壳聚糖季铵盐/有机累托石纳米复合材料的抗菌性能研究

合成了壳聚糖季铵盐, 并通过溶液插层法将其插层进入有机累托石层间制备纳米复合材料, 研究表明, 当壳聚糖季铵盐与有机累托石的质量比为2∶1时, 其获得了4.8nm的最大层间距. 抗菌结果显示, 在偏酸、中性及偏碱性条件下, 所有的纳米复合材料都具有较好的抗菌性能, 且与有机累托石的含量和层间距成正比. 与壳聚糖季铵盐及有机累托石相比, 纳米复合材料对革兰氏阳性菌、革兰氏阴性菌及真菌的抗菌性能大大提高, 对金黄色葡萄球菌和枯草芽孢杆菌的最小抑制浓度仅为0.00313% (W/V), 且能在30min内杀死90%以上的金黄色葡萄球菌, 80%以上的大肠杆菌. 最后, 通过TEM和SEM结果探讨了其抗菌机理.

Antimicrobial Activity of Quaternized Chitosan/Organic Rectorite Nanocomposite

Quaternized chitosan, N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) was synthesized and intercalated into organic rectorite (OREC) to prepare the nanocomposites via solution intercalation method. When the mass ratio of HTCC to OREC was 2∶1, the nanocomposite with the largest interlayer distance of 4.8nm was obtained. Two in vitro antimicrobial assays indicated that all the nanocomposites exhibited strong inhibition effect under weak acid, water and weak basic condition. Moreover, with increasing the amount or the interlayer distance of OREC, the antimicrobial activity was stronger. The lowest minimum inhibition concentrations (MIC) of the nanocomposites against Gram-positive bacteria, Gram-negative bacteria and Fungus were 1/32-1/8, 1/8-1/2 and 1/16-1/8 of that for quaternized chitosan or OREC, respectively. MIC values of the nanocomposites against Staphylococcus aureus and Bacillus subtilis were less than 0.00313% (W/V) in all media tested. The nanocomposites can kill 90% Staphylococcus aureus and 80% Escherichia coli in 30min. The mechanism of the antimicrobial action was briefly discussed on the base of TEM and SEM results.