Plasmid-DNA Delivery by Covalently Functionalized PEI-SPIONs as a Potential ‘Magnetofection’ Agent

René Stein, Felix Pfister, Bernhard Friedrich, Pascal Raphael Blersch, Harald Unterweger, Anton Arkhypov, Andriy Mokhir, Mikhail Kolot, Christoph Alexiou, Rainer Tietze*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Nanoformulations for delivering nucleotides into cells as vaccinations as well as treatment of various diseases have recently gained great attention. Applying such formulations for a local treatment strategy, e.g., for cancer therapy, is still a challenge, for which improved delivery concepts are needed. Hence, this work focuses on the synthesis of superparamagnetic iron oxide nanoparticles (SPIONs) for a prospective “magnetofection” application. By functionalizing SPIONs with an active catechol ester (CafPFP), polyethyleneimine (PEI) was covalently bound to their surface while preserving the desired nanosized particle properties with a hydrodynamic size of 86 nm. When complexed with plasmid-DNA (pDNA) up to a weight ratio of 2.5% pDNA/Fe, no significant changes in particle properties were observed, while 95% of the added pDNA was strongly bound to the SPION surface. The transfection in A375-M cells for 48 h with low amounts (10 ng) of pDNA, which carried a green fluorescent protein (GFP) sequence, resulted in a transfection efficiency of 3.5%. This value was found to be almost 3× higher compared to Lipofectamine (1.2%) for such low pDNA amounts. The pDNA-SPION system did not show cytotoxic effects on cells for the tested particle concentrations and incubation times. Through the possibility of additional covalent functionalization of the SPION surface as well as the PEI layer, Caf-PEI-SPIONs might be a promising candidate as a magnetofection agent in future.

Original languageEnglish
Article number7416
Issue number21
StatePublished - Nov 2022


FundersFunder number
Deutsche ForschungsgemeinschaftAL 552/17-1


    • cytotoxicity
    • ligand exchange
    • magnetofection
    • pentafluorophenyl ester
    • plasmid-DNA
    • superparamagnetic iron oxide nanoparticles (SPIONs)
    • surface functionalization
    • transfection


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