199 research outputs found
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Criminal sentencing in Bangladesh ::from colonial legacies to modernity /
No full textIn Criminal Sentencing in Bangladesh , Muhammad Mahbubur Rahman critically examines the sentencing policies of Bangladesh and demonstrates that the country's sentencing policies are not only yet to be developed in a coherent manner and shaped with an appropriate and contextual balance, but also remain part of the problem rather than part of the solution. The author forcefully argues that the conception of 'sentencing policies' cannot and should not always be confined exclusively to institutional understandings. The typical realities of post-colonial societies call for rethinking the traditional judiciary-centred understanding of what is meant by criminal sentences. This book thus raises the question for theoretical sentencing scholarship whether the prevailing judiciary-centred understanding of sentencing should be rethought
Recommended from our members
Criminal sentencing in Bangladesh ::from colonial legacies to modernity /
No full textIn 'Criminal Sentencing in Bangladesh', Muhammad Mahbubur Rahman critically examines the sentencing policies of Bangladesh and demonstrates that the country?s sentencing policies are not only yet to be developed in a coherent manner and shaped with an appropriate and contextual balance, but also remain part of the problem rather than part of the solution. The author forcefully argues that the conception of 'sentencing policies' cannot and should not always be confined exclusively to institutional understandings. The typical realities of post-colonial societies call for rethinking the traditional judiciary-centred understanding of what is meant by criminal sentences. This book thus raises the question for theoretical sentencing scholarship whether the prevailing judiciary-centred understanding of sentencing should be rethought
Criminal sentencing in Bangladesh ::from colonial legacies to modernity /
No full textIn 'Criminal Sentencing in Bangladesh', Muhammad Mahbubur Rahman critically examines the sentencing policies of Bangladesh and demonstrates that the country?s sentencing policies are not only yet to be developed in a coherent manner and shaped with an appropriate and contextual balance, but also remain part of the problem rather than part of the solution. The author forcefully argues that the conception of 'sentencing policies' cannot and should not always be confined exclusively to institutional understandings. The typical realities of post-colonial societies call for rethinking the traditional judiciary-centred understanding of what is meant by criminal sentences. This book thus raises the question for theoretical sentencing scholarship whether the prevailing judiciary-centred understanding of sentencing should be rethought
Label-free electrochemical aptasensor for the detection of SARS-CoV-2 spike protein based on carbon cloth sputtered gold nanoparticles
No full textThe proliferation and transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), or the (COVID-19) disease, has become a threat to worldwide biosecurity. Therefore, early diagnosis of COVID-19 is crucial to combat the ongoing infection spread. In this study we propose a flexible aptamer-based electrochemical sensor for the rapid, label-free detection of SARS-CoV-2 spike protein (SP). A platform made of a porous and flexible carbon cloth, coated with gold nanoparticles, to increase the conductivity and electrochemical performance of the material, was assembled with a thiol functionalized DNA aptamer via S–Au bonds, for the selective recognition of the SARS-CoV-2 SP. The various steps for the sensor preparation were followed by using scanning electron microscopy, cyclic voltammetry and differential pulse voltammetry (DPV). The proposed platform displayed good mechanical stability, revealing negligible changes on voltammetric responses to bending at various angles. Quantification of SARS-CoV-2 SP was performed by DPV and chronopotentiometry (CP), exploiting the changes of the electrical signals due the [Fe(CN)6]3-/4- redox probe, when SARS-CoV-2 SP binds to the aptamer immobilized on the electrode surface. Current density, in DPV, and square root of the transition time, in CP, varied linearly with the log[ SARS-CoV-2 SP], providing lower limits of detection (LOD) of 0.11 ng/mL and 37.8 ng/mL, respectively. The sensor displayed good selectivity, repeatability, and was tested in diluted human saliva, spiked with different SARS-CoV-2 SP concentrations, providing LODs of 0.167 ng/mL and 46.2 ng/mL for DPV and CP, respectively
Controlled, partially exfoliated, self-supported functionalized flexible graphitic carbon foil for ultrasensitive detection of SARS-CoV-2 spike protein
No full textThis paper reports on an ultrasensitive and label-free electrochemical immunosensor for monitoring the SARSCoV-2 spike protein (SARS-CoV-2 SP). A self-supported electrode, which can simultaneously serve as an antibody immobilization matrix and electron transport channel, was initially fabricated by a controlled partial exfoliation of a flexible graphitic carbon foil (GCF). Mild acidic treatment enabled the partial oxidation and exfoliation (down to a few layers) of the flexible GCF; this also provided a high percentage of oxygen functionality and an enhanced surface roughness. The substrate electrode was further functionalized with ethylenediamine (EDA) to provide a suitable platform with even a higher surface roughness, for the covalent immobilization of an anti-SARS-CoV-2 antibody. The change in the current response for the [Fe(CN)(6)](3-/4-) redox couple, induced by the binding of SARS-CoV-2 SP to the antibody immobilized on the electrode surface, was used to determine the SARS-CoV-2 SP concentration. The immunosensor thus prepared could detect SARSCoV-2 SP within 30 min with high reproducibility and specificity over a wide concentration range (0.2-100 ng/ mL). Detection limits of 25 pg/mL and 27 pg/mL were found in a phosphate buffer solution (pH 7.4), and diluted blood plasma, respectively. The immunosensor was also employed to detect SARS-CoV-2 SP in artificial human saliva
Silver nitroprusside as an efficient chemodynamic therapeutic agent and a peroxynitrite nanogenerator for targeted cancer therapies
No full textIntroduction
Chemodynamic therapy (CDT) holds great promise in achieving cancer therapy through Fenton and Fenton-like reactions, which generate highly toxic reactive species. However, CDT is limited by the lower amount of catalyst ions that can decompose already existing intracellular H2O2 and produce reactive oxygen species (ROS) to attain a therapeutic outcome.
Objectives
To overcome these limitations, a tailored approach, which utilizes dual metals cations (Ag+, Fe2+) based silver pentacyanonitrosylferrate or silver nitroprusside (AgNP) were developed for Fenton like reactions that can specifically kill cancer cells by taking advantage of tumor acidic environment without used of any external stimuli.
Methods
A simple solution mixing procedure was used to synthesize AgNP as CDT agent. AgNP were structurally and morphologically characterized, and it was observed that a minimal dose of AgNP is required to destroy cancer cells with limited effects on normal cells. Moreover, comprehensive in vitro studies were conducted to evaluate antitumoral mechanism.
Results
AgNP have an effective ability to decompose endogenous H2O2 in cells. The decomposed endogenous H2O2 generates several different types of reactive species (•OH, O2•−) including peroxynitrite (ONOO−) species as apoptotic inducers that kill cancer cells, specifically. Cellular internalization data demonstrated that in short time, AgNP enters in lysosomes, avoid degradation and due to the acidic pH of lysosomes significantly generate high ROS levels. These data are further confirmed by the activation of different oxidative genes. Additionally, we demonstrated the biocompatibility of AgNP on mouse liver and ovarian organoids as an ex vivo model while AgNP showed the therapeutic efficacy on patient derived tumor organoids (PDTO).
Conclusion
This work demonstrates the therapeutic application of silver nitroprusside as a multiple ROS generator utilizing Fenton like reaction. Thereby, our study exhibits a potential application of CDT against HGSOC (High Grade Serous Ovarian Cancer), a deadly cancer through altering the redox homeostasis
Biodegradation of hydroxylated boron nitride nanoplatelets, their toxic effect and drug delivery application
No full textBoron nitride is extensively used in various biomedical applications and often interacting with the blood
circulatory system. However, the effect of its biotransformation in blood plasma, drug delivery
applications, and antitumor effects remains unclear. Herein, we synthesized hydroxylated BN
nanoplatelets (–OH/BNNPs) that are used to load doxorubicin (DOX) for cancer therapy. The stability of
the –OH/BNNPs was tested in a lab-made, artificially developed, in vivo system for up to sixty days at
two different pH values (pH 5.5 & 7.4). The results were compared thoroughly with pristine BN, and it is
observed that –OH/BNNPs was very stable for up to two months compared to pristine BN that degraded
during the next day. The –OH functionalization on the BNNP surface improves the DOX loading
compared to the bulk BN since the –OH functional group facilitates drug absorption through hydrogen
bonding. This causes the sustained release of the drug, which is an ideal requirement in drug delivery
systems. The DOX-loaded –OH/BNNPs showed excellent therapeutic abilities on different cancer cell
lines and organoids derived from colorectal cancer patient
Copper nitroprusside: An innovative approach for targeted cancer therapy via ROS modulation
No full textThe clinical application of nanomaterials for chemodynamic therapy (CDT), which generate multiple reactive oxygen species (ROS), presents significant challenges. These challenges arise due to insufficient levels of endogenous hydrogen peroxide and catalytic ions necessary to initiate Fenton reactions. As a result, sophisticated additional delivery systems are required. In this study, a novel bimetallic copper (II) pentacyanonitrosylferrate (Cu(II)NP, Cu[Fe(CN) 5 NO]) material was developed to address these limitations. This material functions as a multiple ROS generator at tumoral sites by self-inducing hydrogen peroxide and producing peroxynitrite (ONOO-) species. The research findings demonstrate that this material exhibits low toxicity towards normal liver organoids, yet shows potent antitumoral effects on High Grade Serous Ovarian Cancer (HGSOC) organoid patients, regardless of platinum resistance. Significantly, this research introduces a promising therapeutic opportunity by proposing a single system capable of replacing the need for H2O2, additional catalysts, and NO-based delivery systems. This innovative system exhibits remarkable multiple therapeutic mechanisms, paving the way for potential advancements in clinical treatments
Iron nitroprusside as a chemodynamic agent and inducer of ferroptosis for ovarian cancer therapy
No full textChemoDynamic Therapy (CDT) is a powerful therapeutic modality using Fenton/Fenton-like reactions to produce oxidative stress for cancer treatment. However, the insufficient amount of catalyst ions and ROS scavenging activity of glutathione peroxidase (GPX4) limit the application of this approach. Therefore, a tailored strategy to regulate the Fenton reaction more efficiently (utilizing dual metal cations) and inhibit the GPX4 activity, is in great demand. Herein, a CDT system is based on dual (Fe2+ metals) iron pentacyanonitrosylferrate or iron nitroprusside (FeNP) having efficient ability to catalyze the reaction of endogenous H2O2 to form highly toxic OH species in cells. Additionally, FeNP is involved in ferroptosis via GPX4 inhibition. In particular, FeNP was structurally characterized, and it is noted that a minimum dose of FeNP is required to kill cancer cells while a comparable dose shows negligible toxicity on normal cells. Detailed in vitro studies confirmed that FeNP participates in sustaining apoptosis, as determined using the annexin V marker. Cellular uptake results showed that in a short time period, FeNP enters lysosomes and, due to the acidic lysosomal pH, releases Fe2+ ions, which are involved in ROS generation (OH species). Western blot analyses confirmed the suppression of GPX4 activity over time. Importantly, FeNP has a therapeutic effect on ovarian cancer organoids derived from High-Grade Serous Ovarian Cancer (HGSOC). Furthermore, FeNP showed biocompatible nature towards normal mouse liver organoids and in vivo. This work presents the effective therapeutic application of FeNP as an efficient Fenton agent along with ferroptosis inducer activity to improve CDT, through disturbing redox homeostasis
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