DNA transfection

> Broad cell line spectrum: jetPEI™ transfection reagent
> Cell-specific derivatives of jetPEI™
> Fluorescent derivative of jetPEI™
> Protein production in serum-free media: Fecturin™ transfection reagent
> Insect cell specific reagents: FectoFly ™ I & II

Gene delivery to eukaryotic cells is the fundamental technique for studying the regulation of gene expression and protein function. Following the use of calcium phosphate and polybrene, various cationic liposomal formulations were developed during the early nineties. Although greatly improving overall efficiency, such self-aggregating formulations are now known to be unstable, often toxic and affected by serum or antibiotics.

Cationic polymers, provided they are pure, are much less affected by these drawbacks. For its core business, i.e., transfection, Polyplus has chosen by far the most efficient structure among polymers : polyethylenimine (PEI). Polyplus-transfection has synthesized and has extensively tested a number of PEI topologies, molecular weights, and purification techniques.

jetPEI™ is a proprietary brand of linear PEIs achieving the most effective gene expression with the lowest residual toxicity. Moreover, the fact that it is a stable water-soluble polymer ensures remarkably reproducible results. This property is particularly important for screening technologies using transfection, where large sets of data with small differences are compared. The company also offers a unique panel of cell-specific jetPEI™ derivatives (HUVEC cells, hepatocytes, macrophages ..) which can improve gene delivery to specific cell types.

The Fluoresceine derivative of jetPEI™ is  designed to track the intracellular fate of jetPEI™/polynucleotide complexes.

Fecturin™ is a new transfection reagent for protein production in serum-free media.  Fecturin™ complies with the most recent regulatory requirements for large-scale production of recombinant proteins.

Fectofly™ reagents are dedicated to insect cell transfection. This set of reagents proposes an adapted solution for protein production for most insect cell types.

Upon mixing, jetPEI™ transfection reagent condenses DNA into ca. 0.2-0.4 µm positively charged particles(Figure 1, 2). This calibration is large enough for fast sedimentation onto the cell layer, yet still small enough to allow cell entry.
Particles then interact with ubiquitously expressed anionic proteoglycans and are taken up by endocytosis ¹. Within acidic endosomes, jetPEI™ exploits its unique property of acting as a « proton sponge » that buffers pH ². Besides providing DNA protection, this leads to endosome swelling and rupture ³. Efficient escape into the cytoplasm is just one of jetPEI™’s distinctive properties. Indeed, only linear PEI (the active principle of jetPEI™) and not branched PEI or cationic liposomes can enhance entry into the nucleus ⁴. This property is particularly useful for transfection of slow-dividing or resting cells ⁵.

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3. Akinc, A., Thomas, M., Klibanov, A.M. & Langer, R. (2005) Exploring polyethylenimine-mediated DNA transfection and the proton sponge hypothesis J Gene Med 7 :657-663.

4. Brunner, S., E. Furtbauer, T. Sauer, M. Kursa and E. Wagner (2002) Overcoming the nuclear barrier: cell cycle independent nonviral gene transfer with linear polyethylenimine or electroporation Mol Ther 5(1): 80-6.

5. Wiseman, J. W., C. A. Goddard, D. McLelland and W. H. Colledge (2003) A comparison of linear and branched polyethylenimine (PEI) with DCChol/DOPE liposomes for gene delivery to epithelial cells in vitro and in vivo Gene Ther 10(19): 1654-62.