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
(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.