Department of Ultrasound, Southwest Hospital, Third Military Medical University, Chongqing, People’s Republic of China.
Nanotechnology. 2013 Aug 16;24(32):325102. doi: 10.1088/0957-4484/24/32/325102.
Nanobubbles as a type of ultrasound contrast agent have attracted much interest in recent years due to their many advantages, such as strong penetrating power and high stability. However, there is still insufficient morphological evidence concerning gas-filled nanobubbles in tumor tissue spaces and tumor angiogenesis. We used a gastric cancer xenograft as an example to study this question. Nanobubbles with a particle size of 435.2 ± 60.53 nm were prepared and compared with SonoVue® microbubbles in vitro and in vivo, and they exhibited a superior contrast imaging effect. After excluding the impact of the nanobubbles in blood vessels through saline flush, we used an ultrasound burst and frozen sectioning to investigate the distribution of nanobubbles in the gastric cancer xenografts and confirmed this by transmission electron microscopy. Preliminary results showed that the nanobubbles were able to pass through the gaps between the endothelial cells in the tumor vascular system to enter the tissue space. These findings could provide morphological evidence for extravascular ultrasound imaging of tumors and serve as a foundation for the application of nanobubbles in extravascular tumor-targeted ultrasonic diagnostics and therapy.
纳米气泡作为一种超声造影剂，因其穿透力强、稳定性高等诸多优点，近年来引起了广泛关注。然而，在肿瘤组织间隙和肿瘤血管生成中充满气体的纳米气泡的形态学证据仍然不足。我们以胃癌异种移植瘤为例对此问题进行了研究。制备了粒径为 435.2±60.53nm 的纳米气泡，并与 SonoVue®微泡进行了体外和体内比较，结果显示其具有更好的对比成像效果。通过生理盐水冲洗排除血管内纳米气泡的影响后，我们使用超声爆破和冷冻切片的方法研究了纳米气泡在胃癌异种移植瘤中的分布，并通过透射电子显微镜进行了确认。初步结果表明，纳米气泡能够穿过肿瘤血管系统内皮细胞之间的间隙进入组织间隙。这些发现可为肿瘤的血管外超声成像提供形态学证据，并为纳米气泡在血管外肿瘤靶向超声诊断和治疗中的应用提供基础。
