The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Ren-xi Zhuo - One of the best experts on this subject based on the ideXlab platform.
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Polymeric micelles stabilized by Polyethylenimine–copper (C2H5N–Cu) coordination for sustained drug release
RSC Advances, 2016Co-Authors: Yu Dai, Xiaojin Zhang, Ren-xi ZhuoAbstract:In order to improve the release properties of water-insoluble drugs from polymeric micelles, we develop polymeric micelles stabilized by Polyethylenimine–copper (C2H5N–Cu) coordination between the amino groups in ABC triblock copolymer poly(ethylene glycol)-block-linear Polyethylenimine-block-poly(e-caprolactone) (PEG-PEI-PCL) and divalent copper cations.
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The effectiveness, cytotoxicity, and intracellular trafficking of nonviral vectors for gene delivery to bone mesenchymal stem cells:
Journal of Bioactive and Compatible Polymers, 2013Co-Authors: Lin Peng, Shi-wen Huang, Ren-xi ZhuoAbstract:Nonviral gene delivery that enables exogenous gene expression in bone mesenchymal stem cells could accelerate clinical application of cell-based gene therapy. This study systematically investigated and compared the potential of Polyethylenimine and Lipofectamine 2000 as gene carriers to modify bone mesenchymal stem cells including transfection efficiency, cytotoxicity, intracellular trafficking as well as cell membrane damage and apoptosis/necrosis. Polyethylenimine at its optimal N/P ratio of 10 demonstrated the same toxic effects but lower transfection efficiency (17.1% vs 39.5%) compared to Lipofectamine. Intracellular trafficking resulted in over 80% of bone mesenchymal stem cells that were able to take up Polyethylenimine polyplexes, but only 20.69% showed nuclear uptake; however, for Lipofectamine, about half bone mesenchymal stem cells were found to uptake lipoplexes but about 30% displayed nuclear localization. Moreover, the percentages of nuclear localization of both vectors were in close relatio...
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Convenient preparation of biodegradable PEI-containing polymers as non-viral vectors for gene transfection.
Macromolecular bioscience, 2009Co-Authors: Fu-wei Huang, Jun Feng, Jun Nie, Si-xue Cheng, Xian-zheng Zhang, Ren-xi ZhuoAbstract:Poly(L-succinimide)-graft-Polyethylenimines (PSPs) were prepared as non-viral vectors for gene transfection. Branched Polyethylenimine (Mw= 800, PEI800) was grafted to poly(L-succinimide) (PSI) in a one-step reaction with no catalyst. Gel retardation assay showed that the mobility of PSP/pDNA complexes was completely retarded at the low N/P ratio of 0.42. In vitro transfection experiments showed that, at N/P ratio of 0.84, PSPs can reach the highest transfection level with ten-fold enhancement in 293T cells and five-fold enhancement in HeLa cells as compared with PEI25k (Mw= 25,000). Fluorescent confocal microscopy showed that pGL-3 plasmids condensed by PSPs could be effectively transported into the nuclei of HeLa cells. Significantly reduced cytotoxicity of polymers was observed towards 293T and HeLa cells, with the 50% inhibition concentration of PSPs being almost four times higher than that of PEI25k.
Achim Aigner - One of the best experts on this subject based on the ideXlab platform.
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PEG grafting of Polyethylenimine (PEI) exerts different effects on DNA transfection and siRNA-induced gene targeting efficacy.
Journal of drug targeting, 2008Co-Authors: Anastasia Malek, Frank Czubayko, Achim AignerAbstract:Background: Gene targeting by RNA interference (RNAi) is mediated through small interfering RNA (siRNA), which, as plasmid DNA molecules, can be delivered into cells by Polyethylenimines (PEI). Grafting with poly(ethylene glycol) has been introduced previously to improve PEI biocompatibility; however, data on the effects of PEGylation have been somewhat contradictory and various PEI(-PEG) need to be evaluated independently for DNA transfection and siRNA gene targeting efficacies.Aim: We directly compare plasmid DNA transfection and siRNA-mediated gene targeting efficacies, employing a larger set of Polyethylenimine-graft-poly(ethylene glycol) (PEI-g-PEG; PEI(-PEG)) with different molecular weights and degrees of PEG substitution.Method: We performed tissue culture-based bioassays on DNA transfection and siRNA-mediated targeting efficacies as well as on toxicity and cellular nucleic acid uptake, and, using sensitive assays based on radioactive labelling, physicochemically characterize the complexes regardi...
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a low molecular weight fraction of Polyethylenimine pei displays increased transfection efficiency of dna and sirna in fresh or lyophilized complexes
Journal of Controlled Release, 2006Co-Authors: Stephanie Werth, Udo Bakowsky, Beata Urbanklein, Lige Dai, Sabrina Hobel, Marius Grzelinski, Frank Czubayko, Achim AignerAbstract:Abstract RNA interference (RNAi) represents a powerful method for specific gene silencing. It is mediated through small double-stranded RNA molecules (small interfering RNAs, siRNAs) which sequence-specifically trigger the cleavage and subsequent degradation of their target mRNA. One critical factor that determines the success of RNAi is the ability to deliver intact siRNAs into target cells. Polyethylenimines (PEIs) are synthetic polymers with a high cationic charge density which function as transfection reagents based on their ability to compact DNA or RNA into complexes. This paper describes the application of lyophilized PEI/siRNA complexes based on a novel Polyethylenimine. By fractionation of a commercially available 25-kDa PEI using gel permeation chromatography, a low molecular weight Polyethylenimine (PEI F25-LMW) with superior transfection efficacy and low toxicity in various cell lines is obtained. Complexes formed in 5% glucose, but not in 150 mM NaCl, can be lyophilized and reconstituted without loss of transfection efficacy. Furthermore, PEI F25-LMW is able to complex and fully protect siRNAs against nucleolytic degradation, and delivers siRNAs into cells where they display bioactivity. Upon lyophilization and reconstitution of PEI F25-LMW-based siRNA complexes, siRNAs are still able to efficiently induce RNAi. To further demonstrate their applicability, lyophilized PEI/siRNA complexes are employed for targeting of the growth factor VEGF. Treatment of PC-3 prostate carcinoma cells with fresh or with lyophilized complexes results in decreased cell proliferation in different assays due to the siRNA-mediated downregulation of VEGF. In conclusion, siRNAs can be applied in lyophilized formulations, and lyophilized PEI F25-LMW-based siRNA complexes represent a powerful, inexpensive, non-toxic and simple ready-to-use platform for the specific and efficient targeting of genes in vitro.
Xiaojin Zhang - One of the best experts on this subject based on the ideXlab platform.
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MicroRNA Delivery with Bioreducible Polyethylenimine as a Non-Viral Vector for Breast Cancer Gene Therapy.
Macromolecular bioscience, 2019Co-Authors: Yu Dai, Xiaojin ZhangAbstract:Polyethylenimines (PEIs) are outstanding macromolecules belonging to the polycations used in gene transfection. The transfection efficiency and cytotoxicity of PEIs increase with the increase in their molecular weight. To break up the correlation between transfection efficiency and cytotoxicity for non-viral gene delivery, disulfide cross-linked Polyethylenimine (PEI-SS) has been widely employed as highly efficient gene vectors for DNA/siRNA delivery in numerous efforts. In this work, PEI-SS is described as a non-viral vector for miRNA delivery for the first time. PEI-SS is synthesized via cross-linking using disulfide bonds as the cross-linker from low molecular weight PEI. PEI-SS can efficiently bind anti-miR-155 to form the polyplex with nano-sized spherical structures in the size range of 10-100 nm. The polyplex is degraded by glutathione (GSH, a reducing agent) in cancer cells. Anti-miR-155 is then released to efficiently inhibit tumor growth.
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Polymeric micelles stabilized by Polyethylenimine–copper (C2H5N–Cu) coordination for sustained drug release
RSC Advances, 2016Co-Authors: Yu Dai, Xiaojin Zhang, Ren-xi ZhuoAbstract:In order to improve the release properties of water-insoluble drugs from polymeric micelles, we develop polymeric micelles stabilized by Polyethylenimine–copper (C2H5N–Cu) coordination between the amino groups in ABC triblock copolymer poly(ethylene glycol)-block-linear Polyethylenimine-block-poly(e-caprolactone) (PEG-PEI-PCL) and divalent copper cations.
Yu Dai - One of the best experts on this subject based on the ideXlab platform.
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MicroRNA Delivery with Bioreducible Polyethylenimine as a Non-Viral Vector for Breast Cancer Gene Therapy.
Macromolecular bioscience, 2019Co-Authors: Yu Dai, Xiaojin ZhangAbstract:Polyethylenimines (PEIs) are outstanding macromolecules belonging to the polycations used in gene transfection. The transfection efficiency and cytotoxicity of PEIs increase with the increase in their molecular weight. To break up the correlation between transfection efficiency and cytotoxicity for non-viral gene delivery, disulfide cross-linked Polyethylenimine (PEI-SS) has been widely employed as highly efficient gene vectors for DNA/siRNA delivery in numerous efforts. In this work, PEI-SS is described as a non-viral vector for miRNA delivery for the first time. PEI-SS is synthesized via cross-linking using disulfide bonds as the cross-linker from low molecular weight PEI. PEI-SS can efficiently bind anti-miR-155 to form the polyplex with nano-sized spherical structures in the size range of 10-100 nm. The polyplex is degraded by glutathione (GSH, a reducing agent) in cancer cells. Anti-miR-155 is then released to efficiently inhibit tumor growth.
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Polymeric micelles stabilized by Polyethylenimine–copper (C2H5N–Cu) coordination for sustained drug release
RSC Advances, 2016Co-Authors: Yu Dai, Xiaojin Zhang, Ren-xi ZhuoAbstract:In order to improve the release properties of water-insoluble drugs from polymeric micelles, we develop polymeric micelles stabilized by Polyethylenimine–copper (C2H5N–Cu) coordination between the amino groups in ABC triblock copolymer poly(ethylene glycol)-block-linear Polyethylenimine-block-poly(e-caprolactone) (PEG-PEI-PCL) and divalent copper cations.
Pradeep Kumar - One of the best experts on this subject based on the ideXlab platform.
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Bifunctionally engineered Polyethylenimines as efficient DNA carriers and antibacterials against resistant pathogens.
Journal of biomaterials applications, 2018Co-Authors: Zeba Ahmadi, Diksha Jha, Hemant K. Gautam, B Kumar, Pradeep KumarAbstract:In this study, we have designed and developed two series of bifunctional conjugates by tethering Polyethylenimine with streptomycin. By varying the amount of streptomycin, conjugates, Polyethylenimine-streptomycin, have been synthesized and characterized spectroscopically. Gel electrophoresis assay revealed a slight decrease in the cationic charge density on the conjugates as these retarded the mobility of pDNA at higher w/w ratios. Further, transfection studies showed that both the series of conjugates transfected the mammalian cells efficiently with low-molecular weight Polyethylenimine-streptomycin conjugates were more competent (∼9-fold enhancement with respect to native bPEI) exhibiting high cell viability too. Besides, both the series of conjugates displayed excellent antibacterial activity on pathogenic bacteria, even better than native streptomycin on resistant strains. Altogether, these results ensure the promising potential of the projected bifunctional conjugates as safe and efficient gene delivery vectors as well as antibacterials for future biomedical applications.
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Nanoparticles for DNA delivery
Advances in Nanomedicine for the Delivery of Therapeutic Nucleic Acids, 2017Co-Authors: Manohar Mahato, Ashwani Kumar Sharma, Pradeep KumarAbstract:Abstract The success of nonviral gene therapy mainly depends on the design and development of safe and effective gene delivery systems. Nonviral vectors have attracted the attention of researchers, as they offer several advantages over their viral counterparts. Among various nonviral vectors, Polyethylenimines have been the most widely used in in vitro and in vivo gene transfer studies. Cationic nanoparticles have been shown to enhance the efficiency of the transfection. These are compact and help in overcoming various biological and cellular barriers. Due to their smaller size, these are less susceptible to reticuloendothelial (RES) clearance and exhibit better uptake and internalization into the cells/tissues. To exploit these properties of the nanoparticles, the present chapter highlights the synthesis of nanoparticles of Polyethylenimine (linear and branched) and their ability to effect gene transfer across the biological systems.