Tetrahydroxy Diboron‐Enabled 3D‐Printable Bioactive Hydrogel Scaffolds for Accelerated Repair of Vaginal Defects

ABSTRACT Effective repair of vaginal defects, including those associated with Mayer–Rokitansky–Küster–Hauser syndrome, requires biomaterials that combine tissue‐mimetic softness, hydration, mechanical resilience, and therapeutic activity. Here, we report a 3D‐printable multifunctional hydrogel scaffold enabled by tetrahydroxy diboron (THDB) chemistry for accelerated vaginal defect repair. THDB triggers rapid radical polymerization of 2‐hydroxyethyl methacrylate under oxygen‐rich conditions, forming a poly(2‐hydroxyethyl methacrylate) network strengthened by hydrogen bonding and B─O coordination from multiple boron species. The incorporation of calcium ions (Ca 2 + ) and N,N′‐methylenebisacrylamide further improves mechanical strength and water stability. The resulting hydrogel exhibits tensile strength above 1.0 MPa, compressive stress of ∼2.0 MPa at ∼70% strain, stable cyclic tensile and compressive performance, and long‐term aqueous stability with a swelling ratio of ∼160% in phosphate‐buffered saline after 30 days. In addition, sustained release of THDB and Ca 2 + provides therapeutic bioactivity, including reactive oxygen species scavenging and activation of redox‐ and metabolism‐related signaling pathways. In a standardized rat model of full‐thickness vaginal defects, the hydrogel effectively promotes tissue repair, demonstrating its potential as a mechanically robust, swelling‐resistant, and bioactive scaffold for vaginal tissue reconstruction.