Effect of miR-146a/bFGF/PEG-PEI Nanoparticles on Inflammation Response and Tissue Regeneration of Human Dental Pulp Cells

Figure 2

Transfection efficiency, cell uptake, and viability of DPCs incubated with miR-146a/PEG-PEI nanoparticles. ((a) and (b)) Flow cytometry showed that transfection efficiency increased along with the upregulation of N/P and reached the peak () at N/P ratio of 5 and then downregulated at N/P 20. Transfection efficiency percentages of miR-146a/PEG-PEI nanoparticles were all over 80%, which were higher than that of lipo2000 (, ). (c) Cell uptake of DPCs incubated with cy3-miRNA/PEG-PEI nanoparticles. Fluorescent images showed that no cy3-label red fluorescence was expressed in cy3-miRNA/PEG-PEI solution after 0 h incubation. After 1 h of incubation, cytoplasm of a few DPCs revealed red fluorescence, which showed the intracellular distribution of miRNA and delivery agents, whereas, after 2 h and 4 h, the number of cy3-positive cells increased and the DPCs showed stronger red fluorescence in comparison with the 0 h and 1 h groups (×200). The nucleus of DPCs was stained with Hoechst 33342 (blue fluorescence). (d) Cell viability of DPCs treated with miR-146a/PEG-PEI nanoparticles downregulated gradually along with the increasing of N/P ratio. There were no significant differences between the experiment groups and control group when the N/P ratio was lower than 20 (). However, at N/P ratio of 40 and 80, the cell viability decreased to 71.23 ± 1.67% and 63.45 ± 2.03%, respectively, which were significantly downregulated comparing with the control group ().

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