Fetoscopic endoluminal tracheal occlusion (FETO) improves the survival rate in fetuses with severe congenital diaphragmatic hernia (CDH). We hypothesize that prenatal therapies into the trachea during FETO can further improve outcomes. Here, we present an microinjection technique with rat lung explants to study prenatal therapy with nanoparticles. We used microsurgery to isolate lungs from rats on embryonic day 18. We injected chitosan nanoparticles loaded with fluorescein (FITC) into the trachea of the lung explants. We compared the difference in biodistribution of two types of nanoparticles, functionalized IgG-conjugated nanoparticles (IgG-nanoparticles) and bare nanoparticles after 24 h culture with immunofluorescence (IF). We used IF to mark lung epithelial cells with E-cadherin and to investigate an apoptosis (Active-caspase 3) and inflammatory marker (Interleukin, IL-6) and compared its abundance between the two experimental groups and control lung explants. We detected the presence of nanoparticles in the lung explants, and the relative number of nanoparticles to cells was 2.49 fold higher in IgG-nanoparticles than bare nanoparticles ( < 0.001). Active caspase-3 protein abundance was similar in the control, bare nanoparticles (1.20 fold higher), and IgG-nanoparticles (1.34 fold higher) groups ( = 0.34). Similarly, IL-6 protein abundance was not different in the control, bare nanoparticles (1.13 fold higher), and IgG-nanoparticles (1.12 fold higher) groups ( = 0.33). Functionalized nanoparticles had a higher presence in lung cells and this did not result in more apoptosis or inflammation. Our proof-of-principle study will guide future research with therapies to improve lung development prenatally. N/A Animal and laboratory study.

中文翻译：

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显微注射纳米粒子在产前肺外植体中输送药物——先天性膈疝产前治疗的初步研究

胎儿镜腔内气管阻塞（FETO）可提高患有严重先天性膈疝（CDH）的胎儿的存活率。我们假设 FETO 期间对气管进行产前治疗可以进一步改善结果。在这里，我们提出了一种使用大鼠肺外植体的显微注射技术来研究纳米颗粒的产前治疗。我们在胚胎第 18 天使用显微外科手术从大鼠中分离出肺部。我们将负载荧光素 (FITC) 的壳聚糖纳米粒子注射到肺外植体的气管中。我们使用免疫荧光（IF）比较了两种类型的纳米颗粒，即功能化 IgG 缀合纳米颗粒（IgG-纳米颗粒）和裸纳米颗粒在培养 24 小时后的生物分布差异。我们使用 IF 用 E-钙粘蛋白标记肺上皮细胞，并研究细胞凋亡（活性半胱天冬酶 3）和炎症标记物（白细胞介素、IL-6），并比较两个实验组和对照肺外植体之间的丰度。我们检测到肺外植体中纳米颗粒的存在，并且 IgG 纳米颗粒中纳米颗粒与细胞的相对数量比裸纳米颗粒高 2.49 倍 (< 0.001)。活性 caspase-3 蛋白丰度在对照组、裸纳米颗粒（高 1.20 倍）和 IgG 纳米颗粒（高 1.34 倍）组中相似 (= 0.34)。同样，IL-6 蛋白丰度在对照组、裸纳米颗粒（高 1.13 倍）和 IgG 纳米颗粒（高 1.12 倍）组中没有差异 (= 0.33)。功能化纳米粒子在肺细胞中的存在量较高，但这不会导致更多的细胞凋亡或炎症。我们的原理验证研究将指导未来的治疗研究，以改善产前肺部发育。 N/A 动物和实验室研究。