Effect of crosslinking densities on decanoyl-group modified Alaska pollock gelatin microparticles as tissue-adhesive hemostatic powders

Endoscopic submucosal dissection (ESD) is widely utilized as a minimally invasive treatment for early-stage gastrointestinal cancers. However, bleeding after ESD remains a major challenge. This clinical problem necessitates biomaterials with tissue-adhesive and hemostatic properties. Recently, we developed decanoyl group-modified Alaska pollock gelatin microparticles (C10-MPs) as tissue-adhesive hemostatic powders. Dried C10-MPs adhered to and formed colloidal gels on the gastrointestinal tissue surface and demonstrated excellent hemostatic properties. However, the effect of crosslinking density on tissue adhesion and hemostatic properties has not yet been clarified. Herein, we investigated the effect of the crosslinking density on C10-MPs' performance as tissue-adhesive hemostatic powders. C10-MPs with different crosslinking densities were prepared by varying the thermal crosslinking time. All C10-MPs with different crosslinking densities exhibited rapid hydration. Additionally, C10-MPs with higher crosslinking densities exhibited increased adhesion strength and underwater adhesion stability, even in moist environments. Contrastingly, in vitro and in vivo hemostatic evaluation models showed that C10-MPs thermally crosslinked for 5 h (C10 5 h) were the most suitable powder in terms of blood coagulation ability. Thus, C10 5 h has great potential for use in preventing post-ESD bleeding.