生物医用钛表面热还原银微纳米颗粒研究

目的尝试改进生物医用钛的常用碱热处理表面改性方法,使钛不仅具有生物活性,而且具有抗菌性能。方法将纯钛片磨光和清洗,在60 2.5 mol/L Na O℃H溶液中进行碱液处理后,分别在0.2、1、5、20mmol/L硝酸银溶液中浸渍,然后把未浸渍和浸渍的试样在600℃热处理1 h,采用X射线衍射、扫描电镜和X射线光电子能谱分析膜层的成分和结构,评价试样的抗菌性能和生物活性。结果在浓度≥1 mmol/L硝酸银溶液中浸渍制备的试样,检测到单质银的X射线衍射峰。扫描电镜观察表明,随着硝酸银浓度的升高,银颗粒从约100 nm增加到1.5μm以上;钛酸钠凝胶层和银颗粒具有较好的附着性。X射线光电子能谱分析检测到金属银和少量银化合物。抗菌实验和模拟体液实验表明,随着硝酸银浓度的升高,试样的抗菌活性升高,但生物活性下降。结论碱液-硝酸银溶液浸渍-热处理方法改善了钛的生物活性和抗菌性能,这为钛基硬组织植入体的表面改性提供了一种简便方法。

Thermally Reduced Silver Micro-Nanoparticles on Surface of Biomedical Titanium

The work aims to improve the traditional alkali-heat treatment surface modification method of biomedical tita-nium, endowing titanium with both bioactivity and antibacterial properties. Pure titanium sheet was polished and cleaned, then alkali treated in 2.5 mol/L NaOH solution at 60℃ , dipped in 0.2, 1, 5 and 20 mmol/L AgNO3 solutions respectively, and then heat treated at 600℃ for 1 h. Composition and structure of the film were analyzed with X-ray diffraction, scanning electron mi-croscopy and X-ray photoelectron spectroscopy. Antibacterial and bioactivity properties of the samples were evaluated. X-ray diffraction peak of metallic silver was detected in samples dipped and prepared in≥1 mmol/L AgNO3 solution. Scanning elec-tron microscopy observation showed that Ag particles increased from nearly 100 nm to over 1.5μm as the AgNO3 concentration increased. The sodium titanate film and Ag particles had good adhesion. Metallic silver and a few silver compounds were de-tected by X-ray photoelectron spectroscopy analysis. Antibacterial test and the simulated body fluid test demonstrated that the antibacterial activity of the samples increased while the bioactivity decreased with as AgNO3 concentration increased. The alkali treatment-dipping in AgNO3 solution-heat treatment method improves bioactivity and antibacterial property of titanium, and thereby provides a conventional method for surface modification of titanium-based hard tissue implants.