| dc.description.abstract | In this study, alginate was electrospun onto polypyrrole surface for polyethyleneimine (PEI) encapsulated DNA nanoparticle adsorption. By treating by an external electric field, positive charged nanoparticles were guided to contact cathodic alginate nanofibers. Although the electric field significantly increased the adsorption of nanoparticles, which did not increase with increasing voltages. The weight experiments demonstrated that the degradation of alginate was promoted under the electric field, which should be relative to the movement of calcium ions within the alginates and thus the structure was destabilized. It also explained that the increasing electric fields may also harmful to the nanoparticle adsorption due to the decrease of alginate fibers. To apply this system for in situ transfection, polycaprolactone (PCL) was coelectrospun with alginate to promote the biocompatibility. After electric field treatment, the loss of composite nanofiber increased with increasing voltages. The contact angle and Fourier-transform infrared spectrometry (FTIR) were applied to investigate the hydrophobicity and functional groups of composite nanofibers, respectively. These results indicated that the loss of composite nanofibers were mainly due to the degradation of alginate fibers. Finally, DNA/PEI nanoparticles were loaded composite nanofibers with electric field treatment and HEK293T cells were seeded onto the fibers for in situ transfection. Compared to the control group, electric fields greatly improve the transfection efficiency which increased with increasing voltages. In addition, higher voltages induced more degradation of alginate nanofibers, which rose the ratio of PCL within composite nanofibers that the cell adhesion, viability, and proliferation were thus improved. Therefore, the use of electric field indeed facilitated the load of gene onto scaffolds. Additionally, it can control the degradation rates to regulate the constitute of composite nanofibers. These properties suggested that our developed scaffold systems can not only provide suitable environment for cell ingrowth, but also be efficient carriers to regulate drug delivery. | en_US |