Science and Engineering Faculty, Queensland University of Technology, Brisbane 4000, Australia.
J Mater Chem B. 2019 Feb 28;7(8):1300-1310. doi: 10.1039/c8tb03295e. Epub 2019 Feb 1.
Recently, multi-biofunctional properties of cicada wings have drawn keen interest for biomedical device applications due to their superhydrophobic, self-cleaning and bactericidal effects. We present a systematic evaluation of bactericidal and cytocompatible properties of cicada wings. We also present biomimetic nanofabrication of a patterned array of titanium nanopillars using electron beam lithography. We have characterized the nanoscale architecture of the wings of three different Australian species of cicadas (Psaltoda claripennis, Aleeta curvicosta and Palapsalta eyrei) using helium ion microscopy (HIM), scanning electron microscopy, atomic force measurement (AFM) and transmission electron microscopy (TEM). The chemical nature of the nanopatterned substrates was investigated using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Pseudomonas aeruginosa and Staphylococcus aureus cells were attached to determine the bactericidal activity of the insect wings. Human osteoblast cells were attached to examine the biocompatibility of the insect wings. It was found that all the three cicada species have unique surface topography on their wing membranes and veins. The height, spacing, diameter, density and aspect ratio of the three species varied between the species and between the membrane and the veins. The density and aspect ratio of the nanopillars on the membranes were significantly higher than on the veins. Bacterial attachment investigation confirmed that P. aeruginosa cells and S. aureus cells were damaged by the nanopatterned array of pillars. A significant reduction in colonies of P. aeruginosa cells was found on the wings of the three species compared to the control after 18 hours. A significant reduction of S. aureus cells on the wings was observed at 2 and 4 hours but not at 18 hours compared to the control. The cell morphology of the human osteoblast cells appeared intact after 24 hours of attachment, indicating the biocompatibility of the insect wings. As a proof of concept, patterned nanopillars of titanium have been fabricated using the electron beam lithography technique directly inspired by the cicada wing architecture. The titanium nanopillars were observed to damage the bacterial cells of P. aeruginosa in a manner similar to the cicada wing species and remain compatible to osteoblast cells. The outcomes of this research can help to engineer an optimum nano-patterned surface to enhance the bioactivity and bactericidal effect on biomedical devices.
最近，蝉翼的多功能特性因其具有超疏水、自清洁和杀菌作用而引起了人们对生物医学设备应用的极大兴趣。我们对蝉翼的杀菌和细胞相容性特性进行了系统评价。我们还使用电子束光刻技术仿生制造了钛纳米柱的图案阵列。我们使用氦离子显微镜 (HIM)、扫描电子显微镜、原子力测量 (AFM) 和透射电子显微镜 (TEM) 对三种不同澳大利亚蝉种（Psaltoda claripennis、Aleeta curvicosta 和 Palapsalta eyrei）的翅膀的纳米级结构进行了表征。使用傅里叶变换红外光谱 (FTIR) 和 X 射线光电子能谱 (XPS) 研究了纳米图案化基底的化学性质。将铜绿假单胞菌和金黄色葡萄球菌细胞附着在昆虫翅膀上来确定其杀菌活性。将人成骨细胞附着在昆虫翅膀上来检查其生物相容性。结果发现，所有三种蝉种的翅膀膜和翅脉上都具有独特的表面形貌。三种蝉种之间以及膜和翅脉之间的高度、间距、直径、密度和纵横比都有所不同。膜上纳米柱的密度和纵横比明显高于翅脉。细菌附着研究证实，铜绿假单胞菌和金黄色葡萄球菌细胞被纳米柱图案阵列损坏。与对照组相比，三种蝉种的翅膀上的铜绿假单胞菌细胞的菌落数在 18 小时后显著减少。与对照组相比，2 小时和 4 小时观察到金黄色葡萄球菌细胞的数量减少，但 18 小时后没有减少。人成骨细胞附着 24 小时后细胞形态完整，表明昆虫翅膀具有生物相容性。作为概念验证，使用电子束光刻技术直接受蝉翼结构启发制造了钛的图案化纳米柱。观察到钛纳米柱以类似于蝉翼物种的方式损坏铜绿假单胞菌的细菌细胞，并且对成骨细胞保持相容性。这项研究的结果可以帮助设计最佳的纳米图案表面，以增强生物医学设备的生物活性和杀菌效果。
