Reactive Oxygen Species Triggered Cleavage of Thioketal-Containing Supramolecular Nanoparticles for Inflammation-Targeted Oral Therapy in Ulcerative Colitis

Abstract

Combating reactive oxygen species (ROS) and targeted drug delivery to inflammatory sites are considered effective therapeutic strategies for ulcerative colitis (UC), a refractory chronic inflammatory disease. Herein, a ROS-responsive thioketal (TK) crosslinked cyclodextrin metal-organic framework (TCOF) is fabricated, to which a non-ROS-sensitive vector, sulfur substituted by carbon chain-crosslinked cyclodextrin metal-organic framework (CCOF) is parallelly designed as ROS negative reference. Dexamethasone (DEX) loaded in TCOF (TCD) and CCOF (CCD) are investigated to demonstrate the advantages of precision medicine for UC. After the ROS-induced collapse of nanoparticles, TCD selectively triggered the release of DEX. Moreover, TCD effectively protected cells from oxidative stress damage and reduced inflammation levels in vitro. Remarkably, the TK group of TCD is oxidatively broken by consuming ROS at the inflammatory site, exposing the thiol group to mucosal adhesion, which enhances the retention of TCD at colons. In vivo studies of UC treatment reveals that oral administration of TCD demonstrated excellent inflammation-targeting properties, remarkably attenuated oxidative stress, and ameliorated both acute and chronic colitis compared to CCD. Furthermore, TCD exhibits an excellent safety profile in mice. These results instill confidence in advancing targeted drug delivery and precision therapy for UC.