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Linear Polyethylenimine (linear + polyethylenimine)

Distribution by Scientific Domains

Life Sciences	66%

Selected Abstracts

Synthesis and characterization of dexamethasone-conjugated linear polyethylenimine as a gene carrier

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2010
Hyunjung Kim
Abstract Linear polyethylenimine (25,kDa, LPEI25k) has been shown to be an effective non-viral gene carrier with higher transfection and lower toxicity than branched polyethylenimine (BPEI) of comparable molecular weight. In this study, dexamethasone was conjugated to LPEI25k to improve the efficiency of gene delivery. Dexamethasone is a synthetic glucocorticoid receptor ligand. Dexamethasone-conjugated LPEI25k (LPEI,Dexa) was evaluated as a gene carrier in various cells. Gel retardation assays showed that LPEI,Dexa completely retarded plasmid DNA (pDNA) at a 0.75:1 weight ratio (LPEI/pDNA). LPEI,Dexa had the highest transfection efficiency at a 2:1 weight ratio (LPEI,Dexa/DNA). At this ratio, the size of the LPEI,Dexa/pDNA complex was approximately 125,nm and the zeta potential was 35,mV. LPEI,Dexa had higher transfection efficiency than LPEI and Lipofectamine 2000. In addition, the cytotoxicity of LPEI,Dexa was much lower than that of BPEI (25,kDa, BPEI25k). In conclusion, LPEI,Dexa has a high transfection efficiency and low toxicity and can therefore be used for non-viral gene delivery. J. Cell. Biochem. 110: 743,751, 2010. © 2010 Wiley-Liss, Inc. [source]

Cell cycle effects resulting from inhibition of hepatocyte growth factor and its receptor c-Met in regenerating rat livers by RNA interference,

HEPATOLOGY, Issue 6 2007
Shirish Paranjpe
Hepatocyte growth factor (HGF) and its receptor c-Met are involved in liver regeneration. The role of HGF and c-Met in liver regeneration in rat following two-thirds partial hepatectomy (PHx) was investigated using RNA interference to silence HGF and c-Met in separate experiments. A mixture of 2 c-Met-specific short hairpin RNA (ShRNA) sequences, ShM1 and ShM2, and 3 HGF-specific ShRNA, ShH1, ShH3, and ShH4, were complexed with linear polyethylenimine. Rats were injected with the ShRNA/PEI complex 24 hours before and at the time of PHx. A mismatch and a scrambled ShRNA served as negative controls. ShRNA treatment resulted in suppression of c-Met and HGF mRNA and protein compared with that in controls. The regenerative response was assessed by PCNA, mitotic index, and BrdU labeling. Treatment with the ShHGF mixture resulted in moderate suppression of hepatocyte proliferation. Immunohistochemical analysis revealed severe suppression of incorporation of BrdU and complete absence of mitosis in rats treated with ShMet 24 hours after PHx compared with that in controls. Gene array analyses indicated abnormal expression patterns in many cell-cycle- and apoptosis-related genes. The active form of caspase 3 was seen to increase in ShMet-treated rats. The TUNEL assay indicated a slight increase in apoptosis in ShMet-treated rats compared with that in controls. Conclusion: The data indicated that in vivo silencing of c-Met and HGF mRNA by RNA interference in normal rats results in suppression of mRNA and protein, which had a measurable effect on proliferation kinetics associated with liver regeneration. (HEPATOLOGY 2007.) [source]

Synthesis and characterization of dexamethasone-conjugated linear polyethylenimine as a gene carrier

Scalable production of adeno-associated virus type 2 vectors via suspension transfection,

BIOTECHNOLOGY & BIOENGINEERING, Issue 3 2006
Joon Young Park
Abstract Vectors derived from adeno-associated virus type 2 (AAV2) are promising gene delivery vehicles, but it is still challenging to get the large number of recombinant adeno-associated virus (rAAV) particles required for large animal and clinical studies. Current transfection technology requires adherent cultures of HEK 293 cells that can only be expanded by preparing multiple culture plates. A single large-scale suspension culture could replace these multiple culture preparations, but there is currently no effective co-transfection scheme for generating rAAV from cells in suspension culture. Here, we weaned HEK 293 cells to suspension culture using hydrogel-coated six-well culture plates and established an efficient transfection strategy suitable for these cells. Then the cultures were gradually scaled up. We used linear polyethylenimine (PEI) to mediate transfection and obtained high transfection efficiencies ranging from 54% to 99%, thereby allowing efficient generation of rAAV vectors. Up to 1013 rAAV particles and, more importantly, up to 1011 infectious particles were generated from a 2-L bioreactor culture. The suspension-transfection strategy of this study facilitates the homogeneous preparation of rAAV at a large scale, and holds further potential as the basis for establishing a manufacturing process in a larger bioreactor. © 2006 Wiley Periodicals, Inc. [source]

Spontaneous Change of Physical State from Hydrogels to Crystalline Precipitates during Poly-pseudorotaxane Formation

CHEMPHYSCHEM, Issue 9 2004
Hak Soo Choi
Spontaneous change: Hydrogels spontaneously changed to crystalline precipitates through heating and cooling processes in linear polyethylenimine-based inclusion complexes with ,-cyclodextrins (see graphic). [source]

Gene transfer with modified polyethylenimines

THE JOURNAL OF GENE MEDICINE, Issue S1 2004
Antoine Kichler
Abstract Branched and linear polyethylenimines (PEIs) have proven to be efficient and versatile agents for gene delivery in vitro. In addition, systemic administration of positively charged DNA/PEI complexes results in significant reporter gene expression in lungs. However, re-targeting of complexes to organs other than the lung is hampered by non-specific interactions of polyplexes with blood components and non-target cells. Thus, despite considerable transfectional activity, the properties of PEIs need to be further improved. Therefore, various modifications of PEIs have been explored in recent years. For example, to increase the circulation half-life of the DNA complexes, the surface charge of the particles was shielded by grafting hydrophilic polymers such as polyethylene glycols (PEGs) onto their surface. Alternatively, incorporation of certain ligands into the DNA complexes also resulted in charge shielding even without PEGylation. Herein, I review the most recent PEI derivatives, with a special focus on PEGylated and targeted polymers. Copyright © 2004 John Wiley & Sons, Ltd. [source]