共查询到20条相似文献,搜索用时 15 毫秒
1.
Microarrays of single macrophage cell-based sensors were developed and demonstrated for potential real-time bacterium detection by synchrotron FTIR microscopy. The cells were patterned on gold electrodes of silicon oxide substrates by a surface engineering technique, in which the gold electrodes were immobilized with fibronectin to mediate cell adhesion and the silicon oxide background was passivated with polyethylene glycol (PEG) to resist protein adsorption and cell adhesion. Cell morphology and IR spectra of single, double, and triple cells on gold electrodes exposed to lipopolysaccharide (LPS) of different concentrations were compared to reveal the detection capability of this cell-based sensing platform. The single-cell-based system was found to generate the most significant and consistent IR spectrum shifts upon exposure to LPS, thus providing the highest detection sensitivity. Changes in cell morphology and IR shifts upon cell exposure to LPS were found to be dependent on the LPS concentration and exposure time, which established a method for the identification of LPS concentration and infected cell population. Possibility of using this single-cell system with conventional IR spectroscopy as well as its limitation was investigated by comparing IR spectra of single-cell arrays with gold electrode surface areas of 25, 100, and 400 microm2 using both synchrotron and conventional FTIR spectromicroscopes. This cell-based platform may potentially provide real-time, label-free, and rapid bacterial detection, and allow for high-throughput statistical analyses, and portability. 相似文献
2.
To elucidate the role of the community effect in cardiomyocytes, we developed an on-chip single-cell-based culture system with which the dynamics of the change of beat rate and beat rate fluctuation of cultured cardiomyocytes can be measured at the single-cell level before and after the formation of a cell network. We examined the dependence of the community effect on cell network pattern by culturing cardiomyocytes in differently shaped microchambers and investigated the relation between the network pattern and the stability of the beat rate. We found that beat rate fluctuation tends to decrease as cell-community size increases, irrespective of cell network pattern. This indicates that on-chip single-cell-based cardiomyocyte communities might be able to model a heart tissue accurately enough to be used in practical applications such as drug screening. 相似文献
3.
Impedance studies of bio-behavior and chemosensitivity of cancer cells by micro-electrode arrays 总被引:1,自引:0,他引:1
Impedimetric analysis on adherently growing cells by micro-electrodes provides information related to cell number, cell adhesion and cellular morphology. In this study, cell-based biosensor with micro-electrode arrays (MEAs) was used to monitor the culture behavior of mammalian cancer cells and evaluate the chemosensitivity of anti-cancer drugs using electrochemical impedance spectroscopy. The platinum electrode arrays were fabricated by semiconductor technology to a 10 x 10 pattern, with diameter of 80 microm of each electrode. The human oesophageal cancer cell lines (KYSE 30) were cultured on the surface of the electrodes with the pre-coated fibronectin, the connecting protein for tumor cells metastasis and adhesion in extracellular matrix. Morphology changes during cells adhesion, spreading, and proliferation can be detected by impedimetric analysis in a real time and non-invasive way. Cisplatin was added to cells for potential drug screening applications. The experimental results show that this well-known anti-cancer drug has characteristic chemosensitivity effects on KYSE 30 cells which can be detected by MEA. Thus, this cell-based chip provides a useful analytical method for cancer research. 相似文献
4.
多细胞生物体的生存依赖于不同类型细胞特异性的功能分工,不同类型的细胞尽管基因组相同,但有其独特的发育过程和应对环境变化的能力。生物学的一大挑战就是揭示基因如何在正确的位置、正确的时间表达到正确的水平,最近出现了很多通过细胞类型特异性方法研究单细胞组学的工具,这些新技术使我们能通过空前分辨率,理解多细胞生物体内不同类型的单个细胞基因表达特点及其适应环境变化的机制。单细胞样品的获取一直是单细胞研究的一大技术瓶颈,因此本文将以如何获得起始材料为重点,探讨单细胞研究的样品标记、单细胞分离及获取、组学数据分析和结果验证等技术方法及其在植物研究中的应用。 相似文献
5.
Cline Barlier Diego Barriales Alexey Samosyuk Sascha Jung Srikanth Ravichandran Yulia A. Medvedeva Juan Anguita Antonio del Sol 《Cell death & disease》2021,12(9)
Immunomodulation strategies are crucial for several biomedical applications. However, the immune system is highly heterogeneous and its functional responses to infections remains elusive. Indeed, the characterization of immune response particularities to different pathogens is needed to identify immunomodulatory candidates. To address this issue, we compiled a comprehensive map of functional immune cell states of mouse in response to 12 pathogens. To create this atlas, we developed a single-cell-based computational method that partitions heterogeneous cell types into functionally distinct states and simultaneously identifies modules of functionally relevant genes characterizing them. We identified 295 functional states using 114 datasets of six immune cell types, creating a Catalogus Immune Muris. As a result, we found common as well as pathogen-specific functional states and experimentally characterized the function of an unknown macrophage cell state that modulates the response to Salmonella Typhimurium infection. Thus, we expect our Catalogus Immune Muris to be an important resource for studies aiming at discovering new immunomodulatory candidates.Subject terms: Immunology, Cell death and immune response 相似文献
6.
Asphahani F Thein M Veiseh O Edmondson D Kosai R Veiseh M Xu J Zhang M 《Biosensors & bioelectronics》2008,23(8):1307-1313
Impedance measurements of cell-based sensors are a primary characterization route for detection and analysis of cellular responses to chemical and biological agents in real time. The detection sensitivity and limitation depend on sensor impedance characteristics and thus on cell patterning techniques. This study introduces a cell patterning approach to bind cells on microarrays of gold electrodes and demonstrates that single-cell patterning can substantially improve impedance characteristics of cell-based sensors. Mouse fibroblast cells (NIH3T3) are immobilized on electrodes through a lysine-arginine-glycine-aspartic acid (KRGD) peptide-mediated natural cell adhesion process. Electrodes are made of three sizes and immobilized with either covalently bound or physically adsorbed KRGD (c-electrodes or p-electrodes). Cells attached to c-electrodes increase the measurable electrical signal strength by 48.4%, 24.2%, and 19.0% for three electrode sizes, respectively, as compared to cells attached to p-electrodes, demonstrating that both the electrode size and surface chemistry play a key role in cell adhesion and spreading and thus the impedance characteristics of cell-based sensors. Single cells patterned on c-electrodes with dimensions comparable to cell size exhibit well-spread cell morphology and substantially outperform cells patterned on electrodes of other configurations. 相似文献
7.
Yasuda K 《Journal of molecular recognition : JMR》2004,17(3):186-193
We have developed an on-chip single-cell based microcultivation method for analyzing the variability of genetic information stored in single cells and their epigenetic correlations. The method uses four systems: an on-chip cell sorter for purifying the cells in a non-destructive manner; an on-chip single-cell cultivation chip for isolating single cells; an on-chip agarose microchamber system for constructive cell-cell network formation during cultivation; and an on-chip single-cell-based expression analysis system. Using these systems, we could measure the variability of prokaryotic cells and eukaryotic cells having the same DNA and found that, although prokaryotic cells have a large variability in their interdivision times, sister eukaryotic cells having the same DNA synchronized well. We also measured the dynamics of synchronization of beating cardiac myocytes and found that two isolated cells synchronize by one cell following the other after a short pause in beating. These results showed the potential of the on-chip microcultivation method's constructive approach to analyzing cell systems. 相似文献
8.
Embryonic stem cells (ESCs) are permanent cell lines that can be maintained in a pluripotent, undifferentiated state. Appropriate environmental stimuli can cause them to differentiate into cell types of all three germ layers both in vitro and in vivo. Embryonic stem cells bear many opportunities for clinical applications in tissue engineering and regenerative medicine. Whereas most of our knowledge on the biology and technology of ESCs is derived from studies with mouse cells, large animal models mimicking important aspects of human anatomy, physiology, and pathology more closely than mouse models are urgently needed for studies evaluating the safety and efficacy of cell therapies. The dog is an excellent model for studying human diseases, and the availability of canine ESCs would open new possibilities for this model in biomedical research. In addition, canine ESCs could be useful for the development of cell-based approaches for the treatment of dogs. Here, we discuss the features of recently reported canine embryo-derived cells and their potential applications in basic and translational biomedical research. 相似文献
9.
The ability to research individual cells has been seen as important in many kinds of biological studies. In the present study, cell impedance analysis is integrated into a single-cell trapping structure. For the purpose of precise positioning, a cell manipulation and measurement microchip, which uses an alternating current electrothermal effect (ACET) and a negative dielectrophoresis (nDEP) force to move a particle and cell on measurement electrodes, is developed. An ACET and an nDEP can be easily combined with subsequent analyses based on electric fields. A microwell presented in a previous study is separated into two parts, which are regarded as the measurement electrodes. The original structure is modified for precise positioning. Numerical simulations and analyses are conducted to compute and analyze the effects of the structural parameters. The results of simulations and analyses are used to obtain the optimum structure for the cell. The capture range of the microwell can be designed for cells of various sizes. In order to demonstrate the precision of the positioning, a particle is captured, measured, and released twice. The results show that the impedance error of the particle is about 3%. Finally, the developed structure is applied to trap and measure the impedance of a HeLa cell. 相似文献
10.
The heterogeneity properties shown by cells or unicellular organisms have led to the development of analytical methods at the single-cell level. In this sense, considering the importance of trace elements in these biological systems, the inductively coupled plasma mass spectrometer (ICP-MS) configured for analyzing single cell has presented a high potential to assess the evaluation of elements in cells. Moreover, advances in instrumentation, such as coupling laser ablation to the tandem configuration (ICP-MS/MS), or alternative mass analyzers (ICP-SFMS and ICP-TOFMS), brought significant benefits, including sensitivity improvement, high-resolution imaging, and the cell fingerprint. From this perspective, the single-cell ICP-MS has been widely reported in studies involving many fields, from oncology to environmental research. Hence, it has contributed to finding important results, such as elucidating nanoparticle toxicity at the cellular level and vaccine development. Therefore, in this review, the theory of single-cell ICP-MS analysis is explored, and the applications in this field are pointed out. In addition, the instrumentation advances for single-cell ICP-MS are addressed. 相似文献
11.
Thierry Voet Parveen Kumar Peter Van Loo Susanna L. Cooke John Marshall Meng-Lay Lin Masoud Zamani Esteki Niels Van der Aa Ligia Mateiu David J. McBride Graham R. Bignell Stuart McLaren Jon Teague Adam Butler Keiran Raine Lucy A. Stebbings Michael A. Quail Thomas D’Hooghe Yves Moreau P. Andrew Futreal Michael R. Stratton Joris R. Vermeesch Peter J. Campbell 《Nucleic acids research》2013,41(12):6119-6138
The nature and pace of genome mutation is largely unknown. Because standard methods sequence DNA from populations of cells, the genetic composition of individual cells is lost, de novo mutations in cells are concealed within the bulk signal and per cell cycle mutation rates and mechanisms remain elusive. Although single-cell genome analyses could resolve these problems, such analyses are error-prone because of whole-genome amplification (WGA) artefacts and are limited in the types of DNA mutation that can be discerned. We developed methods for paired-end sequence analysis of single-cell WGA products that enable (i) detecting multiple classes of DNA mutation, (ii) distinguishing DNA copy number changes from allelic WGA-amplification artefacts by the discovery of matching aberrantly mapping read pairs among the surfeit of paired-end WGA and mapping artefacts and (iii) delineating the break points and architecture of structural variants. By applying the methods, we capture DNA copy number changes acquired over one cell cycle in breast cancer cells and in blastomeres derived from a human zygote after in vitro fertilization. Furthermore, we were able to discover and fine-map a heritable inter-chromosomal rearrangement t(1;16)(p36;p12) by sequencing a single blastomere. The methods will expedite applications in basic genome research and provide a stepping stone to novel approaches for clinical genetic diagnosis. 相似文献
12.
J D Lathia M Hitomi J Gallagher S P Gadani J Adkins A Vasanji L Liu C E Eyler J M Heddleston Q Wu S Minhas A Soeda D J Hoeppner R Ravin R D G McKay R E McLendon D Corbeil A Chenn A B Hjelmeland D M Park J N Rich 《Cell death & disease》2011,2(9):e200
Malignant gliomas contain a population of self-renewing tumorigenic stem-like cells; however, it remains unclear how these glioma stem cells (GSCs) self-renew or generate cellular diversity at the single-cell level. Asymmetric cell division is a proposed mechanism to maintain cancer stem cells, yet the modes of cell division that GSCs utilize remain undetermined. Here, we used single-cell analyses to evaluate the cell division behavior of GSCs. Lineage-tracing analysis revealed that the majority of GSCs were generated through expansive symmetric cell division and not through asymmetric cell division. The majority of differentiated progeny was generated through symmetric pro-commitment divisions under expansion conditions and in the absence of growth factors, occurred mainly through asymmetric cell divisions. Mitotic pair analysis detected asymmetric CD133 segregation and not any other GSC marker in a fraction of mitoses, some of which were associated with Numb asymmetry. Under growth factor withdrawal conditions, the proportion of asymmetric CD133 divisions increased, congruent with the increase in asymmetric cell divisions observed in the lineage-tracing studies. Using single-cell-based observation, we provide definitive evidence that GSCs are capable of different modes of cell division and that the generation of cellular diversity occurs mainly through symmetric cell division, not through asymmetric cell division. 相似文献
13.
Cell-specific targeting of nanoparticles by multivalent attachment of small molecules 总被引:1,自引:0,他引:1
Nanomaterials with precise biological functions have considerable potential for use in biomedical applications. Here we investigate whether multivalent attachment of small molecules can increase specific binding affinity and reveal new biological properties of such nanomaterials. We describe the parallel synthesis of a library comprising 146 nanoparticles decorated with different synthetic small molecules. Using fluorescent magnetic nanoparticles, we rapidly screened the library against different cell lines and discovered a series of nanoparticles with high specificity for endothelial cells, activated human macrophages or pancreatic cancer cells. Hits from the last-mentioned screen were shown to target pancreatic cancer in vivo. The method and described materials could facilitate development of functional nanomaterials for applications such as differentiating cell lines, detecting distinct cellular states and targeting specific cell types. 相似文献
14.
新兴的单细胞测序技术能够从单细胞水平揭示基因组、转录组和表观遗传学等分子水平发生的基因变异与表观修饰状态,也可用于鉴定新的细胞类型和表面标记物。这将帮助人们探明疾病发生时细胞基因、转录或表观修饰方面的变化,了解细胞之间的联系,以及深入理解肿瘤异质性。目前,单细胞测序技术已用于多种疾病的研究,其在肝脏疾病,包括肝硬化、肝癌中已有相关成果。于此,综述了单细胞测序技术在肝脏发育及肝病中的应用,讨论了肝脏疾病发生的内在机制以及该技术仍存在的问题,提出可能的解决方案,如发展三维单细胞测序技术将更能帮助人们深刻理解肝脏疾病发生机制。 相似文献
15.
Cell migration is crucial for both physiological and pathological processes. Current in vitro cell motility assays suffer from various drawbacks, including insufficient temporal and/or optical resolution, or the failure to include a controlled chemotactic stimulus. Here, we address these limitations with a migration chamber that utilizes a self-sustaining chemotactic gradient to induce locomotion through confined environments that emulate physiological settings. Dynamic real-time analysis of both population-scale and single-cell movement are achieved at high resolution. Interior surfaces can be functionalized through adsorption of extracellular matrix components, and pharmacological agents can be administered to cells directly, or indirectly through the chemotactic reservoir. Direct comparison of multiple cell types can be achieved in a single enclosed system to compare inherent migratory potentials. Our novel microfluidic design is therefore a powerful tool for the study of cellular chemotaxis, and is suitable for a wide range of biological and biomedical applications. 相似文献
16.
Factor VIII related antigen (F VIII RAg) is localized in the cytoplasm of vascular endothelial cells. In this study, endothelial cells in frozen lung sections of Fischer-344 rat lungs were surveyed for F VIII RAg using a commercially available primary antibody against human F VIII RAg and an immunofluorescence assay. Rat pulmonary endothelial cells were positively labeled for F VIII RAg, whereas other lung cell types were not. Immunohistologic staining of F VIII RAg is useful in the rat model for identifying pulmonary endothelial cells in lung sections, and may be of use for detecting changes in lung endothelial cells due to environmental insults. 相似文献
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Edith Sch?fer Marco Tarantola Elena Polo Christian Westendorf Noriko Oikawa Eberhard Bodenschatz Burkhard Geil Andreas Janshoff 《PloS one》2013,8(1)
Chemotactic responses of Dictyostelium discoideum cells to periodic self-generated signals of extracellular cAMP comprise a large number of intricate morphological changes on different length scales. Here, we scrutinized chemotaxis of single Dictyostelium discoideum cells under conditions of starvation using a variety of optical, electrical and acoustic methods. Amebas were seeded on gold electrodes displaying impedance oscillations that were simultaneously analyzed by optical video microscopy to relate synchronous changes in cell density, morphology, and distance from the surface to the transient impedance signal. We found that starved amebas periodically reduce their overall distance from the surface producing a larger impedance and higher total fluorescence intensity in total internal reflection fluorescence microscopy. Therefore, we propose that the dominant sources of the observed impedance oscillations observed on electric cell-substrate impedance sensing electrodes are periodic changes of the overall cell-substrate distance of a cell. These synchronous changes of the cell-electrode distance were also observed in the oscillating signal of acoustic resonators covered with amebas. We also found that periodic cell-cell aggregation into transient clusters correlates with changes in the cell-substrate distance and might also contribute to the impedance signal. It turned out that cell-cell contacts as well as cell-substrate contacts form synchronously during chemotaxis of Dictyostelium discoideum cells. 相似文献
20.
Charybdotoxin blocks voltage-gated K+ channels in human and murine T lymphocytes 总被引:15,自引:5,他引:10
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A variety of scorpion venoms and purified toxins were tested for effects on ion channels in human T lymphocytes, a human T leukemia cell line (Jurkat), and murine thymocytes, using the whole-cell patch-clamp method. Nanomolar concentrations of charbdotoxin (CTX), a purified peptide component of Leiurus quinquestriatus venom known to block Ca2+-activated K+ channels from muscle, blocked "type n" voltage-gated K+ channels in human T lymphoid cells. The Na+ channels occasionally expressed in these cells were unaffected by the toxin. From the time course of development and removal of K+ channel block we determined the rates of CTX binding and unbinding. CTX blocks K+ channels in Jurkat cells with a Kd value between 0.5 and 1.5 nM. Of the three types of voltage-gated K+ channels present in murine thymocytes, types n and n' are blocked by CTX at nanomolar concentrations. The third variety of K+ channels, "type l," is unaffected by CTX. Noxiustoxin (NTX), a purified toxin from Centruroides noxius known to block Ca2+-activated K+ channels, also blocked type n K+ channels with a high degree of potency (Kd = 0.2 nM). In addition, several types of crude scorpion venoms from the genera Androctonus, Buthus, Centruroides, and Pandinus blocked type n channels. We conclude that CTX and NTX are not specific for Ca2+ activated K+ channels and that purified scorpion toxins will provide useful probes of voltage-gated K+ channels in T lymphocytes. The existence of high-affinity sites for scorpion toxin binding may help to classify structurally related K+ channels and provide a useful tool for their biochemical purification. 相似文献