谷胱甘肽辅助合成银纳米粒子及其抗菌活性研究

为了制备具有较好的理化性质以及抗菌活性的银纳米粒子,以硝酸银为银源,抗坏血酸为还原剂、谷胱甘肽(GSH)为模板剂,通过一步法制得谷胱甘肽-银纳米粒子(GSH-AgNPs)。此外,以GSH和硝酸银摩尔比、反应时间、pH为影响因素,以GSH-AgNPs的抗菌活性为评价指标,筛选GSH-AgNPs的最佳制备工艺。采用透射电子显微镜、傅里叶变换红外光谱仪和X射线光电子能谱仪等表征产物的形貌、光学性质和化学组成。结果表明,最佳制备条件为GSH/硝酸银摩尔比3∶5,反应体系pH=8,反应时间8h。最优条件下制备的GSH-AgNPs为高度分散的球形纳米粒,平均粒径为(3.1±0.66)nm。GSH-AgNPs表现出广谱的抗菌能力,对革兰氏阴性菌(大肠杆菌、铜绿假单胞菌)、革兰氏阳性菌(金黄色葡萄球菌、枯草芽孢杆菌)、真菌(白色念珠菌)均表现出良好的抗菌效果,其对革兰氏阴性菌和革兰氏阳性菌的最小抑制浓度均为31.25mg/mL,对真菌的最小抑菌浓度为125mg/mL。

维生素E琥珀酸酯对荷瘤小鼠相关免疫功能的影响

目的探讨维生素E琥珀酸酯(VES)对荷瘤小鼠相关免疫功能的影响。方法将人宫颈癌Hela细胞于裸鼠皮下接种,建立荷瘤小鼠模型。将24只雌性荷瘤小鼠随机分为溶剂对照组(CON)、低剂量处理组(VES40mg/kg)和高剂量处理组(VES 80mg/kg),每组8只,隔日腹腔注射入裸鼠体内、测量并观察各组荷瘤小鼠体重及生长情况,试验持续28d,试验结束后眼球取血处死。比较各组小鼠体质量、肿瘤体积和脾脏指数;ELISA法检测细胞因子TNF-α、IFN-γ、IL-10水平;Western blot法检测肿瘤组织CD47蛋白表达。结果实验第0日(D0)和D14 VES处理组(40mg/kg和80mg/kg)与对照组相比,小鼠体质量未见明显差异,实验D28VES组(40mg/kg和80mg/kg)小鼠体质量和脾脏指数均有所升高(P<0.05),肿瘤体积显著减少,VES80mg/kg组具有统计学差异(P<0.05);VES40mg/kg组和VES80mg/kg组血清细胞因子TNF-α和IFN-γ水平显著升高,IL-10水平显著降低,P<0.05,肿瘤组织CD47的翻译水平均显著降低。结论VES具有体内抑制肿瘤作用,能够引起荷瘤小鼠血清炎性因子改变,可能与免疫分子CD47相关。VES 80mg/kg组作用更明显。

Development of the CAS-LIBB single-particlemicrobeam for localizedirradiation of living cells

A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengi- neering (LIBB), Chinese Academy of Sciences (CAS). The system was designed to deliver a defined numbers of hydro- gen ions, produced by a van de Graaff accelerator, in an en- ergy range of 2.0—3.0 MeV, into an area smaller than that of the nucleus of an individual living cell. The beam is colli- mated by a borosilicate glass capillary that forms the beam-line exit. An integrated computer program recognizes the cells and locates them one by one over the microbeam exit for irradiation. We present technical details of the CAS-LIBB microbeam facility, particularly on the collimator, hardware, control program, as well as cell irradiation proto- cols available. Various factors contributing to the targeting and positioning precision are discussed along with accuracy measurement results.