Nanoparticle-Enhanced Injectable GelMA Composite Hydrogel for Gastrointestinal Wound Healing.

Gastrointestinal (GI) wounds remain a major clinical challenge due to the difficulty of achieving effective hemostasis and sustained mucosal repair after endoscopic procedures. Here, we developed a photo-cross-linkable, nanoparticle-reinforced Gelatin Methacryloyl (GelMA) hydrogel for endoscopic application under blue-light activation. The incorporation of nanoparticles─particularly kaolinite─enhanced the injectability, structural integrity, and resistance to enzymatic degradation of GelMA while preserving excellent biocompatibility. Upon illumination, the precursor rapidly cross-linked into a uniform, adhesive hydrogel layer that conformed tightly to irregular wound surfaces. The composite hydrogel exhibited efficient hemostatic activity and cytocompatibility, supporting early epithelial regeneration. In vivo studies using rat skin wounds and a porcine gastric ulcer model demonstrated that the kaolinite-modified GelMA hydrogel accelerated wound closure and improved mucosal restoration compared to pristine GelMA. Overall, this light-activated, mechanically robust GelMA composite provides a precisely injectable and biologically active platform for the endoscopic management of gastrointestinal lesions, offering a practical approach for rapid sealing, bleeding control, and tissue repair in minimally invasive settings.