Center for Ultrasound for Molecular Imaging and Therapeutics, University of Pittsburgh Medical Center, University of Pittsburgh, Pittsburgh, PA, USA.
Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, CA, USA.
Nanotheranostics. 2024 Mar 9;8(3):285-297. doi: 10.7150/ntno.90516. eCollection 2024.
Microbubble () contrast agents combined with ultrasound targeted microbubble cavitation () are a promising platform for site-specific therapeutic oligonucleotide delivery. We investigated UTMC-mediated delivery of siRNA directed against epidermal growth factor receptor (), to squamous cell carcinoma () via a novel MB-liposome complex (). were constructed by conjugation of cationic liposomes to the surface of CF gas-filled lipid MBs using biotin/avidin chemistry, then loaded with siRNA via electrostatic interaction. Luciferase-expressing SCC-VII cells () were cultured in Petri dishes. The Petri dishes were filled with media in which LPXs loaded with siRNA against firefly luciferase () were suspended. Ultrasound () (1 MHz, 100-µs pulse, 10% duty cycle) was delivered to the dishes for 10 sec at varying acoustic pressures and luciferase assay was performed 24 hr later. siRNA delivery was studied in SCC-VII tumor-bearing mice intravenously infused with a 0.5 mL saline suspension of EGFR siRNA LPX (7×10 LPX, 30 µg siRNA) for 20 min during concurrent US (1 MHz, 0.5 MPa spatial peak temporal peak negative pressure, five 100-µs pulses every 1 ms; each pulse train repeated every 2 sec to allow reperfusion of LPX into the tumor). Mice were sacrificed 2 days post treatment and tumor EGFR expression was measured (Western blot). Other mice (=23) received either EGFR siRNA-loaded LPX + UTMC or negative control () siRNA-loaded LPX + UTMC on days 0 and 3, or no treatment ("sham"). Tumor volume was serially measured by high-resolution 3D US imaging. Luc siRNA LPX + UTMC caused significant luciferase knockdown vs. no treatment control, <0.05) in SCC-VII-Luc cells at acoustic pressures 0.25 MPa to 0.9 MPa, while no significant silencing effect was seen at lower pressure (0.125 MPa). EGFR siRNA LPX + UTMC reduced tumor EGFR expression by ~30% and significantly inhibited tumor growth by day 9 (40% decrease in tumor volume vs. NC siRNA LPX + UTMC, <0.05). Luc siRNA LPXs + UTMC achieved functional delivery of Luc siRNA to SCC-VII-Luc cells . EGFR siRNA LPX + UTMC inhibited tumor growth and suppressed EGFR expression , suggesting that this platform holds promise for non-invasive, image-guided targeted delivery of therapeutic siRNA for cancer treatment.
微泡（）对比剂与超声靶向微泡空化（）联合使用是一种很有前途的平台，可用于实现针对特定部位的治疗性寡核苷酸递药。我们通过新型 MB-脂质体复合物（）研究了 UTMC 介导的表皮生长因子受体（）的 siRNA 递药，用于鳞状细胞癌（）。通过生物素/亲和素化学将阳离子脂质体连接到 CF 充气体脂质 MB 的表面，构建了这种 MB-脂质体复合物（），然后通过静电相互作用装载 siRNA。在 Petri 盘中培养表达荧光素酶的 SCC-VII 细胞（）。在 Petri 盘中填充的介质中悬浮有装载针对萤火虫荧光素酶（）的 siRNA 的 LPX。以 1 MHz、100-μs 脉冲、10%占空比的超声（）作用 10 秒，然后在不同声压下进行荧光素酶检测，24 小时后进行检测。在静脉内输注 EGFR siRNA LPX（7×10 LPX，~30 µg siRNA）的同时，对携带 SCC-VII 肿瘤的小鼠进行 20 分钟的超声（1 MHz、0.5 MPa 空间峰-时间峰负压，每 1 ms 重复 5 个 100-μs 脉冲；每个脉冲串每 2 秒重复一次，以允许 LPX 再灌注到肿瘤中），研究了 siRNA 递药。在治疗后 2 天处死小鼠，并测量肿瘤 EGFR 表达（Western blot）。其他 23 只小鼠（=23）在第 0 天和第 3 天分别接受 EGFR 靶向 siRNA 负载的 LPX + UTMC 或阴性对照（）siRNA 负载的 LPX + UTMC，或不进行任何治疗（“假处理”）。通过高分辨率 3D US 成像对肿瘤体积进行连续测量。Luc siRNA LPX + UTMC 在 0.25 MPa 至 0.9 MPa 的声压下导致 SCC-VII-Luc 细胞中的荧光素酶显著下调（与无治疗对照相比，<0.05），而在较低压力（0.125 MPa）下未观察到明显的沉默作用。EGFR siRNA LPX + UTMC 使肿瘤 EGFR 表达降低了约 30%，并在第 9 天显著抑制了肿瘤生长（与 NC siRNA LPX + UTMC 相比，肿瘤体积减少约 40%，<0.05）。Luc siRNA LPXs + UTMC 实现了 Luc siRNA 对 SCC-VII-Luc 细胞的功能性递药。EGFR siRNA LPX + UTMC 抑制了肿瘤生长并抑制了 EGFR 表达，这表明该平台有望用于非侵入性、图像引导的治疗性 siRNA 靶向递药，用于癌症治疗。
