Browsing by Author "Biplob Koch"

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7-Azaspiroketal as a unique and effective auxochrome moiety: demonstration in a fluorescent coumarin dye and application in cell imaging
(Royal Society of Chemistry, 2023) Harish K. Indurthi; Pooja Goswami; Samarpita Das; Pallavi Saha; Biplob Koch; Deepak K. Sharma
Replacement of electron-donating N,N-dialkyl groups with azacyclic groups has been described as a promising auxochrome to improve the low fluorescent quantum yields (ΦF) of conventional fluorophores. However, the insufficient brightness and poor solubility of fluorophores pose a significant bottleneck for bioimaging. A new type of fluorescent coumarin dye was designed and synthesized using 7-azaspiroketals as the electron-donating auxochrome group. Such modifications resulted in high-quality coumarin fluorophores with improved solubility and brightness. To the best of our knowledge, this is the first report of using apex-N-substituted azaspiroketals as an electron donor group in any class of donor-acceptor dye. Furthermore, the successful application of these new dyes in biological imaging for living cells has been demonstrated. © 2023 The Royal Society of Chemistry.
A bexarotene-attached Re(i) tricarbonyl complex for NADH oxidation and ROS-mediated cancer phototherapy
(Royal Society of Chemistry, 2025) Rajesh Kumar Kushwaha; Virendra Pratap Singh; Biplob Koch; Samya Banerjee
An axially substituted polypyridyl Re(CO)3 complex bearing bexarotene triggered caspase-3/7-mediated apoptosis in cancer cells through ROS generation and NADH photo-oxidation. © 2025 The Royal Society of Chemistry.
A Chemodosimeter Exhibiting Fluorescence “Turn-On” Response to Detect Copper(II) Ions: Cell Imaging and Logic Function
(Wiley-Blackwell, 2019) Ramesh C. Gupta; Sushil K. Dwivedi; Syed S. Razi; Priya Singh; Biplob Koch; Arvind Misra
In the present work the photophysical properties of a chemodosimeter, 2-[4’-(N,N’-dimethylamino-biphenyl)-4-methylene]-iminophenol, 5 has been explored to recognize Cu 2+ ion selectively through naked eye sensitive fluorescence “turn-on” response. The observed fluorescence enhancement (∼58 fold) and rise in quantum yield (34%) with rapid response time is attributed to the hydrolysis of aldimine function in the presence of copper. The cell imaging studies showed that chemodosimeter, 5 is well-suited to detect Cu 2+ intracellularly. Additionally, the “Off–On” switching behavior of 5 has been utilized to mimic the function of a sequential logic circuit at molecular level. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
A dihydrazone based “turn–on” fluorescent probe for selective determination of Al3+ ions in aqueous ethanol
(Elsevier B.V., 2017) Divya Pratap Singh; Romi Dwivedi; Ashish Kumar Singh; Biplob Koch; Priya Singh; Vinod Prasad Singh
An efficient and highly selective dihydrazone based fluorescent probe N′,N′–bis((2–hydroxynaphthalen–1–yl)methylene)malonohydrazide (H2nmh), has been synthesized for selective detection of Al3+ ions and characterized by different physico–chemical and spectroscopic techniques. The probe shows an enhanced fluorescence in the presence of Al3+ ions in ethanol–water (2:3 v/v) solution which is not observed in the presence of other cations (Na+, K+, Mg2+, Ca2+, Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+ and Hg2+). The binding modes of H2nmh with Al3+ were studied by UV–vis, fluorescence and 1H NMR titrations. The probe act as dibasic hexa–dentate ligand and interacts with two Al3+ ions with a binding constant KB = 5.74 × 109 M−1 and detection limit 5.78 × 10−8 M. Detailed insights of probe–metal interaction mechanism were studied by mean of density functional theory (DFT) as well as time dependent–DFT calculation. MTT assay on live MCF–7 cells has been performed to evaluate the cytotoxicity of the probe which suggests viability of the probe to MCF–7 cells even at higher concentration (100 μM) with no serious cytotoxicity in cells. Live cell imaging study clearly indicates that the accumulation of Al3+ in the cytoplasm of cells can be detected by H2nmh. © 2016 Elsevier B.V.
A pyrene-benzthiazolium conjugate portraying aggregation induced emission, a ratiometric detection and live cell visualization of HSO3-
(Elsevier B.V., 2016) Uzra Diwan; Virendra Kumar; Rakesh K. Mishra; Nishant Kumar Rana; Biplob Koch; Manish Kumar Singh; K.K. Upadhyay
The present study deals with the photophysical property of a pyrene-benzthiazolium conjugate R1, as a strong intramolecular charge transfer (ICT) probe exhibiting long wavelength emission in the red region. Unlike traditional planar polyaromatic hydrocarbons whose aggregation generally quenches the light emission, the pyrene based R1 was found to display aggregation-induced emission (AIE) property along with simultaneous increase in its quantum yield upon increasing the water content of the medium. The R1 exhibits high specificity towards HSO3-/SO32- by interrupting its own ICT producing there upon a large ratiometric blue shift of ~220 nm in its emission spectrum. The lowest detection limit for the above measurement was found to be 8.90 × 10-8 M. The fluorescent detection of HSO3- was also demonstrated excellently by test paper strip and silica coated TLC plate incorporating R1. The live cell imaging of HSO3 through R1 in HeLa cells was studied using fluorescence microscopic studies. The particle size and morphological features of R1 and R1-HSO3- aggregates in aqueous solution were characterized by DLS along with SEM analysis. © 2016 Elsevier B.V.
A water soluble, highly sensitive and selective fluorescent probe for Al3+ ions and its application in live cell imaging
(Elsevier B.V., 2017) Shraddha Rani Gupta; Priya Singh; Biplob Koch; Vinod P. Singh
An efficient, aminothiazole based, fluorescent probe (E)-2-(2-aminothiazol-5-yl)-N'-((2-hydroxynaphthalen-1-yl)methylene)acetohydrazide (NTH) for the detection of Al3+ ions was synthesized and characterized by different physico-chemical and spectroscopic tools. An attractive glowing blue color was observed in the presence of Al3+ with single channel emissions for NTH (λem 451 & λex 391 nm). NTH, selectively detected Al3+ ions among various other ions without any significant interference in Tris-HCl buffer solution (10 mM, pH ∼ 7.4). The >C[dbnd]N– isomerization was responsible for the turn ‘on’ fluorescence response after Al3+ binding. The stoichiometry of NTH with Al3+ was determined to be 1:1 by Job's plot. The binding constant and limit of detection (LOD) were observed as 3.65 × 109 M−1 and 1.09 × 10−9 M, respectively. The 1H NMR titration and DFT studies were also performed in support of binding details of NTH-Al3+ complex. MTT assay on live A549 cells suggested viability of the probe to A549 cells even at higher concentration (100 μM) with no serious cytotoxicity in cells. Live cell imaging study clearly indicated that the accumulation of Al3+ in the cytoplasm of cells could be detected by NTH. © 2017 Elsevier B.V.
Allylthiourea-mediated self-healing hydrogels based on poly(vinyl alcohol): Enhanced cell viability/biocompatibility and sustained drug release
(John Wiley and Sons Inc, 2024) Paramjeet Yadav; Shere Afgan; Krishtan Pal; Sheetal Jaiswal; Pooja Goswami; Ravi Prakash; Rajesh Kumar; Biplob Koch; Pralay Maiti
Hydrogel-based materials represent promising candidates for drug delivery. In our research, we synthesized a series of hydrogels—PVATU-1 (2:1), PVATU-2 (1:1), and PVATU-3 (0.5:1)—by adjusting the poly(vinyl alcohol) (PVA) ratio while maintaining a constant ratio of allylthiourea (ATU) monomer and glutaraldehyde cross-linker, aiming to understand their impacts on gelation. These PVATU hydrogels displayed impressive swelling in neutral conditions and exhibited visible self-healing capabilities. Notably, PVATU-1 shows superior mechanical strength among the variants. Surface analysis using AFM and SEM unveiled porous structures within the hydrogels, while thermal stability tests indicated their resilience up to 200°C. DSC analysis revealed minimal variation in glass transition temperatures (Tg), affirming stability. A distinct endothermic peak around 250–350°C across all hydrogels confirmed their semi-crystalline nature, corroborated by powder XRD. Noteworthy, PVATU-1 demonstrated optimal loading and releasing efficiency for levofloxacin, with 74.5% loading and 82.8% releasing efficiency within 18 h. Biocompatibility assessments on HeLa cells affirmed the nontoxicity of PVATU hydrogel treatments. © 2024 Wiley Periodicals LLC.
An efficient Hg2+ ensemble based on a triazole bridged anthracene and quinoline system for selective detection of cyanide through fluorescence turn-off–on response in solution and live cell
(Elsevier B.V., 2017) Ramesh C. Gupta; Syed S. Razi; Rashid Ali; Sushil K. Dwivedi; Priyanka Srivastava; Priya Singh; Biplob Koch; Hirdyesh Mishra; Arvind Misra
A simple triazole bridged molecular probe containing anthracene and quinoline moieties has been designed and synthesized as a fluorescent molecular probe (7). The photophysical behavior of the probe 7 has been examined and tested for the recognition of ions in partial aqueous medium and HeLa cell. The probe 7 has shown strong affinity for Hg2+ and has been utilized to develop a stable ensemble, 7·Hg2+. The ensemble, 7·Hg2+ upon interaction with different class of anions showed high affinity for cyanide with ∼16 fold fluorescence enhancement and high limit of detection, 1.25 μM. The live cell imaging studies showed that ensemble 7·Hg2+ is capable to detect CN− intracellularly. The analytical applicability of the probe for Hg2+ and CN− has been tested on the test paper strips. Additionally, the naked eye sensitive “On–Off–On” switching behavior of 7 has been utilized to mimic the function of a sequential logic circuit at molecular level. The 1H NMR titration, ESI-MS spectroscopy and DFT calculation confirms the binding behavior between 7 and Hg2+. © 2017 Elsevier B.V.
An unconventional mechanistic insight on aggregation induced emission in novel boron dipyrromethenes and their rational biological realizations
(American Chemical Society, 2016) Roop Shikha Singh; Ashish Kumar; Sujay Mukhopadhyay; Gunjan Sharma; Biplob Koch; Daya Shankar Pandey
Quinolone and quinoline based boron dipyrromethenes (BODIPYs) viz. BQN1 and BQN2 obtained by relative stabilization of keto and enol forms of N-methylated quinolones via minute substitutional variations (-H/-OCH3) have been reported. The relative disparity in degree of aromaticity arising from quinolone/quinoline strongly affects the free rotation of these molecules. The photophysical and structural characteristics of these compounds revealed an exceptional dissonance between restriction of intramolecular rotation (RIR) and aggregation induced emission (AIE) signifying competitive steric hindrance and conjugation. Despite being an AIE inactive dye, BQN1 experiences maximum RIR and excels as a viscosity sensitive hindered molecular rotor, while an effective J-aggregation irrevocably established AIE in BQN2. This is the first report dealing with utilization of AIE active BODIPY (BQN2) in fabrication of AIEgen loaded bovine serum albumin (BSA) nanoparticles with live cell imaging in human breast cancer cell line MDA-MB-231. Binding mode of human serum albumin (HSA) to BQN2 has also been determined by molecular docking studies. In addition, viscochromism of BQN1 has been visualized through apoptotic marking in the MDA-MB-231 cell line. © 2016 American Chemical Society.
Antibacterial Photodynamic Therapy by Zn(II)-Curcumin Complex: Synthesis, Characterization, DFT Calculation, Antibacterial Activity, and Molecular Docking
(John Wiley and Sons Inc, 2024) Rajesh Kushwaha; Rohit Rai; Vedant Gawande; Virendra Singh; Ashish Kumar Yadav; Biplob Koch; Prodyut Dhar; Samya Banerjee
The increase in antibacterial drug resistance is threatening global health conditions. Recently, antibacterial photodynamic therapy (aPDT) has emerged as an effective antibacterial treatment with high cure gain. In this work, three Zn(II) complexes viz., [Zn(en)(acac)Cl] (1), [Zn(bpy)(acac)Cl] (2), [Zn(en)(cur)Cl] (3), where en=ethylenediamine (1 and 3), bpy=2,2’-bipyridine (2), acac=acetylacetonate (1 and 2), cur=curcumin monoanionic (3) were developed as aPDT agents. Complexes 1–3 were synthesized and fully characterized using NMR, HRMS, FTIR, UV-Vis. and fluorescence spectroscopy. The HOMO–LUMO energy gap (Eg), and adiabatic splittings (ΔS1−T1 and ΔS0−T1) obtained from DFT calculation indicated the photosensivity of the complexes. These complexes have not shown any potent antibacterial activity under dark conditions but the antibacterial activity of these complexes was significantly enhanced upon light exposure (MIC value up to 0.025 μg/mL) due to their light-mediated 1O2 generation abilities. The molecular docking study suggested that complexes 1–3 interact efficiently with DNA gyrase B (PDB ID: 4uro). Importantly, 1–3 did not show any toxicity toward normal HEK-293 cells. Overall, in this work, we have demonstrated the promising potential of Zn(II) complexes as effective antibacterial agents under the influence of visible light. © 2023 Wiley-VCH GmbH.
Anticancer potential of polypyridyl-based Ir(III)-coumarin 6 conjugates under visible light and dark
(Elsevier B.V., 2025) Ashish Kumar Kumar Yadav; Virendra Pratap Singh; Rajesh Kumar Kushwaha; Amit Kunwar; Biplob Koch; Samya Banerjee
We developed and evaluated two novel coumarin 6 conjugated Ir(III) photocatalysts, [Ir(CO6)(Ph-tpy)Cl]Cl (Ir1) and [Ir(CO6)(An-tpy)Cl]Cl (Ir2) (CO6 = Coumarin 6, Ph-tpy = 4′-phenyl-2,2′:6′,2″-terpyridine, An-tpy = 4′-anthracenyl-2,2′:6′,2″-terpyridine), for application in cancer therapy. Upon green light irradiation (525 nm, 50.2 J cm−2), Ir1 and Ir2 effectively catalyzed NADH oxidation with turnover frequencies (TOFs) ranging from 840 to 1100 h−1 in phosphate-buffered saline. Additionally, these complexes generated reactive oxygen species (ROS), including 1O2 and [rad]OH, through type I and type II mechanisms. Ir1 and Ir2 exhibited significant toxicity against human breast (MCF-7) and cervical (HeLa) cancer cells, with Ir2 demonstrating enhanced anticancer activity upon light activation. Notably, both complexes showed minimal dark toxicity toward non-cancerous human embryonic kidney (HEK-293) cells. The selectivity index (SI = Dark IC50 in normal cells/Dark IC50 in cancer cells) for Ir1 and Ir2 reached up to 22, highlighting their preferential activity in cancer cells. Mechanistic studies in MCF-7 cells with the most effective complex, Ir2, revealed that light exposure increased ROS production and induced mitochondrial depolarization and apoptosis via caspase 3/7 activation. © 2025 Elsevier B.V.
Antitumor activity of ethanolic extract of Dendrobium formosum in T-cell lymphoma: An in vitro and in vivo study
(Hindawi Publishing Corporation, 2014) Ritika Prasad; Biplob Koch
Dendrobium, a genus of orchid, was found to possess useful therapeutic activities like anticancer, hypoglycaemic, antimicrobial, immunomodulatory, hepatoprotective, antioxidant, and neuroprotective activities. The study was aimed to evaluate the anticancer property of the ethanolic extract of Dendrobium formosum on Dalton's lymphoma. In vitro cytotoxicity was determined by MTT assay, apoptosis was determined by fluorescence microscopy, and cell cycle progression was analysed using flow cytometry; in vivo antitumor activity was performed in Dalton's lymphoma bearing mice. The IC50 value of ethanolic extract was obtained at 350 g/mL in Dalton's lymphoma cells. Fluorescence microscopy analysis showed significant increase in apoptotic cell death in dose- and time-dependent manner which was further confirmed through the resulting DNA fragmentation. Further, flow cytometry analysis showed that the ethanolic extract arrests the cells in G2/M phase of the cell cycle. The in vivo anticancer activity study illustrates significant increase in the survival time of Dalton's lymphoma bearing mice on treatment with ethanolic extract when compared to control. These results substantiate the antitumor properties of ethanolic extract of Dendrobium formosum and suggest an alternative in treatment of cancer. Further studies are required regarding the isolation and characterization of bioactive components along with the analysis of molecular mechanism involved. © 2014 Ritika Prasad and Biplob Koch.
Aqua-(2-formylbenzoato)triphenyltin(IV) induces cell cycle arrest and apoptosis in hypoxic triple negative breast cancer cells
(Elsevier Ltd, 2023) Virendra Singh; Nishant Kumar Rana; Mohammad Kashif; Partha Pratim Manna; Tushar S. Basu Baul; Biplob Koch
Hypoxia plays a vital role in tumor microenvironment by allowing development and maintenance of cancer cells thereby led to major hindrance for effective anticancer therapy and main reason for failure of most anticancer drugs. We herein investigated the therapeutic efficacy and molecular mechanism of action of aqua-(2-formylbenzoato) triphenyltin (IV) compound (OTC) in MDA-MB-231 cell line. Cobalt chloride induced hypoxic MDA-MB-231 cells treated with OTC were used to access cytotoxicity, ROS, cellular apoptosis, and cell cycle progression. Further, expression of HIF-1α and VEGF, as well as apoptotic proteins like p53, Bax, Bcl-2 and caspase 3 were assessed. The findings indicated that OTC is more effective towards CoCl2 induced hypoxic cells when compared to normoxic cells and the results are far superior to doxorubicin. Additionally, our study revealed that OTC facilitates more ROS production induced cell cycle arrest and promote apoptosis. Furthermore, OTC significantly down regulates the expression of Hif-1α, VEGF and Bcl-2 in hypoxic condition and elevates the level of p53, Bax, cytochrome-C and Caspase 3. Our in vitro studies demonstrated that OTC showed better efficacy than doxorubicin, corroborating that OTC could be a promising compound for hypoxic cancer that also display multi drug resistant. © 2022 Elsevier Ltd
AS1411 aptamer/RGD dual functionalized theranostic chitosan-PLGA nanoparticles for brain cancer treatment and imaging
(Elsevier Ltd, 2024) Mahima Chauhan; Sonali; Saurabh Shekhar; Bhavna Yadav; Vandana Garg; Rohit Dutt; Abhishesh Kumar Mehata; Pooja Goswami; Biplob Koch; Madaswamy S. Muthu; Rahul Pratap Singh
Conventional chemotherapy and poor targeted delivery in brain cancer resulting to poor treatment and develop resistance to anticancer drugs. Meanwhile, it is quite challenging to diagnose/detection of brain tumor at early stage of cancer which resulting in severity of the disease. Despite extensive research, effective treatment with real-time imaging still remains completely unavailable, yet. In this study, two brain cancer cell specific moieties i.e., AS1411 aptamer and RGD are decorated on the surface of chitosan-PLGA nanoparticles to improve targeted co-delivery of docetaxel (DTX) and upconversion nanoparticles (UCNP) for effective brain tumor therapy and real-time imaging. The nanoparticles were developed by a slightly modified emulsion/solvent evaporation method. This investigation also translates the successful synthesis of TPGS-chitosan, TPGS-RGD and TPGS-AS1411 aptamer conjugates for making PLGA nanoparticle as a potential tool of the targeted co-delivery of DTX and UCNP to the brain cancer cells. The developed nanoparticles have shown an average particle size <200 nm, spherical in shape, high encapsulation of DTX and UCNP in the core of nanoparticles, and sustained release of DTX up to 72 h in phosphate buffer saline (pH 7.4). AS1411 aptamer and RGD functionalized theranostic chitosan-PLGA nanoparticles containing DTX and UCNP (DUCPN-RGD-AS1411) have achieved greater cellular uptake, 89-fold improved cytotoxicity, enhanced cancer cell arrest even at lower drug conc., improved bioavailability with higher mean residence time of DTX in systemic circulation and brain tissues. Moreover, DUCPN-RGD-AS1411 have greatly facilitated cellular internalization and higher accumulation of UCNP in brain tissues. Additionally, DUCPN-RGD-AS1411 demonstrated a significant suppression in tumor growth in brain-tumor bearing xenograft BALB/c nude mice with no impressive sign of toxicities. DUCPN-RGD-AS1411 has great potential to be utilized as an effective and safe theranostic tool for brain cancer and other life-threatening cancer therapies. © 2024 Elsevier B.V.
Azaspiroketal as Novel Auxochrome for Enhancing the Fluorescence Brightness and Solubility of Naphthalimide and Nitrobenzoxadiazole Dyes
(John Wiley and Sons Inc, 2024) Harish K. Indurthi; Pooja Goswami; Samarpita Das; Pallavi Saha; Biplob Koch; Deepak K. Sharma
The majority of fluorescence imaging techniques make considerable use of fluorescent dyes. Nevertheless, many structural modification techniques currently in use could not adjust the fluorophores′ properties (such as brightness, photostability, water solubility, and permeability). Herein, we report azaspiroketal-based auxochrome on naphthalimide and nitrobenzoxadiazole dyes. Their photophysical parameters revealed higher brightness and solubility than their azetidine counterparts in aqueous solution. Computational experiments were performed to study the electronic effect of azetidine and azaspiroketal on both dyes. Cytotoxicity assay indicated that azaspiroketal-based fluorophores are safe to use for their biological application. The photobleaching studies and successful application of new dyes in bioimaging were demonstrated in MDA-MB-231 cell lines. © 2024 Wiley-VCH GmbH.
Bioadhesive micelles of D-α-tocopherol polyethylene glycol succinate 1000: Synergism of chitosan and transferrin in targeted drug delivery
(Elsevier B.V., 2017) Poornima Agrawal; Sonali; Rahul Pratap Singh; Gunjan Sharma; Abhishesh K. Mehata; Sanjay Singh; Chellapa V. Rajesh; Bajarangprasad L. Pandey; Biplob Koch; Madaswamy S. Muthu
The aim of this work was to prepare targeted bioadhesive D-α- tocopheryl glycol succinate 1000 (TPGS) micelles containing docetaxel (DTX) for brain targeted cancer therapy. Considering the unique bioadhesive feature of chitosan, herein, we have developed a synergistic transferrin receptor targeted bioadhesive micelles using TPGS conjugated chitosan (TPGS-chitosan), which target the overexpressed transferrin receptors of glioma cells for brain cancer therapy. The micelles were prepared by the solvent casting method and characterized for their particle size, polydispersity, zeta-potential, surface morphology, drug encapsulation efficiency, and in-vitro release. The IC50 values demonstrated transferrin receptor targeted TPGS-chitosan micelles could be 248 folds more effective than Docel™ after 24 h treatment with the C6 glioma cells. Further, time dependent bioadhesive cellular uptake study indicated that a synergistic effect was achieved with the chitosan and transferrin in targeted TPGS-chitosan micelles through the biodhesive property of chitosan as well as transferrin receptor mediated endocytosis. The in-vivo pharmacokinetic results demonstrated that relative bioavailability of non-targeted and targeted micelles were 2.89 and 4.08 times more effective than Docel™ after 48 h of treatments, respectively. © 2017 Elsevier B.V.
Bright fluorescent biocompatible Magnozyme nanoclusters for brain-cell in-vivo live imaging
(Elsevier B.V., 2025) Prachi Srivastava; Vivek Kumar Verma; Abhishesh Kumar Mehata; Mamata K. Singh; Shivesh Sabbarwal; Madaswamy Sona S Muthu; Biplob Koch; Manoj Kumar
Multifluorescent, water-dispersible magnesium nanoclusters (Magnozyme) were obtained using a simple and economical synthesis procedure. The prepared particles were 4 nm in size, and they exhibited significant emission at 450, 545, and 628 nm with multiple excitations of 366,469 and 560 nm wavelengths. The prepared particle exhibited a maximum absolute quantum yield of 21.3, 6.8 % and 5 % in red, green and blue spectrum, respectively, with excellent photostability, good ionic strength tolerability, and broad-range pH stability. The prepared Magnozyme demonstrates 95 % cell viability in human glioma brain cell lines (U-87 MG) and can be used as a probe for cellular imaging. Furthermore, imaging with this brain cell revealed significant cytoplasmic accumulation in the red, green, and blue regions. The confocal Z-stack study revealed the presence of Magnozyme at a depth of the cellular level by capturing a series of images at different planer axes (z-axis). Furthermore, In-vivo toxicity assessments and in-vivo imaging in mice revealed the nontoxicity behavior of Magnozyme with their great staining ability in physiological conditions, confirming their candidature toward biological cell imaging/labeling purposes. © 2025 Elsevier B.V.
Bright-blue-emission nitrogen and phosphorus-doped carbon quantum dots as a promising nanoprobe for detection of Cr(vi) and ascorbic acid in pure aqueous solution and in living cells
(Royal Society of Chemistry, 2018) Vikas Kumar Singh; Virendra Singh; Pradeep Kumar Yadav; Subhash Chandra; Daraksha Bano; Vijay Kumar; Biplob Koch; Mahe Talat; Syed Hadi Hasan
Highly fluorescent nitrogen and phosphorus-doped carbon quantum dots (N,P-CQDs) were synthesized via a one-step hydrothermal method and fully characterized via various techniques such as TEM, DLS, FT-IR, P-XRD and XPS analysis. The as-synthesized N,P-CQDs showed excellent optical properties and exhibited bright blue colour under UV-light with CIE coordinate (0.20, 0.22) along with a high quantum yield of 73%, due to which they could act as on-off fluorescent nanoprobes for the selective and sensitive detection of highly toxic Cr(vi) below its permissible limit via the inner filter effect (IFE) and static quenching mechanism. In addition, Cr(vi) could be reduced to lower valent chromium species. Therefore, the N,P-CQDs + Cr(vi) system further acted as a selective off-on sensor for reductant ascorbic acid (AA) because it reduced Cr(vi) to Cr(iii) species, resulting in the elimination of IFE and recovery of fluorescence of N,P-CQDs. Notably, this system possesses excellent biocompatibility and negligible cytotoxicity; therefore, it can be potentially applied for fluorescence imaging of intracellular Cr(vi) and ascorbic acid (AA) in living cells and complex biological systems. © 2018 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Cabazitaxel-loaded redox-responsive nanocarrier based on d-alpha-tocopheryl-chitosan and hyaluronic acid for improved anti-tumor efficacy in DMBA-induced breast cancer model
(Royal Society of Chemistry, 2024) Abhishek Jha; Manish Kumar; Pooja Goswami; Kanchan Bharti; Manjit Manjit; Ashutosh Gupta; Sudheer Moorkoth; Biplob Koch; Brahmeshwar Mishra
The study involved the formulation of cabazitaxel loaded d-alpha-tocopheryl succinate/chitosan conjugate (CSVE) and hyaluronic acid (HA) based redox-responsive nanoparticles crosslinked using 3,3′-dithiodipropionic acid (DTPA). The nanoparticle surface was functionalized with cetuximab (Cmab) to give CSVE/HA/DTPA/Cmab NP for EGFR targeted delivery of the payload. The formulations were subjected to particle analysis, morphological assessment, solid-state characterization, and in vitro drug release studies. The results showed cationic, sub-200 nm sized spherical particles with the glutathione-responsive release of cabazitaxel. In vitro studies revealed a marked decrease in the IC50 value, improved cellular uptake, and a superior apoptotic effect. To determine the in vivo efficacy of the formulation, pharmacokinetic assessment, tumor regression analysis, and survival analysis were performed. The nanoparticles showed improved pharmacokinetic and anti-tumor efficacy compared to free cabazitaxel. The prepared nanoparticles demonstrated immense potential in targeted delivery of the payload for enhanced breast cancer therapy. © 2024 RSC.
Chitosan nanoplatform for the co-delivery of palbociclib and ultra-small magnesium nanoclusters: dual receptor targeting, therapy and imaging
(Ivyspring International Publisher, 2024) Abhishesh Kumar Mehata; Virendra Singh; Vikas; Prachi Srivastava; Biplob Koch; Manoj Kumar; Madaswamy S. Muthu
Theranostic nanoparticles have gained significant attention in cancer diagnosis and therapy. In this study, estrone (ES) and folic acid (FA) functionalized single and dual receptor targeted theranostic chitosan nanoparticles were developed for breast cancer imaging and therapy. These nanoparticles (NPs) were loaded with palbociclib (PB) and ultra-small magnesium nanoclusters (UMN). The developed nontargeted theranostic NPs (PB-UMN-CS-NPs), estrogen receptor targeted theranostic NPs (PB-UMN-CS-ES-NPs), folate receptor targeted theranostic NPs (PB-UMN-CS-FA-NPs), and dual targeted theranostic NPs (PB-UMN-CS-ES-FA-NPs) have particle sizes of 178.4 ± 1.21 nm, 181.6± 1.35 nm, 185.1± 1.33 nm, and 198.2± 1.43 nm with surface charges of +19.02± 0.382 mV, +13.89±0.410 mV, +16.72±0.527 mV and +15.23±0.377 mV, respectively. Cytotoxicity studies on estrogen receptor (ER) and folate receptor (FR) expressing breast cancer cells revealed that dual-targeted theranostic NPs (PB-UMN-CS-FA-ES-NPs) were more effective, inhibiting cell growth by 54.17 and 42.23 times in MCF-7 and T-47D cells compared to free PB, respectively. Additionally, developed NPs were capable of inhibiting the cell cycle progression of MCF-7 cells from the G1 phase to the S phase more efficiently compared to free PB. Ultrasound and photoacoustic (USG/PA) imaging demonstrated that dual targeted theranostic NPs were capable of effectively reducing hypoxic tumor volume and significantly suppressing tumor vascularity compared to free PB, nontargeted, FR targeted and ER targeted NPs. Moreover, in vivo optical imaging demonstrated tumor specific accumulation of the dual-targeted theranostic NPs. Furthermore, in vitro hemocompatibility and histopathological studies confirmed the biocompatibility of developed nanoformulations. © The author(s).