Publications by authors named "Dipanjan Sengupta"

Currently the prevalence of diabetic wounds brings a huge encumbrance onto patients, causing high disability and mortality rates and a major medical challenge for society. Therefore, in this study, we are targeting to fabricate aloe vera extract infused biocompatible nanofibrous patches to facilitate the process of diabetic wound healing. Additionally, clindamycin has been adsorbed onto the surface of in-house synthesized ceria nanoparticles and again used separately to design a nanofibrous web, as nanoceria can act as a good drug delivery vehicle and exhibit both antimicrobial and antidiabetic properties.

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In view of the depletion of natural energy resources, harvesting energy from waste is a revolution to simultaneously capture, unite, and recycle various types of waste energies in flexible devices. Thus, in this work, a spin-charge-regulated pyro-magneto-electric nanogenerator is devised at a well-known ferroelectric P(VDF-TrFE) copolymer. It promptly stores thermal-magnetic energies in a "capacitor" that generates electricity at room temperature.

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Ferroelectric switching and retention performance of poly(vinylidene fluoride) (PVDF) thin films improve by the incorporation of unmodified smectite montmorillonite (MMT) clay nanodielectric. In the present study, an intercalated PVDF (clay/PVDF) thin film with edge-on β-crystallite is fabricated via a heat-controlled spin coating (HCSC) technique. This provides an efficient and simple way to fabricate the edge-on oriented crystallite lamellae with an electroactive β-phase, facilitating nanoscale ferroelectric switching at a lower voltage compared to the face-on orientation.

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Article Synopsis
  • The accumulation of misfolded amyloid aggregates in neurons is a key factor in the development of Alzheimer's disease (AD) and targeting these aggregates may offer a potential cure.
  • Researchers tested biocompatible polydopamine-coated polyvinylidene fluoride (DPVDF) nanospheres, finding that they effectively disassembled amyloid fibrils when activated by acoustic stimuli.
  • Further studies indicated that these nanospheres not only reduced neurotoxicity in cell models but also helped restore cognitive behavior in animal models, suggesting they might be effective for non-invasive treatment of AD.
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This perspective article emphasizes the significant role of reactive oxygen species (ROS) in remedial therapy of various diseases and complications, capitalizing on their potential reactivity. Among the various influencers, herein, piezoelectric materials driven ROS generation activity is primarily considered. Intrinsic non-centrosymmetry of piezoelectric materials makes them suitable for distinct dipole formation in the presence of external mechanical stimuli.

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Organic nonvolatile memory with low power consumption is a critical research demand for next-generation memory applications. Ferroelectric switching characteristics of poly(vinylidene fluoride) (PVDF) thin films modified with a trace amount of hydrated Cu salt (CuCl·2HO) are explored in the present study. Herein, a Cu salt-mediated PVDF (Cu/PVDF) thin film with preferential edge-on β-crystallites is fabricated through the orientation-controlled spin coating (OCSC) technique.

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Bio-piezoelectric materials are endowed with characteristic features such as non-invasiveness, small energy attenuation and deep tissue penetrability. Thus, they have the ability to serve as both diagnostic and therapeutic modalities for targeting and treating various dreaded disorders scourging mankind. Herein, piezoelectric nanotubes derived from a modified amino acid-containing dipeptide, phenylalanine-αβ-dehydrophenylalanine (Phe-ΔPhe; FΔF), possessing acoustic stimulation-triggered reactive oxygen species (ROS) generating ability, were employed and projected for achieving a piezo-active response enabled anti-cancer effect in glioma cells.

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In recent years, lead-free perovskite materials are exponentially emerging in photovoltaic and optoelectronic applications due to their low toxicity and superior optical properties. On the other hand, the demand for flexible, wearable, and lightweight optoelectronic devices is significantly growing in sensor and actuator technologies. In this scenario, lead-free perovskite-based flexible piezoelectric polymer composites have sparked considerable attention in this field due to their excellent piezo-, pyro-, ferroelectric, and photovoltaic properties.

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Mineral lubricating oils are widely used in various industrial sectors for their applications in maintenance and functioning of machineries. However, indiscriminate dumping of these used oils have resulted in polluting the natural reservoirs which subsequently destroys ecological balance. Bacteria can emulsify or lower surface tension between phases of immiscible substrates and can acquire them as their carbon and energy sources.

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Globally, the underlying peril of cumulative toxicity of heavy metals in water bodies contaminated by industrial effluents is a matter of great concern to the environmentalists. Heavy metals like lead, cadmium, and nickel are particularly liable for this. Such toxic water is not only hazardous to human health but also harmful to aquatic animals.

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Porous carbon nanospheres were synthesized from agro-waste garlic peels by a one-pot facile and easy to scale-up pyrolysis method. Surface morphology and structural features of the nanospheres have been studied by field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and Raman spectroscopy. Fourier transform infrared spectroscopy (FTIR) and N adsorption desorption experiments were explored to detect surface functionality, surface area, and porosity.

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Oxygen evolution reaction (OER) is a demanding step within the water splitting process for its requirement of a high overpotential. Thus, to overcome this unfavourable kinetics, an efficient catalyst is required to expedite the process. In this context, we report on Ni foam functionalised with low cost iron (Fe) and iron hydroxide (Fe(OH) ), wet chemically synthesized as OER catalysts.

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Since the advent of biologics in human welfare various bio-molecules have been explored. Different bacterial exopolysaccharides have proved their worth in many industrial and commercial applications. In this perspective, while exploring a surfactant exopolysaccharide of Ochrobactrum pseudintermedium C1, it is strikingly observed that it possesses a potent antibacterial property which encourages its bio-medical applications.

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During production and characterization of exopolysaccharides (EPS) of Ochrobactrum pseudintermedium C1, it was observed that an experimental change in the basic hydrocarbon type of substrate for bacterial utilization led to elicitation of different surface-active properties in the EPS produced. In the sugar substrate, it elicited surfactant property, while in oil substrates it elicited emulsifying property, which indicated that the EPS might be different. Consequently, attention was focused on a detailed analysis of this substrate-specific EPS.

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Bacterial extracellular polymeric substances, which are basically bacterial metabolites, have currently become a subject of great concern of modern day microbiologists and biotechnologists. Among these metabolites, bacterial exopolysaccharides or EPS, in particular, have gained a significant importance. EPS are formed by the bacteria in their late exponential or stationary phase of growth under special situations for specific purposes.

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Besides potential surface activity and some beneficial physical properties, biosurfactants express antibacterial activity. Bacterial cell membrane disrupting ability of rhamnolipid produced by Pseudomonas aeruginosa C2 and a lipopeptide type biosurfactant, BS15 produced by Bacillus stratosphericus A15 was examined against Staphylococcus aureus ATCC 25923 and Escherichia coli K8813. Broth dilution technique was followed to examine minimum inhibitory concentration (MIC) of both the biosurfactants.

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S1P1 is a validated target for treatment of autoimmune disease, and functional antagonists with superior safety and pharmacokinetic properties are being sought as second generation therapeutics. We describe the discovery and optimization of (7-benzyloxy-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetic acids as potent, centrally available, direct acting S1P1 functional antagonists, with favorable pharmacokinetic and safety properties.

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APD334 was discovered as part of our internal effort to identify potent, centrally available, functional antagonists of the S1P1 receptor for use as next generation therapeutics for treating multiple sclerosis (MS) and other autoimmune diseases. APD334 is a potent functional antagonist of S1P1 and has a favorable PK/PD profile, producing robust lymphocyte lowering at relatively low plasma concentrations in several preclinical species. This new agent was efficacious in a mouse experimental autoimmune encephalomyelitis (EAE) model of MS and a rat collagen induced arthritis (CIA) model and was found to have appreciable central exposure.

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Two distinct and scalable enantioselective approaches to the tricyclic indole (R)-2-(7-hydroxy-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate, an important synthon for a preclinical S1P(1) receptor agonist, are reported. Route 1 employs a modified version of Smith's modular 2-substituted indole synthesis as the key transformation. Route 2 involves a highly enantioselective CuH-catalyzed 1,4-hydrosilylation as the stereodefining step.

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Two series of fused tricyclic indoles were identified as potent and selective S1P(1) agonists. In vivo these agonists produced a significant reduction in circulating lymphocytes which translated into robust efficacy in several rodent models of autoimmune disease. Importantly, these agonists were devoid of any activity at the S1P(3) receptor in vitro, and correspondingly did not produce S1P(3) mediated bradycardia in telemeterized rat.

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Article Synopsis
  • - A series of pyrimidine analogues from ATC0175 were developed and found to effectively block the human MCH-R1 receptor in lab tests.
  • - Some analogues showed better selectivity for the receptor, but there was no enhancement in how well they could penetrate the brain.
  • - One analogue could reduce food intake and body weight in a long-term study, but researchers couldn't link this effect to its concentration in the brain, suggesting it might not work through the MCH-R1 receptor.
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A new family of Histamine H(3) receptor antagonists (5a-t) has been prepared based on the structure of the natural product Conessine, a known H(3) antagonist. Several members of the new series are highly potent and selective binders of rat and human H(3) receptors and display inverse agonism at the human H(3) receptor. Compound 5n exhibited promising rat pharmacokinetic properties and demonstrated functional antagonism of the H(3) receptor in an in-vivo pharmacological model.

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The synthesis and SAR of a novel 3-benzazepine series of 5-HT2C agonists is described. Compound 7d (lorcaserin, APD356) was identified as one of the more potent and selective compounds in vitro (pEC50 values in functional assays measuring [(3)H]phosphoinositol turnover: 5-HT2C = 8.1; 5-HT2A = 6.

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We report on the synthesis, biological evaluation and structure-activity relationships for a series of 3-benzazepine derivatives as 5-HT(2C) receptor agonists. The compounds were evaluated in functional assays measuring [3H] phosphoinositol turnover in HEK-293 cells transiently transfected with h5-HT(2C), h5-HT(2A) or h5-HT(2B) receptors. Several compounds are shown to be potent and selective 5-HT(2C) receptor agonists, which decrease food intake in a rat feeding model.

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