Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hyaluronic acid (HA) plays important biological roles in tissue integrity, angiogenesis, wound healing, and cell motility through the interaction with receptors on cell membranes. In this work, we investigated the effect of HA modification on the receptor-mediated endocytosis labeling HA derivatives with quantum dots (QDots). HA-QDot conjugates with a degree of modification less than ca. 25 mol % appeared to be more efficiently taken up to B16F1 cells by HA receptor mediated endocytosis than QDots alone. On the basis of bioimaging study, polyethyleneimine, PEI-HA conjugate with 24.2 mol % PEI content was developed as a target specific intracellular delivery carrier of siRNA. The siRNA/PEI-HA complex exhibited higher gene silencing efficiency in B16F1 cells with HA receptors than siRNA/PEI complex. Anti-PGL3-Luc siRNA/PEI-HA complex appeared to silence PGL3-Luc gene in the range of 50%-85% depending on the serum concentration up to 50 vol %. According to in vivo biodistribution test, siRNA/PEI-HA complex accumulated mainly in the tissues with HA receptors such as liver, kidney, and tumor. Furthermore, intratumoral injection of anti-VEGF siRNA/PEI-HA complex resulted in an effective inhibition of tumor growth by the HA receptor mediated endocytosis to tumor cells in C57BL/6 mice. Considering all these results, anti-VEGF siRNA/PEI-HA complex was thought to be applied successfully as target specific antiangiogenic therapeutics for the treatment of diseases in the tissues with HA receptors, such as liver cancer and kidney cancer.
Mol Pharm
PMID:Target specific intracellular delivery of siRNA/PEI-HA complex by receptor mediated endocytosis. 1917 44

The development of techniques to efficiently deliver genes using nonviral approaches can broaden the application of gene delivery in medical applications without the safety concerns associated with viral vectors. Here, we designed a clustered integrin-binding platform to enhance the efficiency and targetability of nonviral gene transfer to HeLa cells with low and high densities of alpha(v)beta(3) integrin receptors. Arg-Gly-Asp (RGD) nanoclusters were formed using gold nanoparticles functionalized with RGD peptides and used to modify the surface of DNA/poly(ethylene imine) (PEI) polyplexes. DNA/PEI polyplexes with attached RGD nanoclusters resulted in either 5.4- or 35-fold increase in gene transfer efficiency over unmodified polyplexes for HeLa cells with low- or high-integrin surface density, respectively. The transfection efficiency obtained with the commercially available vector jetPEI-RGD was used for comparison as a vector without clustered binding. JetPEI-RGD exhibited a 1.2-fold enhancement compared to unmodified jetPEI in cells with high densities of alpha(v)beta(3) integrin receptors. The data presented here emphasize the importance of the RGD conformational arrangement on the surface of the polyplex to achieve efficient targeting and gene transfer, and provide an approach to introduce clustering to a wide variety of nanoparticles for gene delivery.
Mol Ther 2009 May
PMID:Engineering clustered ligand binding into nonviral vectors: alphavbeta3 targeting as an example. 1924 Jun 93

A novel co-polymer based on 2-hydroxypropyl-alpha-cyclodextrin cross-linked by low molecular weight polyethylenimine was synthesized as a gene delivery vector. The copolymer could bind and condense DNA tightly. It showed lower cytotoxicity than PEI 25kDa in SK-BR-3 cells. Transfection efficiency was increased over 5.5-fold higher than PEI 25 kDa in SK-BR-3 cells in complete serum medium. It is a potential candidate vector for gene therapy.
Int J Mol Sci 2008 Nov
PMID:A novel co-polymer based on hydroxypropyl alpha-cyclodextrin conjugated to low molecular weight polyethylenimine as an in vitro gene delivery vector. 1933 75

Stromal cell-derived factor-1alpha (SDF-1alpha) mediated mobilization and homing of stem cells showed promising potential in stem cell based tissue engineering and regenerative medicine. However local and sustained release of SDF-1alpha is indispensable for stem cell mediated regenerative process due to its short half-life under inflammatory conditions. In this study, a gene activated collagen substrate (GAC) was formed via assembly of plasmid encoding SDF-1alpha into a collagen substrate to create a microenvironment favoring stem cell homing. Local release of SDF-1alpha from the transfected cells on GAC and its effect on CD117(+) stem cell homing were investigated. Non-viral poly-ethyleneimine (25kDa PEI)/DNA complexes were mixed with rat tail collagen solution to form the GAC. Optimization of GAC was carried out based on collagen effects on the PEI/DNA complexes, viability and luciferase expression of COS7 cells on GAC. CD117(+) stem cells homing in response to SDF-1alpha local expression from transfected cells on GAC were investigated in a flow chamber in vitro and in a mouse hind limb model in vivo. The gene expression, migration of CD117(+) stem cells and the induced inflammation were investigated with immunostaining, reverse transcription polymerase chain reaction (RT-PCR) and H&E staining. The optimized parameters for GAC were DNA dosage 10 microg/cm(2), molar ratio of PEI nitrogen in primary amine to DNA phosphate (N/P ratio) 4 and mass ratio of collagen to DNA (C/D ratio) 1.0. It kept cell viability above 75% and transfection efficiency around 5.8 x 10(5) RLU/mg protein. GAC allowed the sustained gene release up to 60 days. GAC mediated SDF-1alpha gene release induced migration and homing of CD117(+) stem cells in vitro and in vivo significantly, and the inflammation of GAC reduced significantly two weeks after transplantation. GAC is a promising stem cell based therapeutic strategy for regenerative medicine.
J Cell Mol Med 2010 Jan
PMID:Localized SDF-1alpha gene release mediated by collagen substrate induces CD117 stem cells homing. 1941 87

Although non-viral vectors are relatively safe, they have very low gene transfection efficiency, especially in pancreatic islet cells. To provide information on the use of non-viral vectors for transfecting genes into pancreatic islet cells, a comparative evaluation of non-viral options was performed. In vitro experiments were used to compare the transfection efficiency of three classes of non-viral vectors: Effectene, polyethylenimine (PEI, 25 kDa) and hemagglutinating virus of Japan-envelope (HVJ-E), into insulinoma cells (INS-1) and rat islets. Vascular endothelial growth factor (VEGF) gene with hypoxia-inducible RTP801 promoter was delivered into rat islets with Effectene and VEGF secretion under hypoxia was measured in the culture media. Luciferase activity and GFP assays indicated that Effectene exhibited the highest transfection efficiency, and HVJ-E was not suitable for transfection into pancreatic beta-cells. The cytotoxicity of Effectene was found to be similar to that of 25-kDa PEI by 7-amino actinomycin D (7-AAD) flow cytometry and acridine orange/propidium iodide (AO/PI) assays. When RTP801 promoter-VEGF plasmid was delivered to rat islets with Effectene, VEGF secretion increased specifically in islets under hypoxia. In conclusion, Effectene showed higher gene-delivery efficiency for pancreatic islets compared with other classes of non-viral delivery systems and is promising as a gene delivery agent for pretransplant ex vivo gene therapy of islets.
Int J Mol Med 2009 Jun
PMID:A comparison of non-viral vectors for gene delivery to pancreatic beta-cells: delivering a hypoxia-inducible vascular endothelial growth factor gene to rat islets. 1942 1

Low transfection efficiency and inactivation by serum are the major drawbacks for cationic polymers when used as non-viral gene vectors. Here, a series of N-succinyl-chitosan-graft-polyethylenimine (NSC-g-PEI) copolymers with different compositions were synthesized through grafting low molecular weight PEI (800 Da) to N-succinyl-chitosan. An agarose gel electrophoresis assay showed NSC-g-PEIs had good binding capability with DNA and the particle size of the NSC-g-PEI-DNA complexes was between 150 to 300 nm as determined by a Zeta sizer. In vitro transfection of NSC-g-PEI-DNA complexes for 293T, HeLa and CHO cells was investigated. It was found that the transfection efficiency of NSC-g-PEI-DNA complexes was higher than that of DNA combined PEI (25 kDa) and the transfection efficiency increased with the increasing GD of PEI. More importantly, the NSC-g-PEI-DNA complexes were stable and the transfection efficiency was not affected obviously in the presence of serum with different concentrations. In addition, NSC-g-PEIs had a lower cytotoxicity than PEI (25 kDa) and the toxicity increased with increasing GD of PEI. The NSC-g-PEI copolymers will have a good potential as efficient non-viral gene vectors in the presence of serum.
Mol Biosyst 2009 Jun
PMID:N-Succinyl-chitosan grafted with low molecular weight polyethylenimine as a serum-resistant gene vector. 1946 20

Reverse transfection from a solid surface has the potential to deliver genes into various types of cell and tissue more effectively than conventional methods of transfection. We present a method for reverse transfection using a gold colloid (GC) as a nanoscaffold by generating nanoclusters of the DNA/reagent complex on a glass surface, which could then be used for the regulation of the particle size of the complex and delivery of DNA into nuclei. With this method, we have found that the conjugation of gold nanoparticles (20 nm in particle size) to the pEGFP-N1/Jet-PEI complex resulted in an increase in the intensity of fluorescence of enhanced green fluorescent protein (EGFP) (based on the efficiency of transfection) from human mesenchymal stem cells (hMSCs), as compared with the control without GC. In this manner, we constructed a method for reverse transfection using GC to deliver genes into the cells effectively.
Methods Mol Biol 2009
PMID:Reverse transfection using gold nanoparticles. 1948 27

The understanding of internalization pathways of lipo- or polyplexes is crucial for engineering successful reagents for nonviral gene transfection. A known inhibitor of fluid phase endocytosis (FPE), rottlerin, was used to quantify the contribution of this pathway by flow cytometric and fluorescence assays. Rottlerin was shown to be a specific inhibitor of transfection by polyethylene imine (PEI-25)/DNA complexes, leading to a decrease in the amount of transfected HeLa and CHO-K1 cells and a decrease in the expression of enhanced green fluorescent protein (EGFP) reporter gene by up to 50%. Experiments using fluorescently labeled polyplexes result in a decrease of uptake by up to 40%. Additionally, rottlerin does not cross-inhibit clathrin- and caveolin-mediated endocytotic pathways of internalization, consistent with direct uptake inhibition by rottlerin. Nonspecific effects as a result of toxicity were ruled out by control experiments at concentrations where rottlerin inhibition was specific. These findings suggest that for CHO-K1 and HeLa cells, internalization of PEI-25/DNA complexes by FPE plays a decisive role in gene transfection. The establishment of an additional pathway that is independent of clathrin- and caveolin-mediated endocytotic uptake may have an impact on the design of future reagents of nonviral gene therapy and investigations of the uptake pathways and intracellular trafficking involved.
Mol Ther 2009 Aug
PMID:Fluid phase endocytosis contributes to transfection of DNA by PEI-25. 1953 43

Polyethylenimine (PEI) and plasmid DNA (pDNA) complexes (PEI/pDNA) are nonviral vectors for gene delivery. The conventional method for producing these complexes involves bulk mixing (BM) of PEI and DNA followed by vortexing which at low N/P ratios results in large particle size distribution, low cytotoxicity, and poor gene transfection, while at high N/P ratios it results in small particle size and better gene transfection but high cytotoxicity. To improve size control, gene transfection efficiency, and cytotoxicity, in this study, we used a microfluidic hydrodynamic focusing (MF) device to prepare PEI/pDNA complexes at N/P = 3.3 and 6.7. We used bulk mixing as control, mouse NIH 3T3 fibroblast cells and mouse embryonic stem (mES) cells as model cell lines, plasmid encoding green fluorescent protein (pGFP) and secreted alkaline phosphatase (pSEAP) as the reporter gene, and commercially available Lipofectamine 2,000 as a positive control. The complexes were characterized by atomic force microscopy (AFM), dynamic light scattering (DLS), and zeta potential (zeta) measurement. Confocal laser scanning microscopy (CLSM) and fluorescent labeling techniques were used to visualize the complex size distribution, complexation uniformity, and cellular distribution. The results showed that MF produced complexes were smaller and more uniformly complexed and had higher cell viability and improved exogenous gene expression.
Mol Pharm
PMID:Delivery of polyethylenimine/DNA complexes assembled in a microfluidics device. 1955 81

This study describes the physicobiological characterization of PEI- and PEG-PEI polyplexes containing partially 2'-OMe modified 25/27mer dicer substrate siRNAs (DsiRNAs) and their in vivo behavior regarding biodistribution and systemic bioavailability after pulmonary application as well as their ability to knock down gene expression in the lung. Biophysical characterization included circular dichroism of siRNA in polyplexes, condensation efficiency of polymers and in vitro stability. After in vivo application, biodistribution and kinetics of radiolabeled polyplexes were quantified and recorded over time in three-dimensional SPECT images and by end point scintillation counting. The influence on lung tissue and on the humoral and cellular immunosystem was investigated, and finally knockdown of endogenous gene expression in the lung was determined qualitatively. While all of the polymers used in our study were proven to effectively condense siRNA, stability of the complexes depended on the PEG grafting degree. Interestingly, PEI 25 kDa, which showed the least interaction with mucin or surfactant in vitro, performed poorly in vivo. Our nuclear imaging approach enabled us to follow biodistribution of the instilled nanocarriers over time and indicated that PEGylated nanocarriers are more suitable for lung application. While moderate proinflammatory effects were attributed to PEI25k-PEG(2k)(10) nanocarriers, none of the treatments caused histological abnormalities. Our preliminary in vivo knockdown experiment suggests that PEG-PEI/siRNA complexes are promising nanomedicines for pulmonary siRNA delivery. These results encouraged us to further investigate possible adverse effects and to quantify in vivo gene silencing in the lung after intratracheal instillation of PEG-PEI/siRNA complexes.
Mol Pharm
PMID:Nonviral siRNA delivery to the lung: investigation of PEG-PEI polyplexes and their in vivo performance. 1960 64


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