4D-Printed Sandwich-Structured Metamaterial Intestinal Stents for Palliative Tumor Therapy.

Intestinal obstruction is a common complication caused by colorectal cancer, and the implantation of stents has become an indispensable palliative treatment strategy for non-surgical eligible patients. However, the lack of sustained anti-tumor efficacy and wear caused by configuration or deformation discrepancies has led to the recurrence of stenosis, posing a significant challenge in clinical treatment. Here, we reported an intestine-specific, application-driven 4D-printed sandwich-structured metamaterial intestinal stent platform, achieving the triple goals of sustained anti-tumor effects, customized configuration and performance, and rapid relief of intestinal obstruction. Specifically, the platform comprised an outer Janus layer designed for synergistic photothermal-and-drug anti-tumor effects, an intermediate layer of biomimetic gradient metamaterials for structural support and coordinated deformation, and a hydrophobic inner layer to mitigate the risk of restenosis. Overall, this study presented a multifunctional intestinal stent built upon a scalable design paradigm, offering an innovative and clinically translatable therapeutic strategy for personalized colorectal cancer management.