Department of Chemical Engineering , McGill University , Montréal , Québec , Canada H3A 0C5.
Quebec Centre for Advanced Materials, Canada (QCAM/CQMF), Montréal , Québec , Canada H3A 2K6.
ACS Appl Mater Interfaces. 2018 Oct 10;10(40):33827-33838. doi: 10.1021/acsami.8b08770. Epub 2018 Sep 26.
We used hairy nanocrystalline cellulose functionalized with aldehyde groups, otherwise known as sterically stabilized nanocrystalline cellulose (SNCC), to facilitate the attachment of the antibacterial agents lysozyme and nisin. Immobilization was achieved using a simple, green process that does not require any linker or activator. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analyses showed successful attachment of both nisin and lysozyme onto the SNCC. The efficacy of the conjugated nanocellulose against the model bacteria Bacillus subtilis and Staphylococcus aureus was tested in terms of bacterial growth, cell viability, and biofilm formation/removal. The results show that the minimum inhibitory concentration of the conjugated nanocellulose is higher than that of lysozyme and nisin in free form, which was expected given that immobilization reduces the possible spatial orientations of these proteins. We observed that free nisin is not active against S. aureus after 24 h of exposure due to either deactivation of free nisin or development of resistance in S. aureus against free nisin. Interestingly, we did not observe this phenomenon when the bacteria were exposed to antibacterials immobilized on nanocellulose, suggesting that immobilization of antibacterial agents onto SNCC effectively retains their activity over long time periods. We suggest that antibacterial SNCC is a promising candidate for the development of antibacterial wound dressings.
我们使用经过醛基功能化的毛发状纳米纤维素，也称为空间稳定纳米纤维素（SNCC），来促进抗菌剂溶菌酶和乳链菌肽的附着。固定化是通过一种简单、绿色的过程实现的，不需要任何连接剂或活化剂。X 射线光电子能谱和傅里叶变换红外光谱分析表明，乳链菌肽和溶菌酶都成功地附着在 SNCC 上。通过测试模型细菌枯草芽孢杆菌和金黄色葡萄球菌的细菌生长、细胞活力和生物膜形成/去除，来测试共轭纳米纤维素的功效。结果表明，与游离形式的溶菌酶和乳链菌肽相比，共轭纳米纤维素的最小抑菌浓度更高，这是由于固定化降低了这些蛋白质的可能空间取向。我们观察到，游离乳链菌肽在暴露 24 小时后对金黄色葡萄球菌没有活性，这要么是由于游离乳链菌肽失活，要么是由于金黄色葡萄球菌对游离乳链菌肽产生了耐药性。有趣的是，当细菌暴露于固定在纳米纤维素上的抗菌剂时，我们没有观察到这种现象，这表明将抗菌剂固定在 SNCC 上可以有效地在长时间内保持其活性。我们认为，抗菌 SNCC 是开发抗菌伤口敷料的有前途的候选物。
