Nanomagnetic Activation as a Way to Control the Efficacy of Nucleic Acid Delivery
To explore the potential of magnetofection in delivering pDNA to primary mouse embryonic fibroblasts (PMEFs) and porcine fetal fibroblasts (PFFs) and investigate an effect of magnetic cell labeling on transfection efficacy.
The formulation and a dose of the magnetic vector were optimized. The efficacy of the procedure was quantified by vector internalization, transgene expression and cell iron loading upon specific labeling with Ab-conjugated magnetic beads or non-specific labeling with MNPs.
Up to sixty percent of PMEF and PFF cells were transfected at low pDNA doses of 4–16 pg pDNA/cell. Specific labeling of the PMEFs with MNPs, resulted in a 3- and 2-fold increase in pDNA internalization upon magnetofection and lipofection, respectively, that yielded a 2–4-fold increase in percent of transgene-expressing cells. Non-specific cell labeling had no effect on the efficacy of the reporter expression, despite the acquisition of similar magnetic moments per cell. In PFFs, specific magnetic labeling of the cell surface receptors inhibited internalization and transfection efficacy.
Magnetic labeling of cell-surface receptors combined with the application of an inhomogenous magnetic field (nanomagnetic activation) can affect the receptor-mediated internalization of delivery vectors and be used to control nucleic acid delivery to cells.
KEY WORDSmagnetic cell labeling magnetic nanoassemblies magnetic nanoparticles nanomagnetic activation nucleic acid delivery
Counts per minutes
Dulbecco’s modified Eagle’s medium
Fetal bovine serum
Induced pluripotent stem cells
Dulbecco’s phosphate buffered saline
Photon correlation spectroscopy
Porcine fetal fibroblasts
Primary mouse embryonic fibroblasts
Transmission electron microscopy
ACKNOWLEDGMENTS AND DISCLOSURES
We are thankful to Mikołaj Grzeszkowiak for the work on transmission electron microscopy analysis of the microbeads. We gratefully acknowledge the support from the German Research Foundation through the DFG Research Unit FOR917 (Project PL 281/3-1, TR 408/6-1), from the German Federal Ministry of Education and Research through grants ZIM-KOOP ’STEP-MAG’, and from the Excellence Cluster ‘Nanosystems Initiative Munich’. The work was supported by the International PhD Projects Program of the Foundation for Polish Science operated within the Innovative Economy Operational Program (IE OP) 2007–2013 of the European Regional Development Fund.
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