Multifunctional nano-vector for gene delivery into human adipose derived mesenchymal stem cells and in vitro cellular magnetic resonance imaging

Abstract

To examine the feasibility and efficacy of using superparamagnetic iron oxide nanoparticles coated with polyethylene glycol-grafted polyethylenimine (PEG-g-PEI-SPION) as a carrier for gene delivery into human adipose derived mesenchymal stem cells (hADMSCs) and in vitro cellular magnetic resonance imaging (MRI). PEG-g-PEI-SPION was synthesized as previously reported. Gel electrophoresis was performed to assess the pDNA condensation capacity of PEG-g-PEI-SPION. The particle size and zeta potential of PEG-g-PEI-SPION/pDNA complexes were determined by dynamic light scattering. Cytotoxicity of PEG-g-PEI-SPION was evaluated by CCK-8 assay with hADMSCs. Gene transfection efficiency of PEG-g-PEI-SPION in hADMSCs was quantified by flow cytometry. The cellular internalization of PEG-g-PEI-SPION/pDNA nanocomplexes was studied by confocal laser scanning microscopy and Prussian blue staining. MRI function of PEG-g-PEI-SPION was studied by in vitro cellular MRI scanning. PEG-g-PEI-SPION condensed pDNA to form stable complexes of 80-100 nm in diameter and showed low cytotoxicity in hADMSCs. At the optimal N/P ratio of 20, PEG-g-PEI-SPION/pDNA obtained the highest transfection efficiency of 22.8% ± 3.6% in hADMSCs. And it was higher than that obtained with lipofectamine 11.2% ± 2.6% (P < 0.05). Furthermore, hADMSCs labeled with PEG-g-PEI-SPION showed sensitive low signal intensity on MRI T2-weighted images in vitro. PEG-g-PEI-SPION is an efficient and MRI-visible nano-vector for gene delivery into hADMSCs.