不同粒度羧甲基壳聚糖基复合抗菌剂抑菌性能的研究

Study on antimicrobial Activity of complex agents Ag-Carboxymethyl Chitosan-thiabendazole with different size distribution

为增加固体制剂的水溶性以及考查研磨后其抗菌性能的变化,制备了低银含量和低噻苯咪唑含量的羧甲基壳聚糖银噻苯咪唑(Ag-CMCTS-TBZ)复合抗菌剂,通过研磨和粒度分级将其分成C1(150-74μm)、C2(74-45μm)和C3(-45μm)三种制剂,采用粒度分析、紫外、红外光谱及最小抑菌浓度(MIC)对其进行分析。研究表明,低含量银、噻苯咪唑的Ag-CMCTS-TB均具有良好的水溶性,其溶解度都大于0.4%,其0.2%(w/v)的抗菌水溶液中的表观粒度在13-250nm之间;但在研磨分级之后,三种制剂中分子间的络合或者氢键键合状况发生了变化,而且导致其抗菌性能发生改变;其中C1对E.coli和S.aureus有较强的抑制,而其抑制A.niger的能力较弱;C3抗菌活性最低,对E.coli,S.aureus,C.albicans和A.niger的MIC值皆>1000 mg/L;C2的抗菌效果则介于其间。

To increase the solubility and trace its variation in antimicroblal activity after powdering process, Ag - Carbaxymethyl Chitosan - thiabendazole （ Ag - CMCTS - TBZ） with low concentration of Ag ＋ and thiabendazole （TBZ） was prepared and powdered into three agents with size distribution of 150 - 74μm,74 - 45μm and - 45μm by standard sieves separating system and marked with C1 , C2 and C3 respectively. Particle size analysis shows the apparent diameter of the three agents varies from 13-250 nm and all possess good solubility of higher than 0. 4%. FTIR and UV spectroscopy show that binding among Ag ＋ and TBZ to the skeleton of CMCTS changed under the powdering process and led to decreasing in antimicrobial activity. The minimum inhibitory concentration （MIC） assessment shows C1 presented the better antimicrobial activity to E. coli and S. aureus but with poorer performance to A. niger. The antimicrobial activity of C2 is secondary to C1 and and C3 presented the worst antimicrobial performance with MICs all higher than 1000 mg/L for all microbes in tests.