A Novel Ultrasound Microbubble Carrying Gene and Tat Peptide: Preparation and Characterization

Rationale and Objectives

Ultrasound-targeted microbubble destruction is a promising technology for the targeted gene delivery. The purpose of the present study is to prepare a novel lipid ultrasound microbubble-carrying gene and transactivating transcriptional activator (Tat) peptide and to investigate its transfection effect in vivo.

Methods and Materials

Lipid ultrasound microbubbles were prepared using mechanical vibration, and the appearance, distribution, concentration, diameter, and zeta potential of the lipid ultrasound microbubbles were measured. The efficiencies of the microbubble carrying gene and Tat peptide were investigated using the fluorospectrophotometer. Contrast-enhanced ultrasonography was performed on normal rabbits to observe the duration and intensity of enhancement in myocardium. Quantitative analysis was detected using the DFY Ultrasound Image Analyzer. Transfection in vivo was performed using the CGZZ ultrasound gene transfection instrument. The expression of enhanced green fluorescent protein in the organs was observed using confocal laser scanning microscope.

Results

The diameter of the lipid microbubbles carrying gene and Tat was (2.3 ± 0.4) μm, the concentration was (3.1 ± 0.4) ×10⁹/mL, and Zeta potential was (2.0 ± 0.1) mV. The gene encapsulation efficiency of the lipid ultrasound microbubbles was 32%, and the Tat encapsulation efficiency was 35%. In vivo experiment showed that lipid ultrasound microbubbles could enhance the echo intensity and transfection efficiency.

Conclusion

Lipid microbubbles containing gene and Tat peptide can be used as a new vehicle for gene transfection.

Key Words: Microbubble, ultrasound contrast agent, gene, Tat peptide