Improved Transfection in Human Mesenchymal Stem Cells: Effective Intracellular Release of pDNA by Magnetic Polyplexes

Abstract

Aim: Magnetically guided transfection has been shown as a promising approach for the genetic modification of cells. We observed that polyethylenimine (PEI)-condensed pDNA, combined with magnetic nanoparticles (MNPs) via biotin–streptavidin interactions could provide higher transfection efficiency than pDNA/PEI alone, even without the application of a magnetic force. Therefore, we intended to investigate the beneficial properties of MNP-based transfection. Materials & methods: We performed three-color fluorescent labeling of magnetic transfection complexes and traced them inside human mesenchymal stem cells over time using confocal microscopy in order to study pDNA release kinetics by colocalization studies. Results: We demonstrated that MNP-combined pDNA/PEI complexes provide more rapid and efficient release of pDNA than pDNA/PEI alone, which could be explained by the retention of PEI on the surface of the MNPs due to strong biotin–streptavidin interactions. Conclusion: The process of pDNA liberation may significantly influence the efficiency of the transfection vector. Therefore, it should be carefully considered when creating novel gene delivery agents.

Keywords::

• colocalization study
• gene delivery
• magnetic nanoparticle
• mesenchymal stem cell
• polyethylenimine

Financial & competing interests disclosure

This work was supported by Sonderforschungsbereich/Transregio 37 (B5), Marie Curie International Research Staff Exchange Scheme (FKZ PIRSES-GA-2009-247599), the Reference and Translation Center for Cardiac Stem Cell Therapy (BMBF: FKZ 0312138A and Land MV: FKZ V230-630-08-TFMV-F/S-035) and European Social Fund grant (UR11 041; ESF/IV-BM-B35-0010/12). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Acknowledgements

The authors would like to thank M Fritsche for technical assistance in stem cell isolation.

Additional information

Funding

This work was supported by Sonderforschungsbereich/Transregio 37 (B5), Marie Curie International Research Staff Exchange Scheme (FKZ PIRSES-GA-2009-247599), the Reference and Translation Center for Cardiac Stem Cell Therapy (BMBF: FKZ 0312138A and Land MV: FKZ V230-630-08-TFMV-F/S-035) and European Social Fund grant (UR11 041; ESF/IV-BM-B35-0010/12). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.