Research of Gene Delivery Mediated by Ultrasound, Microbubble and Folate-modified Chitosan Nanoparticles

Objective: To study transfection efficiency of folate-modified chitosan (FACS) nanoparticles as a non-viral vector delivering pEGFP-C3plasmid (FA-CS/P) to 293T cells with or without the combination of ultrasound and microbubble. Method: pEGFP-C3 was used as a reporter gene and FA-CS nanoparticles, which were prepared by complex coagulation method, were used as biological carriers. Transfection efficiency to 293T cells mediated by FA-CS/P nanoparticles, ultrasound (US) and microbubble (MB) was assessed by fluorescence microscopy and flow cytometry. Result: FA-CS/P nanoparticles have a particle size of 355.1 nm and zeta potential of 10.4 mV. Significant green fluorescence could be observed in CS/P group, FA-CS/P group, US+MB/P group, US+FA-CS/P group, Liposome 2000 (L) group under an inverted fluorescence microscope, while for US+MB+FA-CS/P group, only scattered fluorescence was observed. Result of flow cytometry showed that the transfection rate of US+MB+FA-CS/P group was (2.0±0.2)%, which was significantly lower than other groups (P<0.05). CCK-8 experiments showed that cell vitality of US+MB+FA-CS/P was groups (P<0.05). CCK-8 experiments showed that cell vitality of US+MB+FA-CS/P was (64.1±4.6)%, which was also lower than other groups (P<0.05). Conclusion: In this study, FA-CS was successfully synthesized. FA-CS could combine with pEGFP-C3 effectively forming nanoparticles with nanoparticle size, well dispersion, high encapsulation efficiency and no significant toxicity to cells. The application of ultrasound increased the transfection rate of FA-CS/P. However, while being exposed to ultrasound and microbubble, the transfection rate of FA-CS/P decreased obviously, may indicate that there was no synergistic effect for gene transfection by the combination of ultrasound, folate modified chitosan and microbubbles.