263 research outputs found

    Immuno-potentiating activity of surfactant vesicles in DNA and subunit vaccination

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    Enhanced immune responses for DNA and subunit vaccines potentiated by surfactant vesicle based delivery systems outlined in the present study, provides proof of principle for the beneficial aspects of vesicle mediated vaccination. The dehydration-rehydration technique was used to entrap plasmid DNA or subunit antigens into lipid-based (liposomes) or non-ionic surfactant-based (niosomes) dehydration-rehydration vesicles (DRV). Using this procedure, it was shown that both these types of antigens can be effectively entrapped in DRV liposomes and DRV niosomes. The vesicle size of DRV niosomes was shown to be twice the diameter (~2µm) of that of their liposome counterparts. Incorporation of cryoprotectants such as sucrose in the DRV procedure resulted in reduced vesicle sizes while retaining high DNA incorporation efficiency (~95%). Transfection studies in COS 7 cells demonstrated that the choice of cationic lipid, the helper lipid, and the method of preparation, all influenced transfection efficiency indicating a strong interdependency of these factors. This phenomenon has been further reinforced when 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE): cholesteryl 3b- [N-(N’ ,N’ -dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol)/DNA complexes were supplemented with non-ionic surfactants. Morphological analysis of these complexes using transmission electron microscopy and environmental scanning electron microscopy (ESEM) revealed the presence of heterogeneous structures which may be essential for an efficient transfection in addition to the fusogenic properties of DOPE. In vivo evaluation of these DNA incorporated vesicle systems in BALB/c mice showed weak antibody and cell-mediated immune (CMI) responses. Subsequent mock challenge with hepatitis B antigen demonstrated that, 1-monopalmitoyl glycerol (MP) based DRV, is a more promising DNA vaccine adjuvant. Studying these DRV systems as adjuvants for the Hepatitis B subunit antigen (HBsAg) revealed a balanced antibody/CMI response profile on the basis of the HBsAg specific antibody and cytokine responses which were higher than unadjuvated antigen. The effect of addition of MP, cholesterol and trehalose 6,6’-dibehenate (TDB) on the stability and immuno-efficacy of dimethyldioctadecylammonium bromide (DDA) vesicles was investigated. Differential scanning calorimetry showed a reduction in transition temperature of DDA vesicles by ~12°C when incorporated with surfactants. ESEM of MP based DRV system indicated an increased vesicle stability upon incorporation of antigen. Adjuvant activity of these systems tested in C57BL/6j mice against three subunit antigens i.e., mycobacterial fusion protein- Ag85B-ESAT-6, and two malarial antigens - merozoite surface protein-1, (MSP1), and glutamate rich protein, (GLURP) revealed that while MP and DDA based systems induced comparable antibody responses, DDA based systems induced powerful CMI responses

    Blockchain-Enabled Authenticated Key Agreement Scheme for Mobile Vehicles-Assisted Precision Agricultural IoT Networks

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    Precision Farming Has a Positive Potential in the Agricultural Industry Regarding Water Conservation, Increased Productivity, Better Development of Rural Areas, and Increased Income. Blockchain Technology is a Better Alternative for Storing and Sharing Farm Data as It is Reliable, Transparent, Immutable, and Decentralized. Remote Monitoring of an Agricultural Field Requires Security Systems to Ensure that Any Sensitive Information is Exchanged Only among Authenticated Entities in the Network. to This End, We Design an Efficient Blockchain-Enabled Authenticated Key Agreement Scheme for Mobile Vehicles-Assisted Precision Agricultural Internet of Things (IoT) Networks Called AgroMobiBlock. the Limited Existing Work on Authentication in Agricultural Networks Shows Passive Usage of Blockchains with Very High Costs. AgroMobiBlock Proposes a Novel Idea using the Elliptic Curve Operations on an Active Hybrid Blockchain over Mobile Farming Vehicles with Low Computation and Communication Costs. Formal and Informal Security Analysis Along with the Formal Security Verification using the Automated Validation of Internet Security Protocols and Applications (AVISPA) Software Tool Have Shown the Robustness of AgroMobiBlock Against Man-In-The-Middle, Impersonation, Replay, Physical Capture, and Ephemeral Secret Leakage Attacks among Other Potential Attacks. the Blockchain-Based Simulation on Large-Scale Nodes Shows the Computational Time for an Increase in the Network and Block Sizes. Moreover, the Real-Time Testbed Experiments Have Been Performed to Show the Practical Usefulness of the Proposed Scheme

    Thermodynamic investigation of carbamazepine-saccharin co-crystal polymorphs

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    YesPolymorphism in active pharmaceutical ingredients (APIs) can be regarded as critical for the potential that crystal form can have on the quality, efficacy and safety of the final drug product. The current contribution aims to characterize thermodynamic interrelationship of a dimorphic co-crystal, FI and FII, involving carbamazepine (CBZ) and saccharin (SAC) molecules. Supramolecular synthesis of CBZ-SAC FI and FII have been performed using thermo-kinetic methods and systematically characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), solubility and slurry measurements. According to Berger and Ramberger’s heat of fusion rule, FI (ΔHfus = 121.1 J/g, mp 172.5 °C) and FII (ΔHfus= 110.3 J/g, mp 164.7 °C) are monotropically related. The solubility and van’t Hoff plot results suggest that FI stable and FII metastable forms. This study reveals that CBZ-SAC co-crystal phases, FI or FII, could be stable to heat induced stresses, however, FII converts to FI during solution mediated transformation.Authors would like to acknowledge UKIERI (TPR 26), EPSRC (EP/J003360/1, EP/L027011/1) for the support. Open Access funded by Engineering and Physical Sciences Research Counci

    Fostering Community Preparedness to Cope with Drought: new initiatives and results from a study involving ODL and ICT from South Central India

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    Drought has emerged as a key concern in the context of climate variability induced by Climate Change processes and over a billion people are vulnerable, according to UN estimates. Drought preparedness is recognized as the preferred way to cope over relief, and information is the key. Improved access to contemporary ICT in the form of mobile phones and the Internet can help address the challenge of information deficiency in this matter. We have tried to develop an integrated approach for improving the capacity of rural communities by bringing together agricultural information with methods of ODL and effective exchange or delivery using video- conferencing. This has also enabled skill building among vulnerable rural communities in the use of color-coded maps derived from satellite imagery and GIS platforms. ICRISAT in partnership with a community based all- women micro-credit organization, the Adarsha Mahila Samaikhya (AMS), in South Central India has developed this blend of techniques to help the AMS and rural communities to anticipate how vulnerable their villages would be to drought in a season. This is an ongoing partnership, and we report here on joint studies carried out during March 2008- September 2009

    Study of hydrogen bonding interactions and chemical reactivity analysis of nitrofurantoin–3-aminobenzoic acid cocrystal using quantum chemical and spectroscopic (IR, Raman, 13C SS-NMR) approaches

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    YesInvestigations of structural reactivity, molecular interactions and vibrational characterization of pharmaceutical drugs are helpful in understanding their behaviour. The aim of this study is to determine the molecular, electronic and chemical properties of the antibiotic drug nitrofurantoin (NF), after cocrystallisation with 3-aminobenzoic acid (3ABA) and to understand how those changes lead to variation of properties in the cocrystal NF–3ABA. NF–3ABA formation is explained by stabilization via the hydrogen-bond network between NF and 3ABA molecules. It is thoroughly characterized by IR, Raman and CP-MAS solid-state 13C NMR techniques, along with quantum chemical calculations. The results of IR, Raman, and 13C NMR analyses showed that imide N–H23 and C12[double bond, length as m-dash]O of NF interact with the acid C[double bond, length as m-dash]O and –OH groups in 3-ABA, respectively. Therefore the IR, Raman, and 13C NMR spectra verified the formation of N–H⋯O and O–H⋯O hydrogen bonds. To study hydrogen bonding interactions theoretically in NF–3ABA, two functionals B3LYP and wB97X-D have been used. A comparison is made between the results obtained by B3LYP and those predicted at the wB97X-D level. It is found that wB97X-D is best applied density functional theory (DFT) functional to describe the hydrogen bonding interactions. The strength and nature of hydrogen bonding in NF–3ABA have been analysed by quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis. To validate the results obtained by QTAIM theory and to study the long-range forces, such as van der Waals interactions, the steric effects in NF–3ABA, the reduced density gradient (RDG) and the isosurface have been plotted using Multiwfn software. QTAIM and isosurface analysis suggested that the hydrogen bonding interactions present in NF–3ABA are moderate in nature. The calculated HOMO–LUMO energy gap shows that NF–3ABA is more active than NF and 3ABA. Chemical reactivity descriptors are calculated to understand the various aspects of pharmacological sciences. Chemical reactivity parameters show that NF–3ABA is softer and chemically more reactive than NF. The results suggest that cocrystals can be a feasible alternative for positively changing the targeted physicochemical properties of an active pharmaceutical ingredient (API).V. R. Vangala acknowledges the financial support of the Royal Society of Chemistry for mobility grant (2015/17)

    Formulation and corneal permeation of ketorolac tromethamine-loaded chitosan nanoparticles

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    The aim of this work was to formulate chitosan (CS)-based nanoparticles (NPs) loaded with ketorolac tromethamine (KT) intended for topical ocular delivery. NPs were prepared using ionic gelation method incorporating tri-polyphosphate (TPP) as cross-linker. Following the preparation, the composition of the system was optimized in terms of their particle size, zeta potential, entrapment efficiency (EE) and morphology, as well as performing structural characterization studies using Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The data suggested that the size of the NPs was affected by CS/TPP ratio where the diameter of the NPs ranged from 108.0 ± 2.4 nm to 257.2 ± 18.6 nm. A correlation between drug EE and the corresponding drug concentration added to the formulation was observed, where the EE of the NPs increased with increasing drug concentration, for up to 10 mg/mL. FT-IR and DSC revealed that KT was dispersed within the NPs where the phosphate groups of TPP were associated with the ammonium groups of CS. The in vitro release profile of KT from CS NPs showed significant differences (p < 0.05) compared to KT solution. Furthermore, mucoadhesion studies revealed adhesive properties of the formulated NPs. The KT-loaded NPs were found to be stable when stored at different storage conditions for a period of 3 months. The ex vivo corneal permeation studies performed on excised porcine eye balls confirmed the ability of NPs in retaining the drug on the eye surface for a relatively longer time. These results demonstrate the potential of CS-based NPs for the ocular delivery of KT

    Nrf1 can be processed and activated in a proteasome-independent manner

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    In response to proteasome inhibition, the transcription factor Nrf1 facilitates de novo synthesis of proteasomes by inducing proteasome subunit (PSM) genes 1 and 2. Previously, we showed that activation of the p120 form of Nrf1, a membrane-bound protein in the endoplasmic reticulum (ER) with the bulk of its polypeptide in the lumen, involves its retrotranslocation into the cytosol in a manner that depends on the AAA-ATPase p97/VCP [3]. This is followed by proteolytic processing and mobilization of the transcriptionally active p110 form of Nrf1 to the nucleus. A subsequent study suggested that site-specific proteolytic processing of Nrf1 by the proteasome yields an active 75 kDa fragment [4]. We show here that under conditions where all three active sites of the proteasome are completely blocked, p120 Nrf1 can still be proteolytically cleaved to the p110 form, which is translocated to the nucleus to activate transcription of PSM genes. Thus, our results indicate that a proteasome-independent pathway can promote the release of active p110 Nrf1 from the ER membrane
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