Penicillin G acylase(PGA) was immobilized on the magnetic hydrophilic polymer microspheres with average pore size of 17.1 nm,specific surface area of 128.2 m2/g and saturate magnetization of 6.4 emu/g.The 96.7%ampicil...Penicillin G acylase(PGA) was immobilized on the magnetic hydrophilic polymer microspheres with average pore size of 17.1 nm,specific surface area of 128.2 m2/g and saturate magnetization of 6.4 emu/g.The 96.7%ampicillin yield with 1.60 of the synthesis/hydrolysis(S/H) ratio from 6-aminopenicillanic acid(6-APA) and D-(-)-alpha-phenylglycine methyl ester(D-PGME) can be achieved using the resultant magnetic biocatalyst in ethylene glycol,where only 82.1%yield with 1.40 of the S/H ratio was obtained using the free PGA under the identical reaction conditions.The immobilized PGA can be separated magnetically and recycled for five times without obvious loss of its catalytic activity.展开更多
目的制备载超顺磁氧化铁(SPIO)纳米粒和DiI荧光高分子微球(DiI-SPIO-PLGA),探讨其作为MRI对比剂体外巨噬细胞成像的效果和作为荧光示踪剂体外示踪巨噬细胞的可行性。方法采用双乳化法制备DiI-SPIO-PLGA微球,并检测其理化性质。培养小鼠R...目的制备载超顺磁氧化铁(SPIO)纳米粒和DiI荧光高分子微球(DiI-SPIO-PLGA),探讨其作为MRI对比剂体外巨噬细胞成像的效果和作为荧光示踪剂体外示踪巨噬细胞的可行性。方法采用双乳化法制备DiI-SPIO-PLGA微球,并检测其理化性质。培养小鼠RAW264.7巨噬细胞,与DiI-SPIO-PLGA微球共孵育12 h后行普鲁士蓝染色和荧光显微镜观察,将吞噬了微球的细胞和空白细胞分别重悬于0.5 ml 1%琼脂糖Eppendof管中,行MR扫描。结果所得样品为外壳装载SPIO颗粒和DiI荧光的微球,粒径(868.00±68.73)nm。普鲁士蓝染色结果显示,几乎所有细胞内都有蓝染颗粒分布,部分区域聚集成堆;倒置荧光显微镜下可见细胞内有大量红色微球。MRI显示吞噬了DiI-SPIO-PLGA微球的实验组管内信号显著降低,管内信号值/背景信号值明显低于对照组(P<0.05)。结论 DiI-SPIO-PLGA微球能有效加强MR成像效果,荧光信号强烈,可同时作为MRI阴性对比剂和荧光示踪剂。展开更多
基金supported by The National Basic Research Program 973 of China(No.2010CB534916)the National Natural Science Foundation of China(Nos.50662004,20564002).
文摘Penicillin G acylase(PGA) was immobilized on the magnetic hydrophilic polymer microspheres with average pore size of 17.1 nm,specific surface area of 128.2 m2/g and saturate magnetization of 6.4 emu/g.The 96.7%ampicillin yield with 1.60 of the synthesis/hydrolysis(S/H) ratio from 6-aminopenicillanic acid(6-APA) and D-(-)-alpha-phenylglycine methyl ester(D-PGME) can be achieved using the resultant magnetic biocatalyst in ethylene glycol,where only 82.1%yield with 1.40 of the S/H ratio was obtained using the free PGA under the identical reaction conditions.The immobilized PGA can be separated magnetically and recycled for five times without obvious loss of its catalytic activity.
文摘目的制备载超顺磁氧化铁(SPIO)纳米粒和DiI荧光高分子微球(DiI-SPIO-PLGA),探讨其作为MRI对比剂体外巨噬细胞成像的效果和作为荧光示踪剂体外示踪巨噬细胞的可行性。方法采用双乳化法制备DiI-SPIO-PLGA微球,并检测其理化性质。培养小鼠RAW264.7巨噬细胞,与DiI-SPIO-PLGA微球共孵育12 h后行普鲁士蓝染色和荧光显微镜观察,将吞噬了微球的细胞和空白细胞分别重悬于0.5 ml 1%琼脂糖Eppendof管中,行MR扫描。结果所得样品为外壳装载SPIO颗粒和DiI荧光的微球,粒径(868.00±68.73)nm。普鲁士蓝染色结果显示,几乎所有细胞内都有蓝染颗粒分布,部分区域聚集成堆;倒置荧光显微镜下可见细胞内有大量红色微球。MRI显示吞噬了DiI-SPIO-PLGA微球的实验组管内信号显著降低,管内信号值/背景信号值明显低于对照组(P<0.05)。结论 DiI-SPIO-PLGA微球能有效加强MR成像效果,荧光信号强烈,可同时作为MRI阴性对比剂和荧光示踪剂。
