APPLICATIONS: Gene transfection research, thin films with reactive surfaces, target molecule attachment

IN A NUTSHELL: Linear polyethyleneimine (PEI) contain all secondary amines, in contrast to branched PEI which contain primary, secondary and tertiary amino groups. The linear PEIs are solids at room temperature where branched PEIs are liquids at all molecular weights. Linear polyethyleneimine is soluble in hot or cold water, at low pH, in methanol, ethanol, or chloroform. It is insoluble in benzene, ethyl ether, and acetone. It has a melting point of 73-75°C. It can be stored at room temperature.

THE STATE OF THE TECHNOLOGY: Polyethyleneimines may be used as attachment promotors. They are used in the cell culture of weakly anchoring cells to increase attachment. Since PEI is a cationic polymer, the negatively charged outer surfaces of cells are attracted to dishes coated in PEI, facilitating stronger attachments between the cells and the plate.

Polyethyleneimine is primarily used as a transfection reagent. PEI condenses DNA into positively charged particles, which bind to anionic cell surface residues and are brought into the cell via endocytosis. Once inside the cell, osmotic swelling results in the swelling and eventual burst of the vesicle, which then releases the DNA into the cytoplasm. The DNA is then free to enter the nucleus.

OUR NOVELTY: Unlike PEI manufactured by other companies, Oxazogen's product is truly linear. This is an important feature because while branched PEIs are strongly toxic, Oxazogen's linear ones are not. Furthermore, because it is made from linear PEOX as the precursor, the hydrolyzed product is the same length of the start material but has enhanced functionality along its chain length. Oxazogen can synthesize PEI of any DP from 5 to 350 with a very narrow polydispersity of 1.1-1.2.