Highly Deformable and Robust Ionic Structure for Multi‐Tissue Adaptive Hemostatic Sponges

Abstract Accidental trauma is always accompanied by tissue defects with noncompressible hemorrhages. Deformable and tough biomaterials are desirable for self‐compressible hemostasis, although their preparation is challenging. Here, a critical‐size calcium phosphate (C–CaP) with polymer‐like high deformability and mineral‐like high bending strength is prepared, which is hybridized with silk fibroin (SF) to fabricate a hemostatic sponge (SF‐C). C–CaP endows SF‐C with an ultrahigh elastic modulus (36.0 kPa) among analogous materials, leading to an ultrafast water absorption rate (1.2 g cm⁻³ s⁻¹) and space‐filling rate (200.0%/s). The deformability of the SF‐C sponge further enables self‐adaptability to defects with micrometre‐scale precision. Consequently, SF‐C achieves rapid hemostasis in both damaged soft tissues and hard tissues in rats, resulting in less blood loss and a shorter hemostatic time than those of clinical materials. This study provides a promising hemostatic material for the treatment of hemorrhages in defective tissues and expands the current knowledge by revealing the critical‐sized ionic structure and unique mechanics of C–CaP.