@article {44127, title = {Super-resolution probe to monitor HNO levels in the endoplasmic reticulum of cells}, journal = {Analytical Chemistry}, volume = {89}, year = {2017}, month = {NOV}, pages = {12087-12093}, type = {Article}, abstract = {Selective detection of nitroxyl (HNO), which has recently been identified as a reactive nitrogen species, is a challenging task. We report a BODIPY-based luminescence ON reagent for detection of HNO in aqueous solution and in live RAW 264.7 cells, based on the soft nucleophilicity of the phosphine oxide functionality toward HNO. The probe shows high selectivity to HNO over other reactive oxygen/nitrogen and sulfur species. Luminescence properties of the BODIPY-based chemodosimetric reagent make it an ideal candidate for use as a reagent for super-resolution structured illumination microscopy. The viability of the reagent for biological in vivo imaging application was also confirmed using Artemia as a model.}, doi = {10.1021/acs.analchem.7b02567}, author = {Ali, Firoj and Sreedharan, Sreejesh and Ashoka, Anila Hoskere and Saeed, Hiwa K. and Smythe, Carl G. W. and Thomas, Jim A. and Das, Amitava} } @article {44550, title = {Polysulfide-triggered fluorescent indicator suitable for super-resolution microscopy and application in imaging}, journal = {Chemical Communications}, volume = {54}, year = {2018}, month = {APR}, pages = {3735-3738}, abstract = {

A new physiologically benign and cell membrane permeable BODIPY based molecular probe, MB-S-n, specifically senses intracellular hydrogen polysulfides (H2Sn, n \> 1) localized in the endoplasmic reticulum. This reagent is suitable for mapping the intracellular distribution of H2Sn by wide-field as well as super-resolution Structured Illumination Microscopy (SIM).

}, issn = {1359-7345}, doi = {10.1039/c8cc01332b}, author = {Hoskere, Anila A. and Sreedharan, Sreejesh and Ali, Firoj and Smythe, Carl G. and Thomas, Jim A. and Das, Amitava} } @article {44183, title = {Tracking HOCl concentrations across cellular organelles in real time using a super resolution microscopy probe}, journal = {Chemical Communications}, volume = {54}, year = {2018}, month = {FEB}, pages = {1849-1852}, type = {Article}, abstract = {

BODIPY derivative, SF-1, exclusively shows a fluorescence ON response to HOCl and images endogenously generated HOCl in RAW 264.7 macrophages. Widefield and super resolution structured illumination microscopy images confirm localization in the Golgi complex and lysosomes, and hence specifically detects HOCl generated in these organelles. SF-1 is compatible with 3D-SIM imaging of individual cells.

}, issn = {1359-7345}, doi = {10.1039/c7cc09433g}, author = {Ali, Firoj and Aute, Sunil and Sreedharan, Sreejesh and Anila, H. A. and Saeed, Hiwa K. and Smythe, Carl G. and Thomas, Jim A. and Das, Amitava} } @article {47061, title = {Photoactivatable prodrug for simultaneous release of mertansine and CO along with a BODIPY derivative as a luminescent marker in mitochondria: a proof of concept for NIR image-guided cancer therapy}, journal = {Chemical Science}, volume = {12}, year = {2021}, month = {FEB}, pages = {2667-2673}, type = {Article}, abstract = {

Controlled and efficient activation is the crucial aspect of designing an effective prodrug. Herein we demonstrate a proof of concept for a light activatable prodrug with desired organelle specificity. Mertansine, a benzoansamacrolide, is an efficient microtubule-targeting compound that binds at or near the vinblastine-binding site in the mitochondrial region to induce mitotic arrest and cell death through apoptosis. Despite its efficacy even in the nanomolar level, this has failed in stage 2 of human clinical trials owing to the lack of drug specificity and the deleterious systemic toxicity. To get around this problem, a recent trend is to develop an antibody-conjugatable maytansinoid with improved tumor/organelle-specificity and lesser systematic toxicity. Endogenous CO is recognized as a regulator of cellular function and for its obligatory role in cell apoptosis. CO blocks the proliferation of cancer cells and effector T cells, and the primary target is reported to be the mitochondria. We report herein a new mitochondria-specific prodrug conjugate (Pro-DC) that undergoes a photocleavage reaction on irradiation with a 400 nm source (1.0 mW cm(-2)) to induce a simultaneous release of the therapeutic components mertansine and CO along with a BODIPY derivative (BODIPY(PPH3)(2)) as a luminescent marker in the mitochondrial matrix. The efficacy of the process is demonstrated using MCF-7 cells and could effectively be visualized by probing the intracellular luminescence of BODIPY(PPH3)(2). This provides a proof-of-concept for designing a prodrug for image-guided combination therapy for mainstream treatment of cancer.

}, issn = {2041-6520}, doi = {10.1039/d0sc06270g}, author = {Tiwari, Rajeshwari and Shinde, Prashant S. and Sreedharan, Sreejesh and Dey, Anik Kumar and Vallis, Katherine A. and Mhaske, Santosh B. and Pramanik, Sumit kumar and Das, Amitava} }