A Microphase Separation‐Driven Supramolecular Tissue Adhesive with Instantaneous Dry/Wet Adhesion, Alcohol‐Triggered Debonding, and Antibacterial Hemostasis

Abstract Tissue adhesives are promising materials for expeditious hemorrhage control, while it remains a grand challenge to engineer a superior formulation with instantaneous adhesion, on‐demand debonding, and the integration of multiple desirable properties such as antibacterial and hemostatic capabilities. Herein, a multifunctional supramolecular tissue adhesive based on guanidinium‐modified polydimethylsiloxane (PDMS) is introduced, driven by a reversible microphase separation mechanism. By optimizing the content of guanidinium ions, precise control over cohesive strength, adhesion, and wettability is achieved, resulting in strong instantaneous adhesion under both dry and wet conditions. Notably, the supramolecular nature of the adhesive allows for convenient on‐demand removal using medical‐grade alcohol, offering a critical advantage for easy debonding. Additionally, the adhesive exhibits remarkable antimicrobial properties while maintaining excellent biocompatibility and hemocompatibility. Its underwater injectability supports minimally invasive surgical procedures. Furthermore, the adhesive's ability to incorporate solid particles enhances its versatility, particularly for the development of drug‐embedded bioadhesives. This work addresses key challenges in tissue adhesive design via a microphase separation‐driven working principle, thereby opening promising new avenues for the development of advanced bioadhesives with tailored properties and enhanced surgical and wound care outcomes.