【摘要】 银纳米粒子比表面积大，抗菌效力强，被广泛应用于生物医学领域，但浓度过高时存在毒性。通过双重化学改性，水相中实现高分子量壳聚糖的溶解分散，并利用邻苯二酚结构的还原稳定作用制得一种儿茶酚化/季铵化双重改性壳聚糖基复合银纳米粒子(CQCS-AgNPs),有望发挥季铵化壳聚糖和银的协同抗菌效应。核磁共振氢谱法(~1H NMR)和X射线衍射(XRD)表征证实CQCS的成功合成，季铵化度为10%,CQCS1的儿茶酚化度为15%,水中溶解度达21.5 mg/mL。透射电子显微镜(TEM)、动态光散射仪(DLS)、分光光度仪(UV)证实CQCS-AgNPs的成功制备，并具有良好的分散性和稳定性，粒径范围为3～25 nm。溶液共培养抗菌试验、抑菌圈试验和CCK-8体外细胞毒性试验证明银浓度仅为0.019 7μg/mL时的CQCS-AgNPs对革兰氏阳性菌金黄色葡萄球菌和革兰氏阴性菌大肠杆菌具有优异的抗菌性能，同时对NIH3T3细胞的毒性较小。CQCS-AgNPs有效减少99.8%的银使用量，从而降低银的毒性，可用作广谱高效低毒抗菌剂。更多还原

【Abstract】 Silver nanoparticles have large specific surface areas and strong antibacterial efficacy, which are widely used in the biomedical field, but it is toxic when the concentration is too high. The dispersion of high molecular weight chitosan was realized by double chemical modification, and catecholized and quaternized chitosan composite sliver nanoparticles（CQCS-AgNPs） were prepared by using the reduction and stability of the catechol structure, which could exert the synergistic antibacterial effect of quaternized chitosan and silver. ¹H NMR and XRD confirmed the successful synthesis of CQCS with quaternized ammonium reduction of 10%, catecholation of CQCS1 of 15%, and water solubility of up to 21.5 mg/mL. TEM, DLS, UV confirmed the successful preparation of CQCS-AgNPs, and had good dispersion and stability, with a particle size range from 3 to 25 nm. Solution co-culture antibacterial test, bacteriostatic circle test and CCK-8 in vitro cytotoxicity tests proved that CQCS-AgNPs at a silver concentration of 0.019 7 μg/mL had excellent antibacterial efficacy against both Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli, while the toxicity to NIH3T3 cells was very small. CQCS-AgNPs are expected to be used as broad-spectrum high-efficiency and low-toxicity antibacterial agents with 99.8% reduction of silver.更多还原