羟基磷灰石涂层钛合金材料生物相容性研究初探

目的探讨一种新型的代骨材料--羟基磷灰石涂层的钛合金材料的生物相容性。方法制备羟基磷灰石涂层钛合金材料浸提液后,采用细胞毒性实验以观察实验样品浸提液对L929小鼠成纤维细胞的毒性反应;通过对小鼠尾静脉及腹腔注射试验样品浸提液后,观察其对小鼠的急性全身毒性反应;Ames实验及迟发型超敏反应实验对其遗传毒性及致敏性进行安全性评价。结果羟基磷灰石涂层钛合金材料浸提液对L929小鼠成纤维细胞的相对增殖率(RGR)为96.9%,细胞毒性反应为1级,无细胞毒性反应;对小鼠亦无明显的急性全身毒性作用,实验样品组与阴性对照组动物体质量差异无统计学意义(P0.05);遗传毒性Ames实验表明,在活化与非活化条件下,该材料浸提液对鼠伤寒沙门氏菌株的回变菌落数与对照组比均未增加2倍,对该菌株无诱变性;迟发型超敏反应实验显示,该材料浸提液无潜在的皮肤接触致敏性。结论羟基磷灰石涂层的钛合金材料具有良好的生物相容性。     

钛合金表面新型生物玻璃/纳米羟基磷灰石涂层的细胞相容性评价

目的为检验前期制备的新型生物玻璃／纳米羟基磷灰石涂层的细胞相容性。方法在本实验中，采用L929成纤维细胞在涂层浸提液中的培养，检测了涂层的细胞毒性，采用人体骨髓基质干细胞存涂层上的培养，检测了涂层对人体骨髓基质下细胞增殖和代谢的影响。结果低于浓度的涂层浸提液（〈10％）埘L929细胞增殖具有促进作用，而高浓度的涂层浸提液（〉50％）对L929细胞的增殖具有抑制作用，其中100％的涂层浸提液对L929细胞的增殖抑制比例为20.9％，在细胞毒性分级中处于合格范围内。结论在培养早期，人体骨髓基质干细胞在涂层表面的增殖要优于对照组，涂层显示出良好的细胞相容性。由于合格的细胞毒性和良好的细胞相容性，该涂层的钛合金具有作为骨植入物的应用潜力。     

钛合金表面新型生物玻璃/羟基磷灰石涂层的体内动物实验

目的为促进钛合金植入体与骨的结合,在其表面制备了生物玻璃/羟基磷灰石复合涂层,并植入兔子股骨内进行动物试验,采用等离子喷涂羟基磷灰石涂层和未涂层的Ti6Al4V合金作为对照。方法种植到期的植入体取出后进行组织学切片,采用品红-苦味酸染色后进行组织学观察,采用SEM高倍观察种植体与骨的结合界面,并对骨接触率和凹槽内骨长入量进行了统计分析和比较。结果三种植入体都具有良好的生物相容性。Ti6Al4V合金与骨之间是一种形态固定,而生物玻璃/羟基磷灰石涂层、等离子喷涂羟基磷灰石涂层可与骨形成骨键合。生物玻璃/羟基磷灰石涂层在植入期间与基体没有脱落,同时其与骨的接触率和凹槽内骨长入量要明显高于其余两个植入体,显示出促进骨生长的作用。结论由于具有良好的生物相容性和促进新骨生长的能力,生物玻璃/羟基磷灰石涂层可加快植入体与骨的愈合速度,在骨替代修复方面显示出优势和广阔的应用前景。     

纳米羟基磷灰石/硫酸钙复合人工骨的生物安全性研究

目的研制纳米羟基磷灰石/半水硫酸钙(n-HA/CSH)复合型人工骨,并对其进行体内、外生物安全性测试。方法对n-HA/CSH人工骨进行急性全身毒性试验、皮内刺激试验、致敏试验、MTT细胞毒性试验和遗传毒性实验(Ames试验)并与对照组比较。结果人工骨浸取液静脉及腹腔注射后不引起小鼠呼吸、进食改变或死亡,体重稳定。家兔皮内注射72小时后仅出现红斑或微弱水肿,豚鼠皮内注射后未出现过敏反应。MTT细胞毒性试验显示含HA10%、20%、40%人工骨及纯n-HA、CSH的细胞增殖率均在77%以上,细胞毒性均为0～1级,Ames试验表明含HA40%人工骨的不同浓度生理盐水浸取液引起鼠伤寒沙门氏菌回复突变数均不超过阴性对照组的2倍。结论n-HA/CSH复合材料不引起全身毒性反应、皮内刺激反应和急性过敏反应。且无MTT细胞毒性,细胞相容性良好。同时,复合材料的生理盐水浸取液不引起鼠伤寒沙门氏菌回复突变数增加。     

聚乳酸/纳米羟基磷灰石复合微球的生物安全性评价

背景：纳米材料以及包含纳米相的医疗器械,因为纳米材料具有尺寸小、比表面积大等独特特性,可能会引发特殊的生物效应,其生物安全性成为人们关注的重点。目的：评价聚乳酸/纳米羟基磷灰石复合微球的生物安全性。方法：采用乳液溶剂挥发法制备聚乳酸/纳米羟基磷灰石复合微球。(1)细胞毒性实验：将聚乳酸/纳米羟基磷灰石复合微球浸提液与小鼠成纤维细胞共培养,同时设置空白对照(完全培养基)、阴性对照(高密度聚乙烯树脂浸提液)与阳性对照(二乙基二硫代氨基甲酸锌浸提液),采用MTT法评价细胞毒性;(2)致敏反应：将复合微球分别进行极性浸提和非极性浸提,进行豚鼠皮内诱导和激发实验,记录结果;(3)皮内反应：将复合微球进行极性浸提和非极性浸提,兔皮内注射后即刻及24,48,72 h,观察各注射部位状况;(4)全身急性毒反应：将复合微球分别进行极性浸提和非极性浸提,通过静脉和腹腔注射到KM小鼠体内,观察小鼠体质量变化;(5)热源反应：将复合微球进行极性浸提,通过耳缘静脉注射至兔体内,记录体温变化;(6)骨植入实验：将圆柱状的复合微球与高密度聚乙烯棒分别植入兔胫骨缺损部位,进行大体观察和局部组织病理学观察。结果与结论：...     

碳纳米管/羟基磷灰石生物复合材料的研究初探

目的 本文主要对碳纳米管／羟基磷灰石生物复合材料进行了初步研究。力争初步找到一条制备CNTs／HAp复合材料的工艺路线，并对所得复合材料的微观结构进行初步研究。方法以球磨和超声分散两种工艺制备了CNTs／HAp复合粉体，并经等静压成型、真空无压烧结制备出了碳纳米管／羟基磷灰石复合材料。结果XRD、IR、TEM及SEM研究发现，所制备羟基磷灰石为纳米级，纯度高，所使用的原料碳纳米管纯度高，碳纳米管在复合粉体中分散均匀。碳纳米管有细化晶粒的作用，但随着烧结温度的升高碳纳米管分解加剧，因此烧结温度以低于1100℃为宜。结论初步找到了一条制备CNTs／HAp复合材料的工艺路线。随温度的升高，复合材料中CNTs的存留量逐渐减少。因此真空下该复合材料的烧结温度应低于1100℃。     

丝素蛋白纳米羟基磷灰石复合材料的生物安全性

BACKGROUND: Silk fibroin has excellent biocompatibility, biodegradability and unique mechanical properties. Its composite, silk fibroin/nano-hydroxyapatite, can simulate the composition and structure of nature bone tissue, contributing to remedying the insufficient mechanical properties of nano-hydroxyapatites. OBJECTIVE: To observe the biological safety of silk fibroin/nano-hydroxyapatite composites. METHODS: Silk fibroin/nano-hydroxyapetite composite biomaterial was synthesized by the coprecipitation method using silk fibroin, calcium chloride and diammonium phosphate as raw materials. According to the demands of International Standard Organization (ISO10993) and Technical Evaluation Standards of Biomedical Materials and Medical Instruments promulgated by Chinese Board of Health (GB/T 16886), experiments of cell toxicity in vitro, acute toxicity and hemolysis were investigated to evaluate the biocompatibility of silk fibroin/nano-hydroxyapetite composite. RESULTS AND CONCLUSION: L929 cells co-cultured with silk fibroin/nano-hydroxyapatite composite leaching liquor had good cell morphology, metabolism and proliferation. The leaching extract of silk fibroin/nano-hydroxyapatite composite injected into mice intraperitoneally had no significant adverse reactions. And silk fibroin/nano-hydroxyapatite composite extracts caused 2.39% blood hemolysis, less than the international standards 5%. These experimental results on cell toxicity test in vitro, acute toxicity and hemolysis met the demands of ISO10993 and GB/T, which show the biological safety of the silk fibroin/nano-hydroxyapatite composite for clinical application.     

羟基磷灰石复合材料的复合作用的研究

羟基磷灰石复合材料的复合作用的研究侯文明综述司徒扑王韦审校（第一军医大学附属珠江医院整形外科，广州５１０２８２）（上海长海医院烧伤科，上海２００４３３）近年来，羟基磷灰石（ｈｙｄｒｏｘｙｌａＰａｔｉｔｅ，ＨＡ）被作为一种人工骨材料广泛用于骨缺损的修复...     

羟基磷灰石/壳聚糖生物复合材料的制备研究进展

羟基磷灰石/壳聚糖复合材料因其生物相容性和合适的力学性能逐渐成为骨替代材料研究的热点。本文综述了羟基磷灰石/壳聚糖复合材料的研究现状,探讨了其特点、制备和性能。并在此基础上提出了此类材料今后的发展方向：三相复合材料和电、磁学性能的研究。     

纳米羟基磷灰石生物安全性评价与研究进展

国内外大多数研究显示羟基磷灰石具有良好的生物相容性和生物活性,医学领域的运用中,普通羟基磷灰石的缺点是脆性大,有很多研究显示纳米羟基磷灰石有更高的强度和韧性,纳米羟基磷灰石晶体在形态、尺寸、组成、结构和结晶度上与人骨羟基磷灰石晶体高度类似,因此纳米羟皋磷灰石在医学领域的应用也日益广泛。对纳米羟基磷灰石生物安全性的评价不断取得进展,大量研究认为纳米羟苯磷灰石具备生物安全性,但是作为一种新型生物材料,纳米羟基磷灰石在评价标准方面有一些问题。     

Biological performance of uncoated and octacalcium phosphate-coated Ti6Al4V

The in vivo behavior of a porous Ti6Al4V material that was produced by a positive replica technique, with and without an octacalcium phosphate (OCP) coating, has been studied both in the back muscle and femur of goats. Macro- and microporous biphasic calcium phosphate (BCP) ceramic, known to be both osteoconductive and able to induce ectopic bone formation, was used for comparison purpose. The three groups of materials (Ti6Al4V, OCP Ti6Al4V and BCP) were implanted transcortically and intramuscularly for 6 and 12 weeks in 10 adult Dutch milk goats in order to study their osteointegration and osteoinductive potential. In femoral defects, both OCP Ti6Al4V and BCP were performing better than the uncoated Ti6Al4V, at both time points. BCP showed a higher bone amount than OCP Ti6Al4V after 6 weeks of implantation, while after 12 weeks, this difference was no longer significant. Ectopic bone formation was found in both OCP Ti6Al4V and BCP implants after 6 and 12 weeks. The quantity of ectopically formed bone was limited as was the amount of animals in which the bone was observed. Ectopic bone formation was not found in uncoated titanium alloy implants, suggesting that the presence of calcium phosphate (CaP) is important for bone induction. This study showed that CaPs in the form of coating on metal implants or in the form of bulk ceramic have a significantly positive effect on the bone healing process.     

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。     

A comparison of the surface characteristics and ion release of Ti6Al4V and heat-treated Ti6Al4V

This work seeks to investigate the nanosurface characteristics and ion release for a Ti6Al4V alloy prepared by various methods (as received and heat treated at 1300 degrees C for 2 h) with three different passivation treatments (34% nitric acid passivation, 400 degrees C heating in air, and aging in 100 degrees C deionized water). The surface and nanosurface composition are not related to the surface passivation treatments and experimental materials as evaluated by energy dispersive spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses. After passivation and autoclaving treatments, the specimens were immersed in 8.0 mM ethylenediaminetetraacetic acid (EDTA) in Hank's solution and maintained at 37 degrees C for periods of time up to 16 days. The 400 degrees C treated specimens exhibit a substantial reduction in constituent release, which may be attributed to the thicker thickness and rutile structure of the surface oxides. After soaking in Hank's-EDTA solution, a significant time-related decrease in constituent release rate is observed for all kinds of specimens throughout the 0-16 day experimental period. The thicker oxides may be a factor in the improved dissolution resistance. Upon immersion, nonelemental Ca and P are both detected on the surfaces of all kinds of specimens by XPS analysis, and this could be explained by the existence of two types of hydroxyl groups (acidic and basic OH groups) on the oxide surface of the specimens.     

Biomimetic collagen/apatite coating formation on Ti6Al4V substrates

Hydroxyapatite and type I collagen are two major components of natural bone. They have been used extensively to engineer biomaterial surfaces for enhanced implant-bone integrations. In this study, a collagen/apatite composite coating was successfully deposited on treated Ti6Al4V surfaces by coprecipitation of type I collagen and apatite in a collagen-containing modified simulated body fluid (m-SBF). X-ray diffraction and Fourier-transform infrared spectroscopy results indicated that the coating achieved was a composite of bone-like carbonated apatite and collagen type I, which is similar to the composition of natural bone. The coating composition and morphology could be tailored by carefully adjusting the collagen concentration in the m-SBF. In addition, both the coating thickness and bonding strength were down regulated by the collagen concentration in the m-SBF. Collagen inhibited the apatite nucleation on the metallic substrate, and thereby reduced the bonding strength of the composite coating. In addition, an in vitro cell culture study was conducted on both the apatite and the collagen-apatite coating surfaces. Addition of collagen promoted osteoblast activities, which may lead to early bone formation.     

Fretting corrosion of CoCrMo and Ti6Al4V interfaces

Mechanically assisted corrosion (fretting corrosion, tribocorrosion etc.,) of metallic biomaterials is a primary concern for numerous implant applications, particularly in the performance of highly-loaded medical devices. While the basic underlying concepts of fretting corrosion or tribocorrosion and fretting crevice corrosion are well known, there remains a need to develop an integrated systematic method for the analysis of fretting corrosion involving metal-on-metal contacts. Such a method can provide detailed and quantitative information on the processes present and explore variations in surfaces, alloys, voltages, loadings, motion and solution conditions. This study reports on development of a fretting corrosion test system and presents elements of an in-depth theoretical fretting corrosion model that incorporates both the mechanical and the electrochemical aspects of fretting corrosion. To demonstrate the capabilities of the new system and validate the proposed model, experiments were performed to understand the effect of applied normal load on fretting corrosion performance of Ti6Al4V/Ti6Al4V, CoCrMo/Ti6Al4V, and CoCrMo/CoCrMo material couples under potentiostatic conditions with a fixed starting surface roughness. The results of this study show that fretting corrosion is affected by material couples, normal load and the motion conditions at the interface. In particular, fretting currents and coefficient of friction (COF)?vary with load and are higher for Ti6Al4V/Ti6Al4V couple reaching 3?mA/cm(2) and 0.63 at about 73?MPa?nominal contact stress, respectively. Ti6Al4V coupled with CoCrMo displayed lower currents (0.6?mA/cm(2)) and COF (0.3), and the fretting corrosion behavior was comparable to CoCrMo/CoCrMo couple (1.2?mA/cm(2) and 0.3, respectively). Information on the mechanical energy dissipated at the interface, the sticking behavior, and the load dependence of the inter-asperity distance calculated using the model elucidated the influence of mechanical factors on the experimental results. It was observed that the lowest amount of work was required to generate some of the highest fretting corrosion currents in Ti6Al4V/Ti6Al4V couples compared to the other combinations. The elements of the model presented here provide an excellent basis to explain many of the observed behaviors of these interfaces.     

Osteoblast response to thermally oxidized Ti6Al4V alloy

We have recently reported that thermal oxidation treatments of Ti6Al4V at 500 degrees and 700 degrees C for 1 h result in the formation of an outer "ceramic" layer of rutile that do not decrease the high in vitro corrosion resistance of the alloy. In the present work, surface roughness was measured and found marginally increased as a consequence of oxidation of the alloy at 700 degrees C, but not at 500 degrees C. We have evaluated the biocompatibility of the oxidized surfaces, by assessing cell adhesion, proliferation, and differentiation of primary cultures of human osteoblastic cells. Compared with polished alloy, both thermal treatments increased osteoblast adhesion measured as cell attachment, beta1 integrin and FAK-Y397 expression, as well as cytoskeletal reorganization. Compared with treatment at 500 degrees C, thermal oxidation at 700 degrees C enhanced cell adhesion. Treatment at 700 degrees C transiently impaired cell proliferation and viability, which were not altered in alloys oxidized at 500 degrees C. Several markers of osteoblastic differentiation such as procollagen I peptide, alkaline phosphatase, osteocalcin, and mineralized nodule formation were found either unaffected or differentially increased by alloys treated either at 500 degrees or 700 degrees C. In addition, thermal oxidation at 700 degrees C also increased osteoprotegerin secretion. Taken together, our results indicate that thermal oxidation treatments at 500 degrees or 700 degrees C for 1 h improve the in vitro biocompatibility of Ti6Al4V.     

Transforming growth factor beta1 immobilized adsorptively on Ti6Al4V and collagen type I coated Ti6Al4V maintains its biological activity

Titanium and titanium alloys are often used for orthopedic and dental implants. Osseointegration of Ti6Al4V may be improved not only by precoating of the surface with extracellular matrix proteins like collagen type I but also by additional immobilization of growth factors. In the present study, transforming growth factor beta1 (TGF-beta1) which is known as an inducer of collagen synthesis was immobilized adsorptively on uncoated and collagen type I coated Ti6Al4V surfaces. TGF-beta1 was found immobilized slightly faster to collagen type I coated than to uncoated Ti6Al4V and released slower from the collagen coated material. Immobilized TGF-beta1 is biologically active for at least 3 weeks storage at 4 degrees C. Sterilization by ethylene oxide inactivates immobilized TGF-beta1. In osteoblasts cultured on implants with adsorptively immobilized TGF-beta1, mRNA level and specific catalytic activity of alkaline phosphatase as well as accumulation of calcium and phosphate were found reduced, whereas procollagen alpha1(I) mRNA level and the rate of collagen synthesis were increased.     

Collagen type I-coating of Ti6Al4V promotes adhesion of osteoblasts

The initial contact of osteoblasts with implant surfaces is an important event for osseointegration of implants. Osseointegration of Ti6Al4V may be improved by precoating of its surface with collagen type I. In this study, the adhesion of rat calvarial osteoblasts to uncoated and collagen type I-coated titanium alloy was investigated over a period of 24 h. Collagen type I-coating accelerates initial adhesion of osteoblasts in the presence of fetal calf serum. One hour after plating, no differences in the percentage of adherent cells between the surfaces investigated were found. Adhesion of osteoblasts to uncoated surfaces was reduced by the GRGDSP peptide by about 70%, whereas adhesion to collagen type I-coated surfaces remained unaffected by treatment of the cells with the peptide. Cell adhesion to coated materials was reduced by about 80% by anti-integrin beta1 antibody. The integrin beta1 antibody did not influence the adhesion to uncoated titanium alloy. The results suggest that osteoblasts adhere to collagen type I-coated materials via integrin beta1 but not by interacting with RGD peptides, whereas adhesion to uncoated titanium alloy is mediated by RGD sequences but not via integrin beta1. Fibronectin does not seem to be involved in the adhesion of osteoblasts to either coated or uncoated titanium alloy.     

Nanometer-scale surface modification of Ti6Al4V alloy for orthopedic applications

This communication presents a novel technology to enhance the biocompatibility of bioinert Ti6Al4V alloy as implant materials for orthopaedic application. The surface of Ti6Al4V alloy was electrochemically activated in NaOH solution to create a porous structure with nanometer topographic features and an alkaline environment, thus promoting the formation of bone-like hydroxyapatite coating and enhancing the bonding strength of the coating. This innovative activation process was proved to be effective and essential. The activated surface was confirmed to be pure TiO2 and the formed coating was characterized of pure hydroxyapatite with a nanometer-scaled grain size structure by means of XPS, FESEM/SEM/EDX, XRD, and TEM techniques.     

The electrochemical and mechanical behavior of passivated and TiN/AlN-coated CoCrMo and Ti6Al4V alloys

The mechanical and electrochemical behavior of the surface oxides of CoCrMo and Ti6Al4V alloys during fracture and repassivation play an important role in the corrosion of the taper interfaces of modular hip implants. This behavior was investigated in one group of CoCrMo and Ti6Al4V alloy samples passivated with nitric acid and another group coated with a novel TiN/AlN coating. The effects of mechanical load and sample potential on peak currents and time constants resulting from fracture of the surface oxide or coating, and the effects of mechanical load on scratch depth were investigated to determine the mechanical and electrochemical properties of the oxides or coating. The polarization behavior of the samples after fracture of the oxide or coating was also investigated. CoCrMo had a stronger surface oxide and higher interfacial adhesion strength, making it more resistant to fracture than Ti6Al4V. If undisturbed, the oxide on the surface of Ti6Al4V significantly reduced dissolution currents at a wider range of potentials than CoCrMo, making Ti6Al4V more resistant to corrosion. The TiN/AlN coating had a higher hardness and modulus of elasticity than CoCrMo and Ti6Al4V. It was much less susceptible to fracture, had a higher interfacial adhesion strength, and was a better barrier to ionic diffusion than the surface oxides on CoCrMo and Ti6Al4V. The coating provided increased corrosion and fretting resistance to the substrate alloys.