Superwetting Injectable Hydrogel with Ultrastrong and Fast Tissue Adhesion for Minimally Invasive Hemostasis.

Injectable hydrogels have recently emerged as alternatives to sutures for various clinical indications. However, existing injectable hydrogels are unsuitable for hemostasis in minimally invasive surgery because of their weak interfacial adhesion and complex/prolonged processing. Herein, a superwetting injectable hydrogel composed of oppositely charged polysaccharides is developed. The spontaneous spreading of the injectable hydrogel on the surfaces achieves complete wetting and forms tight interfacial contact by absorbing the interfacial water. The superwetting ability and subsequent covalent crosslinking perform fast and ultrastrong wet adhesion (140 kPa) on the tissue surface. Ex vivo porcine and in vivo rat models show that the hydrogel successfully leads to the aggregation of erythrocytes for targeted hemostasis (in less than 12 s) without requiring external adjuncts, and no postsurgical adhesions to the peripheral tissues. This further demonstrates that hydrogel can act as an effective hemostasis agent in laparoscopic surgery in a rabbit model. Overall, the strong wet adhesion, antibacterial properties, and easy operability make this injectable hydrogel a promising candidate for hemostasis applications, as it can successfully combine clinical efficacy and transformation opportunities for minimally invasive surgery.