钛表面微弧氧化涂层的细胞生物活性

背景：微弧氧化技术可改善钛或钛合金的表面特征。 目的：研究纯钛表面微弧氧化涂层的表面性能及其对MC3T3-E1细胞早期黏附、增殖及成骨能力的影响。 方法：将46个直径10 mm、厚度2 mm圆盘状纯钛试件分为实验组和对照组。实验组置于含0.02 mol/Lβ-甘油磷酸二钠盐及0.2 mol/L乙酸钙的电解液中进行微弧氧化处理,对照组对试件进行机械抛光。扫描电子显微镜观察试件表面形貌,X射线能谱分析检测涂层表面钙磷比,X射线衍射分析检测涂层晶相构成。将MC3T3-E1细胞接种在两组试件表面,1,2,4 h电镜下观察细胞形态,在2,4,7 d通过CCK-8方法检测细胞增殖,并于7,14 d检测碱性磷酸酶活性。 结果与结论：经微弧氧化处理后,钛表面形成粗糙多孔的钙磷涂层,微弧氧化涂层主要元素为Ca、P、O及Ti,微弧氧化膜层主要由氧化钛、钛酸钙、磷酸钙及偏磷酸钙构成。电镜观察显示1 h 微弧氧化涂层表面细胞已伸出伪足,4 h呈现较典型的细胞形态。细胞在微弧氧化处理钛表面4,7 d的细胞增殖和7,14 d的碱性磷酸酶活性高于对照组。表明微弧氧化技术生成的粗糙多孔钙磷涂层能显著促进MC3T3-E1细胞的早期黏附、增殖及成骨活性。     

多孔纯钛种植体表面快速沉积钙磷涂层的研究

商业纯钛片经磨平、喷砂、清洗、酸洗后分成A、B两组。A组不作任何处理,B组用H2SO4和HCl混合液酸蚀,然后两组钛片同时置于37℃的仿生液SBF-A中1d及SBF-B中2d。结果两组钛片表面均可沉积磷灰石涂层,涂层为多孔片状结构,X射线衍射分析证实其为碳酸化羟基磷灰石和磷酸八钙的混合物,钙磷原子量比约1.51。这说明在多孔纯钛表面可以快速仿生沉积碳酸化磷灰石涂层。     

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.     

不同碱热处理方法对钛表面理化性能及细胞响应特性的影响

目的对骨科常用钛植入材料进行表面处理,赋予其高生物活性。方法利用酸碱腐蚀法对钛基体进行粗化与活化处理,并通过模拟体液浸泡样品,在钛表面制备了含钙、磷的生物活性无机涂层。通过腐蚀率测定、静滴接触角、SEM等方法研究了粗化及活化处理对钛合金样品表面能、润湿性、粗糙度、表面形貌等理化性能的影响;通过MG63细胞培养实验观察了不同表面处理方法对细胞粘附、分化和增殖情况的影响;并通过SEM、XRD等检测方法对不同方法处理样品在模拟体液中浸泡3天后表面形成的含钙磷沉积层进行观察和分析。结果浸泡后样品表面形成的无机沉积层成分为羟基磷灰石(HA),而且采用HCl/H2SO4混合酸于60℃下处理30分钟、5M NaOH 60℃腐蚀24小时并在600℃下保温1小时的酸碱热处理工艺所得到的钛表面粗糙度高,润湿性好,细胞在其上粘附、分化、增殖情况最佳,且其表面沉积的HA层更为致密均匀。结论通过对钛基体表面酸碱热处理工艺条件进行优化筛选,为后期生物学评价提供初步的实验依据和前期基础。     

氧等离子体表面改性P3/4HB无纺支架

研究氧等离子体表面改性对P3/4HB无纺支架的作用。氧等离子体改性P3/4HB无纺支架,改性的效能通过检测接触角及X射线光电子能谱分析进行结构表征,接种大鼠肌成纤维细胞,检测细胞黏附率以进行功能表征,并检测改性前后的最大应力变化。结果表明:等离子体改性后的P3/4HB无纺支架表面氧含量增加了12.1%,C-O(C-OH)峰、COOR(COOH)峰分别增加了0.2%、6.2%,接触角下降了44°,而最大应力无明显变化,改性后支架细胞黏附率较预处理组高。说明氧等离子体处理P3/4HB支架,可引入功能性的-OH、-COOH等活性基团,改善材料的表面亲水性,提高对细胞的黏附力,为进一步共价接枝生物活性单体创造了条件。     

镍钛合金表面溶胶-凝胶TiO2薄膜的低温制备与固定牛血清白蛋白分子

采用溶胶-凝胶法和蒸汽处理,在经过双氧水粗化预处理的镍钛合金表面制备了无裂纹的TiO2薄膜。X射线衍射表明该薄膜由纳米晶粒的锐钛矿TiO2组成,X射线光电子能谱分析表明试样表面的镍含量大大降低。动电位极化和亲水性测试表明,TiO2薄膜改善了镍钛合金的耐蚀性和亲水性。通过结合3-氨丙基三乙氧基硅烷(APTES)的偶联作用,在TiO2涂层的镍钛合金表面固定了牛血清白蛋白(BSA)分子。     

钛合金Ti6Al4V表面钛酸锶生物薄膜的水热合成

采用氢氧化钠和硝酸锶混合溶液对Ti6Al4V合金进行水热处理,温度180℃,时间1、3和6 h。X射线衍射、扫描电镜、电子能谱和X射线光电子能谱分析表明,水热处理后钛合金表面形成了钛酸锶的纳米颗粒薄膜,颗粒尺寸80～230 nm,薄膜中含有极少量铝和钒元素。在无钙Hank’s平衡盐液中的动电位极化和电化学阻抗实验表明,与抛光试样相比,水热处理3h试样的耐蚀性大幅提高。显微硬度压入实验表明,钛酸锶薄膜具有良好的附着性和内聚力。水热处理制备钛酸锶薄膜的方法可用于钛合金Ti6Al4V骨科植入体的表面改性。     

不同表面处理对氧化锆陶瓷表面形貌的影响

目的 探讨不同表面处理后氧化锆陶瓷表面形貌的变化.方法 烧结48个6 mm×6mm×2 mm的氧化锆陶瓷方形试件,按随机数字表法分为空白对照组(n=12)、喷砂组(n=12) 、e-max渗透剂组(n=12) 、In-ceram渗透剂组(n=12).空白对照组不做任何表面处理;喷砂组采用120 μm Al2O3颗粒喷砂处理;e-max渗透剂组和In-ceram渗透剂组分别采用e-max上釉膏和In-ceram氧化铝渗透玻璃粉作为渗透剂进行选择性渗透蚀刻.测量表面处理后各组试件的表面粗糙度,扫描电镜下观察试件表面形貌,能谱分析仪检测试件表面元素含量变化.结果 空白对照组、喷砂组、e-max渗透剂组和Inceram渗透剂组的表面粗糙度Ra值分别为(0.078 0±0.016 0)μm、(0.100 5±0.003 1)μm、(0.410 7±0.037 0)μm、(0.262 3±0.014 3)μm.e-max渗透剂组和In-ceram渗透剂组的表面粗糙度大于空白对照组和喷砂组(均P＜0.01);喷砂组与空白对照组的表面粗糙度的差异无统计学意义(P＞0.05);e-max渗透剂组表面粗糙度大于In-ceram渗透剂组(P＜0.01),e-max渗透剂组表面粗糙度Ra值最大.扫描电镜和能谱分析显示表面处理后氧化锆陶瓷试件表面形貌发生改变,而表面元素含量无变化.结论 选择性渗透蚀刻能使氧化锆陶瓷表面更粗糙,形成网状间隙结构,有利于树脂黏接剂的渗入.     

聚多巴胺辅助溶胶-凝胶TiO_2薄膜表面固定牛血清白蛋白

在钛表面涂覆溶胶-凝胶TiO2薄膜,再利用聚多巴胺薄膜结合牛血清白蛋白(BSA)分子,以改善血液相容性。X射线光电子能谱分析表明TiO2薄膜表面形成了聚多巴胺薄膜和BSA分子层。接触角测试结果表明聚多巴胺薄膜和BSA分子层使试样的接触角升高,但表面能和界面张力下降。血液相容性实验表明,与TiO2涂层试样相比,结合BSA分子的试样具有更好的抗凝血性能和抗血小板聚集性能。     

钛合金表面微弧氧化涂层理化性能及表面形貌研究

目的研究Ti．6A1—4V合金表面微弧氧化（MAO）涂层的表面形貌及理化性能。方法将Ti-6A1-4V合金置于含0．02mol／Lβ-甘油磷酸二钠盐及0．2mol／L乙酸钙的电解液中进行MAO处理后,通过扫描电子显微镜（SEM）观察涂层表面形貌及截面形貌;X线能谱分析（EDX）检测涂层表面钙磷比;X射线衍射分析（XRD）检测涂层晶相构成;纳米压痕试验测量涂层的微弹性模量及微硬度。结果经MAO处理后,钛合金表面形成粗糙多孔的氧化膜;XRD显示涂层主要由锐钛矿相TiO2、金红石相Ti02和羟基磷灰石（HAP）构成;EDX及纳米压痕试验测得膜层的钙磷比为1．64,弹性模量和微硬度分别为（32．07±7．07）GPa和（1．49±0．68）GPa。结论通过MAO技术可制备出具备良好理化性能的含HAP的涂层。     

Acid pretreatment of titanium implants

The purpose of this study was to evaluate the effectiveness of several methods of cleaning titanium surfaces as pretreatment for surface modifications by analyzing the chemical interaction of three acids, such as Na(2)S(2)O(8),H(2)SO(4) and HCl, followed by rinsing with acetone or ultrapure water. Chemical evaluation, using X-ray photoelectron spectroscopy (XPS), and mechanical evaluation, using nanoindentation, were employed. XPS revealed that an untreated Ti surface consisted of carbon- and nitrogen-containing contaminant and titanium oxide layer on metallic titanium substrate. The method involving the combination of 10 N HCl and acetone was the most effective of all the methods investigated. Such a combination most effectively reduced values of contamination parameters C/Ti and N/Ti, as well as the intensity of the titanium oxide component in Ti 2p spectra. Chlorine was barely detected from the surface treated with HCl in any concentration. Sulfur from the residual S(2)O(8)(2-) or SO(4)(2-), however, was detected from the samples treated with either Na(2)S(2)O(8) or H(2)SO(4). The S/Ti values depended on concentration of the acidic solution. In addition, nanoindentation measurements revealed that Young's modulus of the surface treated with 0.1-10 N HCl was not significantly different from that of an untreated surface (p > 0.05). Consequently, the HCl/acetone treatment is proposed as an excellent decontamination method for the surface preparation process of Ti.     

仿生溶液法诱导钛表面形成钙磷涂层的研究

采用3种不同的方法即不作处理，酸和碱处理但不加热、酸和碱处理后600℃加热对商用纯钛进行表面处理，然后将样品浸泡于仿生溶液中2周后，经过处理的两组样品表面均形成一层薄的钙磷涂层，SEM和EDX分析表明：酸碱处理再经600℃加热组较单纯的酸碱处理组涂层晶体构型均一；XRD分析表明晶体组成主要为含有少量氯元素的羟基磷灰石。     

The removal torque of titanium screw inserted in rabbit tibia treated by dual acid etching

Chemical acid etching alone of the titanium implant surface have the potential to greatly enhance osseointegration without adding particulate matter (e.g. TPS or hydroxyapatite) or embedding surface contaminants (e.g. grit particles). The aims of the present study were to evaluate any differences between the machined and dual acid etching implants with the removal torque as well as topographic analysis. A total of 40 custom-made, screw-shaped, commercially pure titanium implants with length of 5 mm and an outer diameter of 3.75 mm were divided into 4 groups, 10 screws in each, and chemical modification of the titanium implant surfaces were achieved using HF and HCl/H(2)SO(4) dual acid etching. The first exposure was to hydrofluoric acid and the second was to a combination of hydrochloric acid and sulfuric acid. The tibia metaphysics was exposed by incisions through the skin, fascia, and periosteum. One implant of each group was inserted in every rabbit, 2 in each proximal tibia metaphysics. Every rabbit received 3 implants with acid etched surfaces and 1 implant with a machined surface. Twelve weeks post-surgically, 7 rabbits were sacrificed, Subsequently, the leg was stabilized and the implant was removed under reverse torque rotation with a digital torque gauge (Mark-10 Corporation, USA) (Fig. 1). Twelve weeks after implant placement, the removal torque mean values were the dual acid etched implants (24%HF+HCl/H(2)SO(4), group C) required a higher average force (34.7 Ncm), than the machined surface implants (group A) (p=0.045) (Mann-Whiteney test). Scanning electron micrographs of acid etching of the titanium surface created an even distribution of very small (1-2 microm) peaks and valleys, while machining of the titanium surface created typical microscopically grooved surface characteristics. Nonetheless, there was no difference in surface topography between each acid etched implant groups. Therefore, chemically acid etching implant surfaces have higher strengths of osseointegration than machined implant surfaces. There is less correlation between removal torque and the difference in HF volume%.     

Fabrication, characterization, and biological assessment of multilayer DNA coatings on sandblasted-dual acid etched titanium surface

As local gene therapy has received attention, immobilizing functional gene onto irregular oral implant surface has become an advanced challenge. Electrostatic layer-by-layer (LBL) assembly technique could achieve this goal and allow local and efficient administration of genes to the target cells. In this study, multilayers of cationic lipid/plasmid DNA (pEGFP-C1) complex (LDc) and anionic hyaluronic acid were assembled onto sandblasted-dual acid etched titanium disks by the LBL technique. Surface characteristics of the coatings were performed by x-ray photospectroscopy (XPS), contact angle measurements, and scanning electron microscopy (SEM). The cell biological characteristics of the coatings were evaluated by in vitro experiments. SEM results demonstrated that the porous titanium surface was gradually flattened with the increase of the multilayer. The XPS survey indicated that the N element was found from the coating. The coating degradation and pEGFP-C1 releasing kinetics showed that the more assembled layer numbers were, the larger the amount of DNA released in the first 30 h. MC3T3-E1 cells were cultured directly on the DNA-loaded surface. Higher enhanced green fluorescent protein (EGFP) expression efficiency was achieved by increasing the number of layers when cells were cultured after 24 or 72 h. The MC3T3-E1 cell viability on the surface of multilayer DNA coatings was significantly higher than that on control porous titanium surface. It was concluded that the approach established by the LBL technique had great potential in immobilizing gene coatings onto the porous titanium surface and subsequently influenced the function of the cultured cell.     

Peroxiredoxin在H2O2介导的信号通路中的作用

Peroxiredoxins(Prxs)家族广泛存在于生物体的各种细胞中,这种抗氧化蛋白在过氧化氢(H2O2)介导的信号通路调节中具有重要作用。在哺乳动物细胞中,Prxs家族成员能催化细胞内的H2O2还原,将其烷化为H2O和乙醇而清除。H2O2行使细胞内的信号分子的作用,需要保证其浓度在细胞内可以迅速上升至一定阈值以上,因此要避免H2O2被Prxs破坏。H2O2超氧化会使Prxs活性位点上的Cys-SH生成Cys-SO2H而失活,随后Prxs在Su lfiredoxin(Srx)催化下又可恢复活性。Prxs的可逆性失活能调节H2O2在细胞内积聚的浓度使其行使信使功能,作用于多种特殊蛋白质。     

低剂量过氧化氢预处理导致牛肺血管内皮细胞耐受过氧化氢损伤

小量过氧化氢（Ｈ２Ｏ２）预处理，能诱导牛肺动脉内皮细胞（ＢＰＡＥＣｓ）中热休克蛋白７０（ＨＳＰ７０）及ＨＳＰ７０ｍＲＮＡ增多，同时使ＢＰＡＥＣｓ获得了对大量Ｈ２Ｏ２损伤的耐受性，表现为大量Ｈ２Ｏ２所致乳酸脱氢酶释放和硫代巴比妥酸反应物含量增加及过氧化氢酶、超氧化歧化酶活性降低等变化减轻。用放线菌酮和放线菌素Ｄ分别抑制ＨＳＰ７０和ＨＳＰ７０ｍＲＮＡ的增多后，此种耐受性消失，说明小量Ｈ２Ｏ２预处理使Ｂ     

Analysing the optimal value for titanium implant roughness in bone attachment using a tensile test

This study aims at studying the effect of surface roughness on bone attachment of coin-shaped titanium implants. All implants in this study were blasted with TiO(2) particles of 180-220 microm, and then divided into three groups. One group had no further surface treatment whereas the other two groups were subsequently etched with hot hydrochloric acid (0.01M or 1M). The surface topography of the implant specimens was examined by SEM and by a confocal laser scanner for a numeric evaluation of S(a), S(t) and S(dr). The ranging implants in the three groups differed significantly in surface structure. The implants with modified surfaces were then placed into the tibias of 12 rabbits (n=16). After 8 weeks healing, the attachment of bone to implants were examined using a standardised tensile test analysis. The implants that were only blasted (positive control) showed significantly better functional attachment (p<0.001) than the acid etched. Implant surfaces etched with 1M HCl solution had the lowest retention in bone. There was a negative correlation between the increasing roughness and mechanical retention in bone of the implants in this study. The results support observations from earlier studies that suggested an optimal surface roughness for bone attachment, identified by in situ tensile tests and expressed as the arithmetic mean deviation (S(a)), to be in the range between 3.62 and 3.90 microm and that a further attachment depended on mechanical interlocking between bone and implant.     

Osteoinductive porous titanium implants: effect of sodium removal by dilute HCl treatment

In a previous study, we observed that chemically and thermally treated plasma-sprayed porous titanium possesses intrinsic osteoinductivity and that bone formation occurs after 12 months in the muscles of beagle dogs. The aim of this study was to optimize the surface treatment and to accelerate the osteoinductivity. Previous studies have reported that sodium removal converts the sodium titanate layer on the surface of an alkali-treated titanium plate into a more bioactive titania layer. In this study, we developed a dilute hydrochloric acid (HCl) treatment for porous titanium, which removed sodium from the complexly shaped porous structure more effectively than conventional hot water treatment. Three types of surface treatments were applied: (a) alkali and heat treatment (AH treatment); (b) alkali, hot water, and heat treatment (Water-AH treatment); and (c) alkali, dilute HCl, hot water, and heat treatment (HCl-AH treatment). The osteoinductivity of the materials implanted in the back muscles of adult beagle dogs was examined at 3, 6, and 12 months. The HCl-AH-treated porous bioactive titanium implant had the highest osteoinductivity, with induction of a large amount of bone formation within 3 months. The dilute HCl treatment was considered to give both chemical (titania formation and sodium removal) and topographic (etching) effects on the titanium surface, although we cannot determine which is the predominant factor. Nevertheless, adding the dilute HCl treatment to the conventional chemical and thermal treatments is a promising candidate for advanced surface treatment of porous titanium implants.     

The effect of UV-photofunctionalization on the time-related bioactivity of titanium and chromium–cobalt alloys

This study examined the possible changes in the bioactivity of titanium surfaces during their aging and investigated the effect of ultraviolet (UV) light treatment during the age-related change of titanium bioactivity. Rat bone marrow-derived osteoblastic cells were cultured on new titanium disks (immediately after either acid-etching, machining, or sandblasting), 4-week-old disks (stored after processing for 4 weeks in dark ambient conditions), and 4-week-old disks treated with UVA (peak wavelength of 365 nm) or UVC (peak wavelength of 250 nm). During incubation for 24 h, only 50% of the cells were attached to the 4-week-old surfaces as compared to the new surface. UVC treatment of the aged surface increased its cell attachment capacity to a level 50% higher than the new surfaces, whereas UVA treatment had no effect. Proliferation, alkaline phosphatase activity, and mineralization of cells were substantially lower on the 4-week-old surfaces than on the new surfaces, while they were higher on the UVC-treated 4-week-old surfaces as compared to the new surfaces. The age-related impaired bioactivity was found on all titanium topographies as well as on a chromium–cobalt alloy, and was associated with an increased percentage of surface carbon. Although both UVA and UVC treatment converted the 4-week-old titanium surfaces from hydrophobic to superhydrophilic, only UVC treatment effectively reduced the surface carbon to a level equivalent to the new surface. Thus, this study uncovered a time-dependent biological degradation of titanium and chromium–cobalt alloy, and its restoration enabled by UVC phototreatment, which surmounts the innate bioactivity of new surfaces, which is more closely linked to hydrocarbon removal than the induced superhydrophilicity.     

自噬抑制剂3-甲基腺嘌呤在H2O2引起的神经胶质瘤U251细胞损伤中的作用

目的: 探讨自噬抑制剂3-甲基腺嘌呤(3-MA)在H₂O₂诱导的神经胶质瘤U251细胞损伤过程中的作用。方法: 实验分为4组:正常对照组、10 mmol/L 3-MA组、1 mmol/L H₂O₂组、1 mmol/L H₂O₂ +10 mmol/L 3-MA组。MTT法检测各组的U251细胞增殖率;MDC染色检测细胞自噬空泡的变化;Hoechst 33342染色检测细胞核染色质凝聚变化;流式细胞术检测细胞凋亡率。结果: 与对照组相比,单独应用3-MA对U251细胞无明显影响。H₂O₂作用组U251细胞增殖率明显降低,细胞内出现自噬空泡,细胞核染色质凝聚,细胞凋亡率增加。3-MA与H₂O₂联合作用于U251细胞时,与单独应用H₂O₂组相比,抑制了H₂O₂引起的胞内自噬空泡的积聚,但细胞凋亡率明显增加。结论: 自噬抑制剂3-MA能够一定程度地抑制H₂O₂诱导的U251细胞自噬,但促进了细胞凋亡,表明自噬在H₂O₂诱导的神经胶质瘤U251细胞损伤过程中很可能起到保护性作用。