A dynamically adaptive wet-adhesive Janus hydrogel patch for sutureless repair of spinal dural defects.

Effective repair of spinal dural defects is essential to prevent cerebrospinal fluid (CSF) leakage and preserve neurological function. However, conventional suture-based methods and clinical bioadhesives often face challenges such as technical complexity, inadequate sealing, and fibrotic adhesion. Here, we present a dynamically adaptive Janus hydrogel patch (DHP) that enables rapid, suture-free sealing while minimizing postoperative adhesion. DHP is fabricated through the self-assembly of viscoelastic polymers into a phase-separated architecture featuring hydrophilic-hydrophobic microdomains, which enables stable and reversible wet adhesion via synergistic interfacial water removal and conformal surface adaptation. The hydrogel exhibits tissue-compliant mechanics, self-healing capability, and stress-relaxation behavior, enabling durable sealing under physiological conditions. Ex vivo and in vivo results demonstrate that DHP outperforms commercial sealants in sealing strength, biocompatibility, and anti-adhesion performance. In a rat dural defect model, DHP restores dural continuity, prevents CSF leakage, preserves motor function, and mitigates inflammation. These findings position DHP as a promising platform for minimally invasive, sutureless repair of soft tissue barriers, with broad translational potential in biomedical applications.