The liquid crystal elastomeric microspheres real time monitoring of single – living cells to release hydrogen peroxide

液晶弹性体微球实时监测单-活细胞释放的过氧化氢 The research shows that hydrogen peroxide (H2O2) is one of the molecular diffusion of cancer cells freely, is considered important for understanding important physiological and pathological cells in cell signaling molecule. Wherein the normal level of H2O2 physiological balance between the production and catabolism. However, H2O2 levels in cancer cells significantly increased, H2O2 viable cells to diffuse from the cell membrane. Therefore, real-time monitoring of live cells to release H2O2 is important to understand the behavior and heterogeneity between tumor cells. However, currently the quantitative and distinguishing living cells released from H2O2 is also challenging because it has a fast diffusion, and diluted to a natural decomposition characteristics of ultralow concentration in the extracellular microenvironment. Although the use of electrochemical, colorimetric analysis and chemiluminescence method or the like can be detected by H2O2, but for better biocompatibility, more simple signal probe prepared, the diffusion distance is shorter and less background interference detection techniques need further studies. Based on this, Tsinghua University Professor LIN Jin-Ming and the National Center for Nanoscience of Lin Ling (co-author) jointly reported [ 123] a liquid crystal functionalized elastomeric microspheres (LCEM-HRP) using horseradish peroxidase (the HRP), which may be directly fixed on the cell membrane, thereby releasing the single cell level real-time monitoring of H2O2 [123 ]. LCEM-HRP can be reported to the radial H2O2 (CR) deformed by the same center, which is due to the catalytic reduction of H2O2 by HRP in LCEM-HRP caused by deprotonation and medium chain or between intrachain hydrogen bond breaking LCEM-HRP due. Wherein the level of deformation LCEM-HRP show different amounts of H2O2 released from the cell. In the detection time of 10 min, fixed on the estimated detection sensitivity LCEM-HRP cells was ~2.2 × 10 -7 μM. In addition, researchers explored the heterogeneity of cell lines and cells from a different configuration of LCEM-HRP. In short, LCEM-HRP released from the living cells by in situ monitoring of real-time imaging is provided a new method for H2O2, and may find a basis for more advanced cellular microenvironment chemical probes of various signaling molecules imaged. The research results entitled \”Monitoring H2O2 on the Surface of Single Cells with Liquid Crystal Elastomer Microspheres \”published in internationally renowned journals Angew. Chem. Int. Ed. on. [Graphic Explanation]

first, researchers dissolving liquid crystal diacrylate (2-methyl-1,4-phenylene bis (4 – (((acryloyloxy) hexyl) oxy) benzoate ester) (RM82), E7 7- suberic acid (LC) in (7OAc) monomers and azobisisobutyronitrile (AIBN) synthesis of about 2 μm and natural radial configuration LCEM diameter. Next, horseradish peroxidase (HRP) liquid crystal elastomeric microspheres (LCEM) chemically modified form LCEM-HRP, and is directly fixed on the cell membrane to release the real-time monitoring of single living cells from H2O2. LCEM and Similarly, LCEM-HRP solution at pH = 7.4 (de-ionized water, DIW), and cell culture medium (MEM) exhibit radial configuration. If HRP (HRPrhd) by binding a fluorescent dye to the rhodamine-labeled LCEM ( LCEM-HRPrhd on), it may be determined HRP immobilized on LCEM.

FIG. 1, the working principle LCEM-HRP and characterization of 液晶弹性体微球实时监测单-活细胞释放的过氧化氢
Subsequently, researchers at pH = under 6.7, different H2O2 concentrations (0.5-5 M) was found to have LCEM LCEM-HRP and responsive in this pH, LCEM LCEM-HRP and exhibited concentric configuration. However, the CH2O2 0.5 M LCEM-HRP was observed at a slight deformation in the radial concentric, in CH2O2> 0.5 M radial configuration when more apparent in the CH2O2 = 1.2 M, LCEM concentric configuration is retained and displayed LCEM-HRP CR modification. spectroscopy the case LCEM-HRP generates radical oxygen species (ROS) in the presence of H2O2 by electron spin resonance (ESR). from H2O2 + HRP and H2O2 + LCEM +HRP was observed DMPO-OH and DMPO-OOH The ESR signal, and in the presence of LCEM-HRP and H2O2, • OH significant signal quenching. The LCEM-HRP pH = 6.7 was placed in the H2O2 (1.2 M) solution, to evaluate its reversible deformation. After the addition of H2O2, LCEM-HRP initial configuration to a radially concentric configuration.
FIG 2, LCEM-HRP response of H2O2 液晶弹性体微球实时监测单-活细胞释放的过氧化氢
Then, researchers LCEM LCEM-HRP or dispersed in a cell culture medium (MEM) and allowed to fixed cells in the microchannel. Initially, LCEM-HRP on HUVEC cells also exhibit a radial configuration, exhibit a concentric configuration in A549, U87 and HepG-2 cells. However, LCEM-HRP did not maintain their concentric configuration, the analysis time for the next 10 min, were observed in the modified C-R A549, U87 and HepG-2 cells. LCEM LCEM-HRP and retains its configuration at the radially HUVEC cells, whereas in U87, A549 and HepG-2 cells was observed in the initial rapid R-C modification. Therefore, this modification is due to the R-C acidic environment caused by tumor cells. LCEM maintain their concentric configuration on tumor cells, whereas LCEM-HRP over time exhibit reverse C-R deformation. Such modification is C-R due to the reduced HRP catalyzed H2O2 released from the cells caused. Further, since the anabolic changes, other signaling molecules are also released from tumor cells, in order to meet the high demand for the biosynthesis of cell proliferation.
FIG. 3, LCEM-HRP immobilized on the membrane of various images at different times POM 液晶弹性体微球实时监测单-活细胞释放的过氧化氢
found that real-time monitoring of release of molecules from living cells can improve the targeting signal disease and learn about new treatments and diagnostic methods. Thus, researchers analyze the differences between the different cell lines up to 100 LCEM-HRP on a single-cell configuration within 10 min. Statistical analysis showed that different cell lines of H2O2 release of a significant difference. LCEM-HRP into a shape concentric to the initial pre-concentric, radial and radial pre four stages. A549,14% 72%The U87 and only 2% of HepG-2 cells released H2O2 enough to bring the complete C-R deformation. These results indicate that, LCEM-HRP provides a reliable way to analyze live cells released from H2O2, and drawn Cell lines and cell – cell heterogeneity FIG.
FIG 4, LCEM-HRP cell line and for mapping between cellular heterogeneity 液晶弹性体微球实时监测单-活细胞释放的过氧化氢

[summary]

Summing described later, LCEM-HRP provides a reliable method of H2O2 in situ detection in real-time imaging of single cell resolution released from living cells. LCEM-HRP explored the same heterogeneity between different cell surface of tumor cell lines. LCEM-HRP endocytosis does not occur, and therefore can be easily fixed on the cell membrane, having a high biocompatibility, low operating costs, high sensitivity and shorter analysis time (10 min). Further, LCEM-HRP can be the basis for the pursuit of more advanced chemical molecular probes to monitor the various imaging signals from living cells. Document Link: Monitoring H 2 O 2 on the Surface of Single Cells with Liquid Crystal Elastomer Microspheres (… Angew Chem Int Ed, 2020, DOI:. 10.1002 / anie.202004326)

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