核酸疗法仍然无法实现口服给药。为此研究了许多基于纳米颗粒的药物递送系统，但大多数都存在肠道稳定性差、粘液扩散差和/或上皮吸收效率低的问题。来自牛乳的细胞外囊泡 (mEV) 具有口服核酸疗法所需的特性，因为它们既能在消化中存活并穿过肠粘膜。使用新工具，我们全面检查了 mEV 的肠道传递，探讨它们是否可以用作，或为口服核酸疗法纳米颗粒的设计提供信息。我们表明，mEV 可以有效地在 Caco-2 肠道模型中移位，并且不会因模拟肠液处理而受到影响。我们还首次证明了 mEV 在新型 3D“顶端输出”和单层人肠上皮类器官 (IEO) 中的转运。重要的是，载有小干扰RNA（siRNA）的mEV可诱导巨噬细胞中的（甘油醛3-磷酸脱氢酶，GAPDH）基因沉默。以炎症性肠病 (IBD) 作为应用示例，我们表明，施用抗肿瘤坏死因子 α (TNFα) siRNA 的 mEV 可减少 IBD 大鼠模型中的炎症。 总之，这项工作表明 mEV 可以作为天然的以及用于口服给药或核酸治疗的安全系统，或为此类应用的合成系统的设计提供信息。© 2023。作者。

Oral delivery remains unattainable for nucleic acid therapies. Many nanoparticle-based drug delivery systems have been investigated for this, but most suffer from poor gut stability, poor mucus diffusion and/or inefficient epithelial uptake. Extracellular vesicles from bovine milk (mEVs) possess desirable characteristics for oral delivery of nucleic acid therapies since they both survive digestion and traverse the intestinal mucosa.Using novel tools, we comprehensively examine the intestinal delivery of mEVs, probing whether they could be used as, or inform the design of, nanoparticles for oral nucleic acid therapies. We show that mEVs efficiently translocate across the Caco-2 intestinal model, which is not compromised by treatment with simulated intestinal fluids. For the first time, we also demonstrate transport of mEVs in novel 3D 'apical-out' and monolayer-based human intestinal epithelial organoids (IEOs). Importantly, mEVs loaded with small interfering RNA (siRNA) induced (glyceraldehyde 3-phosphate dehydrogenase, GAPDH) gene silencing in macrophages. Using inflammatory bowel disease (IBD) as an example application, we show that administration of anti-tumour necrosis factor alpha (TNFα) siRNA-loaded mEVs reduced inflammation in a IBD rat model.Together, this work demonstrates that mEVs could either act as natural and safe systems for oral delivery or nucleic acid therapies, or inform the design of synthetic systems for such application.© 2023. The Author(s).