We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.
Anti-Bacterial Agents ; chemistry ; Graphite ; chemistry ; Light ; Nanoparticles ; chemistry ; Oxides ; chemistry ; Particle Size ; Polyethyleneimine ; chemistry ; Silver Compounds ; chemistry

To study the angiogenic activity of amphoteric brush-type copolymer complex of alginate-graft-PEI/pVEGF (Alg-g-PEI/pVEGF) in vivo, we evaluated the toxicity of Alg-g-PEI/pVEGF complexes to rMSCs and zebra fish first. Then, we used gel retardation assay to investigate the protection of complex to pDNA against DNase I, serum and heparin. For in vivo study, we evaluated the angiogenic activity of Alg-g-PEI/pVEGF complexes by using CAM and zebra fish as animal models, PEI 25K/pVEGF and saline as positive and negative controls. Our results show that Alg-g-PEI protected pVEGF from enzymolysis and displacement of heparin in some degree, and its complexes with pVEGF were less toxic to rMSCs and zebra fish. Alg-g-PEI/pVEGF complexes induced significant angiogenesis, which was dosage-dependent. In CAM, when the dosage of pVEGF was 2.4 microg/CAM, Alg-g-PEI group achieved the maximum of angiogenesis, and the area ratio of vessel to the total surface was 44.04%, which is higher than PEI 25K group (35.90%) and saline group (24.03%) (**P < 0.01). In zebra fish, the angiogenesis increased with the increase of N/P ratios of Alg-g-PEI/pVEGF complexes in our studied range; when N/P ratio was 110, the optimal angiogenesis was obtained with vessel length of 1.11 mm and area of 1.70 x 10(3) pixels, which is higher than saline group (0.69 mm and 0.94 x 10(3) pixels) (**P < 0.01) and PEI 25k group (0.82 mm and 1.11 x 10(3) pixels) (**P < 0.01). Our results demonstratethat Alg-g-PEI/pVEGF significantly induces angiogenesis in CAM and zebra fish, and has a great potential in therapeutic angiogenesis.
Alginates ; chemistry ; Angiogenesis Inducing Agents ; pharmacology ; Animals ; Chick Embryo ; Drug Carriers ; chemistry ; Genetic Vectors ; genetics ; Glucuronic Acid ; chemistry ; Hexuronic Acids ; chemistry ; Mesenchymal Stromal Cells ; cytology ; drug effects ; Polyethyleneimine ; chemistry ; Polymers ; pharmacology ; toxicity ; Vascular Endothelial Growth Factor A ; chemistry ; Zebrafish

Cell Adhesion ; Cell Proliferation ; Cells, Cultured ; Chitosan ; chemistry ; Coated Materials, Biocompatible ; Collagen ; chemistry ; Humans ; Materials Testing ; Polyethyleneimine ; chemistry ; Static Electricity ; Surface Properties ; Titanium ; chemistry

OBJECTIVETo synthesize a biodegradable non-viral gene carrier with a high transfection efficiency and a low cytotoxicity.

METHODSPoly(ethylene glycol)-block-(poly(L-glutamic acid)-graft-polyethylenimine) was prepared via ammonolysis of poly(ethylene glycol)-block-poly (γ-benzyl L-glutamate) with the low-molecular-mass polyethylenimine (600 Da). The synthesized copolymer was characterized by 1H nuclear magnetic resonance spectroscopy and gel permeation chromatography. The polyplex micelle from PEG-b-(PG-g-PEI) and plasmid DNA (pDNA) was studied using dynamic light scattering, zeta-potential measurements, and gel retardation assay. The in vitro cytotoxicity and transfection efficiency of PEG-b-(PG-g-PEI) were tested by MTT assay and luciferase assay in HEK 293T cells using PEI (25 kDa) as the control.

RESULTSPEG-b-(PG-g-PEI) could efficiently condense DNA into nanosized particles with positive surface charges when the N/P ratio of polymer and DNA was above 5:1. The zeta potential of the polyplexes was about 25 mV, and the particle size was 120 nm at a N/P ratio of 10. The cell toxicity and gene transfection evaluations showed a lower cytotoxicity and a higher gene transfection efficiency of the copolymer than PEI 25000 in HEK 293T cells.

CONCLUSIONSThe polymer can be used as a potential non-viral gene carrier for gene therapy.

Cell Survival ; Gene Transfer Techniques ; Genetic Vectors ; Glutamic Acid ; chemistry ; HEK293 Cells ; Humans ; Particle Size ; Plasmids ; Polyethylene Glycols ; chemical synthesis ; chemistry ; Polyethyleneimine ; analogs & derivatives ; chemical synthesis ; chemistry ; Polyglutamic Acid ; analogs & derivatives ; chemical synthesis ; chemistry ; Polymers ; Transfection

OBJECTIVETo explore the feasibility of magnetic resonance cell imaging technology by using polyethylene imine (PEI)-coated magnetic nanoparticles of Fe₄O₄ (PEI-Fe₄O₄-MNPs) to track cell biology behavior.

METHODSEndocytic PEI-Fe₄O₄-MNPs in SHI-1 cells were observed by transmission electron microscopy (TEM) . Iron contents of nano-labeled cells were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Prussian blue staining. The proliferation ability of labeled cells was detected by cell counting kit-8 (CCK-8) assay; the differentiation and colony-forming abilities were also observed. SHI-1 cells without endocytosing PEI-Fe₄O₄-MNPs were used as control.

RESULTSOur data showed that PEI-Fe₄O₄-MNPs could label SHI-1 cells. The labeling efficiency depended on the nanoparticles' concentration and the duration of cells treating. Inhibition rates of SHI-1cells labeled by 60-100 μg Fe/ml PEI-Fe₄O₄-MNPs were much higher than of 5-50 μg Fe/ml ones following treating by 5-100 μg Fe/ml PEI-Fe₄O₄-MNPs for 48 hrs. The expressions of CD11b and CD14 were (78.4±18.5)% and (18.7±2.9)% in control vs (83.3±14.2)% and (20.4±2.1)% in cells fractions treated by 30 μg Fe/ml PEI-Fe₄O₄-MNPs. Clony-forming rates of SHI-1 cells labeled by 0, 20 , 50 μg Fe/ml PEI-Fe₄O₄-MNPs were (25.20±7.22)%, (25.93±13.15)%, (23.37±9.33)%, respectively. Differentiation and colony-forming potentials of labeled cells were similar with control in the certain range of PEI-Fe₄O₄-MNPs concentration.

CONCLUSIONSHI-1 cells were efficiently labeled by PEI-Fe₄O₄-MNPs with well biocompatibilities in proper range of concentration, the latter could be coupled with magnetic resonance imaging (MRI) to track cells in vivo.

Cell Line, Tumor ; Coated Materials, Biocompatible ; chemistry ; Ferric Compounds ; chemistry ; Humans ; Magnetic Resonance Imaging ; Magnetics ; Microscopy, Electron, Transmission ; Nanoparticles ; chemistry ; Polyethyleneimine ; chemistry

Apoptosis is a physiologically essential mechanism of cell and plays an important role in reducing the development and progression of tumors. The appealing strategy for cancer therapy is to target the lesions that induce apoptosis in cancer cells. Survivin, the smallest member of the mammalian inhibitors of the apoptosis protein family, is upregulated in various malignancies to protect cells from apoptosis. Survivin knockdown could induce cancer cell apoptosis and inhibit tumor-angiogenesis. Survivin expression would be silenced by microRNA (miRNA)-mediated RNA interference. However, noninvasive and tissue-specific gene delivery techniques remain absent recently and the utilizations of miRNA expression vectors have been limited by inefficient delivery technique, especially in vivo. On the other hand, safe and promising technologies of gene transfection would be valuable in clinical gene therapy. Successful treatment of gene transfer method would lead to a new and readily available approach in the anticancer research. Sonoporation is an alternative technique of gene delivery that uses ultrasound targeted microbubble destruction to create pores in the cell membrane. Based on our previous studies, in this article, we postulated that the transfection of miRNA could be mediated by the combination of sonoporation and polyethylenimine (PEI) which was one of the most effective poly-cationic gene vectors and enhance the endocytosis of plasmids DNA and hypothesized that the gene silencing and apoptosis induction with miRNA targeting human Survivin would be improved by this novel technique. In our opinion, this novel combination of sonoporation and PEI could enhance targeted gene delivery effectively and might be a feasible, novel candidate for gene therapy.
Genetic Therapy ; methods ; Humans ; Inhibitor of Apoptosis Proteins ; genetics ; MicroRNAs ; genetics ; Neoplasms ; therapy ; Polyethyleneimine ; chemistry ; Transfection ; methods

Polyelectrolyte with a large number of cations or anions could precipitate the oppositely charged proteins to form polyelectrolyte-protein complexes, which then aggregated to form larger particles via electrostatic attraction or hydrophobic interaction. The precipitation was affected by the molecular weight and concentration of the polyelectrolyte as well as the ionic strength and pH of the solution. The use of precipitation is an efficient method for selective separation of proteins from crude biological mixtures in the downstream processes of bioengineering.
Acrylic Resins ; chemistry ; Chemical Precipitation ; Electrolytes ; chemistry ; Polyethyleneimine ; chemistry ; Protein Binding ; Proteins ; isolation & purification

Polyethylenimine (PEI) is a kind of nanometer nonviral vector frequently applied in gene transfection. It is simple and easy to prepare and to modify and relatively safe compared to viral vectors. In recent years, PEI has been utilized in many research areas for gene delivery to stem cells in vitro or targeted gene delivery to cells in the brain. This review reveals that the cytotoxicity and low transfection efficiency of PEI requires to be improved. However brain-targeted modification indicates the promising prospect of PEI for gene therapy in cerebrovascular diseases.
Genetic Therapy ; Genetic Vectors ; Humans ; Nanostructures ; chemistry ; Polyethyleneimine ; chemistry ; Stem Cell Transplantation ; methods ; Transfection ; methods

This study was aimed to develop non-toxic, high transfection efficiency polyethyleneimine(PEI) cationic nanoparticles. The exosyndrome of PEI cationic nanoparticles was measured by zeta sizer, ultraviolet and visible spectroscopy. The condensation ability and the resistance to DNaseI of pEGFP-N1/PEI and pEGFP-N1/PEI modified polyethylene glycol(PEG) were evaluated by agarose gel electrophoresis. The cell toxicity of polyethyleneimine cationic nanoparticles was measured by using MTT test. The orthogonal design was used to optimize the transfection efficiency with the N/P ratio, the grafting ratio and the gene dosage as the factors. The experimental results showed that pEGFP-N1/PEI nanoparticles have lower cell toxicity, better composite ability and better resistance to DNAseI. The highest transfection efficiency of PEI cationic nanoparticles was 91% by using the PEI nanoparticles with the N/P ratio 40:1 and gene dosages 6 microg/well. PEI cationic nanoparticle modified by PEG effectively transferred DNA to hepatoma carcinoma cells and it is a non-toxic, with high transfection efficiency, and a promising non-viral carrier for gene delivery. The transfection efficiency will be improved by optimizing the experiment condition.
Carcinoma, Hepatocellular ; genetics ; pathology ; Cell Line, Tumor ; Gene Transfer Techniques ; Humans ; Liver Neoplasms ; genetics ; pathology ; Nanoparticles ; chemistry ; Polyethylene Glycols ; chemistry ; Polyethyleneimine ; chemistry ; Transfection ; methods

The aim of this paper is to report the synthesis of the mPEG-PCL-g-PEI copolymers as small interfering RNA (siRNA) delivery vector, and exploration of the siRNA delivery potential of mPEG-PCL-g-PEI in vitro. The diblock copolymers mPEG-PCL-OH was prepared through the ring-opening polymerization. Then, the hydroxyl terminal (-OH) of mPEG-PCL-OH was chemically converted into the carboxy (-COOH) and N-hydroxysuccinimide (NHS) in turn to prepare mPEG-PCL-NHS. The branched PEI was reacted with mPEG-PCL-NHS to synthesize the ternary copolymers mPEG-PCL-g-PEI. The structure of mPEG-PCL-g-PEI copolymers was characterized with Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The mPEG-PCL-g-PEI/siRNA nanoparticles were prepared by complex coacervation, and the nanoparticles size and zeta potential were determined, separately. The cytotoxicities of mPEG-PCL-g-PEI/siRNA nanoparticles and PEI/siRNA nanoparticles were compared through cells MTT assays in vitro. The inhibition efficiencies of firefly luciferase gene expression by mPEG-PCL-g-PEI/ siRNA nanoparticle at various N/P ratios were investigated through cell transfection in vitro. The experimental results suggested that the ternary (mPEG5k-PCL(1.2k))1.4-g-PEI(10k) copolymers were successfully synthesized. (mPEG(5k)-PCL(1.2k))1.4-g-PEI(10k) could condense siRNA into nanoparticles (50-200 nm) with positive zeta potential. MTT assay results showed that the cytotoxicity of (mPEG(5k)-PCL(1.2k))1.4-g-PEI(10k)/siRNA nanoparticles was significantly lower than that of PEI(10k)/siRNA nanoparticles (P < 0.05). The expression of firefly luciferase gene could be significantly down-regulated at a range of N/P ratio from 50 to 150 (P < 0.01), and maximally inhibited at the N/P ratio of 125. The mPEG-PCL-g-PEI polymers could delivery siRNA into cells to inhibit the expression of target gene with very low cytotoxicity, which suggested that mPEG-PCL-g-PEI could serve as a new type of siRNA delivery vector.
Cell Line, Tumor ; Cell Survival ; Drug Carriers ; Genes, Reporter ; Genetic Vectors ; Humans ; Luciferases ; metabolism ; Molecular Weight ; Nanoparticles ; Particle Size ; Polyesters ; chemistry ; Polyethylene Glycols ; chemistry ; Polyethyleneimine ; chemistry ; Polymers ; chemistry ; RNA, Small Interfering ; administration & dosage ; genetics ; metabolism ; Transfection