Department of Microbiology, Chungbuk National University, 52 Naesudong-Ro, Heungduk-Gu, Cheongju 361-763, South Korea.
Int J Biol Macromol. 2013 Mar;54:37-43. doi: 10.1016/j.ijbiomac.2012.11.025. Epub 2012 Nov 29.
Chitosan (CS) nanofibers with a diameter of 150-200nm were fabricated from a mixed chitosan/poly (vinyl alcohol) (PVA) solution by the electrospinning method. The nascent CS/PVA nanofibers were treated with 0.5M NaOH solution to make stable CS nanofibers by removing PVA under aqueous conditions. Hen egg-white lysozyme was immobilized on electrospun CS nanofibers via cross-linked enzyme aggregates (CLEAs) and used for effective and continuous antibacterial applications. The maximum amount of lysozyme immobilized on the CS nanofibers was determined to be 62.3mg/g of nanofibers under the optimum conditions. The immobilized lysozyme-CLEA retained more than 75.4% of its initial activity after 80 days of storage at room temperature, while the free lysozyme lost all of its activity under the same conditions. In addition, the immobilized lysozyme-CLEA retained more than 76% of its activity after 100 consecutive uses. Finally, the durability of the lysozyme-CLEA immobilized CS nanofibers showed bacteriostasis ratios of 82.4%, 79.8%, 83.4%, and 84.1% after 10 cycles against 4 pathogenic bacteria, viz. Staphylococcus aureus, Bacillus subtilis, Shigella flexneri, and Psedomonas aeruginosa, respectively. These results demonstrated that lysozyme-CLEA immobilized CS nanofibers could be used as a promising material for enhanced and continuous antibacterial applications.
直径为 150-200nm 的壳聚糖（CS）纳米纤维是通过静电纺丝法从壳聚糖/聚乙烯醇（PVA）混合溶液中制备的。初生的 CS/PVA 纳米纤维用 0.5M NaOH 溶液处理，在水相条件下去除 PVA 得到稳定的 CS 纳米纤维。通过交联酶聚集体（CLEAs）将蛋清溶菌酶固定在静电纺 CS 纳米纤维上，用于有效和连续的抗菌应用。在最佳条件下，CS 纳米纤维上固定的溶菌酶的最大量为 62.3mg/g 纳米纤维。在室温下储存 80 天后，固定化溶菌酶-CLEA 保留了其初始活性的 75.4%以上，而相同条件下的游离溶菌酶则失去了全部活性。此外，固定化溶菌酶-CLEA 在连续使用 100 次后仍保留了超过 76%的活性。最后，固定化溶菌酶-CLEA 的 CS 纳米纤维在 10 次循环中对 4 种致病菌（金黄色葡萄球菌、枯草芽孢杆菌、福氏志贺菌和铜绿假单胞菌）的抑菌率分别为 82.4%、79.8%、83.4%和 84.1%，表明溶菌酶-CLEA 固定化 CS 纳米纤维可用作增强和连续抗菌应用的有前途的材料。
