超声波光催化法制备亚微米银胶体及其抑菌特性研究

Preparation of Submicron Silver Colloid by Ultrasonic Photocatalysis and Its Bacteriostatic Properties

关键词:  亚微米银胶体  高效抑菌  遗传毒性  低扩散性

Key words:  submicron silver colloid  high-efficiency bacteriostasis  genotoxicity  low diffusivity

摘要:

目的 对亚微米级银材料的遗传毒性、抑菌性能及扩散能力进行研究。方法 在超声波清洗器和高压汞灯作用下，以AgNO₃为银源、PVP为分散剂，在水溶液中反应制备银胶体。以TEM、UV-Vis、XRD进行表征分析。将胶体银设高、中、低（500，50，5 mg·L^-1）剂量组、阴性对照组（生理盐水）和阳性对照组（环磷酰胺），于同一部位（股骨）取材观察小鼠骨髓细胞微核率的变化。以土霉素、氟康唑等为阳性对照，去离子水为阴性对照，通过银胶体对痢疾杆菌、伤寒杆菌、大肠杆菌、变形杆菌、金黄色葡萄球菌、白色葡萄球菌、柠檬色葡萄球菌、枯草芽孢杆菌等8种细菌和真菌（白色念珠菌）进行抑菌圈试验，以常量肉汤稀释法进行MIC试验。结果 与阴性对照组相比较，高、中剂量组的小鼠骨髓细胞微核率明显升高，而低剂量组微核率无显著性差异，小鼠骨髓细胞微核率与银胶体浓度存在剂量关系，结果呈阳性并具有统计学意义，该银胶体呈现出剂量依赖性的遗传毒性。通过抑菌圈试验发现银胶体抑菌圈更清晰，抑菌效果更彻底。通过MIC试验发现该银胶体对白葡萄球菌的最小抑菌浓度为0.6 mg·L^-1，对白色念珠菌的最小抑菌浓度为5 mg·L^-1。结论 本试验成功制备了粒径均匀的簇状亚微米级银胶体，其作为抑菌剂，性质稳定，扩散性低，抑菌效果良好，但口服仍存在遗传毒性，不宜直接用于体内。

Abstract:

OBJECTIVE To study the genotoxicity, bacteriostasis and diffusion ability of submicron silver colloid. METHODS Under the action of ultrasonic cleaner and high pressure mercury lamp, AgNO₃ was used as silver source and PVP as dispersant to prepare silver colloid in aqueous solution. TEM, UV-Vis, XRD were used for characterization and analysis. Colloidal silver was divided into high, medium and low dose groups(500, 50, 5 mg·L^-1), negative control group(stroke- physiological saline solution) and positive control group(cyclophosphamide). The micronucleus rate of bone marrow cells in mice was observed at the same site(femur). With oxytetracycline and fluconazole used as positive control and deionized water as negative control, eight kinds of bacteria and fungi(Candida albicans) including Shigella castellani, Salmonella enterica, Escherichia coli, Proteus, Staphylococcus aureus, Staphylococcus albicans, Staphylococcus lemonis and Bacillus subtilis were tested by silver colloid. MIC was performed by constant broth dilution method. RESULTS Compared with the negative control group, the micronucleus rate of bone marrow cells in the high and medium dose groups increased significantly, but there was no significant difference in the low dose groups. There was a dose-response relationship between the micronucleus rate of bone marrow cells and the concentration of silver colloid in mice. The results were positive and statistically significant. The silver colloid showed dose-dependent genetic toxicity. The silver colloid bacteriostatic circle was found to be clearer and the bacteriostatic effect was more thorough through the bacteriostatic circle test. MIC test showed that the minimum inhibitory concentration of the silver colloid to Staphylococcus albicans was 0.6 mg·L^-1, and to Candida albicans was 5 mg·L^-1. CONCLUSION The silver colloid with uniform particle size is successfully prepared. As a bacteriostatic agent, it has stable properties and good bacteriostasis effect. However, it is not suitable for direct use in vivo because of its genotoxicity in oral administration.