Nucleic acids are negatively charged due to their polyphosphate backbone and are thus able to interact with positively charged transfection reagents (polymers or lipids). This results in the formation of transfection complexes or nanoparticles, which protect nucleic acids from nuclease-mediated degradation.

Most cells express negatively charged heparan sulfate proteoglycans on the external surface of their cell membrane, with which positively charged transfection complexes are able to interact. This interaction is key to trigger cellular uptake via an endocytosis process.

Upon cellular uptake, transfection complexes are sequestrated into intracellular vesicles. Our transfection reagents are able to induce the release of the nucleic acids into the cytoplasm through vesicle membrane rupture or fusion. Most nucleic acids (oligonucleotides, siRNA, mRNA, etc…) stay in the cytoplasm where they are active. In case of gene transfer, plasmid DNA is transported into the nucleus for transient expression) which can become permanent after genome integration (stable expression).

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