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

Abstract

Bone marrow derived human mesenchymal stem cells (hMSCs) show promising potential in regeneration of defective tissue. Recently, gene silencing strategies using microRNAs (miR) emerged with the aim to expand the therapeutic potential of hMSCs. However, researchers are still searching for effective miR delivery methods for clinical applications. Therefore, we aimed to develop a technique to efficiently deliver miR into hMSCs with the help of a magnetic non-viral vector based on cationic polymer polyethylenimine (PEI) bound to iron oxide magnetic nanoparticles (MNP). We tested different magnetic complex compositions and determined uptake efficiency and cytotoxicity by flow cytometry. Additionally, we monitored the release, processing and functionality of delivered miR-335 with confocal laser scanning microscopy, real-time PCR and live cell imaging, respectively. On this basis, we established parameters for construction of magnetic non-viral vectors with optimized uptake efficiency (~75%) and moderate cytotoxicity in hMSCs. Furthermore, we observed a better transfection performance of magnetic complexes compared to PEI complexes 72 h after transfection. We conclude that MNP-mediated transfection provides a long term effect beneficial for successful genetic modification of stem cells. Hence, our findings may become of great importance for future in vivo applications.

Nanocarrier mediated delivery of siRNA/miRNA in combination with chemotherapeutic agents for cancer therapy: Current progress and advances

“…The miRNA based combination therapies are in its early stage of development. Various carriers such as cationic lipoplexes [120], polyethylenimine (PEI) bound to iron oxide magnetic nanoparticles (MNP) [121], PLGA [122] have been used to deliver miRNA for cancer therapy. Following section of article systematically reviews the work done in the field of nanocarrier based approaches for the delivery of RNAi based combinations.…”

Ethanol deregulates Mecp2/MeCP2 in differentiating neural stem cells via interplay between 5-methylcytosine and 5-hydroxymethylcytosine at the Mecp2 regulatory elements

“…For quantification of the surface area of GFAP + astrocytes, superimposed Z-stacked images taken at 0.32 μm sections were analyzed. The surface area of GFAP + astrocytes was measured using the spline contour tool within Zen 2011 software, as shown in a previous study (Schade et al, 2013). The signal intensity was adjusted to observe all the cellular processes of GFAP + cells and the outer margin of each cell was carefully marked using the spline contour tool, which directly provides the area in μm 2 .…”

Scaffold‐Based microRNA Therapies in Regenerative Medicine and Cancer

“…[90] Qureshi et al developed an interesting photocleavable-Ag nanoparticle system, which showed improved delivery of miR-148b mimic to human adipose-derived stem cells (hASCs) over the commercial transfection reagent TurboFect; [91] the preclinical in vivo evaluation of a therapeutic incorporating this system onto Matrigel and polycaprolactone (PCL) scaffolds is described in further detail in Section 5.1. [92] Fe 3 O 4 paramagnetic NPs were skillfully combined with PEI to deliver miR-335 to human mesenchymal stem cells (MSC), with intended application in the treatment of cardiovascular diseases, in work carried out by Schade et al [62] The range of 80% uptake efficiency reported in this work was in exchange for acceptable dead cell levels -below 20%, with the added possibility of magnet-controlled tissue targeting following administration of this potential therapeutic system. CaPs are an often overlooked option in gene therapy, disregarded for their traditionally low transfection efficiencies delivering pDNA and their instability in solution.…”

“…[59] However, this is counterbalanced by their reported cytotoxic and proinflammatory effects, some of which have been associated with their ability to trigger the generation of intracellular vacuoles. [60] Polyethyleneimine (PEI) derivatives have also been extensively studied as miRNA delivery systems, [19,61,62] and specifically PEI-poly(ethylene glycol) (PEG) nanoparticles (NP) have recently demonstrated interesting profiles when encapsulated within poly(lactic-co-glycolic acid) (PLGA) microspheres in a poly(l-lactic acid) (PLLA) scaffold [63] or as part of a calcium chloride cross-linked alginate hydrogel system. [64] PEI is watersoluble and easily attracts negatively charged ions to aid the polyplex cargo escape the endolysosomal compartment in what is known as "the proton sponge effect."…”