Mannose-Decorated Stimuli-Responsive Fluorescent Poly(aminoamide) Microgels for Lectin Binding and Sensing.

Development of suitable carbohydrate-decorated, biocompatible, and stimuli-responsive fluorescent microgels that can selectively bind and detect proteins (such as lectins) is an important research topic. Herein, we report the development of mannose-decorated, dual-stimuli (temperature and pH)-responsive fluorescent poly(aminoamide) microgels, which can selectively bind to and thereby detect the presence of concanavalin A (Con A). The resultant stimuli-responsive microgels have a lower critical solution temperature (VPTT) of 37.

A fluorescent nonconjugated zwitterionic polymer dot: hydrothermal synthesis and application in the nano-molar sensing of 2,4,6-trinitrophenol.

Developing nonconjugated polymer dot-based sensors with high quantum yield for a targeted application is a challenging research field. Herein, we report the synthesis of a zwitterionic polymer dot (PD PAMAM 2.5, average diameter 12 nm), which contains a poly(aminoamide) core and amine and acid groups on the surface.

Stimuli-responsive fluorescent nanogel: a nonconventional donor for ratiometric temperature and pH sensing.

A reactive stimuli responsive fluorescent polyaminoamide nanogel (NANO-PAMAM) is synthesized an aza-Michael polyaddition reaction in water. In the next stage, doxorubicin (a FRET acceptor) is covalently linked with the nanogel (NANO-PAMAM, a nonconventional FRET donor) to form a ratiometric nanosensor for temperature and pH sensing. MTT assay revealed comparable biocompatibility of the donor nanogels (NANO-PAMAM) and nanosensors (NANO-PAMAM-DOX).

Quantitative functionalization of chitosan using green and efficient azetidinium-amine reactions.

Despite significant advances in the field, quantitative post-polymer modification of chitosan, specifically attaching diverse hydrophobic moieties with experimentally predefined (via the ratio of reagents) degree of functionalization remain extremely challenging. In this context, we report our studies towards the use of green and efficient azetidinium-amine reactions to prepare a library of modified chitosan with a predefined degree of functionalization, with excellent conversion (>90%), atom economy and very low E-factor (<0.1).

A BODIPY--glycoside based near-infrared fluorescent sensor for serum albumin.

Highly sensitive and selective near-infrared fluorescent bioprobes for serum albumin detection and quantification are in high demand for biomedical applications. Herein, we report a near-infrared emitting BODIPY--glycoside dye as a turn-on emission sensor for serum albumin. To the best of our knowledge, this is the first report of NIR-emitting BODIPY dyes for serum albumin sensing.

Degradable and processable polymer monoliths with open-pore porosity for selective CO and iodine adsorption.

A task-specific design of biodegradable and processable porous polymers is one of the primary requisite for their efficient day-to-day use to minimize polymer waste. Herein, a surfactant (or additive)-free method is reported for the synthesis of a processable and degradable aliphatic open-pore porous polyelectrolyte monolith for the removal of gaseous pollutants such as iodine and CO2. This is achieved via a colloidal templating method.

A regression-based three-phase approach to assess outdoor thermal comfort in informal micro-entrepreneurial settings in tropical Mumbai.

Urban heat poses a public health risk to the residents of megacities in developing countries because the population spends a significant amount of time outdoors to work and socialize with limited cooling resources. Understanding the drivers of outdoor comfort and heat stress in informal work settings is important to design climate-sensitive outdoor spaces and reduce heat vulnerability. We present outdoor thermal comfort perceptions (OTCPs) of people engaged in outdoor micro entrepreneurial activities in Mumbai using seasonal surveys and biometeorological observations.

Synthesis of Bioactive Diarylheptanoids from and Their Mechanism of Action for Anticancer Properties in Breast Cancer Cells.

An efficient synthesis of the -derived diarylheptanoids, viz., enantiomers of a β-hydroxyketone () and an α,β-unsaturated ketone () was developed starting from commercially available eugenol. Among these, compound showed a superior antiproliferative effect against human breast adenocarcinoma MCF-7 cells.

Pharmacological targeting of differential DNA repair, radio-sensitizes WRN-deficient cancer cells in vitro and in vivo.

Werner (WRN) expression is epigenetically downregulated in various tumors. It is imperative to understand differential repair process in WRN-proficient and WRN-deficient cancers to find pharmacological targets for radio-sensitization of WRN-deficient cancer. In the current investigation, we showed that pharmacological inhibition of CHK1 mediated homologous recombination repair (HRR), but not non-homologous end joining (NHEJ) repair, can causes hyper-radiosensitization of WRN-deficient cancers.

Iron modulatory property of a polysaccharide from Indian medicinal plant .

Despite being an essential element for normal functioning of cells and organisms, iron, in excess, can induce oxidative stress by generating reactive oxygen species. A water-soluble, non-toxic iron chelator can reduce the iron-induced oxidative stress in the body as well as help in extricating excess iron. Herein, we report an -derived antioxidant polysaccharide (OSP) that inhibits the deleterious effect of iron.

Monitoring the formation of insulin oligomers using a NIR emitting glucose-conjugated BODIPY dye.

Protein oligomers, which are formed due to the aggregation of protein molecules under physiological stress, are neurotoxic and responsible for several neurological diseases. Early detection of protein oligomers is essential for the timely intervention in the associated diseases. Although several probes have been developed for the detection of insoluble matured protein fibrils, fluorescent probes with emission in the near infrared (NIR) region for probing protein oligomers are very rare.

Outdoor thermal comfort in various microentrepreneurial settings in hot humid tropical Kolkata: Human biometeorological assessment of objective and subjective parameters.

Extreme heat and associated health risks increasingly become threats to urban populations, especially in developing countries of the tropics. Although human thermal exposure in cities has been studied across the globe, current narratives insufficiently discuss mixed-used spaces, informal economic activity settings, and informal settlements. This study assessed outdoor human thermal comfort in the tropical city of Kolkata, India where uncomfortable hot and humid climatic conditions prevail year-round.

Thiol antioxidants sensitize malabaricone C induced cancer cell death via reprogramming redox sensitive p53 and NF-κB proteins in vitro and in vivo.

Specific focus on "redox cancer therapy" by targeting drugs to redox homeostasis of the cancer cells is growing rapidly. Recent clinical studies showed that N-acetyl cysteine (NAC) treatment significantly decreased the metabolic heterogeneity and reduced Ki67 (a proliferation marker) with simultaneous enhancement in apoptosis of tumor cells in patients. However, it is not yet precisely known how thiol antioxidants enhance killing of cancer cells in a context dependent manner.

Tuning of electron tunneling: a case study using BODIPY molecular layers.

Redox active π-conjugated organic molecules have shown the potential to be used as electronic components such as diode and memory elements. Here, we demonstrate that using simple surface chemistry, rectification characteristics can be tuned to reproducible negative differential resistance (NDR) with a very high peak-to-valley ratio (PVR) up to 1000 in 2,6-diethyl-4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indecene (BODIPY) grafted on Si. The change in properties is related to oxidation and reduction of BODIPY, which results in the change in resonant to non-resonant tunneling of electrons under bias.

A bis-resorcinol resveratrol congener prevents indomethacin-induced gastric ulceration by inhibiting TNF-α as well as NF-κB and JNK pathways.

The cytoprotective action of the synthetic resveratrol (Resv) congener, -3,3',5,5'-tetrahydroxystilbene (designated as HST-1) against indomethacin (IND)-induced stomach ulceration has been established using a mice model. HST-1 reversed the adverse effects of IND on several inflammatory (myeloperoxidase, cytokines, adhesion molecules etc.) and ulcer-healing (cyclooxygenases, prostaglandin, growth factors and their receptors etc.

Mechanism of coralyne-mediated DNA photo-nicking process.

Previously, we reported that coralyne and UVA combination sensitized a wide range of human carcinoma cells regardless of their p53 status. The coralyne induced photosensitization of cancer cells may be clinically attractive, as mutation in the p53 gene is prevalent in many types of tumors. Coralyne mediated photosensitization of cancer cells is attributable to its ability to cause extensive DNA single strand breaks (SSB).

A chemoenzymatic synthesis of ceramide trafficking inhibitor HPA-12.

A chemoenzymatic synthesis of the title compound has been developed using an efficient and highly enantioselective lipase-catalyzed acylation in a hydrophobic ionic liquid, [bmim][PF], followed by a diastereoselective asymmetric dihydroxylation as the key steps for incorporating the stereogenic centers. The further conversion to the appropriate intermediates and subsequent acylation with lauric acid furnished the target compound.

Spice-derived phenolic, malabaricone B induces mitochondrial damage in lung cancer cells via a p53-independent pathway.

The spice-derived phenolic, malabaricone B (mal B) showed selective toxicity to human lung cancer (A549), malignant melanoma (A375) and T cell leukemia (Jurkat) cell lines, without showing toxicity to human normal intestinal (INT407), human kidney (HEK293) and lung fibroblast (WI-38) cells. Among the chosen cancer cell lines, mal B showed maximum cytotoxicity to the A549 cells (IC50 = 8.1 ± 1.

Resveratrol analogue, trans-4,4'-dihydroxystilbene (DHS), inhibits melanoma tumor growth and suppresses its metastatic colonization in lungs.

The prevalence of melanoma and the lack of effective therapy for metastatic melanoma warrant extensive and systematic evaluations of small molecules in cellular and pre-clinical models. We investigated, herein, the antitumor and anti-metastatic effects of trans-4,4'-dihydroxystilbene (DHS), a natural product present in bark of Yucca periculosa, using in vitro and in vivo melanoma murine models. DHS showed potent melanoma cytotoxicity, as determined by MTT and clonogenic assay.

Bi-mediated allylation of aldehydes in [bmim][Br]: a mechanistic investigation.

The inexpensive room temperature ionic liquid (RTIL), [bmim][Br] has been found to be a superior medium for the Bi-mediated Barbier-type allylation of aldehydes compared to other conventional solvents. It plays the dual role of a solvent and a metal activator enabling higher yields of the products in a shorter reaction time using stoichiometric/near-stoichiometric amounts of reagents. Plausibly, [bmim][Br] activates Bi metal by a charge transfer mechanism.

Allylpyrocatechol attenuates methotrexate-induced hepatotoxicity in a collagen-induced model of arthritis.

The cornerstone of treatment for rheumatoid arthritis is low dose methotrexate (MTX), but its use is limited by concerns regarding its potential for hepatotoxicity. Allylpyrocatechol (APC), a phytoconstituent sourced from leaves of Piper betle demonstrated antioxidant, anti-inflammatory, and antiarthritic properties. The present study aimed to evaluate the combined effect of APC and MTX on limiting progression of lipopolysaccharide accelerated collagen-induced arthritis, along with reduction of MTX-induced hepatic damage.

Coralyne, a protoberberine alkaloid, causes robust photosenstization of cancer cells through ATR-p38 MAPK-BAX and JAK2-STAT1-BAX pathways.

Photodynamic therapy (PDT) provides an effective cancer treatment option but it requires sufficient cellular oxygen concentration to exert its photosensitizing effects. Due to hypoxic nature of most tumors, widespread clinical application of PDT is restricted and warrants development of photosensitizers which can kill cancer cells in ROS independent manner. Previously, we reported significant enhancement of the anti-cancer property of coralyne in presence of ultraviolet-A (UVA) light exposure against several human carcinoma cell lines.

A chiral template-driven synthesis of a 3'-deoxy-3'-F-fluorothymidine precursor.

An asymmetric synthesis of a 3'-deoxy-3'-F-fluorothymidine (F-FLT) precursor has been developed wherein the deoxysugar moiety was synthesized using a novel Ga-mediated allylation of (R)-2,3-cyclohexylideneglyceraldehyde as the key step. The synthesis deviates significantly from the previous syntheses of the F-FLT precursors wherein the expensive starting material, thymidine was used.

-4,4'-Dihydroxystilbene (DHS) inhibits human neuroblastoma tumor growth and induces mitochondrial and lysosomal damages in neuroblastoma cell lines.

In view of the inadequacy of neuroblastoma treatment, five hydroxystilbenes and resveratrol (Resv) were screened for their cytotoxic property against human neuroblastoma cell lines. The mechanism of cytotoxic action of the most potent compound, -4,4'-dihydroxystilbene (DHS) was investigated using human neuroblastoma cell lines. DHS was also tested in a mouse xenograft model of human neuroblastoma tumor.