Oral Delivery of siRNA Using Fluorinated, Small-Sized Nanocapsules toward Anti-Inflammation Treatment

Oral delivery of small interfering RNA (siRNA) provides a promising paradigm for treating diseases that require regular injections. However, the multiple gastrointestinal (GI) and systemic barriers often lead to inefficient oral absorption and low bioavailability of siRNA. Technologies that can overcome these barriers are still lacking, which hinders the clinical potential of orally delivered siRNA. Herein, small-sized, fluorinated nanocapsules (F-NCs) are developed to mediate efficient oral delivery of tumor necrosis factor α (TNF-α) siRNA for anti-inflammation treatment. The NCs possess a disulfide-cross-linked shell structure, thus featuring robust stability in the GI tract. Because of their small size (≈30 nm) and fluorocarbon-assisted repelling of mucin adsorption, the best-performing F₃ -NCs show excellent mucus penetration and intestinal transport capabilities without impairing the intestinal tight junction, conferring the oral bioavailability of 20.4% in relative to intravenous injection. The disulfide cross-linker can be cleaved inside target cells, causing NCs dissociation and siRNA release to potentiate the TNF-α silencing efficiency. In murine models of acute and chronic inflammation, orally delivered F₃ -NCs provoke efficient TNF-α silencing and pronounced anti-inflammatory efficacies. This study therefore provides a transformative strategy for oral siRNA delivery, and will render promising utilities for anti-inflammation treatment.