Objective: To investigate the effects of micro/nano-structure and antimicrobial peptides (AMPs) on antibacterial properties for titanium (Ti) metal surface.
Methods: Ti disks were treated via sandblasted large-grit acid-etched (SLA) and alkali-heat treatment (AHT) to build the micor/nano-structure, on which AMPs were spin-coated with a certain amount (10, 30, 50, 70, and 90 μg). Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) were used to observe the surface structure and characterize the surface elements (i.e. contents of C, N, O, and Ti). Ti disks loaded with AMPs of difference amounts were co-cultured with Staphylococcus aureus ( S. aureus) for 24 hours. After that, the formation and dimension of antibacterial circle were measured. Furthermore, the Ti disks treated with different approaches (untreated, SLA treatment, SLA+THA treatment, and loaded with 90 μg AMPs) were co-cultured with S. aureus and Escherichia coli ( E.coli) for 3 hours, bacterial adhesion on the disks were evaluated by using SEM. The antibacterial performances in solution were quantitatively evaluated by immersing the Ti disks in bacterial solutions and measuring the absorbance ( A) values.
Results: It was found that the nanoporous structure could be easily constructed by SLA+AHT approach. After spin-coating AMPs, the nanopores with the diameter less than 200 nm were almost covered. According to the element analysis, with the increase of AMPs, the C content gradually increased; the N content was not detected until AMPs amount reached 70 μg on the disks. The diameter of antibacterial circle clearly depended on the AMPs amount. The Ti disks loaded with 90 μg AMPs had significantly larger antibacterial circles than the other Ti disks ( P<0.05). Based on the SEM observation, the Ti disks loaded with 90 μg AMPs has the least bacterial attachment compared with the other Ti disks ( P<0.05). The A value of bacterial solution immersed with the Ti disks loaded with 90 μg AMPs was much lower than the other Ti disks ( P<0.05).
Conclusion: The approach of micro/nano-structure and AMPs can improve the antibacterial properties of Ti metal surface.
目的: 探讨通过构建材料表面微纳结构联合涂覆抗菌肽提升钛金属抗菌性能的可行性。.
方法: 取钛片进行喷砂酸蚀（sandblasted large-grit acid-etched，SLA）及碱热处理（alkali-heat treatment，AHT），构建微纳结构；然后表面旋涂 10、30、50、70、90 μg 抗菌肽聚合物。扫描电镜观察处理前后钛片表面形貌，能谱仪分析表面 C、N、O、Ti 4 种元素含量比例。将表面载有不同量抗菌肽聚合物的钛片与金黄色葡萄球菌液共培养，24 h 后观察抑菌圈形成情况，并测量抑菌圈直径。另将处理前、SLA 处理、SLA+ AHT 处理、载有 90 μg 抗菌肽聚合物的钛片分别与金黄色葡萄球菌以及大肠杆菌共培养，3 h 后扫描电镜观察两种细菌在材料表面的黏附情况，3、6、9、12、20、24 h 测量菌液吸光度（ A）值，评价钛片杀菌效果。.
结果: 扫描电镜下观察，SLA+AHT 处理钛片表面构建包含微米及纳米级孔洞的多级结构；旋涂抗菌肽聚合物后表面孔径<200 nm 的孔洞几乎已被覆盖。元素分析显示，随着抗菌肽聚合物旋涂量的增加，C 元素含量不断增加；但直至含量达 70 μg 时才检测到 N 元素。培养 24 h，载有不同量抗菌肽聚合物钛片周围均表现出明显抑菌圈，其中 90 μg 钛片大于其余钛片，比较差异均有统计学意义（ P<0.05）。杀菌实验结果显示，载抗菌肽聚合物的钛片表面细菌黏附量较其余钛片明显减少，菌液 A 值明显降低，比较差异有统计学意义（ P<0.05）。.
结论: 通过在材料表面制备微纳结构并涂覆抗菌肽，可赋予钛金属表面优良的抗菌性能。.
Keywords: Titanium; antibacterial peptides; antibacterial properties; implant material; micro/nano-structure.