Abstract:

BACKGROUND: In recent years, ultrasound microbubble gene transfer system has been applied for gene transfection in many parts of the body, but it has been seldom reported to be used for gene transfection in bone parts.
OBJECTIVE: To investigate the efficiency and feasibility of ultrasound-targeted microbubble destruction applied for transfection of enhanced green fluorescent protein plasmid into the femoral head of rabbits. 
METHODS: Japanese big-ear rabbits were randomly divided into five groups: bare transfection, pre-irradiation + bare transfection, ultrasound transfection, pre-irradiation+ultrasound transfection, and repeatable transfection. In the first two groups, ultrasound-targeted gene transfection and irradiation was not used, but in the latter three groups, ultrasound-targeted microbubble destruction was used to transfect enhanced green fluorescent protein (EGFP) plasmid into the femoral head of rabbits. At 1 week after transfection, EGFP expression in femoral head was observed under the fluorescence microscope.
RESULTS AND CONCLUSION: EGFP expression appeared in the ultrasound transfection, pre-irradiation + ultrasound transfection and repeatable transfection. The transfection efficiency of EGFP plasmid was significantly higher in the repeatable transfection group than in the other groups (P < 0.01). Obvious injury loci were not observed in the soft tissue and bone tissue slices of ultrasonic irradiation parts in the ultrasound transfection, pre-irradiation + ultrasound transfection and repeatable transfection groups. These results confirm that ultrasound-targeted microbubble destruction is a safe and effective method to transfect EGFP plasmid into the femoral head of rabbits.