白蛋白微泡促进报告基因在细胞表达的实验研究

目的: 探讨白蛋白微泡作为非病毒载体在基因传输中的作用。方法:6孔板培养脐静脉内皮细胞(EC)和血管平滑肌细胞(VSMC),每孔加pcDNA3.1/His/LacZ质粒20 μg,加不同浓度微泡或不加微泡,超声条件为连续波,频率2MHz,机械指数1.8,照射时间1 min,48 h后计算蓝染细胞百分率和β-半乳糖苷酶活性。另以不同浓度微泡及超声照射时间处理细胞,测定细胞增殖情况。结果:与单纯超声质粒组相比,含微泡组蓝染细胞率增加约10-15倍(其中内皮细胞组11.6倍,平滑肌细胞组15.2倍),报告基因表达定量增加近8倍。微泡浓度为10％时细胞转染效率最高。超声照射对细胞增殖无影响,微泡浓度为50％时有明显的细胞毒作用。结论:白蛋白微泡在超声作用下能明显增加基因的传输效率,有可能成为一种安全有效的基因治疗的载体。

Albumin-coated microbubbles enhance report gene expression

AIM: To investigate the use of therapy ultrasound to enhance nonviral gene delivery. METHODS: Endothelial cells (EC) and vascular smooth muscle cells (VSMC) were cultured in 6-well plates. Plasmid (pcDNA3.1/His/LacZ) with or without microbubbles at the different concentrations was transfected into the cells with the use of ultrasound for 1 min at 2 MHz, 1.8 mechanical index (MI). Additional controls included ultrasound alone, microbubble alone and microbubble plus plasmid. The rate of blue cells and the activities of β-Gal were measured. In addition, cell viability was detected with different time from 1 to 30 min of ultrasound irradiation and the different concentrations of microbubbles. RESULTS: In the group of ultrasound with microbubble, the rate of blue cells and activity of β-Gal markedly increased by 60% and 9-fold, respectively. Microbubbles at concentration of 10% led to the highest transfection effect. Ultrasoud exposure at 1 to 30 minute had no cell toxic effects, while microbubbles at the concentration of 50% had significant effect on cell survival. CONCLUSIONS: Albumin-coated microbubbles markedly enhance gene delivery by therapeutic ultrasound-mediated microbubble destruction, which can be used as a safe and practicality vectors in gene therapy.