The Experts below are selected from a list of 7200 Experts worldwide ranked by ideXlab platform
Paul A Millner - One of the best experts on this subject based on the ideXlab platform.
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acetylecholinesterase based biosensor electrodes for organophosphate pesticide detection ii immobilization and stabilization of acetylecholinesterase
Biosensors and Bioelectronics, 2005Co-Authors: Alexander Vakurov, C E Simpson, Catherine Daly, Tim Gibson, Paul A MillnerAbstract:The dry and wet stability of Drosophila acetylcholinesterase non-covalently immobilized onto Polyethyleneimine modified screen-printed carbon electrodes was improved when compared to non-immobilized acetylcholinesterase, and acetylcholinesterase covalently immobilized onto dialdehyde and Polyethyleneimine modified electrodes. Stabilizer mixtures were characterized for additional stabilization of acetylcholinesterase during storage in the dry state, with dextran-sulphate/sucrose and polygalacturonic acid/sucrose mixtures proving highly effective for long-term storage of biosensor electrodes.
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acetylcholinesterase based biosensor electrodes for organophosphate pesticide detection i modification of carbon surface for immobilization of acetylcholinesterase
Biosensors and Bioelectronics, 2004Co-Authors: Alexander Vakurov, C E Simpson, Catherine Daly, Tim Gibson, Paul A MillnerAbstract:Abstract Screen-printed carbon electrodes modified with the dialdehydes, glutaraldehyde and terephthaldicarboxaldehyde, and then Polyethyleneimine have been utilized for production of pesticide biosensors based on acetylcholinesterase. To improve the extent of dialdehyde modification, the electrodes were NH 2 -derivatized, initially by electrochemical reduction of 4-nitrobenzenediazonium to a nitroaryl radical permitting attachment to the carbon surface. Subsequent reduction of the 4-nitrobenzene yields a 4-aminobenzene modified carbon surface. Drosophila melanogaster acetylcholinesterase was immobilized either covalently onto dialdehyde modified electrodes or non-covalently onto Polyethyleneimine modified electrodes. Internal diffusion limitations due to the dialdehyde and Polyethyleneimine modifications increased the apparent K m of the immobilized enzyme. The thiocholine sensitivity was about 90% for dialdehyde modified electrodes and about 10% for Polyethyleneimine modified electrodes as compared with non-modified carbon electrodes. The detection limit of the biosensors produced by non-covalent immobilization of acetylcholinesterase onto Polyethyleneimine modified carbon electrodes was found to be about 10 −10 M for the organophosphate pesticide dichlorvos.
Xiangyang Shi - One of the best experts on this subject based on the ideXlab platform.
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targeted ct mr dual mode imaging of human hepatocellular carcinoma using lactobionic acid modified Polyethyleneimine entrapped gold nanoparticles
Journal of Materials Chemistry B, 2017Co-Authors: Jia Yang, Shihui Wen, Mingwu Shen, Linfeng Zheng, Guixiang Zhang, Xiangyang ShiAbstract:We report the synthesis and characterization of lactobionic acid-modified multifunctional Polyethyleneimine-entrapped gold nanoparticles for targeted dual mode computed tomography/magnetic resonance imaging. The nanodevice displays good X-ray attenuation properties, good r1 relaxivity, and hepatocellular carcinoma targeting specificity, and can be used for targeted CT/MR imaging of hepatocellular carcinoma in vitro and in vivo.
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short term dynamic observation of the color change and enhancement effect of polyethylenimine entrapped gold nanoparticles used for indirect lymphography
Operations Research Letters, 2016Co-Authors: Yue Yang, Xiangyang Shi, Fang Shi, Jian Zhou, Yan ShaAbstract:Aims: To dynamically observe the color change and enhancement effect of gadolinium-loaded polyethylenimine-entrapped gold nanoparticles (Gd-Au PENPs) as a dual-mo
Guowei Wang - One of the best experts on this subject based on the ideXlab platform.
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kidney targeted drug delivery via rhein loaded polyethyleneglycol co polycaprolactone co Polyethyleneimine nanoparticles for diabetic nephropathy therapy
International Journal of Nanomedicine, 2018Co-Authors: Danfei Chen, Shunping Han, Yongqin Zhu, Yinghui Wei, Guowei WangAbstract:Introduction Diabetic nephropathy (DN) is the primary root of morbidity and mortality in diabetic patients. Unfortunately, currently, no effective therapeutic strategies are available to ameliorate and reverse the progression of DN. Rhein (RH) is an anthraquinone derivative extracted from herbal medicines with various pharmacological effects on DN. However, its clinical administration is limited by its poor solubility, low bioavailability, reduced distribution into the kidney and adverse effects. Methods and results To improve the delivery of RH into kidney and the therapeutic effect on DN, we synthesized and utilized polyethyleneglycol-co-polycaprolactone-co-polyethylenimine triblock amphiphilic polymers to prepare RH-loaded polyethyleneglycol-co-polycaprolactone-co-polyethylenimine nanoparticles (PPP-RH-NPs). PPP-RH-NP size was optimized to 75 ± 25 nm for kidney-targeted drug delivery; the positive zeta potential allowed an effective cellular uptake and the polyethylenimine amine groups facilitate the endosomal escape quickly. The distribution and pharmacodynamics of PPP-RH-NPs were studied in a streptozocin-induced DN model, which explicitly demonstrated kidney-targeted distribution and improved the therapeutic effects of RH on DN by ameliorating several pathological indicators. Conclusion Therefore, this study not only stimulates further clinical research on RH but also, more importantly, proposes a promising DN therapy consisting of an effective kidney-targeted drug delivery.
Daniel W Pack - One of the best experts on this subject based on the ideXlab platform.
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efficient polyethylenimine mediated gene delivery proceeds via a caveolar pathway in hela cells
Journal of Controlled Release, 2009Co-Authors: Nathan P Gabrielson, Daniel W PackAbstract:Abstract Most in vivo gene therapies will require cell-specific targeting. Although vector targeting through ligand attachment has met with success in generating gene delivery particles that are capable of specific cellular interactions, little attention has been given to the possible effects of such ligands on subsequent intracellular processing. In this study, we examine the impact of targeting two distinct endocytic routes—the caveolar and clathrin pathways—on polyethylenimine-mediated gene delivery in HeLa cells. Targeting complexes to the caveolar pathway with folic acid and the clathrin pathway with transferrin yields enhanced gene delivery relative to unmodified polyethylenimine. Colocalization studies with caveolin-1 and clathrin heavy chain indicate that the ligands successfully deliver their cargo to the intended pathways. However, inhibition of only the caveolar pathway—whether through the use of small molecule drugs or RNA interference—reduces gene delivery efficiency, suggesting that successful polyethylenimine-mediated gene delivery proceeds via a caveolar pathway in HeLa cells. Transfections in the presence of chloroquine and pH tracking studies reveal that a contributing factor to the success of the caveolar pathway is avoidance of lysosomes. Collectively, these data demonstrate that uptake mechanism and subsequent endocytic processing are important design parameters for gene delivery materials.
Eric A. Albrecht - One of the best experts on this subject based on the ideXlab platform.
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Characterization of crude Echis carinatus venom-induced cytotoxicity in HEK 293T cells.
Journal of venom research, 2011Co-Authors: Rebecca D Pierce, Ethan S Kim, Lance W Girton, Jonathan L. Mcmurry, Joshua W. Francis, Eric A. AlbrechtAbstract:Echis carinatus (saw-scaled viper) produces potent hemorrhagic venom that causes the development of apoptotic and necrotic tissues. In this study, we used Polyethyleneimine (PEI) to enhance cellular adherence, and to determine whether the substrate attachment influenced the survival of cells treated with crude E. carinatus venom. Human embryonic kidney (HEK) 293T cells were grown for 18hr in tissue culture plates with or without Polyethyleneimine (PEI), and were then stimulated with crude E. carinatus venom for 3 or 12hr. HEK 293T cells grown without PEI displayed a robust oxidative response to corresponding substrate detachment, loss of plasma membrane integrity and decreased cell viability. Cells grown on PEI adsorbed substrates demonstrated prolonged substrate attachment resulting in significantly higher cell viabilities. These observations suggest that the cytotoxicity of crude E. carinatus venom is dependent upon cellular detachment.
