New imaging reagents for lipid dense regions in live cells and the nucleus in fixed MCF-7 cells

Abstract

a Two new Uracil (U) and 5-flurouracil (5-FU) labeled Ruthenium(II)-polypyridyl based cellular imaging reagents are reported. Confocal laser scaning microscopic images with live and paraformaldehyde (PFA) fixed MCF-7 cells are examined using these two low-cytotoxic reagents. Experimental results show that these two complexes, appropriately functionalized with U (1) and 5-FU (2), have specific affinity for the lipid dense regions like endoplasmic reticulum, cell membrane, and cytoplasmic vacuoles in live MCF-7 cells and dye internalization in these regions happened following an endocytosis pathway. Interestingly, these two complexes are found to be localized in the nucleus of the PFA fixed cells. For fixed cell, presumably the lipid layer disruption helped in the explicit localization of the complexes 1 and 2 in cell nucleus through specific interaction with cellular DNA. Poor and non-specific internalization of an analogous model complex 3, without having U or 5-FU moiety, reveals the definite influence of U or 5-FU as well as the role of lipophilicity of the respective complex 1 and 2 for the cellular internalization process. Apart from these, large Stokes shift (~160 nm) and appreciably long lived 3 MLCT excited state (~ 320 ns) in aq. buffer medium (pH 7.4) are other key features for complexes 1 and 2. Unlike the common nuclear DNA staining reagents like DAPI, these low-cytotoxic reagents are found to be highly stable towards photo-bleaching on irradiation with 455 nm at the MLCT band for these complexes.

Imaging Cancer Cells Expressing the Folate Receptor with Carbon Dots Produced from Folic Acid

“…Intensive efforts have been directed towards development of chemical compounds that would target and selectively label cancer cells . Fluorescent dyes, in particular, have been widely used as vehicles for cell labeling . Fluorescent semiconductor nanoparticles (often termed quantum dots), have also been extensively used in recent years for cell labeling .…”

GSH Induced Controlled Release of Levofloxacin from a Purpose-Built Prodrug: Luminescence Response for Probing the Drug Release in Escherichia coli and Staphylococcus aureus

“…Colocalization studies were performed with ER-Tracker-Green (BODIPY FL Glibenclamide) − and LSSDMTr. Merged image (having Pearson’s coefficient 0.78 with overlap of 0.93) (Figure and SI Figure S28) clearly revealed that the Levofloxacin produced from the lipophilic prodrug PD2 (LSSDMTr) was localized solely in the lipid dense regions (cytoplasm and ER region) of cells and not in the nucleus.…”

Two‐Photon‐Induced CO‐Releasing Molecules as Molecular Logic Systems in Solution, Polymers, and Cells

“…As photoCORM 2 has a higher lipophilicity than 1 (log P =+1.5 and −0.5, respectively), one could anticipate that 2 has higher cellular uptake. From the one‐photon fluorescence images in Figure c, it is clear that 2 localized not only in the cell membrane, but also in the cytoplasm. The fluorescence intensity profile plot (Figure d) suggested that the emission intensity for 2 was increased after 2PA irradiation in HeLa cells.…”