scholarly journals Stable and Reversible Functionalization of the Native Phosphate Groups on Live Cells

2018 ◽  
Author(s):  
Joydeb Majumder ◽  
Gaurav Chopra
Keyword(s):  
Cell Membrane ◽  
Cell Surface ◽  
Surface Engineering ◽  
Live Cell ◽  
Live Cells ◽  
General Strategy ◽  
Cell Surfaces ◽  
Covalent Bonds ◽  
Phosphate Groups

AbstractSurface modification of live cells has important biomedical and therapeutic applications. Current methods to label cells require artificial cell surface engineering (via metabolic, docking or anchoring methods) before conjugative chemistries, which is not always trivial to accomplish and/or not appropriate for multiple cell types. A new method without the need of initial cell surface anchoring will greatly facilitate live cell surface labelling. Herein, we provide a general strategy for live cell functionalization that utilizes the native phosphate groups on every cell. We have designed a dual conjugation cargo molecule with a cationic side chain for non-covalent bonds with the negatively-charged cell surface and a phosphoric acid containing ligand for covalent bonding with the cell membrane phospholipid phosphate. Our dual conjugation strategy on live cell surfaces is non-toxic with enhanced stability to functionalize live cells. This provides a stable, reversible and reusable reagent with direct conjugation strategy to image live cell membranes.SignificanceThe ability to label live cell surfaces has many applications ranging fromin vivomonitoring of cell populations to diagnostics and use of cells as drugs. Thus far, most reported strategies to label cell surfaces are not broadly applicable or easy to use for any cell type as it has relied on engineering cells with artificial moieties or conjugations that may affect cellular function. We provide a general solution to this long-standing problem by developing two-sided functionalization of the phosphate moieties that are ubiquitous on all cells. We show one application of our chemical strategy as a general-purpose live-cell membrane imaging reagent with long-time stability. Our strategy is broadly applicable to imaging, sensing, drug delivery, bioengineering, diagnostics and cell therapy.

scholarly journals Stable and Reversible Functionalization of the Native Phosphate Groups on Live Cells

2018 ◽  
Author(s):  
Joydeb Majumder ◽  
Gaurav Chopra
Keyword(s):  
Label Cell ◽  
General Purpose ◽  
Live Cell ◽  
Live Cells ◽  
Cell Type ◽  
Cell Surfaces ◽  
Long Time ◽  
Chemical Strategy ◽  
Phosphate Groups

The ability to label live cell surfaces has many applications ranging from in vivo monitoring of cell populations to diagnostics and use of cells as drugs. Thus far, most reported strategies to label cell surfaces are not broadly applicable or easy to use for any cell type as it has relied on engineering cells with artificial moieties or conjugations that may affect cellular function. We provide a general solution to this long-standing problem by developing two-sided functionalization of the phosphate moieties that are ubiquitous on all cells. We show one application of our chemical strategy as a general-purpose live-cell membrane imaging reagent with long-time stability. Our strategy is broadly applicable to imaging, sensing, drug delivery, bioengineering, diagnostics and cell therapy.<br>

scholarly journals Stable and Reversible Functionalization of the Native Phosphate Groups on Live Cells

2018 ◽  
Author(s):  
Joydeb Majumder ◽  
Gaurav Chopra
Keyword(s):  
Label Cell ◽  
General Purpose ◽  
Live Cell ◽  
Live Cells ◽  
Cell Type ◽  
Cell Surfaces ◽  
Long Time ◽  
Chemical Strategy ◽  
Phosphate Groups

The ability to label live cell surfaces has many applications ranging from in vivo monitoring of cell populations to diagnostics and use of cells as drugs. Thus far, most reported strategies to label cell surfaces are not broadly applicable or easy to use for any cell type as it has relied on engineering cells with artificial moieties or conjugations that may affect cellular function. We provide a general solution to this long-standing problem by developing two-sided functionalization of the phosphate moieties that are ubiquitous on all cells. We show one application of our chemical strategy as a general-purpose live-cell membrane imaging reagent with long-time stability. Our strategy is broadly applicable to imaging, sensing, drug delivery, bioengineering, diagnostics and cell therapy.<br>

A thin hydrogel barrier linked onto cell surface sialic acids through covalent bonds induces cancer cell death in vivo

2020 ◽  
Vol 8 (2) ◽  
pp. 577-585 ◽  
Author(s):  
Kimika Ono ◽  
Yuka Sanada ◽  
Yuka Kimura ◽  
Seika Aoyama ◽  
Natsumi Ueda ◽  
...  
Keyword(s):  
Cell Death ◽  
Sialic Acid ◽  
Cell Surface ◽  
Cancer Cell ◽  
Sialic Acids ◽  
Cell Surfaces ◽  
Covalent Bonds ◽  
Novel Technique ◽  
Cancer Cell Death

A novel technique to form a thin hydrogel barrier on aberrantly expressed sialic acid residues on cancer cell surfaces was developed.

scholarly journals Monomer–dimer dynamics and distribution of GPI-anchored uPAR are determined by cell surface protein assemblies

2007 ◽  
Vol 179 (5) ◽  
pp. 1067-1082 ◽  
Author(s):  
Valeria R. Caiolfa ◽  
Moreno Zamai ◽  
Gabriele Malengo ◽  
Annapaola Andolfo ◽  
Chris D. Madsen ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Cell Surface ◽  
Plasminogen Activator ◽  
Fluorescent Protein ◽  
Surface Protein ◽  
Basal Membrane ◽  
Membrane Dynamics ◽  
Live Cells ◽  
Cell Surface Protein ◽  
Protein Assemblies

To search for functional links between glycosylphosphatidylinositol (GPI) protein monomer–oligomer exchange and membrane dynamics and confinement, we studied urokinase plasminogen activator (uPA) receptor (uPAR), a GPI receptor involved in the regulation of cell adhesion, migration, and proliferation. Using a functionally active fluorescent protein–uPAR in live cells, we analyzed the effect that extracellular matrix proteins and uPAR ligands have on uPAR dynamics and dimerization at the cell membrane. Vitronectin directs the recruitment of dimers and slows down the diffusion of the receptors at the basal membrane. The commitment to uPA–plasminogen activator inhibitor type 1–mediated endocytosis and recycling modifies uPAR diffusion and induces an exchange between uPAR monomers and dimers. This exchange is fully reversible. The data demonstrate that cell surface protein assemblies are important in regulating the dynamics and localization of uPAR at the cell membrane and the exchange of monomers and dimers. These results also provide a strong rationale for dynamic studies of GPI-anchored molecules in live cells at steady state and in the absence of cross-linker/clustering agents.

scholarly journals Probe for the measurement of cell surface pH in vivo and ex vivo

2016 ◽  
Vol 113 (29) ◽  
pp. 8177-8181 ◽  
Author(s):  
Michael Anderson ◽  
Anna Moshnikova ◽  
Donald M. Engelman ◽  
Yana K. Reshetnyak ◽  
Oleg A. Andreev
Keyword(s):  
Cell Surface ◽  
Tumor Cell ◽  
Cancer Cells ◽  
Metastatic Cancer ◽  
Surface Acidity ◽  
Measurement Tool ◽  
Mouse Tumor ◽  
Cell Surfaces ◽  
Surface Ph

We have developed a way to measure cell surface pH by positioning a pH-sensitive fluorescent dye, seminaphtharhodafluor (SNARF), conjugated to the pH low insertion peptide (pHLIP). It has been observed that many diseased tissues are acidic and that tumors are especially so. A combination of effects acidifies tumor cell interiors, and cells pump out lactic acid and protons to maintain intracellular pH, acidifying the extracellular space. Overexpression of carbonic anhydrases on cell surfaces further contributes to acidification. Thus, the pH near tumor cell surfaces is expected to be low and to increase with distance from the membrane, so bulk pH measurements will not report surface acidity. Our new surface pH-measurement tool was validated in cancer cells grown in spheroids, in mouse tumor models in vivo, and in excised tumors. We found that the surface pH is sensitive to cell glycolytic activity: the pH decreases in high glucose and increases if glucose is replaced with nonmetabolized deoxyglucose. For highly metastatic cancer cells, the pH measured at the surface was 6.7–6.8, when the surrounding external pH was 7.4. The approach is sensitive enough to detect 0.2–0.3 pH unit changes in vivo in tumors induced by i.p. injection of glucose. The pH at the surfaces of highly metastatic cells within tumors was found to be about 6.1–6.4, whereas in nonmetastatic tumors, it was 6.7–6.9, possibly creating a way to distinguish more aggressive from less aggressive tumors. Other biological roles of surface acidity may be found, now that targeted measurements are possible.

Ligand-displacement-based two-photon fluorogenic probe for visualizing mercapto biomolecules in live cells, Drosophila brains and zebrafish

The Analyst ◽  
2018 ◽  
Vol 143 (14) ◽  
pp. 3433-3441 ◽  
Author(s):  
Yanfei Zhao ◽  
Yun Ni ◽  
Liulin Wang ◽  
Chenchen Xu ◽  
Chenqi Xin ◽  
...  
Keyword(s):  
Rapid Detection ◽  
Live Cell ◽  
Live Cells ◽  
Two Photon ◽  
Ligand Displacement ◽  
Cell Tissue ◽  
Fluorogenic Probe ◽  
Displacement Based

We report the Fe(iii)-based complex TPFeS which acts as a novel ligand-displacement-based TP fluorogenic probe for the rapid detection of mercapto biomolecules both in vitro and in live cell/tissue/in vivo imaging.

scholarly journals Nanoarchitectonics meets cell surface engineering: shape recognition of human cells by halloysite-doped silica cell imprints

2019 ◽  
Vol 10 ◽  
pp. 1818-1825 ◽  
Author(s):  
Elvira Rozhina ◽  
Ilnur Ishmukhametov ◽  
Svetlana Batasheva ◽  
Farida Akhatova ◽  
Rawil Fakhrullin
Keyword(s):  
Cell Surface ◽  
Hela Cells ◽  
Surface Engineering ◽  
Human Cells ◽  
Live Cells ◽  
Liquid Media ◽  
Cell Surface Engineering ◽  
Produce Cell ◽  
Silica Cell ◽  
Clay Nanotubes

Cell surface engineering, as a practical manifestation of nanoarchitectonics, is a powerful tool to modify and enhance properties of live cells. In turn, cells may serve as sacrificial templates to fabricate cell-mimicking materials. Herein we report a facile method to produce cell-recognising silica imprints capable of the selective detection of human cells. We used HeLa cells to template silica inorganic shells doped with halloysite clay nanotubes. The shells were destroyed by sonication resulting in the formation of polydisperse hybrid imprints that were used to recognise HeLa cells in liquid media supplemented with yeast. We believe that methodology reported here will find applications in biomedical and clinical research.

scholarly journals PinMol: Python application for designing molecular beacons for live cell imaging of endogenous mRNAs

2018 ◽  
Author(s):  
Livia V. Bayer ◽  
Omar S. Omar ◽  
Diana P. Bratu ◽  
Irina E. Catrina
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Molecular Beacon ◽  
Structural Information ◽  
Live Cell ◽  
Molecular Beacons ◽  
Intramolecular Interactions ◽  
Live Cells ◽  
Target Rna

ABSTRACTMolecular beacons are nucleic acid oligomers labeled with a fluorophore and a quencher that fold in a hairpin-shaped structure, which fluoresce only when bound to their target RNA. They are used for the visualization of endogenous mRNAs in live cells. Here, we report a Python program (PinMol) that designs molecular beacons best suited for live cell imaging by using structural information from secondary structures of the target RNA, predicted via energy minimization approaches. PinMol takes into account the accessibility of the targeted regions, as well as the inter- and intramolecular interactions of each selected probe. To demonstrate its applicability, we synthesized an oskar mRNA-specific molecular beacon (osk1236), which is selected by PinMol to target a more accessible region than a manually designed oskar-specific molecular beacon (osk2216). We previously demonstrated osk2216 to be efficient in detecting oskar mRNA in in vivo experiments. Here, we show that osk1236 outperformed osk2216 in live cell imaging experiments.

scholarly journals A general method to fine-tune fluorophores for live-cell and in vivo imaging

2017 ◽  
Author(s):  
Jonathan B. Grimm ◽  
Anand K. Muthusamy ◽  
Yajie Liang ◽  
Timothy A. Brown ◽  
William C. Lemon ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
In Vivo Imaging ◽  
Chemical Properties ◽  
Live Cell ◽  
Live Cells ◽  
Fine Tune ◽  
General Method ◽  
And Chemical Properties

ABSTRACTPushing the frontier of fluorescence microscopy requires the design of enhanced fluorophores with finely tuned properties. We recently discovered that incorporation of four-membered azetidine rings into classic fluorophore structures elicits substantial increases in brightness and photostability, resulting in the ‘Janelia Fluor’ (JF) series of dyes. Here, we refine and extend this strategy, showing that incorporation of 3-substituted azetidine groups allows rational tuning of the spectral and chemical properties with unprecedented precision. This strategy yields a palette of new fluorescent and fluorogenic labels with excitation ranging from blue to the far-red with utility in live cells, tissue, and animals.

scholarly journals SurfaceGenie: a web-based application for prioritizing cell-type specific marker candidates

2019 ◽  
Author(s):  
Matthew Waas ◽  
Shana T. Snarrenberg ◽  
Jack Littrell ◽  
Rachel A. Jones Lipinski ◽  
Polly A. Hansen ◽  
...  
Keyword(s):  
Cell Surface ◽  
Specific Surface ◽  
Web Application ◽  
Rank Order ◽  
Surface Proteins ◽  
Live Cells ◽  
Specific Marker ◽  
Cell Type ◽  
Cell Type Specific

AbstractMotivationCell-type specific surface proteins can be exploited as valuable markers for a range of applications including immunophenotyping live cells, targeted drug delivery, and in vivo imaging. Despite their utility and relevance, the unique combination of molecules present at the cell surface are not yet described for most cell types. A significant challenge in analyzing ‘omic’ discovery datasets is the selection of candidate markers that are most applicable for downstream applications.ResultsHere, we developed GenieScore, a prioritization metric that integrates a consensus-based prediction of cell surface localization with user-input data to rank-order candidate cell-type specific surface markers. In this report, we demonstrate the utility of GenieScore for analyzing human and rodent data from proteomic and transcriptomic experiments in the areas of cancer, stem cell, and islet biology. We also demonstrate that permutations of GenieScore, termed IsoGenieScore and OmniGenieScore, can efficiently prioritize co-expressed and intracellular cell-type specific markers, respectively.Availability and ImplementationCalculation of GenieScores and lookup of SPC scores is made freely accessible via the SurfaceGenie web-application: www.cellsurfer.net/surfacegenie.

Sign in / Sign up

Export Citation Format

Share Document