[Research of enhanced green fluorescent protein gene transfer with ultrasound-mediated microbubble destruction in bone defects].

Objective: To investigate the effect of ultrasonic irradiation time on enhanced green fluorescent protein (EGFP) gene transfection efficiency and local tissue in bone defects using ultrasound-mediated microbubble destruction. Methods: Thirty 3-month-old New Zealand rabbits (2.5-3.0 kg in weight) were randomly divided into 5 groups ( n=6) and bone defect models were made on the right ulna. At 10 days after modeling, suspension of microbubbles and EGFP plasmids were locally injected (0.3 mL/kg) and then ultrasound was performed on defect at a frequency of 1 MHz, a intensity of 0.5 W/cm 2, and a duty ratio of 20% for 1, 2, 3, 4, and 5 minutes respectively (in 1, 2, 3, 4, and 5 minutes groups respectively). The survival condition was observed. Rabbits were sacrificed for gross observation at 7 days after transfer. The gene expression was observed by fluorescence staining. HE staining and transmission electron microscopy were used to observe the local tissue damage. 结果: 各组动物均存活至实验完成。转染后 1 周各组骨缺损处有软组织生长，周围肌肉组织部分内陷填充于其间。荧光显微镜下观察，各组兔骨缺损处均有绿色荧光表达，其中 2 min 组表达最强，1 min 组表达最弱，其吸光度（ A）值与其他各组比较差异有统计学意义（ P 0.05）。HE 染色及透射电镜观察示，各组骨缺损处局部均有不同程度组织损伤，损伤程度随辐照时间的延长而加重。. 结论: 超声微泡转基因技术介导 EGFP 质粒在兔骨缺损部位转染时，其转染效率和超声辐照时间相关。当超声参数为 1 MHz、0.5 W/cm 2、20% 占空比时，超声辐照 2 min 可获得最佳转染效率及相对较轻的组织损伤。.