Journals
2025 EN
Sahu Nihar · Guchhait Chandrakanta · Mohanta Indrajit
+2 more
Abstract Certain proteins and synthetic covalent polymers experience aqueous phase transitions, driving functional self‐assembly. Herein, we unveil the ability of supramolecular polymers (SPs) formed by G 4 .Cu + to undergo heating‐induced unexpected aqueous phase transitions. For the first time, guided by Cu + , guanosine (G) formed a highly stable G‐quartet (G 4 .Cu + )/G‐quadruplex as a non‐canonical DNA secondary structure with temperature tolerance, distinct from the well‐known G 4 .K + . The G 4 .Cu + self‐assembled in water through π‐π stacking, metallophilic and hydrophobic interactions, forming thermally robust SPs. This enhanced stability is attributed to the stronger coordination of Cu + to four carbonyl oxygens of G‐quartet and the presence of Cu + ‐ ‐ ‐Cu + attractive metallophilic interactions in Cu + ‐induced G‐quadruplex, exhibiting a significantly higher interaction energy than K + as determined computationally. Remarkably, the aqueous SP solution exhibited heating‐induced phase transitions—forming a hydrogel through dehydration‐driven crosslinking of SPs below cloud temperature ( T cp ) and a hydrophobic collapse‐induced solid precipitate above T cp , showcasing a lower critical solution temperature (LCST) behavior. Notably, this LCST behavior of G 4 .Cu + SP originates from biomolecular functionality rather than commonly exploited thermo‐responsive oligoethylene glycols with supramolecular assemblies. Furthermore, exploiting the redox reversibility of Cu + /Cu 2+ , we demonstrated control over the assembly and disassembly of G‐quartets/G‐quadruplex and gelation reversibly.
Journals
2025 EN
Das Sujit · Jain Amul · Ahamed Subuhan
+9 more
Abstract Two unprecedented redox‐active, low‐spin Fe(III)‐triradical complexes, [Fe(III)(SS‐NHC═S •− ) 3 ]·NHC═S ( 1 ·NHC═S; E═S) and [Fe(III)(SS‐NHC═Se •− ) 3 ] ( 2 ; E═Se) have been synthesized and structurally characterized by SCXRD. They were further characterized spectroscopically using IR, Raman, EPR, and UV–vis‐NIR spectroscopy. The low‐spin electronic configuration of the central Fe(III) ion ( 1 ) and the nature of the magnetic interaction between the Fe(III) center and the three unpaired electrons in 1 have been investigated by magnetic measurements. In addition, the bonding stability and electron density distribution in 1 were studied by quantum chemical calculations and correlated with experimental results. Finally, a series of well‐defined functional homopolymers were synthesized via catalytic polymerization reactions using [Fe(III)(SS‐NHC═S •− ) 3 ] ( 1 ) as a catalyst at ambient temperature. These reactions yielded poly( N , N ‐dimethylacrylamide) (PDMA), poly( N ‐isopropyl acrylamide) (PNIPAM), poly(dimethyl amino ethyl methacrylate) (PDMAEMA), and poly(benzyl methacrylate) (PBzMA) with low dispersities ranging from 1.2 to 1.22. The successful synthesis of various diblock copolymers confirmed excellent chain‐end fidelity of the synthesized homopolymers. These homopolymers and diblock copolymers highlight the versatile catalytic polymerization reactions of these Fe‐radical complexes. Herein, we present a report on the polymerization of various acrylamides and methacrylates using a redox‐active Fe‐dithiolene complex for the first time.
Journals
2025 EN
Sahu Bhanendra · Paul Sudipta · Sinha Priyank
+1 more
Abstract Sulfur‐dots (S‐dots) serve as a cost‐effective and non‐toxic alternative to traditional photocatalysts or transition metals typically required in photoinduced reversible deactivation radical polymerization (photoRDRP). Herein, we report a facile and efficient method for synthesizing well‐defined multi‐arm star polymers through S‐dots mediated photoRDRP under ambient conditions. This approach enables precise control over polymer growth with excellent spatiotemporal control over polymerization, as evidenced by the ability to pause and resume polymerization with UVA light (“ON/OFF” switching). This methodology was successfully applied to produce a variety of polymer architectures, including multi‐arm star homopolymers and dual‐responsive diblock and triblock copolymers. Among these, the synthesized 4‐arm star [poly(N,N‐dimethyl acrylamide)‐ block ‐poly(dimethyl amino ethyl methacrylate)‐ block ‐poly(butyl acrylate)] 4 ‐Br [4‐arm star (PDMA‐ b ‐PDMAEMA‐ b ‐PBA) 4 ‐Br] triblock copolymer was used to assess pH and temperature responsiveness. This work introduces a sustainable, metal‐free route for the development of next‐generation smart polymers suitable for biomedical and environmental applications and highlights the versatility of S‐dots as a catalyst.
Journals
2025 EN
Sahu Ashish · Bhavsar Vaidehi · Taware Ravindra
ABSTRACT This study utilized an untargeted metabolomic approach using LC‐MS/MS to analyze the metabolic alterations in extracellular vesicles (EVs) secreted by breast cancer cells under hypoxic conditions. EVs were isolated using an established ultracentrifugation protocol, and their homogeneity was assessed through TEM, SEM, NTA, and immunoblotting. Metabolic extracts from hypoxic EVs were found to enhance breast cancer cell migration, invasion, and epithelial–mesenchymal transition (EMT), underscoring their role in tumor progression. Metabolomic analysis identified over 400 annotated metabolites, with univariate statistical analysis ( p < 0.05, Log 2 FC > 0.58/< −0.58) revealing 48 significantly altered metabolites in MDA‐MB‐231‐ and MCF‐7‐derived EVs, respectively, indicating substantial metabolic reprogramming under hypoxia. Integrated univariate and multivariate analyses ( p < 0.05, Log 2 FC > 0.58/< −0.58, VIP > 1) identified key upregulated metabolites, including riboflavin, 5,6‐epoxy‐8,11,14‐eicosatrienoic acid, and furandicarboxylic acid, in hypoxic EVs from both cell lines. Additionally, N‐acetyl‐ l ‐methionine, 2,6‐diamino‐4‐hydroxy‐5‐N‐methylformamidopyrimidine, and 5,10‐methenyltetrahydrofolic acid were identified as critical metabolites potentially influencing cell proliferation, DNA damage, and epigenetic regulation. Metabolic pathway analysis highlighted heightened activity in aromatic amino acid and riboflavin metabolism. These findings reveal significant metabolic alterations in hypoxic EVs, providing insights into their potential role in driving tumor progression.
Journals
2025 EN
Umeda Masataka · Karino Kohei · Satyam Abhigyan
+14 more
Objective Enhanced expression of transforming growth factor (TGF) β in the kidneys of patients with lupus nephritis (LN) can lead to progressive fibrosis, resulting in end‐organ damage. ADAM9 activates TGFβ1 by cleaving the latency‐associated peptide (LAP). We hypothesized that ADAM9 in the kidney may accelerate fibrogenesis by activating TGFβ1. Methods We assessed the expression of ADAM9 in the kidneys of mice and humans who were lupus prone. In vitro experiments were conducted using tubular epithelial cells (TECs) isolated from mice and explored the mechanisms responsible for the up‐regulation of ADAM9 and the subsequent activation of TGFβ1. To assess the role of ADAM9 in the development of tubular‐intestinal fibrosis in individuals with LN, we generated MRL/ lpr mice who were Adam9 deficient. Results ADAM9 was highly expressed in tubules from MRL /lpr mice. The transcription factor hypoxia‐inducible factor–1α was found to promote the transcription of ADAM9 in TECs. TECs from mice who were Adam9 deficient and exposed to the hypoxia mimetic agent dimethyloxalylglycine failed to cleave the LAP to produce bioactive TGFβ1 from latent TGFβ1. Coculture of TECs from mice who were Adam9 deficient with fibroblasts in the presence of dimethyloxalylglycine and latent TGFβ1 produced decreased amounts of type I collagen and α–smooth muscle actin (SMA) by fibroblasts. MRL/ lpr mice who were Adam9 deficient showed reduced interstitial fibrosis. At the translational level, ADAM9 expression in tissues and urine of patients with LN was found to increase. Conclusion Hypoxia promotes the expression of ADAM9 by TECs, which is responsible for the development of interstitial fibrosis in patients with LN by enhancing the TGFβ1 activation, which promotes fibroblasts to produce collagen and α‐SMA.
Journals
2025 EN
Sahu Neety · Bedi Yudhishtar Singh · Grandi Fiorella
+3 more
Objective Osteoarthritis (OA) is a chronic, debilitating disease with no available disease‐modifying drugs. Biomarker identification in patients with OA has hitherto been limited to serum proteins and bulk epigenomic feature identification. Methods Peripheral blood mononuclear cells (PBMCs) from 21 healthy donors, 17 patients with OA, and 10 patients with degenerative meniscal tears (DMTs) were immunophenotyped at single‐cell resolution by mass cytometry by time‐of‐flight using a 29‐marker panel to identify OA‐associated features in the circulating immune cells. Single‐cell RNA sequencing was used to discern mechanistic attributes of perturbed immune cell populations in OA. Results Comparison of the PBMCs of healthy donors and OA patients revealed distinct perturbations in OA. Although subsets of naive B cells were depleted, switched memory B cells were significantly expanded in OA, including a CD25 hi CXCR5 hi CD27 + IgD − subpopulation. Single‐cell RNA sequencing revealed a dysfunction of interleukin 2/Stat5 and tumor necrosis factor signaling in the CD25 hi switched memory B cells in OA. A similar expansion of CD25 hi switched memory B cells was observed in patients with DMT, a population at enhanced risk for OA. Conclusion A CD25 hi switched memory B cell population was identified to be a potential cellular biomarker for OA that can be detected in the early stages of OA in the readily accessible circulating blood cells.
Journals
2025 EN
Vasudevan Ashwini · Ghosal Doyel · Ram Sahu Sita
+4 more
Abstract Injectable hydrogels are a sub‐type of hydrogels which can be delivered into the host in a minimally invasive manner. They can act as carriers to encapsulate and deliver cells, drugs or active biomolecules across several disease conditions. Polymers, either synthetic or natural, or even a combination of the two, can be used to create injectable hydrogels. Clinically approved injectable hydrogels are being used as dressings for burn wounds, bone and cartilage reconstruction. Injectable hydrogels have recently gained tremendous attention for their delivery into the liver in pre‐clinical models. However, their efficacy in clinical studies remains yet to be established. In this article, we describe principles for the design of these injectable hydrogels, delivery strategies and their potential applications in facilitating liver regeneration and ameliorating injury. We also discuss the several constraints related to translation of these hydrogels into clinical settings for liver diseases and deliberate some potential solutions to combat these challenges.
Journals
2025 EN
Parsai Priya · Choudhary Neha · Sahu Rajib
+1 more
Abstract This study presents a highly efficient and cost‐effective Cu/CeO 2 catalyst for the acceptorless dehydrogenative coupling (ADC) of o ‐aminobenzyl alcohols and secondary alcohols to synthesize quinolines. The catalyst demonstrated over 90 % yield in quinoline production under mild conditions, exhibiting excellent tolerance to various functional groups. The Cu/CeO 2 catalyst, synthesized via a co‐precipitation method, was thoroughly characterized through various techniques like PXRD, XPS, and AC‐STEM. Control experiments confirmed the ADC pathway, where both alcohol substrates underwent dehydrogenation, forming key intermediates that subsequently condensed to produce quinolines. This catalytic system, offering recyclability and high efficiency, is a promising alternative to noble metal‐based catalysts for sustainable quinoline synthesis.
Journals
2025 EN
Nandi Nilanjana · Sarkar Priyanka · Barnwal Neha
+1 more
Abstract Discovered only in 2004, carbon dots (CDs) have already traversed a long journey, generating many promising research directions. Its cheapness, ease of synthesis, high water‐solubility, tunable emission, and excellent biocompatibility make it a single‐point solution to many problems, and tremendous efforts were invested into understanding the structure‐property‐function relationship, which eases the engineering of the CD properties suitable for a desired application. From the usual random choice of precursors or carbon materials as a starting point in the early days, more systematic approaches are now available for choosing proper starting materials and appropriate experimental conditions (solvent medium, reaction temperature, reaction duration, pH, etc) to customize its photoluminescence. The presence of impurities has a crucial role in the outcome and applicability of photoluminescence. Recently, a significant focus has been on the long‐wavelength emissive CDs, particularly in the red to near‐infrared (NIR) regions, for better penetration into live cells and to circumvent autofluorescence problems. Proper design can harvest phosphorescence from CDs. Many excellent reviews are available, focusing on different facets of CD prospects. Hence, we will only highlight the importance of the optical properties of CDs and ways to modulate them. We will mention some of the new works that have appeared in the last five years.
Journals
2025 EN
Sahu Jitendra K. · Adhikary Rajsekhar · Dalal Sancharika
+2 more
Abstract Interactions of aromatic nitrogen and carboxylate group of 1H‐pyrazole‐3,5‐dicarboxylic acid (PDC) with bivalent Zn(II) metal ions and gold nanoparticle (AuNP, average diameter ~16 nm) surface has been targeted in this current study. The time‐dependent absorption and structural analysis experimentally demonstrate the combined role of PDC and metal ion towards the self‐assembly of AuNP. The collective interaction in solution triggers self‐assembly, which results in the synthesis of unique Au/Zn@PDC supra‐plates at room temperature. The Zn(II) induced supra‐plates have been further characterized by X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). The selectivity of the self‐assembly for supra‐plate architectures has been verified with handful of other metal ions such as Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Mg(II) and Pb(II). Among these studied metal ions, Pb(II) only provides the self‐assembled supra‐sphere formation under identical conditions. Pb(II) being a toxic metal ion, antibacterial properties have been explored for Au/Zn@PDC supra‐plates with four significant human pathogens: Methicillin‐resistant Staphylococcus aureus (MRSA) ATCC BAA‐44, Methicillin‐sensitive Staphylococcus aureus (MSSA) S18 (clinical isolate), Klebsiella pneumoniae ATCC BAA‐1706, and Klebsiella pneumoniae MDR 36 (clinical isolate). Compared to the parent constituents, these bacterial cells experience greater damage to the cell wall, when treated with Au/Zn@PDC supra‐plates with a minimum inhibitory concentration (MIC) of 0.2‐0.8 ng/mL.