Ag-羧甲基壳聚糖复合微粒的制备及其抑菌活性

壳聚糖经羧甲基化改性后得到水溶性较高的羧甲基壳聚糖（OCMC），它具有优良的稳定性和抗菌性。对比OCMC在不同溶剂中的溶解度，发现OCMC在2wt%乙酸溶液中的溶解性最好。将OCMC与纳米Ag（AgNPs）复合得到Ag-OCMC复合微粒，采用UV-Vis、FTIR、XPS、TEM、SEM和TG-DTA对Ag-OCMC复合微粒的组成、微观结构和热性能进行表征。以大肠杆菌和金黄色葡萄球菌为模型菌种测试Ag-OCMC复合微粒对革兰氏菌的抗菌性能。结果表明:AgNPs为面心立方晶型，平均粒径为40~50 nm；AgNPs的引入提高了壳聚糖和OCMC的分解温度。Ag-OCMC复合微粒对革兰氏菌的抑菌活性明显高于单一壳聚糖基抗菌剂。 

Preparation and antibacterial activity of Ag-carboxymethyl chitosan composite particles

Carboxymethyl-chitosan (OCMC)with high water solubilities was obtained by carboxymethylation of chitosan.It has good stability and antibacterial property.Comparing the solubility of OCMC dissolving in difference solvents,it is found that the best solvent condition of OCMC is 2wt% acetic acid aqueous.The Ag-OCMC compos-ite particles were obtained by complex of OCMC and Ag nanoparticles (AgNPs).The composition,microstructure and thermal properties of Ag-OCMC composite particles were characterized by UV-Vis,FTIR,XPS,TEM,SEM and TG-DTA.Antimicrobial activities of Ag-OCMC composite particles were performed by using typical bacteria of E.coli and S.aureus.The results show that AgNPs are face-centered cubic crystallites with the average diameter size in 40-50 nm.The decomposition temperatures of chitosan and OCMC are raised by the introduction of AgNPs. The antibacterial activity of Ag-OCMC composite particles is significantly higher than single chitosan based antibac-terials.