羧甲基壳聚糖/纳米银抗菌剂的制备及缓释性能研究

Preparation and sustained-release performance study of carboxymethyl chitosan/nano-silver antimicrobial agents

以羧甲基壳聚糖(CMCS)、银氨溶液为主要原料,采用微波辐射法合成具有缓释抗菌作用的羧甲基壳聚糖/纳米银(CMCS-Ag)抗菌剂。研究反应时间与温度对CMCS-Ag抗菌剂中纳米银生成量的影响,以较优条件制备抗菌剂并通过紫外-可见光谱、X射线衍射、透射电镜及红外光谱对抗菌剂进行结构表征,与商用纳米银进行对比测试,对CMCS-Ag抗菌剂的抗菌性能与Ag^(+)缓释性能进行评价。结果表明:羧甲基壳聚糖与银氨溶液比例为100mg∶0.4mmol时,在70℃、40min条件下制备出CMCS-Ag抗菌剂的纳米银含量最高,纳米银浓度为(1250±2.8)mg/L;CMCS-Ag抗菌剂中纳米银晶型良好且粒径较小,平均粒径为(26±0.12)nm,能够均匀地负载于CMCS网状结构中;CMCS-Ag抗菌剂对大肠杆菌最小抑菌浓度为7.81mg/L、对金黄色葡萄球菌为15.63mg/L,抗菌效果优于商用纳米银;CMCS-Ag抗菌剂240h累计Ag^(+)释放浓度为(26±0.5)μg/L,Ag^(+)释放总量低于商用纳米银,Ag^(+)缓释性能优于商用纳米银。

Sustained-released carboxymethyl chitosan/nano-silver(CMCS-Ag) antimicrobial agents were synthesized under microwave irradiation using carboxymethyl chitosan and silver ammonia solution as primary raw materials.The effects of reaction time and temperature on the amount of nano-silver production in CMCS-Ag antimicrobial agents were investigated.The antimicrobial agents were prepared under optimal conditions and structurally characterized by UV-Vis spectroscopy,XRD,transmission electron microscopy,and infrared spectroscopy.Comparative tests were conducted with commercial nano-silver to evaluate the antimicrobial performance and Ag^(+) sustained-release performance of CMCS-Ag antimicrobial agents.The results showed that when the ratio of carboxymethyl chitosan to silver ammonia solution was 100mg∶0.4mmol,CMCS-Ag antimicrobial agent with the highest nano-silver content was prepared at 70℃ and 40min with a nano-silver concentration of 1250±2.8mg/L.The nano-silver in CMCS-Ag antimicrobial agent had a good crystalline shape and small particle size,with an average particle size of 26±0.12 nm,and was uniformly loaded in the CMCS mesh structure.The minimum inhibitory concentration of CMCS-Ag was 7.81mg/L for Escherichia coli and 15.63mg/L for Staphylococcus aureus,showing better antimicrobial effect than that of commercial nano-silver.The cumulative Ag^(+) release concentration of CMCS-Ag antimicrobial agent for 240 h was 26±0.5μg/L.The total Ag^(+) release was lower than that of commercial nano-silver,and the sustained-release performance of Ag^(+) was better than that of commercial nano-silver.