Department of Ultrasound, The First Medical Center of PLA General Hospital, Beijing, China.
Pharmacology Research Department, Beijing Institute of Pharmacology and Toxicology, Beijing, China.
J Ultrasound Med. 2022 Nov;41(11):2789-2802. doi: 10.1002/jum.15967. Epub 2022 Mar 1.
High-risk papillary thyroid carcinoma (PTC) patients with BRAF mutation have lymph node and distant metastases and poor prognosis. Therefore, this study aims to develop a targeted ultrasound contrast agent for the BRAF mutation to screen high-risk PTC at early stage.
The targeted lipid nanobubbles carrying BRAF antibody were prepared using thin film hydration-sonication and avidin-biotin binding methods. The physicochemical properties and stability of the targeted nanobubbles were detected by transmission electron microscopy, atomic force microscopy, and confocal laser scanning microscopy. The target binding abilities of the targeted nanobubbles in the PTC cells (B-CPAP) overexpressed mutant BRAF were evaluated by immunofluorescence staining, quantitative real-time polymerase chain reaction, western blot, and fluorescence microscopy. After PTC tumor models overexpressed mutant BRAF were established, the enhanced images of targeted lipid nanobubbles and untargeted lipid nanobubbles on PTC tumors in nude mice were observed using contrast-enhanced ultrasound imaging.
The targeted lipid nanobubbles revealed uniform, round morphology, and good stability with a nanoscale size. Besides, BRAF monoclonal antibody was observed to be combined on the surface of lipid nanobubbles. Furthermore, the targeted nanobubbles had a good targeting diagnosis ability in PTC cells with BRAF overexpression. Moreover, the targeted nanobubbles had better ultrasound enhancement and peak intensity of the time-intensity curve (P < .001) in PTC tumors with BRAF overexpression as compared to the untargeted lipid nanobubbles.
The targeted lipid nanobubbles carrying BRAF antibody could be regarded as a potential targeted ultrasound contrast agent for the diagnosis of high-risk PTC.
具有 BRAF 突变的高危甲状腺乳头状癌（PTC）患者存在淋巴结和远处转移，预后不良。因此，本研究旨在开发一种针对 BRAF 突变的靶向超声造影剂，以早期筛查高危 PTC。
采用薄膜水化-超声和亲和素-生物素结合的方法制备载有 BRAF 抗体的靶向脂质纳米气泡。通过透射电子显微镜、原子力显微镜和共聚焦激光扫描显微镜检测靶向纳米气泡的理化性质和稳定性。通过免疫荧光染色、实时定量聚合酶链反应、western blot 和荧光显微镜评估靶向纳米气泡在过表达突变 BRAF 的 PTC 细胞（B-CPAP）中的靶结合能力。在建立过表达突变 BRAF 的 PTC 肿瘤模型后，通过对比增强超声成像观察靶向脂质纳米气泡和非靶向脂质纳米气泡在裸鼠 PTC 肿瘤中的增强图像。
靶向脂质纳米气泡呈现均匀、圆形的形态，具有良好的纳米级稳定性，并且可以观察到 BRAF 单克隆抗体结合在脂质纳米气泡的表面。此外，靶向纳米气泡在过表达 BRAF 的 PTC 细胞中具有良好的靶向诊断能力。此外，与非靶向脂质纳米气泡相比，靶向纳米气泡在过表达 BRAF 的 PTC 肿瘤中具有更好的超声增强和时间强度曲线的峰值强度（P < .001）。
携带 BRAF 抗体的靶向脂质纳米气泡可作为一种有潜力的针对高危 PTC 的靶向超声造影剂。
