处理的时间对玻璃表面织构形貌及陷光特性的影响.实验发现,快速辐射加热法退火2 h,就可在玻璃表面形成较好的陷光织构,织构的特征尺寸较小时,陷光作用较好.     

不同浓度硝酸处理的多孔钛及其体外生物活性

多种表面活化改性方法已用于致密钛表面活化改性, 本研究尝试用不同浓度的硝酸溶液处理浆料发泡法制备的多孔钛. 酸处理多孔钛内孔壁上出现了微小尺寸的酸蚀坑, 其微结构随酸浓度的变化而略有不同, 处理后表面磷灰石沉积能力随酸浓度变化差异显著, 其中以1:1和1:5两种浓度(体积比)的硝酸处理组最强, 并显著促进MG63细胞增殖, 细胞在样品表面和孔内得到良好粘附和铺展. 本研究结果表明硝酸处理活化多孔钛, 方法简单, 不引入杂质, 渗透性好, 可有效活化多孔钛内外表面, 是一种有效的制备生物活性多孔钛的方法.     

Ti、Ti6Al4V和Ti6Al7Nb对成骨细胞生物活性影响的研究

研究Ti、Ti6Al4V和Ti6Al7Nb 3种钛金属表面经喷砂酸蚀处理后的表面形貌、亲水性及对成骨细胞生物活性的影响。在Ti、Ti6Al4V和Ti6Al7Nb 3种钛金属表面进行Al2O3喷砂和盐酸、硫酸混合物酸蚀的表面改性处理(SLA),通过扫描电子显微镜(scanning electron microscope,SEM)观察样品的表面形貌,通过接触角测量仪在显微镜下测量接触角的大小;将SD大鼠成骨细胞以1×104cells/m L密度接种于Ti、Ti6Al4V和Ti6Al7Nb表面后通过MTT活性实验观察成骨细胞在样品表面的增殖,通过SEM观察细胞在样品表面生长的形态,通过碱性磷酸酶(AKP)活性实验,检测成骨细胞的分化能力。Ti、Ti6Al4V和Ti6Al7Nb在经过喷砂酸蚀处理后,表面均呈现出微米级多孔形貌,3种样品均为亲水性表面;细胞在SLA处理后的Ti、Ti6Al4V和Ti6Al7Nb表面增殖良好,细胞伸展显著;其中在Ti6Al7Nb表面细胞的增殖、黏附、分化能力最强。大颗粒喷砂酸蚀技术的表面处理方法能够促进Ti、Ti6Al4V和Ti6Al7Nb的生物活性;经SLA处理的Ti6Al7Nb比Ti和Ti6Al4V表现出更好的生物学活性,成骨细胞在其表面呈现出更好的增殖、黏附及分化能力。     

氢还原氢氟酸刻蚀的TiO2纳米薄膜光电化学性能

TiO2是一种价格低廉、稳定的半导体材料,被广泛应用于光催化水裂解、污水处理等众多领域,但其只能吸收高能量的紫外光,限制了实际应用.本工作采用氢氟酸溶液刻蚀纯钛片,然后在一系列温度下对其进行热处理,使其表面与氧气反应生成TiO2薄膜,随后将样品置于氢气气氛下进行还原处理.通过XRD对其进行物相表征,SEM观察微观形貌,利用电化学工作站测试样品的光响应曲线、线性扫描伏安曲线以及电化学阻抗谱,并根据线性扫描伏安曲线计算出样品的光转换效率.结果表明,经过HF处理后,所形成的TiO2纳米薄膜暴露(101)晶面.同时,经过HF处理和氢气还原制备的样品的光电性能有了较大提升,光电流密度最高可达1.04 mA/cm2,是未经HF处理和氢气还原薄膜的11.5倍,是仅经HF处理薄膜的2.97倍,最大光转换效率提升了70％.该方法制备的纳米薄膜材料在光催化降解、产氢等领域具有潜在的应用价值.     

钛表面等离子体氧化及其对细胞粘附增殖的影响

采用真空射频辉光放电技术对喷砂酸蚀工艺处理后的钛表面进行了等离子体氧化处理,利用扫描电子显微镜、接触角测量仪及X射线光电子能谱仪研究了氧化膜对钛表面形貌和亲水性的影响以及其化学组成和价键状态;同时通过体外细胞培养研究了钛表面等离子体氧化膜对细胞粘附增殖的影响。结果表明:等离子体氧化处理保留了钛表面喷砂酸蚀形成的微观孔洞结构,获得了平均接触角低于10°的超亲水性表面;钛表面出现Ti 4+、Ti 3+和Ti 2+离子,其中主要以Ti 4+存在;相比未氧化的钛表面,氧化后的钛表面对成骨细胞的粘附增殖有更显著的促进作用,这表明钛表面等离子体氧化膜具有很好的润湿性,利于细胞的粘附增殖。     

医用钛表面生物分子自组装薄膜的制备

采用分子自组装(SAM)方法在医用钛表面制备了硫酸软骨素薄膜.通过激光共聚焦显微镜,傅立叶红外光谱,X射线光电子能谱以及接触角测定仪等分析测试手段,比较研究了表面预处理方法的活化作用以及成膜反应时间对自组装薄膜的影响规律.实验结果表明,用等体积比的浓硫酸和双氧水混合溶液在75C对钛表面处理1h后的钛片能获得最高的表面自由能,而自组装膜的反应在12h内即可完成.     

钛表面自组装牛血清白蛋白以控制血小板粘附行为的研究

将牛血清白蛋白通过自组装方法组装到钛表面,以改善其血液相容性.首先,用氢氧化钠活化钛,得到有活性羟基且带负电荷的多孔表面,然后浸入带正电荷的聚赖氨酸溶液,最后浸入带负电荷的牛血清白蛋白溶液.通过扫描电子显微镜(SEM)和原子力显微镜(AFM)观察自组装前后表面形貌变化,通过傅立叶红外漫反射(FTIR)检测各步处理层表面基团变化,通过视频接触角观察各步处理后钛表面接触角变化,通过体外血小板粘附实验评价自组装前后表面血液相容性变化.实验结果表明,牛血清白蛋白组装到钛表面后,血小板的粘附行为得到有效控制,钛表面的血液相容性显著改善.     

The relationship of surface roughness and cell response of chemical surface modification of titanium

Implant surface topography influences osteoblastic proliferation, differentiation and extracellular matrix protein expressions. Previous researches proved that chemical surface modification of titanium implants could be used to improve Bone-to-implant contact. In this study, the surface topography, chemistry and biocompatibility of polished titanium surfaces treated with mixed solution of three acids containing HCl, HF and H(3)PO(4) with different etched conditions for example concentration, time and addition of calcium chloride were studied. Osteoblast cells (MG-63) were cultured on different groups of titanium surfaces. In order to investigate titanium surfaces, SEM, AFM and EDS analyses were carried out. The results showed that surfaces treated with HCl-HF-H(3)PO(4) had higher roughness, lower cytotoxicity level and better biocompatibility than controls. Moreover, addition of calcium chloride into mixed solution of three acids containing HCl, HF and H(3)PO(4) is an important, predominant and new technique for obtaining biofunction in metals for biomedical use including dentistry.     

Biocompatibility of TiO2 nanotubes fabricated on Ti using different surfactant additives in electrolyte

This study examined the in vitro cell-material interactions on four different types of titanium surfaces: a polished Ti surface, TiO₂ nanotube surfaces fabricated in a fluorinated glycerol solution (TN), fluorinated glycerol solution with 1 wt% anionic surfactant sodium dodecyl sulphate (TN-SDS), and fluorinated glycerol solution with 1 wt% cationic surfactant cetyl trimethyl ammonium bromide (TN-CTAB), respectively. The surfaces exhibited distinct surface morphologies and geometrical features. Surface energy calculation shows that TN surface enhances the hydrophilic character by significantly increasing the surface energy. The osteoblast cell growth behavior on the four different surfaces was examined using the MC3T3-E1 cell line for 1 day. When the anodized surfaces were compared for the cell-materials interaction, each of the surfaces showed different properties that affected the cell–material interactions. Proliferation of the cells was noticed with distinctive cell-to-cell attachment on the TN surfaces. Good cellular adhesion with extracellular matrix extensions between the cells was noticed in the TN samples. The TiO₂ nanotubes grown in the surfactant-assisted fluorinated electrolyte did not show significant cell growth on the surface and some cell death was observed. The cell adhesion, differentiation and alkaline phosphatase activity were more pronounced on the TN surface. The MTT assays also revealed an increase in living cell density and proliferation on the TN surfaces. Overall, a rough surface morphology and surface energy are important factors for better cell material interactions.     

Effect of microstructure of titanium surface on the behaviour of osteogenic cell line MC3T3-E1

Three different microstructures were obtained on a titanium surface via immersion in HCl, H3PO4, or mixed acid of HNO3 and HF (HNO3/HF) solution. The microstructure and Rmax of the acid-treated surfaces were dependent on the acid type and immersion conditions. The growth rate of the osteogenic cell line MC3T3-E1 on each acid-treated sample, which was measured using MTT-formazan assay, was significantly higher than that of the standard which was ground with #400 SiC grit paper. Moreover, both the H3PO4 treated sample and the HNO3/HF-treated surface showed a tendency to enhance the alkaline phosphatase activity of MC3T3-E1 cells, which were grown on each acid-treated surface. These results suggest that the acid treatment of titanium is effective for the improvement of its osteocompatibility. © 1998 Chapman & Hall     

两步酸修饰的多晶硅绒面结构

本文提出两步法制备多晶硅表面绒面技术,用两次化学腐蚀修饰多晶硅片的表面。实验中首先采用腐蚀液HF/NaNO2/H2O对多晶硅表面进行腐蚀,然后采用腐蚀液HF/HNO3/（NH4）2C2O4/H2O对其表面进一步修饰。通过多晶硅SEM表面形貌图分析,两步法修饰的多晶硅表面有形状如蚯蚓状的腐蚀坑,腐蚀坑的深度和分布密度相对较大。通过反射谱分析了多晶硅片表面陷光效果,并与用其它方法修饰的硅表面陷光效果进行了对比,与传统配方HF/HNO3/H2O获得的多晶硅表面相比,综合平均反射率下降了7%左右。这种方法获得的多晶硅表面能有效收集太阳光,有利于提高太阳能电池的转换效率。     

Bioactivity study of the titanium plates treated with microarc oxidation and alkali

Microarc oxidation (MAO) and alkali treatment was used to modify the surface of titanium, which prepared different microstructure and nanostructure TiO2-based coating on titanium. The samples were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and contact angle measuring instrument. The sample's surface treated by MAO process was microporous structure and looks like a crate. In vitro bioactivity experiment indicated that the hydroxyapatite precipitates was as squama and grew perpendicularly on the sample's surface. In vitro cell culture and MTT assay the MAO-NaOH samples showed distinct proliferation levels compared to the MAO samples. It has no toxicity to the growth of MSC cell and had better biocompatibility. According to the calculation of surface energy, that better hydrophilicity of materials will induce the more growth of hydroxyapatite.     

不同电解液组成对TiO2纳米管形成的影响

电解液在阳极氧化中发挥着重要作用,对TiO2纳米管的形成与否,形成后管的成分、形貌都有着很大的影响.本实验采用了恒压阳极氧化方式,分别以HF(0.5wt%),(NH4)2SO4 HF(0.5wt%),(NH4)H2PO4 HF(0.5wt%),NaNO3 HF(0.5wt%)为电解液,在钛箔表面获得多孔TiO2膜.用FESEM观察了多孔膜的形貌并用EDX和XPS能谱对膜表面成分和构成进行测试分析.实验结果表明:在单一的HF酸电解液中加入(NH4)2SO4或(NH4)H2PO4后,阳极氧化生成的膜孔径明显减小,并且膜表面形态较差.加入NaNO3后,对膜的形貌影响不是很大.由EDX和XPS能谱分析得出,阴离子中的大部分非金属元素较难进入膜表面,而氮元素却很容易掺杂进入膜的表面形成N-Ti-O结构,从而影响膜的成分构成.这表明本实验利用简单电化学方法实现了N的掺杂.通过XRD测试得出,含不同阴离子的电解液对TiO2膜的晶型转变温度影响不大.     

Reduced fibroblast adhesion and proliferation on plasma-modified titanium surfaces

Soft tissue complications are clinically relevant problems after osteosynthesis of fractures. The goal is to develop a method for reduction of fibroblast adhesion and proliferation on titanium implant surfaces by plasma polymerisation of the organo-silicon monomer hexamethyldisiloxane (HMDSO). HMDSO was deposited under continuous wave conditions in excess oxygen (ppHMDSO surface) and selected samples were further modified with an additional oxygen plasma (ppHMDSO + O₂ surface). Surface characterization was performed by scanning electron microscopy, profilometry, water contact angle measurements, infrared reflection absorption spectroscopy and X-ray photoelectron spectroscopy. In our experimental setup the mechanical properties, roughness and topography of the titanium were preserved, while surface chemistry was drastically changed. Fibroblast proliferation was assessed by alamarBlue assay, cell morphology by confocal microscopy visualization of eGFP-transducted fibroblasts, and cell viability by Annexine V/propidium iodide assay. Both modified surfaces, non-activated hydrophobic ppHMDSO and activated hydrophilic ppHMDSO + O₂ were able to dramatically reduce fibroblast colonization and proliferation compared to standard titanium. However, this effect was more strongly pronounced on the hydrophobic ppHMDSO surface, which caused reduced cell adhesion and prevented proliferation of fibroblasts. The results demonstrate that plasma modifications of titanium using HMDSO are valuable candidates for future developments in anti-adhesive and anti-proliferative coatings for titanium fracture implants.     

Human-osteoblast proliferation and differentiation on grit-blasted and bioactive titanium for dental applications

Physico-chemical and topographical surface quality of commercially pure titanium (c.p. Ti) dental implants is one of the most influencing factors in the improvement of their osseointegration. In this sense, previously, a two-step method (2S) for obtaining bioactive blasted-rough titanium surfaces was developed for improving short-term (due to its bioactivity) and long-term (due to its roughness) osseointegration. This 2S-method consists of: (1) Grit blasting on titanium surface in order to roughen it, and (2) thermo-chemical (TCh) treatment in order to obtain a bioactive surface with bone-bonding ability. The aim of the present work is to evaluate the in vitro human-osteoblast response (proliferation, differentiation – ALP activity- and cell morphology-studied by environmental scanning electron microscopy) of rough c.p. Ti (grit blasted), bioactive c.p. Ti (thermo-chemically treated) and rough-bioactive c.p. Ti (2S-treated). Different grit materials (Al₂O₃ and SiC) have been used in order to investigate their influence. The results showed that cell adhesion was statistically higher for the rough and bioactive surfaces, whatever the grit used. Cells proliferated very well on all the c.p. Ti surfaces. If comparing groups with and without TCh (all other treatments being equal) the ALP was always higher in the groups with TCh, indicating stimulation of osteoblast differentiation because of TCh, more significantlly in the groups that were first blasted. Those ALP results were accompanied by a decrease in the value of proliferation, which shows the good behavior of the cells. This results suggest that a rough and bioactive-titanium surface obtained by 2S-treatment enhances adhesion and differentiation activity of human osteoblasts cells.     

Fibrin-mediated endothelial cell adhesion to vascular biomaterials resists shear stress due to flow

In vitro endothelial cell (EC) seeding onto biomaterials for blood-contacting applications can improve the blood compatibility of materials. Adhesive proteins adsorbed from serum that is supplemented with the culture medium intercede the initial cell adhesion and subsequent spreading on material surface during culture. Nevertheless, physical and chemical properties of vascular biomaterial surface fluctuate widely between materials resulting in dissimilarity in protein adsorption characteristics. Thus, a variation is expected in cell adhesion, growth and the ability of cell to resist shear stress when tissue engineering on to vascular biomaterials is attempted. This study was carried out with an objective to determine the significance of a matrix coating on cell adhesion and shear stress resistance when cells are cultured on materials such as polytetrafluoroethylene (PTFE, Teflon) and polyethyleneterephthalate (Dacron), ultra high molecular weight polyethylene (UHMWPE) and titanium (Ti), that are used for prosthetic devices. The study illustrates the distinction of EC attachment and proliferation between uncoated and matrix-coated surfaces. The cell attachment and proliferation on uncoated UHMWPE and titanium surfaces were not significantly different from matrix-coated surfaces. However, shear stress resistance of the cells grown on composite coated surfaces appeared superior compared to the cells grown on uncoated surface. On uncoated vascular graft materials, the cell adhesion was not supported by serum alone and proliferation was scanty as compared to matrix-coated surface. Therefore, coating of implant devices with a composite of adhesive proteins and growth factors can improve EC attachment and resistance of the cells to the forces of flow.