Creat membership Creat membership
Sign in

Forgot password?

Confirm
  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 17 - 32 of 41

  • Lectin anchored PLGA nanoparticles for oral mucosal immunization against hepatitis B.

    Mishra, Neeraj   Tiwari, Shailja   Vaidya, Bhuvaneshwar   Agrawal, Govind P   Vyas, Suresh P  

    Present study aimed at exploring the potential of alpha-l-fucose specific, LTA (Lotus tetragonolobus from Winged or Asparagus pea) as a homing device for nanocarriers to target the M cell for elicitation of strong immune response. LTA grafted poly(lactic-co-glycolic acids) (PLGA) nanoparticles encapsulating hepatitis B surface antigen (HBsAg) was developed and characterized for shape, size, polydispersity index, zeta potential, and antigen loading efficiency. The peyer's patch uptake was studied by using confocal laser scanning microscopy technique using dual staining technique. The immune stimulating potential was assessed by measuring anti-HBsAg titer in serum of balb/c mice. Induction of the mucosal immunity was assessed by estimating secretory immunoglobulin A level in the salivary, intestinal, and vaginal secretion and cytokine (interleukin-2 and interferon-gamma) levels in the spleen homogenates. Furthermore, IgG1 and IgG2a isotype were determined to confirm the T(H)1/T(H)2 mixed immune response. The LTA anchored PLGA nanoparticles have demonstrated approximately four-fold increase in the degree of interaction with the bovine submaxillary mucin (BSM). The results demonstrated that LTA anchored PLGA nanoparticles elicited strong mucosal and systemic response and hence could be a promising carrier adjuvant for the M cell targeted oral mucosal immunization against Hepatitis B.
    Download Collect
  • Single layer graphene functionalized MEA for enhanced detection of neuronal network development

    El Merhie, Amira   Ito, Daisuke   Colombi, Ilaria   Keshavan, Sandeep   Mishra, Neeraj   Miseikis, Vaidotas   Diaspro, Alberto   Coletti, Camilla   Chiappalone, Michela   Dante, Silvia  

    The exploitation of graphene for neuro-interfacing applications requires a complete, yet missing, understanding of neuron-graphene interaction. Here, we have explored the interplay between the carbon based interface and neuronal networks during the complete developmental phase at whole network scale. To this purpose, we have, first, successfully transferred large grains single layer graphene (LG-SLG) via wet etching onto commercial planar 60 electrode devices; then, we have compared to control the neuronal growth on the functionalized devices, recording the spontaneous activity up to completion of network maturation, i.e., from 7 to 25 days-in-vitro. The immunohistochemistry investigation demonstrated a comparable morphology of the neuronal network on SLG and control substrates but with a higher number of neurons on SLG. The most striking results of the electrophysiological investigation were the observation of spikes and bursts activity at an earlier developmental phase and of strongly synchronized neuronal networks on SLG-MEA versus control, suggesting an improved neuron/electrode coupling. These observations agree with our previous study of single neuron synaptogenesis by patch clamp, where earlier synaptogenesis on SLG compared to the control was detected. The results have been corroborated by the firing and bursting analysis showing higher and statistically significant values on SLG-MEA.
    Download Collect
  • Evaluation of Mucoadhesive PLGA Microparticles for Nasal Immunization RID F-8953-2010

    Pawar, Dilip   Goyal, Amit K.   Mangal, Sharad   Mishra, Neeraj   Vaidya, Bhuvaneshwar   Tiwari, Shailja   Jain, Arvind K.   Vyas, Suresh P.  

    In this study, hepatitis B surface antigen (HBsAg) loaded poly(lactic-co-glycolic acid) (PLGA) microparticles were prepared and coated with chitosan and trimethyl chitosan (TMC) to evaluate the effect of coating material for nasal vaccine delivery. The developed formulations were characterized for size, zeta potential, entrapment efficiency, and mucin adsorption ability. Plain PLGA microparticles demonstrated negative zeta potential. However, coated microparticles showed higher positive zeta potential. Results indicated that TMC microparticles demonstrated substantially higher mucin adsorption when compared to chitosan-coated microparticles and plain PLGA microparticles. The coated and uncoated microparticles showed deposition in nasal-associated lymphoid tissue under fluorescence microscopy. The coated and uncoated microparticles were then administered intranasally to mice. Immune-adjuvant effect was determined on the basis of specific antibody titer observed in serum and secretions using enzyme-linked immunosorbent assay. It was observed that coated particles showed a markedly increased anti-HBsAg titer as compared to plain PLGA microparticles, but the results were more pronounced with the TMC-coated PLGA microparticles.
    Download Collect
  • Structure-dependent electrical properties of graphene nanoribbon devices with graphene electrodes

    Martini, Leonardo   Chen, Zongping   Mishra, Neeraj   Barin, Gabriela Borin   Fantuzzi, Paolo   Ruffieux, Pascal   Fasel, Roman   Feng, Xinliang   Narita, Akimitsu   Coletti, Camilla   Müllen, Klaus   Candini, Andrea  

    Download Collect
  • Development of self-assembled nanoceramic carrier construct(s) for vaccine delivery.

    Goyal, Amit K   Khatri, Kapil   Mishra, Neeraj   Mehta, Abhinav   Vaidya, Bhuvaneshwar   Tiwari, Shailja   Paliwal, Rishi   Paliwal, Shivani   Vyas, Suresh P  

    Hydroxyapatite (HA) has been extensively investigated as scaffolds for tissue engineering, as drug delivery agents, as non-viral gene carriers, as prosthetic coatings, and composites. Recent studies in our laboratory demonstrated the immunoadjuvant properties of HA when administered with malarial merozoite surface protein-1(19) (MSP-1(19)). HA nanoceramic carrier was prepared by co-precipitation method that comprises of sintering and spray-drying technique. Prepared systems were characterized for crystallinity, size, shape, and antigen loading efficiency. Small size and large surface area of prepared HA demonstrated good adsorption efficiency of immunogens. Prepared nanoceramic formulations also showed slower in vitro antigen release and slower biodegrability behavior, which may lead to a prolonged exposure to antigen-presenting cells and lymphocytes. Furthermore, addition of mannose in nanoceramic formulation may additionally lead to increased stability and immunological reactions. Immunization with MSP-1(19) in nanoceramic-based adjuvant systems induced a vigorous immunoglobulin G (IgG) response, with higher IgG2a than IgG1 titers. In addition considerable amount of IFN-g and IL-2 was observed in spleen cells of mice immunized with nanoceramic-based vaccines. On the contrary, mice immunized with MSP-1(19) alone or with alum did not exhibit a significant cytotoxic response. The antibody responses to vaccine co-administered with HA was a mixed Th1/Th2 compared to the Th2-biased response obtained with alum. The prepared HA nanoparticles exhibit physicochemical properties that appear promising to make them a suitable immunoadjuvant to be used as antigen carriers for immunopotentiation.
    Download Collect
  • Green synthesis of biocompatible carbon dots using aqueous extract of Trapa bispinosa peel.

    Mewada, Ashmi   Pandey, Sunil   Shinde, Sachin   Mishra, Neeraj   Oza, Goldie   Thakur, Mukeshchand   Sharon, Maheshwar   Sharon, Madhuri  

    We are reporting highly economical plant based method for the production of luminescent water soluble carbon dots (C-dot) using Indian water plant Trapa bispinosa peel extract without adding any external oxidizing agent at 90掳C. C-dots ranging from 5 to 10nm were found in the solution with a prominent green fluorescence under UV-light (lambdaex=365nm). UV-vis spectra recorded at different time intervals (30-120min) displayed signature absorption of C-dots between 400 and 600nm. Fluorescence spectra of the dispersion after 120min of synthesis exhibited characteristic emission peaks of C-dots when excited at 350, 400, 450 and 500nm. C-dots were further analyzed using X-ray diffraction (XRD), Raman Spectroscopy and Thermo-Gravimetric Analysis (TGA). Structure of the C-dots was found to be turbostratic when studied using XRD. C-dots synthesized by our method were found to be exceptionally biocompatible against MDCK cells. Copyright 2013 Elsevier B.V. All rights reserved.
    Download Collect
  • p-Type Epitaxial Graphene on Cubic Silicon Carbide on Silicon for Integrated Silicon Technologies

    Pradeepkumar, Aiswarya   Amjadipour, Mojtaba   Mishra, Neeraj   Liu, Chang   Fuhrer, Michael S.   Bendavid, Avi   Isa, Fabio   Zielinski, Marcin   Sirikumara, Hansika I.   Jayasekara, Thushari   Gaskill, D. Kurt   Iacopi, Francesca  

    Download Collect
  • Biodegradable Polymer Based Particulate Carrier(s) for the Delivery of Proteins and Peptides

    Mishra, Neeraj   Goyal, Amit   Khatri, Kapil   Vaidya, Bhuvaneshwar   Paliwal, Rishi   Rai, Shivani   Mehta, Abhinav   Tiwari, Shailja   Vyas, Shiva   Vyas, Suresh  

    Construction of safe and effective delivery systems for proteins and peptides is demand of current clinical practices. Biodegradable polymers based particulates carriers fulfill much of the requirement in this applicable field. Number of marketed products related to biodegradable polymers encapsulating proteins is increasing. However, it has not achieved its proper place since problems related to the protein processing and stabilization limits the scientific community. In this present review we have summarized various aspects related to the formulation and processing of biodegradable polymerized microparticles/nanoparticles for delivery of therapeutic proteins and peptides. A brief introduction of biodegradable polymers has been incorporated for reader's benefit. In addition, biodegradable polymers based carriers designed for vaccine delivery has been incorporated in detail. Functionalized biodegradable carrier(s) for site specific delivery of proteineous matter has also been discussed.
    Download Collect
  • Recent advances in mucosal delivery of vaccines: role of mucoadhesive/biodegradable polymeric carriers

    Mishra, Neeraj   Goyal, Amit K   Tiwari, Shailja   Paliwal, Rishi   Paliwal, Shivani R   Vaidya, Bhuvaneshwar   Mangal, Sharad   Gupta, Madhu   Dube, Devyani   Mehta, Abhinav   Vyas, Suresh P  

    Importance of the field: The mucosal delivery of vaccines provides the basis for induction of humoral, cellular and mucosal immune responses against infectious diseases. The delivery of antigens to and through mucosal barriers always remains challenging due to adverse physiological conditions (pH and enzymes) and biological barriers created by tight epithelial junctions restricting transportation of macromolecules. Mucoadhesive and biodegradable polymers offer numerous advantages in therapeutic delivery of proteins/antigens particularly through the mucosal route by protecting antigens from degradation, increasing concentration of antigen in the vicinity of mucosal tissue for better absorption, extending their residence time in the body and/or targeting them to sites of antigen uptake. Furthermore, antigen can be delivered more effectively to the antigen presenting cells by anchoring the ligand having affinity on the surface of carrier for the receptors present on the mucosal epithelial cells. Areas covered in this review: The present review covers various polymeric carriers, which allow the possibility of modification and manipulation of their properties, thereby, enhancing the effectiveness of mucosal vaccines. This article reviews the recent literature and patents in the field of vaccine delivery using mucoadhesive polymeric carriers. What the reader will gain: The reader will gain insights into various natural polymers, synthetic polymers and ligand derived polymeric carrier systems studied to enhance mucosal immunization. Take home message: Biodegradable polymeric carriers represent a promising approach for mucosal delivery of vaccine.
    Download Collect
  • PEG-PLA-PEG block copolymeric nanoparticles for oral immunization against hepatitis B RID F-8953-2010

    Jain, Arvind K.   Goyal, Amit K.   Mishra, Neeraj   Vaidya, Bhuvaneshwar   Mangal, Sharad   Vyas, Suresh P.  

    PLA/PLGA nanoparticles are well known as efficient vaccine delivery systems, but they have got limitation in oral vaccine delivery because of their sensitivity to harsh gastric environment. The aim of present study was to improve the stability of PLA nanoparticles in such environment by copolymerizing PLA with PEG. Nanoparticles Were formulated using different block copolymers AB, ABA and BAB (where 'A' is PLA and 'B' is PEG) encapsulating hepatitis B surface antigen (HBsAg) to evaluate their efficacy as oral vaccine delivery system. The results of in vitro studies engrave the efficiency of copolymeric nanoparticles to retain encapsulated antigen and average particle size even after 2 h incubation in Simulated gastric fluid and simulated intestinal fluid. Fluorescence microscopic studies indicated efficient uptake of copolymeric nanoparticles by gut mucosa of immunized mice model as compared to control. Finally copolymeric and PLA nanoparticles, encapsulating HBsAg, were evaluated for their adjuvancity in generating immune response after oral administration. PLA nanoparticles could not generate an effective immune response due to stability issues. On the other hand, oral administration of copolymeric nanoparticles exhibited effective levels of humoral immunity along with the mucosal (sIgA) and cellular immune response (T(H)1). The results of in vitro and in vivo studies demonstrate that BAB nanoparticles depict enhanced mucosal uptake leading to effective immune response as compared to other copolymeric nanoparticles. Present study indicates the efficacy of BAB nanoparticles as a promising carrier for oral immunization. (C) 2009 Elsevier B.V. All rights reserved.
    Download Collect
  • Polyol osmolytes stabilize native-like cooperative intermediate state of yeast hexokinase A at low pH

    Devaraneni, Prasanna K.   Mishra, Neeraj   Bhat, Rajiv  

    Osmolytes produced under stress in animal and plant systems have been shown to increase thermal stability of the native state of a number of proteins as well as induce the formation of molten globule (MG) in acid denatured states and compact conformations in natively unfolded proteins. However, it is not clear whether these solutes stabilize native state relative to the MG state under partially denaturing conditions. Yeast hexokinase A exists as a MG state at pH 2.5 that does not show any cooperative transition upon heating. Does the presence of some of these osmolytes at pH 2.5 help in the retention of structure that is typical of native state? To answer this question, the effect of ethylene glycol (EG), glycerol, xylitol, sorbitol, trehalose and glucose at pH 2.5 on the structure and stability of yeast hexokinase A was investigated using spectroscopy and calorimetry. In presence of the above osmolytes, except EG, yeast hexokinase at pH 2.5 retains native secondary structure and hydrophobic core and unfolds with excessive heat absorption upon thermal denaturation. However, the cooperative structure binds to ANS suggesting that it is an intermediate between MG and the native state. Further, we show that at high concentration of polyols at pH 2.5, except EG, which populates a non-native ensemble, Delta H-cal/Delta H-van approaches unity indicative of two-state unfolding. The results suggest that osmolytes stabilize cooperative protein structure relative to non-cooperative ensemble. These findings have implications toward the structure formation, folding and stability of proteins produced under stress in cellular systems. (C) 2011 Elsevier Masson SAS. All rights reserved.
    Download Collect
  • Investigation of (S)-(–)-acidomycin: A selective antimycobacterial natural product that inhibits biotin synthase

    Bockman, Matthew R   Engelhart, Curtis A.   Cramer, Julia D   Howe, Michael   Mishra, Neeraj   Zimmerman, Matthew   Larson, Peter   Alvarez-Cabrera, Nadine   Park, Sae Woong   Boshoff, Helena I. M.   Bean, James M   Young, Victor   Ferguson, David M.   Dartois, Veronique   Jarrett, Joseph T.   Schnappinger, Dirk   Aldrich, Courtney C.  

    Download Collect
  • High Photoresponsivity in Graphene Nanoribbon Field-Effect Transistor Devices Contacted with Graphene Electrodes

    Candini, Andrea   Martini, Leonardo   Chen, Zongping   Mishra, Neeraj   Convertino, Domenica   Coletti, Camilla   Narita, Akimitsu   Feng, Xinliang   Muellen, Klaus   Affronte, Marco  

    Ultranarrow graphene nanoribbons (GNRs) with atomically precise structures are considered a promising class of materials for the realization of optoelectronic and photonic devices with improved functionalities. Here we report the optoelectronic characterization of a field-effect transistor device made of a layer of bottom-up synthesized GNRs contacted with multilayer graphene electrodes, showing high photoresponsivity of 5 x 10(5) A/W for small incident power in the visible-UV range. Our results show that combining the properties of intrinsic graphene with that of semiconducting GNRs is a viable route to realize novel devices for optoelectronic and sensing applications.
    Download Collect
  • Development and characterization of LTA-appended chitosan nanoparticles for mucosal immunization against hepatitis B

    Mishra, Neeraj   Khatri, Kapil   Gupta, Madhu   Vyas, Suresh P.  

    The present study was aimed at exploring the targeting potential of LTA-anchored chitosan nanoparticles (CH-NP) specifically to M cell following oral immunization. The lectinized CH-NP exhibited 7-29% coupling capacity depending upon the amount of glutaraldehyde added. Induction of the mucosal immunity was assessed by estimating secretory IgA level in the salivary, intestinal and vaginal secretions, and cytokine (IL-2 and IFN-gamma) levels in the spleen homogenates. The results demonstrated that LTA-anchored CH-NP elicited strong humoral and cellular responses and hence could be a competent carrier-adjuvant delivery system for oral mucosal immunization against Hepatitis B.
    Download Collect
  • Development and characterization of effective topical liposomal system for localized treatment of cutaneous candidiasis

    Gupta, Madhu   Goyal, Amit K.   Paliwal, Shivani Rai   Paliwal, Rishi   Mishra, Neeraj   Vaidya, Bhuvaneshwar   Dube, Devyani   Jain, Sanjay K.   Vyas, Suresh P.  

    The localized delivery of fluconazole (FLZ) by conventional therapy is a major impediment in achieving its therapeutic efficacy against skin infections, such as cutaneous candidiasis. Therefore, the present study was aimed to develop FLZ-loaded vesicular construct(s), such as liposomes and niosomes, incorporated into carbopol gel (1%; w/w) for sustained, localized application. The liposomes and niosomes were prepared by the lipid/nonionic surfactant-based dry-film hydration method and were characterized for different parameters. In addition, antifungal activity was carried out on experimentally induced cutaneous candidiasis in immunosuppressed albino rats. The results showed that the size of liposomes and niosomes was found to be 0.348 +/- 0.054 and 0.326 +/- 0.033 mu m with encapsulation efficiency of 31.8 +/- 1.36 and 27.6 +/- 1.08%, respectively. The skin-retention studies of FLZ from in vitro and in vivo experiments showed significantly higher accumulation of drug in the case of liposomal gel. The in vivo localization studies in viable skin showed that liposomal gel could produce 14.2-fold higher drug accumulation, compared with plain gel, while it was 3.3-fold more in the case of an equivalent-dose application in the form of niosomal gel. The antifungal study also confirmed the maximum therapeutic efficacy of liposomal gel, as the lowest number of cfu/mL was recorded following liposomal FLZ application. The studies signify the potential of liposomal gel for topical delivery of FLZ with increased accumulation of drug in various strata of skin vis-a-vis through sustained release of drug could maintain the localized effect, resulting in an effective treatment of a life-threatening cutaneous fungal infection.
    Download Collect
  • Effect of lipid core material on characteristics of solid lipid nanoparticles designed for oral lymphatic delivery

    Paliwal, Rishi   Rai, Shivani   Vaidya, Bhuvaneshwar   Khatri, Kapil   Goyal, Amit K.   Mishra, Neeraj   Mehta, Abhinav  

    Solid lipid nanoparticles (SLNs) are essentially composed of triglyceride(s) that orient to form a polar core with polar heads oriented toward the aqueous phase, resembling chylomicrons. The composition of such SLNs may alter the course of drug absorption predominantly to and through lymphatic route and regions, presumably following a transcellular path of lipid absorption, especially by enterocytes and polar epithelial cells of the intestine. SLNs were prepared using stearic acid, glycerol monostearate, tristearin, and Compritol 888 ATO by solvent diffusion method using demineralized double-distilled water as the dispersion medium. The SLNs were characterized for shape, size, zeta potential, and percentage drug content and its release. The characterization of SLNs suggests that Compritol 888 ATO-based nanoparticles were heterogeneous with better drug-loading and release characteristics as compared with the other formulations. The selected products were studied for in vivo absorption and hence bioavailability by measure of area under the blood plasma curve plotted as a function of time. Periodic lymphatic concentration of drug following oral administration of respective formulations was also determined by mesenteric duct cannulation and collection of samples. The comparative study conducted on methotrexate (MTX)-bearing SLNs revealed that the formulation based on Compritol 888 ATO could noticeably improve the oral bioavailability of MTX, presumably following SLNs constituting lipid digestion and co-absorption through lymphatic transport and route. (C) 2009 Elsevier Inc. All rights reserved.
    Download Collect
1 2 3

Contact

If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback