Integrated fabrication of a shape-adaptable, antioxidative composite stent for effective closure and biological repair of enteroatmospheric fistula

Enteroatmospheric fistulas (EAFs) pose significant clinical challenges due to persistent leakage, inflammation, and impaired epithelial repair. Transcriptomic analyses of fistula tissues reveal elevated oxidative stress, mitochondrial dysfunction, and barrier disruption. Current provisional closure devices lack adaptability to complex fistula anatomy and fail to provide bioactive support, limiting tissue repair. Here, we report a body-temperature-responsive shape memory polymer stent coated with a bioactive hydrogel, fabricated through an integrated process, for effective EAF closure and repair. The stent can be delivered in a compact state and self-deployed in vivo , ensuring minimally invasive implantation and conformal closure. The composite stent enhances epithelial cell migration, attenuates oxidative stress, and alleviates inflammation, thereby establishing a microenvironment that promotes repair. In rabbit EAF models, the composite stent effectively closed the fistula, improved nutritional status, restored epithelial integrity, reduced inflammation, and enhanced goblet cell regeneration. Transcriptomic profiling and pathway validation revealed activation of oxidative phosphorylation, HIF-1, PI3K-Akt signaling, tight junction, and mucosal immune pathways, highlighting restoration of redox balance, mitochondrial metabolism, barrier integrity, and immune defense. These findings demonstrate that integrating dynamic shape adaptability with bioactive functionality can promote both physical closure and biological repair. This strategy provides a generalizable platform for treating complex epithelial defects in gastrointestinal organs. Schematic illustration of the therapeutic application of the shape-memory polymer-hydrogel composite stent for EAF repair. Stage I: the stent is noninvasively delivered in a folded state. Stage II: it self-deploys upon implantation at body temperature and bends under intestinal fluid stimulation to conform to the fistula. Stage III: the stent promotes repair by reducing oxidative stress, restoring mitochondrial function, enhancing epithelial regeneration, and reinforcing intestinal barrier integrity. • Integrated shape memory polymer-hydrogel stent combines shape adaptability and bioactivity. • Composite stent enables noninvasive delivery, self-deployment and stable fistula closure. • It mechanistically alleviates oxidative stress, restores mitochondria and enhances epithelial integrity. • The study provides a dual-functional platform for complex gastrointestinal defect repair.