Biomacromolecules. 2018 Apr 9;19(4):1340-1346. doi: 10.1021/acs.biomac.8b00200. Epub 2018 Mar 5.
Chitosan derived from chitin is one of the most abundant naturally occurring biocompatible polymers obtained from fungi and arthropods. In this work, we report the enhancement in the bactericidal efficacy of CHI in the presence of a sharp nanotopography. High-aspect ratio nanostructured surface (NSS) was fabricated using a single-step deep reactive ion etching technique (DRIE). Post fabrication, CHI coating was carried out using a layer-by-layer (LBL) dip coating process on the flat and nanostructured surfaces. Antibacterial efficacy of the flat silicon surface coated with CHI (Si_CHI) and NSS coated with CHI (NSS_CHI) was tested against both Gram-negative (G-ve) bacteria E. coli and Gram-positive (G+ve) bacteria S. aureus. NSS_CHI exhibited superior antibacterial property against G-ve and G+ve microbes as compared with Si_CHI and NSS substrates. Scanning electron microscopy (SEM) and fluorescence microscopy were used to study the morphology and viability of the bacteria on all the surfaces. Also, biofilm quantification was carried out on all the engineered surfaces for both E. coli and S. aureus using crystal violet (CV) staining. NSS_CHI was found to have the minimum biofilm formation on its surface exhibiting its superior antibacterial property. This study shows that the antibacterial and antibiofilm efficiency of CHI can be augmented by combining it with a sharp nanotopography.
壳聚糖是一种从真菌和节肢动物中提取的最丰富的天然存在的生物相容性聚合物之一。在这项工作中，我们报告了在尖锐的纳米形貌存在下 CHI 的杀菌功效得到增强。高纵横比纳米结构表面（NSS）是使用单步深反应离子刻蚀技术（DRIE）制造的。制造后，通过逐层（LBL）浸涂工艺在平整和纳米结构表面上进行 CHI 涂层。用 CHI （Si_CHI）涂覆的平整硅表面和用 CHI （NSS_CHI）涂覆的 NSS 的抗菌功效针对革兰氏阴性（G-ve）细菌大肠杆菌和革兰氏阳性（G+ve）细菌金黄色葡萄球菌进行了测试。与 Si_CHI 和 NSS 相比，NSS_CHI 对 G-ve 和 G+ve 微生物表现出更好的抗菌性能。扫描电子显微镜（SEM）和荧光显微镜用于研究所有表面上细菌的形态和活力。此外，使用结晶紫（CV）染色对所有工程表面上的大肠杆菌和金黄色葡萄球菌进行了生物膜定量。结果表明，NSS_CHI 表面的生物膜形成最少，表现出其优异的抗菌性能。这项研究表明，通过将 CHI 与尖锐的纳米形貌结合，可以增强 CHI 的抗菌和抗生物膜效率。
