Abstract: The invention relates to a method for the production of recombinant proteins by eucaryotic cells in synthetic culture media, wherein said eucaryotic cells are transfected with a composition comprising a synthetic transfection reagent based on a polyhydroxylated polyalkyleneimine.

Abstract: The invention concerns a method of synthesising and preparing linear polyethylenimine (PEI) for use as a transfection vector, and the product obtained with such a method. It comprises drying a monomer 2-ethyl-2-oxazoline and polymerising said monomer for obtaining poly (2-ethyl-2-oxazoline) (PEOX) by: using acetonitrile as solvent, adding a dried initiator of the reaction of polymerisation, and mixing them altogether, purifying said obtained PEOX by evaporation, while performing at least three times successive washing/precipitation steps with methanol and diethyl ether and corresponding filtrations, in order to obtain (i), by performing 1H-NMR tests, correct identification of said PEOX polymer, confirmation of absence of monomer to a level <1.0% and confirmation of absence of solvent to a level <5.0% and (ii), by performing Gel Permeation Chromatography, a mean of molecular weight (Mw)>23,000 Da and polydispersity (Mw/Mn) of said PEOX<1.5, hydrolysing said PEOX.

Abstract: The invention relates to a method for the production of recombinant proteins by eucaryotic cells in synthetic culture media, wherein said eucaryotic cells are transfected with a composition comprising a synthetic transfection reagent based on a polyhydroxylated polyalkyleneimine.