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

Abstract

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.

Innovative Strategy for MicroRNA Delivery in Human Mesenchymal Stem Cells via Magnetic Nanoparticles

“…To further improve uptake efficiencies, different NP ratios and MNP concentrations were tested and analyzed by flow cytometry while miR amount was kept constant (5 pmol/cm 2 miR, Figure 3C,D). In our previous experiments with delivery of plasmid DNA using the same carrier system, we found that NP ratio 2.5 was optimal for transfection of hMSCs [28]. Nevertheless, miR and plasmid DNA differ in terms of structure, function and stability.…”

“…Thereby, we took advantages of a labeling method for DNA containing transfection complexes, recently developed by our group. This technique does not affect transfection efficiency and cell viability [28]. Therefore, it is a reliable method for intracellular imaging of transfection processes.…”

“…Furthermore, we have recently shown for plasmid based complexes, that transfection efficiency was enhanced by conjugation of PEI complexes to MNPs even without application of magnetic field, as magnetic polyplexes provided a faster release of DNA into the cytosol compared to PEI polyplexes. Moreover, DNA/PEI/MNP transfection complexes did not pass the nuclear membrane due to strong biotin-streptavidin connections between PEI and MNPs while polyplexes were able to enter the nucleus [28]. Therefore, the transport and release mechanism of MNP bound polyplexes may be beneficial for miR delivery as opposed to DNA because miRs exert their function in the cytosol close to the nucleus.…”

Magnetic Nanoparticle Based Nonviral MicroRNA Delivery into Freshly Isolated CD105+hMSCs

“…Thus, for our studies, as well as for clinical trials, hMSCs so far were expanded in vitro [21, 22, 25]. However, in vitro expansion of primary hMSCs is a costly and time-consuming procedure.…”

Stem cell-based gene therapy activated using magnetic hyperthermia to enhance the treatment of cancer

“…As a result, this would facilitate MCNP complexation with negatively-charged plasmid DNA and induce endosomolysis within the cytoplasm [37]. To minimize cytotoxicity while maximizing transfection efficiency, we used 10 kDa branched PEI, which has previously been demonstrated to be biocompatible with stem cells [21, 38]. The resulting water soluble PEI-coated MCNPs (MCNP-PEI) had a hydrodynamic size of 117.2 ± 37 nm (polydispersity index [PDI] = 0.177) as measured by dynamic light scattering (DLS) and a zeta potential of +44.23 ± 0.72 mV (Figures 2C and S2A).…”