School of Metallurgy and Materials, University of Birmingham, Birmingham B152TT, UK.
Biomed Mater. 2010 Oct;5(5):054105. doi: 10.1088/1748-6041/5/5/054105. Epub 2010 Sep 28.
Antibacterial modification of medical materials has already been developed as a potentially effective method for preventing device-associated infections. However, the thin layer generated, often less than 1 µm, cannot ensure durability for metal devices in constant use. A novel stainless steel surface with both a quick bacterial killing rate and durability has been developed by synthesizing Cu and a supersaturated phase (S-phase) using a new active screen plasma alloying technology. This paper investigated the microstructure of a multilayer (using EDS/WDS, SEM, TEM and XRD) and the viability of bacteria attached to biofunctional surfaces (using the spread plate method). The experimental results demonstrate that the plasma alloyed multilayered surface case consists of three sublayers: a nano-crystalline (Fe, Cr, Ni)3N deposition layer (∼200 nm), a unique Cu-containing face-centred cubic (f.c.c.) γ'-M4N (M=Fe, Cr, Ni, Cu) layer and a Cu/N S-phase layer. The thicknesses of the total treated case and the Cu-containing layers are 15 and 8 µm, respectively. Copper exists as substitutional atoms in the γ'-M4N (with a constant concentration of about 5 at%) and in the S-phase lattice (reduces from 5 to 0 at%). The crystal constant of the Cu/N S-phase layer ranged from 0.386 to 0.375 nm, which is expanded by γ from 4.4% to 7.5%. An effective reduction of 99% of Escherichia coli (E. coli) within 3 h was achieved by contact with the homogeneous Cu alloyed surface. No viable E. coli was found after 6 h (100% killed).
抗菌改性医用材料已被开发为预防器械相关感染的一种潜在有效方法。然而，生成的薄层通常小于 1 µm，不能确保金属器械在持续使用中的耐久性。通过使用新的活性屏等离子体合金化技术合成 Cu 和过饱和相（S 相），开发出一种具有快速杀菌率和耐久性的新型不锈钢表面。本文研究了多层结构的微观结构（使用 EDS/WDS、SEM、TEM 和 XRD）和附着在生物功能表面上的细菌的生存能力（使用平板法）。实验结果表明，等离子体合金化多层表面处理层由三个亚层组成：纳米晶（Fe、Cr、Ni）3N 沉积层（约 200nm）、独特的含 Cu 面心立方（f.c.c.）γ'-M4N（M=Fe、Cr、Ni、Cu）层和 Cu/N S 相层。总处理层和含 Cu 层的厚度分别为 15μm 和 8μm。Cu 以替代原子的形式存在于γ'-M4N（浓度约为 5%）和 S 相晶格中（从 5%减少到 0%）。Cu/N S 相层的晶体常数从 0.386nm 到 0.375nm 变化，γ从 4.4%增加到 7.5%。与均匀的 Cu 合金化表面接触可在 3 小时内有效减少 99%的大肠杆菌（E. coli）。6 小时后（100%杀死）未发现存活的 E. coli。
