W. T. Godbey

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Poly(ethylenimine) (PEI) is one of a number of polycations that has been used successfully to transfer genes into living cells. Although PEI shows promise in the field of gene therapy, to date no rigorous proof of mechanism has been published regarding the fate of PEI/DNA administered for transfection. Here we show, by using fluorescent labeling and(More)
Poly(ethylenimine) (PEI) samples of various molecular weights and pHs were used to transfect endothelial cells to achieve levels of gene expression for comparison. PEIs with nominal molecular weights of 600, 1200, 1800, 10,000, and 70,000 Da were examined at pHs of 5. 0, 6.0, 7.0, and 8.0, and the results were recorded in terms of transfection efficiencies(More)
Poly(ethylenimine) (PEI) is a synthetic polycation that has been used successfully for gene delivery both in vitro and in vivo due, in theory, to a form of protection that is afforded to the carried plasmids. In this study the stability of PEI/DNA complexes was demonstrated using deoxyribonuclease (DNase) 1 and DNase 2, various levels of pH, and increasing(More)
Since the first published examination of poly(ethylenimine) (PEI) as a gene delivery vehicle, there has been a flurry of research aimed at this polycation and its role in gene therapy. Here we will briefly review PEI chemistry and the characterization of PEI/DNA complexes used for gene delivery. Additionally, we will note various PEI transfection(More)
Poly(ethylenimine) (PEI) was used to transfect the endothelial cell line EA.hy 926, and the secreted levels of three gene products, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1), and von Willebrand Factor (vWF), were assessed via ELISA. We found that the levels of these gene products in cell supernatants increased(More)
We have developed a modified poly(ethylenimine) (PEI) transfection procedure that significantly increases PEI’s transfection efficiency. While the basic transfection procedure had a transfection efficiency of 37%, our modified procedure yielded a 53% transfection efficiency. The altered procedure gives improved results because of two simultaneous actions:(More)
The delivery of genetic material into cells is a field that is expanding very rapidly. Non-viral delivery methods, especially ones that focus on the use of chemical agents complexed with genetic material, are the focus of this mini-review. More-recent uses of known transfection agents such as poly(ethylenimine), poly(L-lysine), and various liposomes are(More)
The principle of promoter-targeted gene delivery was used to direct the expression of reporter genes and inducible caspases to Cox-2-overexpressing cancer cells. The polycation poly(ethylenimine) was used in unmodified form to nonvirally deliver genes into cells, and targeting was achieved at the transcriptional level. Results demonstrated that reporter(More)
Tissue engineering, by necessity, encompasses a wide array of experimental directions and scientific disciplines. In vitro tissue engineering involves the manipulation of cells in vitro, prior to implantation into the in vivo environment. In contrast, in vivo tissue engineering relies on the body's natural ability to regenerate over non-cell-seeded(More)
Quaternary ammonium salt hydrogels from a cationic monomer, (3-acrylamidopropyl)-trimethylammonium chloride (APTMACl), in a variety sizes such as bulk, microand nanohas been prepared. The synthesis of microand nanogels were carried out in the microenvironment of water-in-oil microemulsions using two types of surfactants, namely, L-αphosphatidylcholine(More)