Plasmid DNA interactions with NMB, CMB and CMB105. (A) Red fluorescence represents plasmid DNA successfully bound to microbubbles; green fluorescence represents anti-CD105 antibody successfully bound to CMB; and yellow fluorescence represents the superposition of red fluorescence and green fluorescence. For NMB, almost no red fluorescence was observed; for CMB and CMB105, red fluorescence could be observed. (B) Quantitative assessment of DNA binding to NMB, CMB and CMB105 (n=3 per group). The DNA loading capacity of CMB and CMB105 was significantly higher than for NMB, regardless of how many plasmids were added to the microbubble solution (**P<0.0001). The difference in DNA loading capacity between CMB and CMB105 was not significant. *P<0.01 compared with 10, 40, and 80 μg plasmid DNA, within-group comparisons; #P>0.05 compared with 80 μg plasmid DNA, within-group comparisons. (C) Binding with DNA had a slight effect on the ability to target HUVECs for CMB (*P<0.05), whereas no effect was observed for CMB105 and NMB (#P>0.05), n=3 per group.