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Surface-Engineered Nanomaterials for Optical Array Based Sensing. Chempluschem 2024; 89:e202300610. [PMID: 38109071 DOI: 10.1002/cplu.202300610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/01/2023] [Indexed: 12/19/2023]
Abstract
Array based sensing governed by optical methods provides fast and economic way for detection of wide variety of analytes where the ideality of detection processes depends on the sensor element's versatile mode of interaction with multiple analytes in an unbiased manner. This can be achieved by either the receptor unit having multiple recognition moiety, or their surface property should possess tuning ability upon fabrication called surface engineering. Nanomaterials have a high surface to volume ratio, making them viable candidates for molecule recognition through surface adsorption phenomena, which makes it ideal to meet the above requirements. Most crucially, by engineering a nanomaterial's surface, one may produce cross-reactive responses for a variety of analytes while focusing solely on a single nanomaterial. Depending on the nature of receptor elements, in the last decade the array-based sensing has been considering as multimodal detection platform which operates through various pathway including single channel, multichannel, binding and indicator displacement assay, sequential ON-OFF sensing, enzyme amplified and nanozyme based sensing etc. In this review we will deliver the working principle for Array-based sensing by using various nanomaterials like nanoparticles, nanosheets, nanodots and self-assembled nanomaterials and their surface functionality for suitable molecular recognition.
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Reversing the Trend: Deciphering Self-Assembly of Unconventional Amphiphiles Having Both Alkyl-Chain and PEG. Chempluschem 2024:e202400147. [PMID: 38623044 DOI: 10.1002/cplu.202400147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 04/17/2024]
Abstract
In the field of molecular self-assembly, the core of an assembly is always made up of hydrophobic moiety like a long alkyl chain, whereas the outer part has always been a hydrophilic moiety such as poly(ethylene glycol) (PEG), or charged species. Hence, reversing the trend to manifest self-assembled structures with a PEG core and a surface consisting of alkyl chains in aqueous system is incredibly challenging. Herein, we architected a unique class of cationic bolaamphiphiles containing low molecular weight PEG and alkyl chains of different lengths. The bolaamphiphiles spontaneously form vesicles without external stimuli. These vesicles are unprecedented because PEG makes up the vesicle core, while the alkyl chains appear on the vesicles' exterior. Hence, this particular design reverses the usual trend of self-assembly formation. The vesicle size increases with the increase in alkyl chain-length. To our great surprise, we obtained large micelles for longest alkyl-chain amphiphile, which in turn act as a gemini amphiphile. The shift from a particular bolaamphiphile to gemini amphiphile with the variation of alkyl chain is also unexplored. Therefore, this specific class of self-assembled structure would compound a new paradigm in molecular self-assembly and supramolecular chemistry.
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Thiol ligand-mediated exfoliation of bulk sulfur to nanosheets and nanodots: applications in antibacterial activity. J Mater Chem B 2024; 12:973-983. [PMID: 38175035 DOI: 10.1039/d3tb02403b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Reducing bulk materials to layers or dots results in profound alterations in their physiochemical and optoelectronic properties, leading to a wide array of applications, spanning from device manufacturing to biomedicine. In this regard, the preparation of sulfur nanomaterials has garnered significant attention due to their low toxicity. Traditional methods for sulfur nanomaterial synthesis often involve harsh reaction conditions, leaving a gap for convenient approaches to create nanomaterials, such as nanosheets (NSs) and nanodots (NDs). Herein, the mechanical exfoliation of bulk sulfur using a surfactant thiol ligand with probe sonication is reported, making a unique contribution to existing methods. In the reported method, the thiol group binds to sulfur surfaces, facilitating exfoliation and stabilization, while the hydrophilic ends provide functional groups for exfoliated nanomaterials. Exfoliation can yield either nanosheets or nanodots, depending on the thiol ligand and exfoliation time. This approach offers the opportunity to exfoliate bulk sulfur using bioactive thiol ligands. With this goal in mind, bulk sulfur was exfoliated with 4-mercaptophenylboronic acid (BA) to target Gram-positive bacteria. This innovative exfoliation strategy of bulk sulfur using thiol ligands holds immense promise for synthesizing functionalized sulfur nanomaterials with wide-ranging applications, particularly in biomedicine.
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Photo-Controlled Gating of Selective Bacterial Membrane Interaction and Enhanced Antibacterial Activity for Wound Healing. Angew Chem Int Ed Engl 2024; 63:e202314804. [PMID: 37955346 DOI: 10.1002/anie.202314804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/11/2023] [Accepted: 11/13/2023] [Indexed: 11/14/2023]
Abstract
Reversible biointerfaces are essential for on-demand molecular recognition to regulate stimuli-responsive bioactivity such as specific interactions with cell membranes. The reversibility on a single platform allows the smart material to kill pathogens or attach/detach cells. Herein, we introduce a 2D-MoS2 functionalized with cationic azobenzene that interacts selectively with either Gram-positive or Gram-negative bacteria in a light-gated fashion. The trans conformation (trans-Azo-MoS2 ) selectively kills Gram-negative bacteria, whereas the cis form (cis-Azo-MoS2 ), under UV light, exhibits antibacterial activity against Gram-positive strains. The mechanistic investigation indicates that the cis-Azo-MoS2 exhibits higher affinity towards the membrane of Gram-positive bacteria compared to trans-Azo-MoS2 . In case of Gram-negative bacteria, trans-Azo-MoS2 internalizes more efficiently than cis-Azo-MoS2 and generates intracellular ROS to kill the bacteria. While the trans-Azo-MoS2 exhibits strong electrostatic interactions and internalizes faster into Gram-negative bacterial cells, cis-Azo-MoS2 primarily interacts with Gram-positive bacteria through hydrophobic and H-bonding interactions. The difference in molecular mechanism leads to photo-controlled Gram-selectivity and enhanced antibacterial activity. We found strain-specific and high bactericidal activity (minimal bactericidal concentration, 0.65 μg/ml) with low cytotoxicity, which we extended to wound healing applications. This methodology provides a single platform for efficiently switching between conformers to reversibly control the strain-selective bactericidal activity regulated by light.
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2D-MoS 2-supported copper peroxide nanodots with enhanced nanozyme activity: application in antibacterial activity. NANOSCALE 2023; 15:19801-19814. [PMID: 38051093 DOI: 10.1039/d3nr05458f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Peroxidase (POD)-like nanozymes are an upcoming class of new-generation antibiotics that are efficient for broad-spectrum antibacterial action. The POD-like activity employs the generation of reactive oxygen species (ROS), which have been utilized for bactericidal action. However, their intrinsic low catalytic activity and stability limit their bactericidal properties. In this study, we prepared a MoS2-based nanocomposite with copper peroxide nanodots (MoS2@CP) to achieve pH-dependent light-induced nanozyme-based antibacterial action. It has shown superior peroxidase and antibacterial activity at low pH. The mechanism behind the enhanced POD-like activity and high antibacterial activity was established. The mechanistic pathway involves estimating ROS generation, membrane depolarization, inner membrane permeabilization, metal ion release, and the effect of NIR on photothermal and photodynamic activities. Overall, our work highlighted the combinatorial approach for eradicating bacterial infections using enzyme-based antibacterial agents.
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Semiconductor Quantum Dots Act as Photocatalysts for Carbon-Carbon Bond Formation: Selective Functionalization of Xanthene's 9H Position. J Org Chem 2023; 88:16292-16301. [PMID: 37978938 DOI: 10.1021/acs.joc.3c01801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The potential of CdSe, CdS, MoS2, and WS2 QDs as semiconductor photocatalysts for selective functionalization of the xanthene 9H position through carbon-carbon bond formation has been investigated. Our study reveals valuable insights into the energy-transfer and electron-transfer pathways involved in these reactions, as well as the radical polar crossover (RPC) and triplet-to-triplet energy transfer (TTEnT) processes. Notably, this approach offers a range of intriguing features, including visible-light-mediated processes, inexpensive catalytic systems, mild reaction conditions, broad substrate scope, unfunctionalized starting materials, and suitability for gram-scale synthesis. This study makes a significant contribution to the newly emerging field of QD-catalyzed reactions, paving the way for future explorations.
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Post-functionalization of sulfur quantum dots and their aggregation-dependent antibacterial activity. NANOSCALE 2023; 15:18624-18638. [PMID: 37975185 DOI: 10.1039/d3nr04287a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Sulfur quantum dots (SQDs) have emerged as an intriguing class of luminescent nanomaterial due to their exceptional physiochemical and optoelectronic properties. However, their biomedical application is still in its infancy due to the limited scope of their surface functionalization. Herein, we explored the surface functionalization of SQDs through different thiol ligands with tuneable functionality and tested their antibacterial efficacy. Notably, very high antibacterial activity of functionalized SQDs (10-25 ng ml-1) was noted, which is 105 times higher compared to that of nonfunctionalized SQDs. Moreover, a rare phenomenon of the reverse trend of antibacterial activity through surface modification was observed, with increasing surface hydrophobicity of various nanomaterials as the antibacterial activity increased. However, we also noted that as the surface hydrophobicity increased, the SQDs tended to exhibit a propensity for aggregation, which consequently decreased their antibacterial efficacy. This identical pattern was also evident in in vivo assessments. Overall, this study illuminates the importance of surface modifications of SQDs and the role of surface hydrophobicity in the development of antibacterial agents.
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Synthesis of biologically important tetrahydroisoquinoline (THIQ) motifs using quantum dot photocatalyst and evaluation of their anti-bacterial activity. Org Biomol Chem 2023; 21:9049-9053. [PMID: 37936558 DOI: 10.1039/d3ob01305g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Our study introduces an efficient photocatalytic approach for synthesizing biologically significant C1-substituted tetrahydroisoquinoline (THIQ) motifs, employing WS2 quantum dots (QDs) as catalysts. This method enables the formation of C-C and C-P bonds at the C1 position of the THIQ motif. The resulting compounds exhibit substantial antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) bacteria, with low minimum inhibitory concentration (MIC) values. Notably, the WS2 QD catalyst demonstrates recyclability and suitability for gram-scale reactions, underscoring the sustainability and scalability of our approach. Overall, our research presents a versatile and cost-effective strategy for synthesizing C1-substituted THIQ derivatives, highlighting their potential as novel therapeutic agents in biology and medicinal chemistry.
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012 facets modulated LDH composite for neurotoxicity risk assessment through direct electrochemical profiling of dopamine. CHEMOSPHERE 2023; 342:140177. [PMID: 37716554 DOI: 10.1016/j.chemosphere.2023.140177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/01/2023] [Accepted: 09/12/2023] [Indexed: 09/18/2023]
Abstract
Rising concerns of pesticide-induced neurotoxicity and neurodegenerative diseases like Parkinson's, Alzheimer's, and Multiple Sclerosis, are exacerbated by overexposure to contaminated waterbodies. Therefore, evaluating the risk accurately requires reliable monitoring of related biomarkers like dopamine (DA) through electrochemical detection. Layered double hydroxides (LDHs) have shown great potential in sensors. However, to meet the challenges of rapid detection of large patient cohorts in real-time biological media, they should be further tailored to display superior analytical readouts. Herein, a ternary LDH (Ni2CoMn0.5) was integrated with the sheets of thermally reduced graphene oxide (trGO), to expose more highly active edge planes of the LDH, as opposed to its generally observed inert basal planes. The improvement in detection performance through such a modulated structure-property is a prospect that hasn't been previously explored for any other LDH-based materials employed in sensing applications. The 2 folds superior electrochemical activity exhibited by the face-on oriented LDH with trGO as compared to the pristine LDH material was further employed for direct detection of DA in real blood plasma samples. Moreover, the designed sensor exhibited exceptional selectivity towards the detection of DA with a limit of detection of 34.6 nM for a wide dynamic range of 0.001-5 mM with exceptional stability retaining 88.56% of the initial current even after storage in ambient conditions for 30 days.
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Liposome-Based Antibacterial Delivery: An Emergent Approach to Combat Bacterial Infections. ACS OMEGA 2023; 8:35442-35451. [PMID: 37810644 PMCID: PMC10551917 DOI: 10.1021/acsomega.3c04893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 09/08/2023] [Indexed: 10/10/2023]
Abstract
The continued emergence and spread of drug-resistant pathogens and the decline in the approval of new antimicrobial drugs pose a major threat to managing infectious diseases, resulting in high morbidity and mortality. Even though a significant variety of antibiotics can effectively cure many bacterial infectious diseases, microbial infections remain one of the biggest global health problems, which may be due to the traditional drug delivery system's shortcomings which lead to poor therapeutic index, low drug absorption, and numerous other drawbacks. Further, the use of traditional antibiotics to treat infectious diseases has always been accompanied by the emergence of multidrug resistance and adverse side effects. Despite developing numerous new antibiotics, nanomaterials, and various techniques to combat infectious diseases, they have persisted as major global health issues. Improving the current antibiotic delivery systems is a promising approach to solving many life-threatening infections. In this context, nanoliposomal systems have recently attracted much attention. Herein, we attempt to provide a concise summary of recent studies that have used liposomal nanoparticles as delivery systems for antibacterial medicines. The minireview also highlights the enormous potential of liposomal nanoparticles as antibiotic delivery systems. The future of these promising approaches lies in developing more efficient delivery systems by precisely targeting bacterial cells with antibiotics with minimum cytotoxicity and high bacterial combating efficacy.
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Nanomaterials in photocatalysed organic transformations: development, prospects and challenges. Chem Commun (Camb) 2023; 59:5987-6003. [PMID: 37098878 DOI: 10.1039/d3cc00993a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Photoredox catalysis has gained widespread attention in recent years as a powerful tool to drive chemical transformations in the presence of light, particularly for molecules that are capable of showing redox activity. A typical photocatalytic pathway may involve electron or energy transfer processes. To date, photoredox catalysis has been explored mainly with Ru, Ir and other metal or small molecule based photocatalysts. Due to their homogeneous nature, they cannot be reused and are not economical. These factors have motivated researchers to look for an alternate class of photocatalysts which are more economical and reusable, thus paving the way for protocols that can be easily transferred to the industrial sectors as well. In this regard, scientists have come up with various nanomaterials as sustainable and economical alternatives. These have unique properties that arise from their structure, surface functionalization, etc. Apart from that, at the lower dimensions, they bear an increased surface to volume ratio, which can provide an enhanced number of active sites for catalysis. Nanomaterials have been used for various applications like sensing, bioimaging, drug delivery, energy generation, etc. However, their potential as photocatalysts for organic transformations has been taken up as a subject of research quite recently. This article focusses on the use of nanomaterials in photo-mediated organic transformations with a wider goal to motivate readers from materials as well as organic synthetic backgrounds to dig deeper into this area of research. Various reports have been included to cover the plethora of reactions that have been explored with nanomaterials as a photocatalyst. The scientific community has also been introduced to the challenges and prospects of the field, which will further help in its growth. In a nutshell, this writeup will help to cater to the interest of a large group of researchers to highlight the prospects of nanomaterials in photocatalysis.
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Solvent Induced Conversion of a Self-Assembled Gyrobifastigium to a Barrel and Encapsulation of Zinc-Phthalocyanine within the Barrel for Enhanced Photodynamic Therapy. Angew Chem Int Ed Engl 2023; 62:e202218226. [PMID: 36715420 DOI: 10.1002/anie.202218226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/28/2023] [Accepted: 01/30/2023] [Indexed: 01/31/2023]
Abstract
A rare gyrobifastigium architecture (GB) was constructed by self-assembly of a tetradentate donor (L) with PdII acceptor in DMSO. The GB was converted to its isomeric tetragonal barrel (MB) upon treatment with water. The hydrophobic cavity of MB has been explored for the encapsulation of zinc-phthalocyanine (ZnPc), which is an excellent photosensitizer for photodynamic therapy (PDT). However, the poor water-solubility and aggregation tendency are the main reasons for the suboptimal PDT performance of free ZnPc in the aqueous medium. Effective solubilization of ZnPc in an aqueous medium was achieved by encapsulating it in the cavity of MB. The inclusion complex (ZnPc⊂MB) showed enhanced singlet oxygen generation in water. Higher cellular uptake and anticancer activity of the ZnPc⊂MB compared to free ZnPc on HeLa cells indicate that encapsulation of ZnPc in an aqueous host is a potential strategy for enhancement of its PDT activity in water.
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Solvent Induced Conversion of a Self‐Assembled Gyrobifastigium to a Barrel and Encapsulation of Zinc‐Phthalocyanine within the Barrel for Enhanced Photodynamic Therapy. Angew Chem Int Ed Engl 2023. [DOI: 10.1002/ange.202218226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Ligand-Mediated Exfoliation and Antibacterial Activity of 2H Transition-Metal Dichalcogenides. ACS APPLIED BIO MATERIALS 2023; 6:126-133. [PMID: 36512447 DOI: 10.1021/acsabm.2c00791] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Transition-metal dichalcogenides (TMDs) exists mainly in two polymorphs, namely, 1T (metallic) and 2H (semiconducting). To tailor the characteristics and practical utility of TMDs for different applications, functionalization is essential. In our earlier studies, we have shown that functionalized 1T and 2H MoS2 exhibit exceptionally high antibacterial activity. The functionalization and related biological applications of other 1T (chemically exfoliated) TMDs were reported, but regarding other 2H TMDs, the functionalization and antibacterial activity are not explored yet. Hence, here we prepared functionalized 2H TMDs such as WS2, WSe2, and MoSe2 other than MoS2 by using a positively charged thiolate surfactant ligand. Further, functionalized 2H TMDs were utilized for antibacterial activity against Gram-positive and Gram-negative bacteria for a comparative antibacterial analysis. Interestingly, we found disparity in activity among the functionalized 2H TMDs, that is, MoS2 shows higher activity than WS2 followed by MoSe2 and WSe2. The intracellular reactive oxygen species measurement was found to be in the order MoS2 > WS2 > MoSe2 > WSe2, which is solely responsible for variation in the activity of functionalized TMDs. These results indicate that the easy functionalization of all types TMDs by using thiol ligand and importance of core material should be considered while designing functionalized material for specific applications.
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Time resolved fluorescence sensor array for discrimination of phosphate anions by using transition metal dichalcogenide quantum dots and Tb (III). LUMINESCENCE 2022. [PMID: 36515684 DOI: 10.1002/bio.4424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/28/2022] [Accepted: 12/06/2022] [Indexed: 12/15/2022]
Abstract
Phosphate detection has garnered widespread attention due to their biological and environmental impact. Among several optical techniques, time resolved fluorescence (TRF) provides a sensitive way for discrimination of analytes in a complex mixture as it suffers less interference from the background, thus providing a high signal to noise ratio. The sensitization of rare earth metal (REM) ions by semiconducting quantum dots (QDs) can help the former overcome the drawback of low absorption coefficient, thus allowing one to exploit the additional advantage of the REM, viz, the long-excited state lifetime. Herein, we have developed a TRF based sensor array consisting of three QDs, i.e., MoS2 , WS2 and MoSe2 as energy sensitizers to Tb3+ ion. Different QDs possess variable energy transfer ability to Tb3+ ion. Hence, they can be used for discrimination of phosphates. It was also observed that CrO4 2- can competitively bind to Tb3+ and further, enhance the efficiency of the sensor array which could discriminate six different phosphates at 200 μM concentration in aqueous as well as serum media with a detection limit of 10 μM in aqueous media. Thus, the sensitivity of the TRF based sensor array is rarely compromised in a complex mixture, which is advantageous over a fluorescence-based sensor array.
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Ligand Exchange on MoS 2 Nanosheets: Applications in Array-Based Sensing and Drug Delivery. ACS NANO 2022; 17:1000-1011. [PMID: 36482513 DOI: 10.1021/acsnano.2c06994] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Two-dimensional MoS2 nanosheets (2D-MoS2) have been widely used in many biological applications due to their distinctive physicochemical properties. Further, the development of surface modification using thiolated ligands allows us to use them for many specific applications. But the effect of possible ligand exchange on 2D-MoS2 has never been explored, which can play an important role in diverse biological applications. In this study, we have observed the ligand-exchange phenomenon on 2D-MoS2 in the presence of different thiolated ligands. The initial study proceeded with boron-dipyrromethene (BODIPY) functionalized MoS2 with different concentrations of glutathione (GSH), which is the most abundant thiol species in the cytoplasm of various cancer cells. It was found that in the presence of GSH the fluorescence of BODIPY can be regenerated, which is time and concentration dependent. We have also examined this phenomenon with different thiol ligands and transition-metal dichalcogenides (TMDs). We observed a variable rate of ligand exchange in different solvents, surface functionality, and receptor environments that helped us to construct sensor arrays. Interestingly, a ligand-exchange process was not observed in the presence of dithiols. Further, this concept was applied to a cancerous cell line for in vitro delivery. We found that BODIPY-functionalized 2D-MoS2 undergoes thiol exchange by intracellular GSH and subsequently enhanced the fluorescence in the cytoplasm of cancer cells. This strategy can be applied to the development of 2D-TMD-based materials for various biological applications related to ligand exchange.
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Shifting the Triangle-Square Equilibrium of Self-Assembled Metallocycles by Guest Binding with Enhanced Photosensitization. Inorg Chem 2022; 61:17289-17298. [PMID: 36252183 DOI: 10.1021/acs.inorgchem.2c02920] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Shifting a triangle-square equilibrium in one direction is an important problem in supramolecular self-assembly. Reaction of a benzothiadiazole-based diimidazole donor with a cis-Pt(II) acceptor yielded an equilibrium mixture of a triangle ([C18H24N10O6S1Pt1]3≡ PtMCT) and a square ([C18H24N10O6S1Pt1]4≡ PtMCS). We report here the shifting of such equilibrium toward a triangle using a guest (pyrene aldehyde, G1). While both benzothiadiazole and pyrene aldehyde can form reactive oxygen species (ROS) in organic solvents, their therapeutic use in water is restricted due to aqueous insolubility. The enhanced water solubility of the benzothiadiazole unit and G1 by macrocycle formation and host-guest complexation, respectively, enabled enhanced ROS generation by the host-guest complex (G1' ⊂ PtMCT) in water (G1' = hydrated form of G1). The guest-encapsulated metallacycle (G1' ⊂ PtMCT) has shown synergistic antibacterial activity compared to the mixture of macrocycles upon white-light irradiation due to enhanced ROS generation. The mechanism for such enhanced activity was established by measuring the oxidative stress and relative internalization of PtMCs and G1' ⊂ PtMCT.
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Fe-Doped MoS 2 Nanozyme for Antibacterial Activity and Detoxification of Mustard Gas Simulant. ACS APPLIED MATERIALS & INTERFACES 2022; 14:42940-42949. [PMID: 36122369 DOI: 10.1021/acsami.2c11245] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The peroxidase-like catalytic activity of various nanozymes was extensively applied in various fields. In this study, we have demonstrated the preparation of Fe-doped MoS2 (Fe@MoS2) nanomaterials with enhanced peroxidase-like activity of MoS2 in a co-catalytic pathway. In view of Fenton reaction, the peroxidase-like Fe@MoS2 nanozyme prompted the decomposition of hydrogen peroxide (H2O2) to a reactive hydroxyl radical (·OH). The efficient decomposition of H2O2 in the presence of Fe@MoS2 has been employed toward the antibacterial activity and detoxification of mustard gas simulant. The combined effect of Fe@MoS2 and H2O2 showed remarkable antibacterial activity against the drug-resistant bacterial strain methicillin-resistant Staphylococcus aureus and Escherichia coli with the use of minimal concentration of H2O2. Fe@MoS2 was further applied for the detoxification of the chemical warfare agent sulfur mustard simulant, 2-chloroethyl ethyl sulfide, by selective conversion to the nontoxic sulfoxide. This work demonstrates the development of a hybrid nanozyme and its environmental remediation from harmful chemicals to microbes.
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Cover Feature: Rapid Discrimination of Bacterial Drug Resistivity by Array‐Based Cross‐Validation Using 2D MoS
2
(Chem. Eur. J. 47/2022). Chemistry 2022. [DOI: 10.1002/chem.202202272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Rapid Discrimination of Bacterial Drug Resistivity by Array‐Based Cross‐Validation Using 2D MoS
2. Chemistry 2022; 28:e202201386. [DOI: 10.1002/chem.202201386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Indexed: 11/10/2022]
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Photoredox C(sp3)‐C(sp2) Cross‐Dehydrogenative Coupling of Xanthene with β‐keto moiety using MoS2 Quantum Dot (QD) Catalyst. Adv Synth Catal 2022. [DOI: 10.1002/adsc.202200231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Superparamagnetic Nickel Nanocluster-Embedded MoS 2 Nanosheets for Gram-Selective Bacterial Adhesion and Antibacterial Activity. ACS Biomater Sci Eng 2022; 8:2932-2942. [PMID: 35666676 DOI: 10.1021/acsbiomaterials.2c00257] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Ever increasing infectious diseases caused by pathogenic bacteria are creating one of the greatest health problems. The extensive use of numerous antibiotics and antimicrobial agents has prompted the growth of multidrug-resistant bacterial strains. The ancient biomedical application of metals and the recent advancement in the field of nanotechnology have encouraged us to explore the antimicrobial activity of nanomaterials. Herein, we have synthesized a magnetically separable superparamagnetic nickel nanocluster-loaded two-dimensional molybdenum disulfide nanocomposite (Ni@2D-MoS2). It can selectively bind with Gram-positive bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis over Gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa. After the functionalization of Ni@2D-MoS2 with a positively charged ligand, it showed an excellent Gram-selective antibacterial activity toward MRSA and E. faecalis. Furthermore, the superparamagnetic property of the synthesized material can be used for the simultaneous removal and killing of the microbes and recycled for further use. This study demonstrates strategies to develop hybrid antimicrobial nanomaterial systems for selective antibacterial activity with recyclability.
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Abstract
Artificial template-mediated fabrication of secondary structures within peptides always attracts great interest in biological systems due to several biomimetic interactions. In all earlier studies, a uniform template containing molecules/nanomaterials was used to target only one type of peptide at a time, which extensively limits the diversity in the generation of artificial protein surface/binding sites. This limitation can be overcome by the incorporation of more than one binding template (heterogeneity) in a single system, for example, Janus nanomaterials, which are challenging and difficult to synthesize. In this context, graphene oxide (GO) is considered an artificial binding site (template). It contains two distinctive binding zones, i.e., surface and edge, which can induce the secondary structure of peptides based on complementary interactions. To establish our concept, we have implemented a hybrid sequence i.e., i, i + 4, i + 7 and i + 11 pattern peptides, which defines a more linear surface, suitable for recognition by the two-dimensional GO. Depending on the amino acid residue at the specific locations, we observed substantial enhancement of peptide helicity either at the surface or at the edges of GO from the random coil. However, non-interacting peptides remain as a random coil. We have established this by circular dichroism study at various conditions, as well as atomic force microscopy and optical imaging study. Furthermore, we have also established our observations using molecular dynamics (MD) simulations. This study reveals that the synthesized GO-peptides composite with different secondary structures and recognition residues can mimic biological systems.
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Abstract
Modern day research focuses on the development of greener and eco-friendlier protocols to fabricate biologically relevant targets with minimal waste generation. C-C bond formation reactions are of prime importance in this regard. In a typical photocatalytic hydrogen evolution reaction, three components are used, viz, catalyst, photosensitizer, and sacrificial amine donor. Among these, the photosensitizer and sacrificial amine donors are wasted at the end of the reaction. Considering these drawbacks, in this work, we have developed a methodology targeted at the utilization of sacrificial amine donors for C-H functionalization with MoS2 quantum dots (QDs) as the catalyst as well as the photosensitizer. QDs indeed emerged to be an active participant in the heterogeneous electron transfer process. This concept opens up new possibilities in the field of nanomaterial-based photomediated organic transformations without the aid of any external photosensitizers via a clean and sustainable protocol with no side product.
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Correction to "Facile Green Approach for Developing Electrochemically Reduced Graphene Oxide-Embedded Platinum Nanoparticles for Ultrasensitive Detection of Nitric Oxide". ACS OMEGA 2022; 7:4722. [PMID: 35155964 PMCID: PMC8829919 DOI: 10.1021/acsomega.1c07224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 06/14/2023]
Abstract
[This corrects the article DOI: 10.1021/acsomega.0c05644.].
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Abstract
Development of nanomaterial-based antibiotics can be the most potent alternative due to the increasing resistance against conventional antibiotics. But one of the important parameters in development of antibacterial agent is...
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Investigations into the supercapacitor activity of bisphosphonate-polyoxovanadate compounds. J SOLID STATE CHEM 2021. [DOI: 10.1016/j.jssc.2021.122566] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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One-pot bottom-up synthesis of a 2D graphene derivative: application in biomolecular recognition and nanozyme activity. NANOSCALE ADVANCES 2021; 3:5102-5110. [PMID: 36132346 PMCID: PMC9419244 DOI: 10.1039/d1na00226k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/20/2021] [Indexed: 06/15/2023]
Abstract
The synthesis of two-dimensional (2D) nanosheets such as graphene and its derivatives through a bottom-up approach has many advantages such as growth control and functionalization, but it is always challenging to get the desired material. Herein, we have reported the synthesis of water soluble 2D-nanosheets through a bottom-up approach from 2,4,6-tribromo-3-hydroxybenzoic acid via a self-coupling pathway and characterized them using several techniques. AFM and TEM analyses reveal that the synthesized material has a layered structure with a thickness of ∼1.2 nm. Also, the prepared nanosheets are amorphous in nature with high negative charge (-38 ± 2.5 mV). The flexible nature of 2D-nanosheets and their functionality can be used in many related applications. Therefore, we have utilized the synthesized 2D-nanosheets in biomolecular recognition studies. It was found that the enzymatic activity of α-chymotrypsin can be controlled reversibly in the presence of the synthesized 2D-nanosheets. The kinetic study revealed that the nanosheet surface selectively binds to the active sites of the enzyme through a competitive pathway. Furthermore, we explored the nanozyme activity of the material in a peroxidase-like activity assay of two bio-active molecules: Nicotinamide Adenine Dinucleotide Phosphate (NADH) and dopamine. The results suggest that the prepared material efficiently catalyzed the oxidation of NADH to biological cofactor NAD+ and dopamine to aminochrome in the presence of H2O2. These synthesized graphene-like 2D-nanosheets with functional groups can be further tuned with other functionalities, which can open a new window for other related applications.
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Differentiating between micronucleus dose-responses induced by whole cigarette smoke solutions with Benchmark Dose potency ranking. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2021; 866:503351. [PMID: 33985695 DOI: 10.1016/j.mrgentox.2021.503351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 02/22/2021] [Accepted: 03/19/2021] [Indexed: 01/20/2023]
Abstract
Dose-response modeling of in vitro micronucleus test (IVMNT) data was evaluated to determine if the approach has value in discriminating among different tobacco products. Micronucleus responses were generated in L5178Y/Tk+/- mouse lymphoma cells and TK6 human lymphoblastoid cells from a series of whole smoke solutions (WSSs) expected to have different levels of genotoxicity based on differences in their machine-generated smoke constituents. Eight WSSs were prepared by machine smoking different numbers (20 or 60) of two commercial cigarettes (Marlboro Silver or Red) under International Standardization Organization (ISO) or Health Canada Intense (HCI) smoking machine regimens and tested in the two cell lines with and without rat liver S9 activation. The S9-mediated IVMNT dose-response data from the WSSs were evaluated with PROAST software and Benchmark Doses (BMDs) and their upper and lower confidence intervals (CIs) were generated. IVMNT data differed based on the number and type of cigarettes smoked and smoking machine regimen. The IVMNT responses produced in mouse lymphoma cells generally were greater than in TK6 cells, but the ability of the two cell types to differentiate between WSSs was similar. The results indicate that BMD potency ranking was useful for differentiating between IVMNT responses.
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Surface engineered amphiphilic carbon dots: solvatochromic behavior and applicability as a molecular probe. J Mater Chem B 2021; 9:1432-1440. [PMID: 33465228 DOI: 10.1039/d0tb02007a] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Carbon dots (C-dots) have attracted great attention in the fields of nanotechnology and bioengineering owing to their unique and tunable optical properties with excellent photoluminescence characteristics. Herein, we have engineered amphiphilic C-dots (AC-dots) using positional isomers of diamino benzene with citric acid under mild microwave irradiation to minimize any background reactions. The optical properties changed from excitation-dependent to excitation-independent depending on the isomer used. This unique optical property of the AC-dots was studied in the presence of various solvents and we extensively inspected the AC-dot-solvent interactions. The intensity of the emission wavelength varied with solvent polarity and showed a linear relationship. Furthermore, we extended this property to investigate the molecular environment in biomolecular systems such as proteins. Interestingly, we found that, in the presence of various proteins, the emission intensity was enhanced, quenched or remained unchanged depending on the nature of the protein surface. The mode of interaction between AC-dots and protein was determined using temperature-dependent fluorescence spectroscopy. This study could provide vital information about the surfaces of proteins and the potential application of C-Dots as a fluorescent probe to detect biological molecules and environments.
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Supramolecular Interaction of Molecular Cage and β-Galactosidase: Application in Enzymatic Inhibition, Drug Delivery and Antimicrobial Activity. Chembiochem 2021; 22:1955-1960. [PMID: 33817948 DOI: 10.1002/cbic.202100008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/31/2021] [Indexed: 12/20/2022]
Abstract
Enzyme inhibitors play a crucial role in diagnosis of a wide spectrum of diseases related to bacterial infections. We report here the effect of a water-soluble self-assembled PdII 8 molecular cage towards β-galactosidase enzyme activity. The molecular cage is composed of a tetrapyridyl donor (L) and cis-[(en)Pd(NO3 )2 ] (en=ethane-1,2-diamine) acceptor and it has a hydrophobic internal cavity. We have observed that the acceptor moiety mainly possesses the ability to inactivate the β-galactosidase enzyme activity. Kinetic investigation revealed the mixed mode of inhibition. This inhibition strategy was extended to control the growth of methicillin-resistant Staphylococcus aureus. The internalization of the Pd(II) cage inside the bacteria was confirmed when bacterial solutions were incubated with curcumin loaded cage. The intrinsic green fluorescence of curcumin made the bacteria glow when put under an optical microscope. Furthermore, this curcumin loaded molecular cage shows an enhanced antibacterial activity. Thus, PdII 8 molecular cage is quite attractive due to its dual role as enzyme inhibitor and drug carrier.
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Machine Learning-Assisted Array-Based Detection of Proteins in Serum Using Functionalized MoS 2 Nanosheets and Green Fluorescent Protein Conjugates. ACS APPLIED NANO MATERIALS 2021; 4:3843-3851. [PMID: 37556232 PMCID: PMC8043198 DOI: 10.1021/acsanm.1c00244] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/19/2021] [Indexed: 05/08/2023]
Abstract
Abnormal concentrations of a specific protein or the presence of some biomarker proteins may indicate life-threatening diseases. Pattern-based detection of specific analytes using affinity-regulated receptors is one of the potential alternatives to specific antigen-antibody-based detection. In this report, we have schemed a sensor array by using various functionalized two-dimensional (2D)-MoS2 nanosheets and green fluorescent protein (GFP) as the receptor and the signal transducer, respectively. Two-dimensional MoS2 has been used as a promising candidate for recognition of the bioanalytes because of its high surface-to-volume ratio compared to those of other nanomaterials. Easy surface tunability of this material provides additional advantages to analyze the target of interest. The optimized 2D-MoS2-GFP conjugates are able to discriminate 15 different proteins at 50 nM concentration with a detection limit of 1 nM. Moreover, proteins in the binary mixture and in the presence of serum were discriminated successfully. Ten different proteins in serum media at relevant concentrations were classified successfully with 100% jackknifed classification accuracy, which proves the potentiality of the above system. We have also implemented and discussed the implication of using different machine learning models on the pattern recognition problem associated with array-based sensing.
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Facile Green Approach for Developing Electrochemically Reduced Graphene Oxide-Embedded Platinum Nanoparticles for Ultrasensitive Detection of Nitric Oxide. ACS OMEGA 2021; 6:8068-8080. [PMID: 33817466 PMCID: PMC8014916 DOI: 10.1021/acsomega.0c05644] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
Nitric oxide (NO) plays a crucial and important role in cellular physiology and also acts as a signaling molecule for cancer in humans. However, conventional detection methods have their own limitations in the detection of NO at low concentrations because of its high reactivity and low lifetime. Herein, we report a strategy to fabricate Pt nanoparticle-decorated electrochemically reduced graphene oxide (erGO)-modified glassy carbon electrode (GCE) with efficiency to detect NO at a low concentration. For this study, Pt@erGO/GCE was fabricated by employing two different sequential methods [first GO reduction followed by Pt electrodeposition (SQ-I) and Pt electrodeposition followed by GO reduction (SQ-II)]. It was interesting to note that the electrocatalytic current response for SQ-I (184 μA) was ∼15 and ∼3 folds higher than those of the bare GCE (11.7 μA) and SQ-II (61.5 μA). The higher current response was mainly attributed to a higher diffusion coefficient and electrochemically active surface area. The proposed SQ-I electrode exhibited a considerably low LOD of 52 nM (S/N = 3) in a linear range of 0.25-40 μM with a short response time (0.7 s). In addition, the practical analytical applicability of the proposed sensor was also verified.
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Self-Assembled Pd12 Coordination Cage as Photoregulated Oxidase-Like Nanozyme. J Am Chem Soc 2020; 142:18981-18989. [DOI: 10.1021/jacs.0c09567] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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36
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Self-Assembled PtII8 Metallosupramolecular Tubular Cage as Dual Warhead Antibacterial Agent in Water. Inorg Chem 2020; 59:12690-12699. [DOI: 10.1021/acs.inorgchem.0c01777] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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37
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In Situ Synthesis of Amino Acid Functionalized Carbon Dots with Tunable Properties and Their Biological Applications. ACS APPLIED BIO MATERIALS 2019; 2:3393-3403. [DOI: 10.1021/acsabm.9b00374] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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38
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Nano-Graphene Oxide Based Multichannel Sensor Arrays towards Sensing of Protein Mixtures. Chem Asian J 2019; 14:553-560. [DOI: 10.1002/asia.201801756] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/27/2018] [Indexed: 11/10/2022]
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39
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2D-MoS2 photocatalyzed cross dehydrogenative coupling reaction synchronized with hydrogen evolution reaction. Catal Sci Technol 2019. [DOI: 10.1039/c8cy02532k] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The chemically exfoliated 2D-MoS2 has a mixture of 1T (metallic) and 2H (semiconducting) phases.
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Simultaneous Exfoliation and Functionalization of 2H-MoS2 by Thiolated Surfactants: Applications in Enhanced Antibacterial Activity. J Am Chem Soc 2018; 140:12634-12644. [DOI: 10.1021/jacs.8b08994] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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41
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2D-MoS2-Based β-Lactamase Inhibitor for Combination Therapy against Drug-Resistant Bacteria. ACS APPLIED BIO MATERIALS 2018; 1:967-974. [DOI: 10.1021/acsabm.8b00105] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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42
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Mixed-Phase 2D-MoS2
as an Effective Photocatalyst for Selective Aerobic Oxidative Coupling of Amines under Visible-Light Irradiation. Chemistry 2018; 24:13871-13878. [DOI: 10.1002/chem.201802468] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Indexed: 01/19/2023]
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43
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Empirical Correlation and Validation of Lateral Size-Dependent Absorption Coefficient of Graphene Oxides. ChemistrySelect 2017. [DOI: 10.1002/slct.201701893] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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44
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Graphene Oxide as a Carbocatalyst for a Diels-Alder Reaction in an Aqueous Medium. Chem Asian J 2017; 12:2393-2398. [DOI: 10.1002/asia.201701072] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/14/2017] [Indexed: 12/26/2022]
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45
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Comparative Study of Exfoliated Oral Mucosal Cell Micronuclei Frequency in Normal, Precancerous and Malignant Epithelium. INT J HUM GENET 2017. [DOI: 10.1080/09723757.2004.11885903] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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46
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High Antibacterial Activity of Functionalized Chemically Exfoliated MoS 2. ACS APPLIED MATERIALS & INTERFACES 2016; 8:31567-31573. [PMID: 27933975 DOI: 10.1021/acsami.6b10916] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In view of the implications of inherent resistance of pathogenic bacteria, especially ESKAPE pathogens toward most of the commercially available antibiotics and the importance of these bacteria-induced biofilm formation leading to chronic infection, it is important to develop new-generation synthetic materials with greater efficacy toward antibacterial property. In addressing this issue, this paper reports a proof-of-principle study to evaluate the potential of functionalized two-dimensional chemically exfoliated MoS2 (ce-MoS2) toward inhibitory and bactericidal property against two representative ESKAPE pathogenic strain-a Gram-positive Staphylococcus aureus (MRSA) and a Gram-negative Pseudomonas aeruginosa. More significantly, the mechanistic study establishes a different extent of oxidative stress together with rapid membrane depolarization in contact with ce-MoS2 having ligands of varied charge and hydrophobicity. The implication of our results is discussed in the light of the lack of survivability of planktonic bacteria and biofilm destruction in vitro. A comparison with widely used small molecules and other nanomaterial-based therapeutics conclusively establishes a better efficacy of 2D ce-MoS2 as a new class of antibiotics.
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Engineered Theranostic Magnetic Nanostructures: Role of Composition and Surface Coating on Magnetic Resonance Imaging Contrast and Thermal Activation. ACS APPLIED MATERIALS & INTERFACES 2016; 8:6953-61. [PMID: 26936392 DOI: 10.1021/acsami.6b01377] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Magnetic nanostructures (MNS) have emerged as promising functional probes for simultaneous diagnostics and therapeutics (theranostic) applications due to their ability to enhance localized contrast in magnetic resonance imaging (MRI) and heat under external radio frequency (RF) field, respectively. We show that the "theranostic" potential of the MNS can be significantly enhanced by tuning their core composition and architecture of surface coating. Metal ferrite (e.g., MFe2O4) nanoparticles of ∼8 nm size and nitrodopamine conjugated polyethylene glycol (NDOPA-PEG) were used as the core and surface coating of the MNS, respectively. The composition was controlled by tuning the stoichiometry of MFe2O4 nanoparticles (M = Fe, Mn, Zn, ZnxMn1-x) while the architecture of surface coating was tuned by changing the molecular weight of PEG, such that larger weight is expected to result in longer length extended away from the MNS surface. Our results suggest that both core as well as surface coating are important factors to take into consideration during the design of MNS as theranostic agents which is illustrated by relaxivity and thermal activation plots of MNS with different core composition and surface coating thickness. After optimization of these parameters, the r2 relaxivity and specific absorption rate (SAR) up to 552 mM(-1) s(-1) and 385 W/g were obtained, respectively, which are among the highest values reported for MNS with core magnetic nanoparticles of size below 10 nm. In addition, NDOPA-PEG coated MFe2O4 nanostructures showed enhanced biocompatibility (up to [Fe] = 200 μg/mL) and reduced nonspecific uptake in macrophage cells in comparison to other well established FDA approved Fe based MR contrast agents.
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Magneto-thermally responsive hydrogels for bladder cancer treatment: Therapeutic efficacy and in vivo biodistribution. Colloids Surf B Biointerfaces 2015; 136:625-33. [PMID: 26477008 DOI: 10.1016/j.colsurfb.2015.09.058] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 09/21/2015] [Accepted: 09/27/2015] [Indexed: 12/15/2022]
Abstract
Bladder cancer is one of the deadliest forms of cancer in modern medicine which despite recent progress has remained incurable and challenging for researchers. There is unmet need to address this endemic as the number of patients are growing by about 10,000 every year world-wide. Here, we report a minimally invasive magnetic chemotherapy method to address this problem where polyethylene glycol (PEG) functionalized Fe3O4 magnetic nanostructures (MNS) are homogeneously embedded in thermally responsive poly(N-isopropylacrylamide, NIPAAm) hydrogels (HG). The system (HG-MNS) loaded with anti-cancer drug doxorubicin (DOX) incubated with cancer cell lines subjected to external radiofrequency (RF) field can remotely stimulate the release of drug smartly at the site. The in vitro efficacy investigated on bladder cancer (T-24) cell lines showed the potential of the system in dealing with the disease successfully. Further, the materials preferential accumulation via systemic delivery was studied using swiss mice model. Vital tissue organs like liver, lung and heart were analysed by magnetic resonance imaging (MRI). A detail accounts of the materials optimization, cytotoxicity and anti-proliferation activity tests with apoptosis analysis by flow cytometry after RF exposure (250 kHz) to the cells and in vivo biodistribution data are discussed in the paper.
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The role of primary transoral laser microsurgery in laryngeal cancer: a retrospective study. Clin Otolaryngol 2015; 40:449-55. [DOI: 10.1111/coa.12397] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2015] [Indexed: 11/28/2022]
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50
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Abstract
Despite the complexities of cancer, remarkable diagnostic and therapeutic advances have been made during the past decade, which include improved genetic, molecular, and nanoscale understanding of the disease. Physical science and engineering, and nanotechnology in particular, have contributed to these developments through out-of-the-box ideas and initiatives from perspectives that are far removed from classical biological and medicinal aspects of cancer. Nanostructures, in particular, are being effectively utilized in sensing/diagnostics of cancer while nanoscale carriers are able to deliver therapeutic cargo for timed and controlled release at localized tumor sites. Magnetic nanostructures (MNS) have especially attracted considerable attention of researchers to address cancer diagnostics and therapy. A significant part of the promise of MNS lies in their potential for "theranostic" applications, wherein diagnostics makes use of the enhanced localized contrast in magnetic resonance imaging (MRI) while therapy leverages the ability of MNS to heat under external radio frequency (RF) field for thermal therapy or use of thermal activation for release of therapy cargo. In this chapter, we report some of the key developments in recent years in regard to MNS as potential theranostic carriers. We describe that the r₂relaxivity of MNS can be maximized by allowing water (proton) diffusion in the vicinity of MNS by polyethylene glycol (PEG) anchoring, which also facilitates excellent fluidic stability in various media and extended in vivo circulation while maintaining high r₂values needed for T₂-weighted MRI contrast. Further, the specific absorption rate (SAR) required for thermal activation of MNS can be tailored by controlling composition and size of MNS. Together, emerging MNS show considerable promise to realize theranostic potential. We discuss that properly functionalized MNS can be designed to provide remarkable in vivo stability and accompanying pharmacokinetics exhibit organ localization that can be tailored for specific applications. In this context, even iron-based MNS show extended circulation as well as diverse organ accumulation beyond liver, which otherwise renders MNS potentially toxic to liver function. We believe that MNS, including those based on iron oxides, have entered a renaissance era where intelligent synthesis, functionalization, stabilization, and targeting provide ample evidence for applications in localized cancer theranostics.
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