Department of Pediatrics, Seattle Children's Research Institute, University of Washington, Seattle, WA 98101, USA.
Gene Ther. 2011 Oct;18(10):1006-14. doi: 10.1038/gt.2011.34. Epub 2011 Mar 31.
Ultrasound (US) combined with microbubbles (MBs) is a promising technology for non-viral gene delivery. Significant enhancements of gene expression have been obtained in our previous studies. To optimize and prepare for application to larger animal models, the luciferase reporter gene transfer efficacy of lipid-based Definity MBs of various concentrations, pressure amplitudes and a novel unfocused high-intensity therapeutic US (HITU) system were explored. Luciferase expression exhibited a dependence on MB dose over the range of 0-25 vol%, and a strong dependence on acoustic peak negative pressure at over the range of 0-3.2 MPa. Gene expression reached an apparent plateau at MB concentration ≥2.5 vol% or at negative pressures >1.8 MPa. Maximum gene expression in treated animals was 700-fold greater than in negative controls. Pulse train US exposure protocols produced an upward trend of gene expression with increasing quiescent time. The hyperbolic correlation of gene expression and transaminase levels suggested that an optimum gene delivery effect can be achieved by maximizing acoustic cavitation-induced enhancement of DNA uptake and minimizing unproductive tissue damage. This study validated the new HITU system equipped with an unfocused transducer with a larger footprint capable of scanning large tissue areas to effectively enhance gene transfer efficiencies.
超声（US）联合微泡（MBs）是一种很有前途的非病毒基因传递技术。在我们之前的研究中已经获得了基因表达的显著增强。为了优化并准备应用于更大的动物模型，研究了各种浓度的基于脂质的 Definity MBs、不同声压幅度和新型非聚焦高强度治疗超声（HITU）系统的报告基因转染效率。荧光素酶表达表现出对 MB 剂量的依赖性，范围为 0-25%，对声压峰值的依赖性很强，范围为 0-3.2 MPa。当 MB 浓度≥2.5%或负压力>1.8 MPa 时，基因表达达到明显的平台期。处理动物中的最大基因表达比阴性对照高 700 倍。脉冲串 US 暴露方案随着静止时间的增加呈现出基因表达的上升趋势。基因表达与转氨酶水平的双曲线相关性表明，可以通过最大化声空化诱导的 DNA 摄取增强作用和最小化无效组织损伤来实现最佳的基因传递效果。本研究验证了新的配备非聚焦换能器的 HITU 系统，该换能器具有更大的足迹，能够扫描大面积组织，有效提高基因传递效率。
