RGD修饰纯钛表面对人牙龈成纤维细胞生物学行为的影响

用羰基二咪唑(1,1′-carbonyldiimidazole,CDI),将含RGD的短肽共价连接到纯钛的表面,将HGFs分别接种到涂层和未涂层材料表面并培养一定时间后,定量对比接枝和未接枝材料表面的细胞纤粘连蛋白(fibronectin,FN)和粘着斑的形成情况,研究接枝后的纯钛表面对原代培养的人牙龈成纤维细胞(Human Gingival Fibroblasts,HGF)生物学行为的影响.结果表明,RGD修饰的纯钛表面粘着斑的形成比钛表面早.RGD接枝钛表面有利于人牙龈成纤维细胞的粘附,改善了纯钛的生物相容性.     

RGD修饰钛表面对人牙龈成纤维细胞初期黏附和铺展的影响

用羰基二咪唑(1,1'-carbonyldiimidazole,CDI)将含RGD的短肽共价连接到纯钛表面,研究接枝后的钛表面对原代培养的人牙龈成纤维细胞(human gingival fibroblasts,HGF)初期黏附和铺展的影响.结果表明,RGD修饰的纯钛表面粘附的细胞数比未修饰钛表面多,细胞铺展面积比钛表面的大,应力纤维的形成比钛表面早.RGD接枝钛表面更有利于人牙龈成纤维细胞的粘附,改善了纯钛的生物相容性.     

石墨烯/环氧树脂复合涂层的γ射线辐照损伤及其腐蚀防护性能

用硅烷偶联剂对石墨烯表面进行修饰, 制备石墨烯/环氧树脂复合涂层。通过交流阻抗(EIS)和塔菲尔极化曲线(Tafel slope)等电化学方法分析复合涂层经伽马射线辐照后的腐蚀防护性能。采用电子自旋共振(ESR)和傅里叶红外光谱分析仪(FTIR)等测试复合涂层的γ射线辐照损伤, 探索了石墨烯在环氧树脂中抗辐照损伤的作用机理。Tafel结果显示复合涂层经280 kGy辐照后, 腐蚀电流为6.140×10^-9 A/cm², 而纯环氧树脂涂层的腐蚀电流则为1.340×10^-8 A/cm², 说明石墨烯可以使复合涂层保持较好的腐蚀防护性能。ESR分析表明, 复合涂层中的石墨烯可以降低环氧树脂基体在γ射线辐照过程中产生的过氧自由基, 表明石墨烯可有效吸收辐照过程中的自由基。辐照前后复合涂层的FT-IR图谱没有发生明显变化, 说明石墨烯有效降低了伽马射线对环氧树脂的结构损伤。因此, 可以认为石墨烯能够减缓环氧树脂在高能辐照环境中的老化, 从而延长其使用寿命。     

SLA表面PDA/CPP复合涂层的制备及其性能研究

在大颗粒喷砂酸蚀(SLA)工艺形成的三维多级嵌套孔洞结构纯钛表面, 利用聚多巴胺(PDA)的超强粘附性和二次修饰功能, 接枝生物大分子酪蛋白磷酸肽(CPP), 制备PDA/CPP复合涂层。采用FESEM、EDS、XPS、水接触角分析仪、体外仿生矿化测试以及人骨髓间充质干细胞(hBMSCs)实验对样品表面进行表征分析和性能测试。结果表明, 两步浸泡法成功在SLA表面制得PDA/CPP复合涂层。该涂层在保留SLA多孔形貌的同时, 使水接触角从47.7°减小到25.5°, 明显提高了SLA表面亲水性; 在模拟体液浸泡1 d后的修饰表面即沉积了致密羟基磷灰石(HA), 说明PDA/CPP显著加快了SLA表面生物矿化的速度。同时, SLA/PDA/CPP表面细胞粘附、增殖以及矿化活性都得到了明显改善。     

微弧氧化和碱处理对钛的细胞粘附和骨植入行为的影响研究

考察了微弧氧化处理和碱处理对钛表面形貌、涂层成分、羟基磷灰石沉积能力、细胞黏附、骨内植入的影响。结果表明,微弧氧化和碱复合处理后的钛表面TiO2薄膜呈现大量裂缝,表现出表面含大量OH-极性基团的纳米多孔网状结构,此微观结构和组成使材料诱导羟基磷灰石生成能力显著,利于成骨细胞黏附及繁殖,无细胞毒性,细胞兼容性好。通过植入兔股骨4和12周体内动物实验组织学切片表明,材料无毒、无刺激性,与周围组织间有良好的组织相容性,该材料植入动物骨环境中可刺激成骨,具有骨传导作用。相比下,微弧氧化和碱复合处理样品的生物相容性较为优异。     

一步溶剂热法合成高催化性能的Gd~(3+)掺杂氧化锌纳米晶体（英文）

近年来,ZnO作为性能优异的光催化剂受到广大研究者的密切关注。它是一种宽带隙半导体,禁带宽度为3.37 e V,具有良好的稳定性。但也不可避免地存在一些不足,如光生电子空穴复合率太高、光能利用率太低等。为进一步提高ZnO的光催化降解活性,研究者们对其进行了一系列改性。其中,掺杂是一种行之有效的方法,它可以通过调控ZnO禁带宽度、晶体结构和缺陷利用,进而提高光催化性能。本工作采用具有特殊电子结构的稀土离子钆(Gd)作为掺杂剂,研究了其对ZnO晶体结构、形貌及光催化性能的影响。通过一步溶剂热法合成了纯氧化锌(ZnO)和不同Gd~(3+)掺杂浓度的ZnO纳米颗粒。采用X射线衍射(XRD)、扫描电镜(SEM)、比表面积分析、傅里叶变换红外(FT-IR)光谱、紫外-可见(UV-vis)吸收光谱和光致发光(PL)光谱等手段对所得样品进行了表征。光催化降解实验以20 mg/L罗丹明B为模拟污染物,在300W氙灯光源下进行。同时也分析了Gd~(3+)掺杂氧化锌纳米颗粒的光催化机理。实验结果显示,稀土Gd掺杂后ZnO晶体结构没有发生改变,仍为六方纤锌矿结构。在Gd~(3+)浓度较低时,Gd~(3+)进入ZnO晶格,取代部分Zn~(2+)或进入间隙位置;但是当Gd~(3+)浓度达到3 mol%时,检测到了少量Gd_2O_3的衍射峰,可能的原因是两种离子的半径和化合价存在差异,ZnO晶格难以容纳较多的Gd~(3+)。同时,Gd离子掺杂引起ZnO衍射峰位置向低角度偏移,晶胞参数发生变化,这也进一步证实Gd~(3+)进入到了ZnO晶格中。观察样品的形貌发现,Gd离子掺杂对ZnO纳米颗粒的生长有较强的抑制作用,使得晶粒尺寸相比纯ZnO有较明显的减小,这主要是由于稀土离子掺杂后会在ZnO表面形成Re-O键,抑制ZnO的生长,通过XRD结果计算也可得出同样的晶粒尺寸变化趋势。比表面积测试发现掺杂Gd离子后ZnO的比表面积显著提高,暗示着更多的反应活性位点和更强的吸附污染物能力。UV-vis吸收谱中掺杂Gd离子后ZnO在紫外和可见光区域的吸收都明显增强,且吸收边出现红移,表明禁带宽度减小,在可见光区的吸收增强。另外,PL光谱测试表明掺杂Gd离子后ZnO光生电子空穴的复合率显著降低,意味着将有更多的光生电子、空穴参与到光催化降解反应中,从而使光催化活性提升。Gd~(3+)掺入ZnO基质将导致系统内产生更多数量的电荷载流子和缺陷,这些Gd~(3+)和缺陷会充当俘获中心抑制光生载流子的复合,增强光催化活性。但是,过量Gd~(3+)掺杂将产生过多的缺陷,反而会成为光诱导电子-空穴复合的中心,不利于光催化反应。罗丹明B降解实验进一步印证了Gd离子掺杂引起的ZnO光催化性能的明显提升,其中3 mol%Gd-ZnO的催化效果最佳,对应的罗丹明B降解率为70.9%(模拟太阳光照射120 min)。降解实验同时表明,对于ZnO而言Gd~(3+)的掺杂量并不是越大越好。适度提高Gd~(3+)的引入量(3 mol%)会使表面势垒变高及空间电荷区变窄,因此可以有效地分离电子-空穴对。然而,当Gd~(3+)浓度增加到4 mol%时,空间电荷区变得非常狭窄,光可以完全穿越空间电荷层,使得电子-空穴对的重组变得更容易;同时过量的Gd~(3+)不能继续进入ZnO的晶格,而只能附着在晶体表面,影响光子对晶体的作用,最终的结果是ZnO光催化活性又出现降低。     

Influence of Coating Parameter and Sintering Atmosphere on the Corrosion Resistance Behavior of Electrophoretically Deposited Composite Coatings

The purpose of this study is to synthesize and characterize nanosized titania (TiO₂), zinc oxide (ZnO), and its composite coating on Ti–6Al–4V to enhance its corrosion protection behavior in Ringer's solution. Nanosized powders of TiO₂ and ZnO was characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and scanning electron microscopy - energy dispersive atomic spectroscopy (SEM-EDAX) analysis. As a result of antibacterial activity, both ZnO and TiO₂/ZnO have produce remarkable inhibition zone on Escherichia coli. The antibacterial activity of composites are due to the combined effect of ZnO on TiO₂. The adherence and surface uniformity of TiO₂/ZnO composite film on titanium implant was examined by optical microscopy and Vickers microhardness test. Corrosion resistant behavior of the coating on titanium implant was investigated by tafel polarization and impedance analysis. The composite coatings on Ti–6Al–4V have produced improved corrosion resistance with a pronounced shift in the anodic corrosion potential (E_corr) with a corresponding less corrosion current density (I_corr) compared to monophase coating. Similar results have been obtained for impedance analysis which indicated a reduction in double layer capacitance (C_dl) and with enhancement in charge transfer resistance (R_ct). These observations suggest improved corrosion resistance property of TiO₂/ZnO composite coating on Ti–6Al–4V.     

纳米ZnO-氧化石墨烯及ZnO-氧化石墨烯/水性聚氨酯复合涂层的抗菌性能

循环冷却水系统滋生细菌会导致生物黏泥产生及设备腐蚀,为解决这一问题,由硅烷偶联剂γ-氨丙基三乙氧基硅烷（KH550）改性纳米ZnO,改性纳米ZnO与氧化石墨烯（GO）在二甲基乙酰胺中复合,获得纳米ZnO-GO复合抗菌材料,并利用纳米ZnO-GO改性水性聚氨酯（PU）,得到纳米ZnO-GO/PU复合涂层。对纳米ZnO-GO复合抗菌材料进行表征分析及抗菌性能测试,对纳米ZnO-GO/PU复合涂层进行抗菌性能测试及物理性能分析。结果表明,纳米ZnO成功负载在GO表面,纳米ZnO-GO纯度较高,当GO质量分数为35wt%、纳米ZnO-GO使用量为160 mgL^-1时,其抗菌率可达97.16%;当纳米ZnO-GO质量分数为2.33wt%时,纳米ZnO-GO/PU复合涂层抗菌率可达90.29%,同时拥有4 H的铅笔硬度及93.26%的缓蚀性能。     

The changes of structure upon thermal treatment of gold coatings electrodeposited on vacuum-sputtered Ti and electrodeposited Ni---B or Ni---Fe layers

The changes in structure and chemical composition of gold coatings after thermal treatment in dependence on the composition of metallic layers has been studied by transmission electron microscopy, scanning electron microscopy and X-ray diffraction (XRD). An electrodeposited gold coating on Ti as well as on Fe---Ni/Cu and Ni---B/Cu systems had no observable changes in phase composition and structure after thermal treatment of 200 h at 150–200 °C. Spontaneous growth of gold crystal whiskers were observed on the gold coating on a Ti substratum (50–100 h, 350 °C). There were changed friable structures in some places. XRD data testify a presence of Au₂Ti and AuTi₃. A changed structure containing big grains developed in some places on the gold coating of the system Au/Fe---Ni/Cu after thermal treatment (50 h, 350 °C). Nickel diffusion and the presence of intermetallic AuCu in the gold coating was also observed. The gold coating of the system Au/Ni---B/Cu remains stable with respect to structure and chemical purity. The electrodeposited Ni---B layer (B, 4–8 wt.%; C, 3–7 and 10⁻² wt.% in dependence of the technique of electrodeposition) is amorphous. The gold coating on a Ni---B substratum had no observable changes in structure after a thermal treatment of 200 h, 350 °C.     

Ag的掺入对MTa2O5多层复合涂层的微观结构、 耐蚀性和抗菌性能的影响

采用磁控溅射技术在Ti6Al4V合金表面制备了含Ag和不含Ag的Ta_2O_5/Ta_2O_5/Ta_2O_5-TiO_2/TiO_2/Ti多层复合涂层(分别用Ag-MTa_2O_5和MTa_2O_5表示),通过SEM、XRD、EDS、纳米压痕仪、电化学工作站和平板计数法,对涂层试样进行表征与检测。研究结果表明,Ag的掺杂对MTa_2O_5多层涂层的结构和性能有重要影响。与MTa_2O_5涂层相比,Ag-MTa_2O_5涂层表面的晶粒变粗、致密度降低、机械性能和耐腐蚀性能略有下降;但Ag-MTa_2O_5涂层的抗菌率为100%,显示出优异的抗菌性能。     

In vivo examination of the local inflammatory response after implantation of Ti6Al4V samples with a combined low-temperature plasma treatment using pulsed magnetron sputtering of copper and plasma-polymerized ethylenediamine

Copper (Cu) could serve as antibacterial coating for Ti6Al4V implants. An additional cell-adhesive layer might compensate Cu cytotoxicity. This study aimed at in vitro and in vivo evaluation of low-temperature plasma treatment of Ti6Al4V plates with Ti/Cu magnetron sputtering (Ti6Al4V–Ti/Cu), plasma-polymerized ethylenediamine (Ti6Al4V–PPEDA), or both (Ti6Al4V–Ti/Cu–PPEDA). Ti6Al4V–Ti/Cu and Ti6Al4V–Ti/Cu–PPEDA had comparable in vitro Cu release and antibacterial effectiveness. Following intramuscular implantation of Ti6Al4V–Ti/Cu, Ti6Al4V–PPEDA, Ti6Al4V–Ti/Cu–PPEDA and Ti6Al4V controls for 7, 14 and 56 days with 8 rats/day, peri-implant tissue was immunohistochemically examined for different inflammatory cells. Ti6Al4V–PPEDA had more mast cells and NK cells than Ti6Al4V, and more tissue macrophages, T lymphocytes, mast cells and NK cells than Ti6Al4V–Ti/Cu–PPEDA. Ti6Al4V–Ti/Cu had more mast cells than Ti6Al4V and Ti6Al4V–Ti/Cu–PPEDA. Results indicate that PPEDA-mediated cell adhesion counteracted Cu cytotoxicity. Ti6Al4V–Ti/Cu–PPEDA differed from Ti6Al4V only for mast cells on day 56. Altogether, implants with both plasma treatments had antibacterial properties and did not increase inflammatory reactions.     

Biomimetic coatings functionalized with adhesion peptides for dental implants

A complete biological integration into the surrounding tissues (bone, gingiva) is a critical step for clinical success of a dental implant. In this work biomimetic coatings consisting either of collagen type I (for the gingiva region) and hydroxyapatite (HAP) or mineralized collagen (for the bone interface) have been developed as suitable surfaces regarding the interfaces. Additionally, using these biomimetic coatings as a matrix, adhesion peptides were bound to further increase the specificity of titanium implant surfaces. To enhance cell attachment in the gingiva region, a linear adhesion peptide developed from a laminin sequence (TWYKIAFQRNRK) was bound to collagen, whereas for the bone interface, a cyclic RGD peptide was bound to HAP and mineralized collagen using adequate anchor systems. The biological potential of these coatings deduced from cell attachment experiments with HaCaT human keratinocytes and MC3T3-E1 mouse osteoblasts showed the best results for collagen and laminin sequence coating for the gingiva region and mineralized collagen and RGD peptide coatings for regions with bone contact. Our concept opens promising approaches to improve the biological integration of dental implants.     

Detoxification of Tunisian landfill leachates by selected fungi

Young landfill leachates (LFL) collected from Djebel Chekir (Tunisia) discharge area were found to be highly loaded with organic matter, ammonia, salts, heavy metals, phenols and hydrocarbons. Despite the possibility of their biodegradability, they represent a threat to the environment and show some resistance to conventional wastewater treatment processes. For these reasons, this study attempted to develop a biological process for the treatment of LFL using selected strains of Trametes trogii, Phanerochaete chrysosporium, Lentinus tigrinus and Aspergillus niger. Experiments were undertaken at different concentrations of the effluent up to 100%. COD removal efficiencies for P. chrysosporium, T. trogii and L. tigrinus were of 68, 79 and 90%, respectively, when LFL underwent a two-fold dilution. COD abatements were accompanied with an important enzyme secretion and a high reduction in the toxicity, expressed as percent bioluminescence inhibition (%BI < 20%). Above 50% of LFL, the effluent was toxic to these strains and caused growth inhibition indicating the sensitivity of these strains to concentrated LFL. Comparatively to the other tested strains, A. niger showed to tolerate raw LFL since it grew at 100% of LFL. However, this strain is inefficient in removing phenols and hydrocarbons. Consequently, toxicity abatement was very low (%BI > 70%).     

羟基磷灰石/钛合金骨替代材料体外培养成骨细胞的实验研究

实验选用小鼠头盖骨成骨细胞,采用体外细胞培养技术对具有羟基磷灰石涂层的钛合金(HA/Ti)与未经过表面改性的钛合金两种骨替代材料进行细胞相容性评价,动态观察两种骨替代材料对成骨细胞生长、附着的影响。结果表明两种骨替代材料对成骨细胞生长无抑制作用,未发生细胞毒性反应,细胞在两种材料表面均能正常粘附、生长、增殖,均具有良好的细胞附着形态和细胞增殖率,而HA/钛合金材料具有更好的成骨性,是一种骨细胞相容性良好的骨替代材料。     

基于ZnO纳米片多级结构的柔性染料敏化太阳能电池的制备

采用水热合成法制备基于钛箔的ZnO纳米片薄膜, 采用化学浴沉积法在ZnO纳米片薄膜表面原位沉积ZnO纳米粒和微球, 制备了ZnO纳米片/纳米粒/微球复合结构薄膜, 并将膜组装成柔性染料敏化太阳能电池。研究了钛箔预处理方式、化学浴沉积工艺对ZnO薄膜和电池性能的影响。采用X射线衍射仪、透射电子显微镜和扫描电子显微镜对钛箔和ZnO薄膜的物相组成和形貌进行表征, 采用太阳光模拟器和数字源表测试了电池的J-V光电性能曲线, 通过电化学阻抗谱分析了电池内部电子传输情况。研究结果表明: 当钛箔基底采用酸抛光处理, 将所得ZnO纳米片膜用已经预热24 h的0.15 mol/L二水乙酸锌甲醇溶液改性5 h, 所得电池光电性能最好, 其短路电流密度、开路电压、填充因子和光电转化率分别为11.26 mA/cm², 0.67 V, 0.60和4.51%。     

Facile fabrication of superior antibacterial cotton fabric based on ZnO nanoparticles/quaternary ammonium salts hybrid composites and mechanism study

In the research for the safe and efficiently antibacterial cotton fabrics to minimize risk for human health, an organic–inorganic hybrid material of ZnO nanoparticles (NPs) and quaternary ammonium salt (QAS) was employed to modify cotton fabrics by a dipping–padding–drying method. The synergistic effects of ZnO NPs and QAS on the structure and antibacterial properties of cotton fabrics were studied in detail. Results displayed that the QAS and ZnO NPs were immobilized firmly in cotton fabric by the formation of chemical covalent bonds and silica gel structure. ZnO/QAS/cotton had a good inhibitory effect on the growth of E. coli and S. aureus, with superior antibacterial efficiency of >99.99%. ZnO/QAS/cotton preserved good mechanical property, water absorbability, and limpness. We also provided a detailed analysis of antibacterial mechanism for the hybrid materials. The contact mechanism and the Zn²⁺ release were considered as the main mechanisms for the ZnO/QAS/cotton, while the reactive oxygen species (ROS) generation only had a little contribution to the antibacterial activity. In short, the excellent integrated properties endowed the hybrid cotton fabrics as potential application in many fields, like healthcare, food packaging.