title: A Sensitive and simple macrophage-based electrochemical biosensor for evaluating lipopolysaccharide cytotoxicity of pathogenic bacteria.
abstract: In this study, a sensitive and simple electrochemical murine macrophage (Ana-1) cell sensor has been developed for early detection of lipopolysaccharides (LPS) to evaluate the toxicity of pathogenic bacteria. Magnetic glassy carbon electrode (MGCE), which possesses excellent reproducibility and regeneration qualities, was modified with a nanocomposite to improve electrochemical signals and enhance the sensitivity. The synthesized magnetic nanoparticles (MNPs) were internalized into murine macrophages, which completed the immobilization of macrophages onto the modified electrode for evaluating the cytotoxicity of LPS by electrochemical impedance spectroscopy (EIS). The MNPs facilitated reusability of the proposed sensor by allowing removal of the magnetic core from the electrode. Our results indicated that LPS caused a marked decrease in electrochemical impedance in a dose-dependent manner in range of 1-5μg/mL. By SEM, we found that microvilli on the plasma membrane became scarce and the membrane became smooth on cells incubated with LPS, which lessens the absorption of cells to reduce the impedance. And biological assay indicated that EIS patterns were correlated with the calcium concentration in cells, and suggested that [Ca(2+)]i production increased in cells incubated with LPS and its mobilization altered electrochemical signals. Compared with conventional methods, this electrochemical test is inexpensive, highly sensitive, and has a quick response, and thus provides a new avenue for evaluating the cytotoxicity of pathogens.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address: m15190278768@163.com.
authors.forename: Xiumei
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Dairy Biotechnology, Dairy Research institute, Bright Dairy & Food Co., Ltd., Shanghai 200436, PR China.
authors.forename: Pei
authors.initials: P
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Fuwei
authors.initials: F
authors.lastname: Pi
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Zhangjiagang Entry-Exit Inspection and Quarantine Bureau, Zhangjiagang, Jiangsu 215600, China.
authors.forename: Jingdong
authors.initials: J
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Yinzhi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address: sxlzzz@jiangnan.edu.cn.
authors.forename: Xiulan
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000191:economics / Q000295:instrumentation*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D018914:Cells, Immobilized / Q000166:cytology / Q000187:drug effects; D058266:Dielectric Spectroscopy / Q000191:economics / Q000295:instrumentation*; D004867:Equipment Design; D008070:Lipopolysaccharides / Q000633:toxicity*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008280:Magnetics / Q000295:instrumentation; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D051379:Mice; D015203:Reproducibility of Results; D018675:Toxicity Tests / Q000191:economics / Q000295:instrumentation
chemical_list: D008070:Lipopolysaccharides; D058185:Magnetite Nanoparticles; D002118:Calcium
keywords: Ana-1 cells; EIS; LPS Of pathogenic bacteria; MNPs; MWNT-GNP/Chi/MGCE