面向心血管应用的电子束蒸发氧化钛薄膜的特性——润湿性与血液相容性

用电子束蒸发的方法在钛盘上沉积氧化钛薄膜以检验其在心血管支架方面的应用.用接触角仪测定水滴在所制备氧化钛薄膜表面的接触角,随着沉积过程中氧气流量的增加,薄膜的接触角不断降低,经过热处理后薄膜的亲水性得到了增强.通过观察猪主动脉平滑肌细胞(PASMC)在样品表面的生长行为,研究薄膜的结构与细胞活性的关系.结果表明,覆有薄膜的钛盘具有更好的生物相容性,而沉积后的热处理能够进一步改善氧化钛薄膜的生物相容性.通过观察血小板的吸附行为研究薄膜的血液相容性,发现在所制备的氧化钛薄膜上吸附了极少的血小板.研究结果表明,用电子束蒸发制备的氧化钛薄膜能够用于心血管支架的表面改性.     

聚氨酯/ 羧甲基壳聚糖/壳聚糖) n 复合涂层血液相容性

在心血管支架表面构建仿生细胞外基质结构的涂层是提高支架生物相容性的有效方法.结合静电纺丝及静电自组装技术,在316L医用不锈钢基底上制备出网状聚氨酯/(羧甲基壳聚糖/壳聚糖)n复合涂层.血小板黏附实验表明,对于网状聚氨酯涂层,血小板较易黏附在直径小于1μm的纤维上,在直径大于1μm的纤维上几乎无血小板黏附;而聚氨酯/(羧甲基壳聚糖/壳聚糖)n复合涂层的血小板黏附数量明显下降,血液相容性得到改善.     

活化钛表面及其生物学性能评价

采用碱、碱热和酸碱、酸碱热处理的方法对钛表面进行活化，发现活化处理后的钛表面在细胞培养液中表现出了良好的生物相容性，能够促进成骨细胞粘附增值．材料表面的孔隙结构有利于细胞的粘附．细胞的粘附数量和形态与表面粗糙度有关．     

表面接枝透明质酸聚氨酯的合成及其血液相容性

通过两步溶液法合成了侧链带有羧基的聚氨酯(PU),成膜后其表面羧基经1-乙基-3-(二甲基丙胺)碳二亚胺(EDC)活化后与1,3-丙二胺反应,合成了氨基化聚氨酯材料。透明质酸(HA)经EDC活化后共价接枝到氨基化的聚氨酯膜表面。通过衰减全反射光谱法(ATR-FTIR),静态水接触角测试和扫描电镜(SEM)对聚氨酯接枝前后的结构和形态进行表征,并通过凝血实验和内皮细胞培养实验,测试材料的抗凝血性和细胞毒性。结果表明:透明质酸成功地接枝到聚氨酯膜表面,接枝透明质酸后的聚氨酯膜亲水性提高,凝血时间大幅延长,且能促进内皮细胞的黏附和生长,体现较好的血液相容性。     

光接枝技术构筑仿细胞外层膜两性离子表面

采用硅烷化反应将叔胺氢给体偶联到羟基化盖玻片表面,在含二苯甲酮(BP)光敏剂的2-甲基丙烯酰乙氧基磷酰胆碱(MPC)单体溶液中进行光接枝聚合。用X射线光电子能谱(XPS)对改性表面的化学结构进行表征,接触角对改性表面亲/疏水性能进行测定,蛋白质吸附和血小板黏附评价其抗生物污染性能。结果发现,与未改性表面相比,经含叔胺的硅烷化试剂处理后,基材表面形成了一层胺基化有机无机杂化过渡层;光接枝PMPC后表面于400.2 eV处和131.6 eV处分别出现了N峰和P峰,相对含量分别为4.47%和4.80%,且表面Si2p相对含量显著降低,同时,光接枝各步反应表面接触角变化可间接表明材料表面成功接枝PMPC聚合物。所得两性离子表面蛋白质吸附量降低了91.3%~92.4%,基本不发生血小板黏附。硅烷偶联剂的应用不仅能够提供表面接枝反应所需的自由基源,而且还可增强两性离子聚合物刷涂层与基材表面的黏结强度,对进一步研究涂层稳定性与血液相容性之间的关系奠定了基础。     

胶原修饰快速成形PLGA/TCP人工骨支架体外生物相容性研究

探讨经Ⅰ型胶原修饰的快速成型(RP)聚乳酸-羟基乙酸/磷酸三钙(PLGA/TCP)支架的生物相容性,为进一步体内实验提供研究基础.以经Ⅰ型胶原修饰改性的PLGA/TCP支架作为实验组,未经胶原修饰的原始支架作为对照组,检测两组支架材料的亲水性.BMSCs接种两组支架,分别测定细胞黏附率、细胞增殖率.扫描电镜(SEM)观察细胞黏附形态,以检验支架材料的细胞相容性.结果表明胶原改性支架具有较高的亲水性,实验组细胞黏附率在接种4、8和12 h者,明显优于对照组(P<0.05).实验组在培养2、4、6和8 d的细胞增殖率也明显高于对照组(P<0.05).扫描电镜可见骨髓基质细胞在实验组支架上的增殖数量多于对照组.说明Ⅰ型胶原改性的PLGA/TCP支架具有良好的细胞生物相容性,可作为骨组织工程支架应用于骨缺损的修复研究.     

多孔BCP支架及其仿ECM涂层对MG63细胞功能的影响

通过改良冰模板法制备一种由内向外呈放射状排列、全开孔板层状多孔结构的仿生多孔双相磷酸钙(BCP)支架,并在支架表面制备不同的仿细胞外基质(ECM)涂层。通过体外细胞实验,评价支架结构及表面4种仿ECM生物涂层对人成骨肉瘤MG63细胞(MG63)的细胞功能影响。研究结果表明:支架及其仿ECM涂层均无细胞毒性,仿生ECM涂层支架对MG63细胞功能的作用优于未涂层支架,且明胶-透明质酸复合涂层试样对MG63细胞功能的作用优于单一涂层,明胶-透明质酸-掺RGD涂层试样对MG63细胞增殖、黏附、分化功能的作用均优于其他各涂层组。     

羧基离子注入石墨烯的血液相容性研究

为解决石墨烯不亲水、不亲脂、难于在溶剂中稳定分散的缺陷,运用了离子注入的方法,分别将剂量为1×1017、5×1017和1×1018 ions/cm2的羧基离子(COOH+)注入到石墨烯表面.利用X线光电子能谱(XPS)、扫描电子显微镜(SEM)和水接触角(CA)分析证明注入可引入含氧官能团,如C—O、O—C=O等;并显著提高了材料的含氧量,从而使石墨烯表现出优异的亲水性,这可能是生物相容性改善的主要原因.血小板黏附实验、溶血实验和与红细胞相互作用实验表明:羧基离子注入后,石墨烯的溶血率降低,注入几乎没有对红细胞产生破坏,且显著抑制了血小板的黏附、聚集和活化.研究结果表明羧基离子的注入可显著提高石墨烯的血液相容性.     

依折麦布对高迁移率族蛋白1诱导血管内皮细胞激活的影响机制研究

目的探讨依折麦布对高迁移率族蛋白1(HMGB1)诱导血管内皮细胞激活影响的分子机制.方法分离、培养雄性SD大鼠胸主动脉内皮细胞,分为空白对照组、HMGB1刺激组、依折麦布组(HMGB1刺激前10μmol/L依折麦布预处理)、CLI-095组(HMGB1刺激前1μmol/L CLI-095预处理).荧光定量分析中性粒细胞与内皮细胞的黏附能力;RT-PCR和Western blot检测内皮细胞中TLR4,ICAM-1、可溶性E选择素mRNA和蛋白表达水平;EMSA法检测NF-κb-p65的DNA结合活性.结果 HMGB1活化的内皮细胞与中性粒细胞黏附活力均明显高于空白对照组,差异具有统计学意义(P0.05);依折麦布组、CLI-095组内皮细胞与中性粒细胞黏附活力均明显低于HMGB1诱导组,差异具有统计学意义(P0.05).HMGB1刺激组的内皮细胞TLR4,mRNA和蛋白表达量明显高于空白对照组,差异具有统计学意义(P0.05);依折麦布组和CLI-095组mRNA和蛋白表达量均明显低于HMGB1组,差异具有统计学意义(P0.05).HMGB1组内皮细胞NF-κb p65亚单位核位移明显强于空白对照组,差异具有统计学意义(P0.05);依折麦布组和CLI-095组较HMGB1组核位移明显减弱,差异具有统计学意义(P0.05).HMGB1组ICAM-1、可溶性E选择素表达水平明显高于空白对照组,差异具有统计学意义(P0.05).而经依折麦布、CLI-095干预后可明显降低ICAM-1、可溶性E选择素表达水平,与HMGB1组之间差异具有统计学意义(P0.05).结论依折麦布可通过调节黏附分子(ICAM-1、可溶性E选择素)的表达而有效抑制HMGB1诱导的血管内皮细胞活化效应,其机制与抑制TLR4的表达和NF-κb激活有关.     

P选择素在肿瘤转移中的作用

P选择素属选择素黏附分子家族成员,越来越多的研究表明P选择素在多种疾病中发挥重要作用,本文主要对P选择素在肿瘤转移中的相关研究作一综述。肿瘤发生时,在多种因子的作用下P选择素的表达水平增高,并通过结合肿瘤细胞表面的多种配体介导瘤细胞与活化血小板及内皮细胞黏附并相互作用,促进肿瘤细胞的转移。肝素及其衍生物能阻止P选择素与配体的结合,降低肿瘤转移的发生。     

INVESTIGATION INTO THE SURFACE ENERGY OF IMPLANTED SURFACES

The critical surface energy of steels surface modified by ion implantation was evaluated. Zisman's method was used to investigate the critical surface energy of 40Cr, # 45, GCr15, 1Crl8Ni9Ti steels implanted under the different conditions from the contact angle data. The critical surface energy in steel shows a general tendency to decrease with the increase of implanting energy and dose. On the grounds of the relationship between the energy of adhesion of sliding interfaces and the solid surface energy, reduction of friction and increase of wear resistance of the implanted surfaces have been demonstrated experimentally.     

In vitro study of human endothelial progenitor cells behaviour on nitrided Ni-free Ti–27Nb alloy

A superelastic Ni-free Ti–27Nb alloy has been synthesized and gas nitrided at high temperature to investigate its suitability for vascular implant applications. The cellular responses of human endothelial progenitor cells (EPCs) to both bare and nitrided Ti–27Nb alloy have been analyzed using Live/Dead staining, MTT assay, fluorescence microscopy and ELISA technique, as well as NiTi alloy for comparison. Live/Dead staining and MTT assay were performed to assess the cellular viability and proliferation, while fluorescence microscopy was used to analyze cell adhesion, cell morphology, and the expression of endothelial cell markers (VE-cadherin and von Willebrand factor). Secretion of the pro-inflammatory chemokine MCP (monocyte chemoattractant protein)-1 by the cells grown in contact with the analyzed materials was further verified using the enzyme-linked immunosorbent assay. The results obtained revealed that adhesion, spreading, viability, proliferation rate and phenotypic markers expression of EPCs were similar on the surfaces of Ti–27Nb and NiTi alloys. Cells exposed to nitrided Ti–27Nb surface exhibited significantly decreased inflammatory response, which may be beneficial for reducing in-stent restenosis incidence.     

Investigation on thermal aging and scaling of NBR in alkaline solution

The thermal aging and scaling tests of Butadiene-acrylonitrile rubber (NBR) samples in alkaline solution were done, and after the tests the surface contact angle of samples was measured and the sample surface was analyzed by infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS) and scanning electronic microscope (SEM). The test results shows that after the NBR samples were dipped in pH 11, 70 °C alkaline solution for 215 d, many microcracks were observed on the surface of NBR samples and a lot of small sized scales existed near the cracks; element constituents of scale adhering on the surface were: Ca, Fe and Al, of which Ca was from saturated CaCO₃, Fe was from rust scale and Al was from Al₂O₃ ceramic existing also in the test environment; IR and XPS inspection indicate that there were outgrowths of carboxy group, acyloxy group, hydroxyl group, CaO and Ca₃Si₃O₉, which showed that oxidation degradation and hydrolyzation happened on NBR and the scale appeared on the samples’ surfaces. Dissolution, aging or scale adhesion led to non-uniformity of contact angle and surface energy data. Foundation item: Supported by the Science and Technology Foundation of China National Petroleum Corporation (04B70303).     

人脐静脉内皮细胞培养液的选择

目的:筛选出人脐静脉内皮细胞(HUVECs)原代、传代最适培养液.方法:0.02%II型胶原酶灌注脐静脉消化15min获得细胞,用不同的培养液培养.24h后观察细胞贴壁状况,细胞计数法得到贴壁细胞数量;内皮细胞标志性蛋白vWF进行细胞鉴定.传代培养后,用MTT法比较不同培养液对HUVECs活力的影响.结果:用含ECGS、20%FBS的ECM组进行原代培养,可获得贴壁细胞数量最多的HUVECs,且与其他组间有显著差异;用含30ng·mL-1 VEGF165、10%FBS的M199进行传代培养,HUVECs活力较ECM组无明显差异.结论:HUVECs原代、传代培养分别选用优化后的培养液,既保证原代HUVECs的质量和数量,又使传代培养成本降低60.8%.     

Adhesion Enhancement Mechanism of Plasma-Modified Tire Cord

Tire cord was treated with oxygen glow-discharge plasma in order to enhance the adhesion.The treated surfaces were characterized by scanning electron microscopy (SEM),specific surface area analysis Brunauer-Emmett-Teller (BET),X-ray photoelectron spectroscopy (XPS),contact angle measurement,and the standard H-pull test.Results indicated that the plasma treatment could increase the surface roughness,modify the nature and density of surface functional groups,and greatly improve the surface energy and adhesion of tire cord.After long term storage in ambient air,the enhanced adhesion decreased slightly.     

Method of Stabilizing the Surface Energy of Fabrics Coated with Silicone

Silicone coatings have been used in this study. The method adopted was the liquid drop analysis on the coated fabrics. The contact angle between a liquid drop and the fabric surface was measured with two liquids continuously and recorded by a computer. The surface energy was calculated by means of Owens method. Kinetic measurement was adopted. The contact angle of liquids on the fabric coated silicone decreased with time was found. A compound solution DX has been found, so that the contact angle of the liquids on the fabric washed with DX becomes constant, and the surface energy of the fabric can be reduced to below 15 mJ/m2.     

非铁基材料化学镀镍基合金

采用化学镀的方法在钨振子、PVC表面沉积镍基合金。为获得钨振子与镀层同较强的结合力，通过采用不同预处理、热处理方法来完成。实验表明，用以双氧水为主的混合液预处理，Ni-P合金镀层结合力最佳；在保护性气氛中热处理，可大大增强镀层与基体结合力。PVC表面用氯化钯活化可得到导电性良好的镍基合金镀层。     

Ohmic contact properties of p-type surface conductive layer on H-terminated diamond films prepared by DC arc jet CVD

With the advantages of high deposition rate and large deposition area, polycrystalline diamond films prepared by direct current (DC) arc jet chemical vapor deposition (CVD) are considered to be one of the most promising materials for high-frequency and high-power electronic devices. In this paper, high-quality self-standing polycrystalline diamond films with the diameter of 100 mm were prepared by DC arc jet CVD, and then, the p-type surface conductive layer with the sheet carrier density of 1011-1013 cm?2 on the H-terminated diamond film was obtained by micro-wave hydrogen plasma treatment for 40 min. Ti/Au and Au films were deposited on the H-terminated diamond surface as the ohmic contact electrode, respectively, afterwards, they were treated by rapid vacuum annealing at different temperatures. The properties of these two types of ohmic contacts were investigated by measuring the specific contact resistance using the transmission line method (TLM). Due to the formation of Ti-related carbide at high temperature, the specific contact resistance of Ti/Au contact gradually decreases to 9.95 × 10?5 Ω·cm2 as the temperature increases to 820℃. However, when the annealing temperature reaches 850℃, the ohmic contact for Ti/Au is degraded significantly due to the strong diffusion and reaction between Ti and Au. As for the as-deposited Au contact, it shows an ohmic contact. After annealing treatment at 550℃, low specific contact resistance was detected for Au contact, which is derived from the enhancement of interdiffusion between Au and diamond films.     

超疏水涂料在自清洁与防腐蚀方面的应用

选取实验室自制环保型超疏水涂料,主要从所制备涂料涂层的自清洁性和防腐蚀性两方面来研究此涂料的实际应用价值和开发前景.以玻璃片和金属片为基底通过制备超疏水涂料并跟踪观察其置于自然条件下的表面清洁程度和防腐蚀状况,以接触角的大小和稳定性作为此涂料在自清洁性和防腐蚀性能方面的主要指标.实验结果表明,在水晶液蜡涂料和空白基片的对比下,超疏水涂料构建的涂层表面,在自然条件下清洁程度和防腐蚀性能最佳,说明了实验室自制超疏水涂料在自清洁和防腐蚀性能方面的优势,也证明了其在自清洁和防腐蚀材料领域的研究价值.