Gelation mechanisms, structure-property relationships, and wound management applications of self-gelling powders.

Traumatic blood loss is a key issue in emergency medicine and wound management. Developing materials that can both quickly inhibit bleeding and properly treat wounds is of great significance. Traditional hemostatic materials are widely used in clinical settings, but they still have limitations in terms of adaptability to irregular wounds, limited stability in wet environments, single functionality, and difficulty in balancing subsequent therapy. In recent years, self-gelling powders have attracted considerable interest owing to their translational advantages, including convenient storage, portability, and ease of application, as well as their capacity to undergo rapid in situ gelation upon contact with blood or tissue exudate. These materials can not only achieve rapid hemostasis through liquid absorption concentration, physical filling, promoting blood cell aggregation, and enhancing wound sealing, but also improve the wound microenvironment through moisturizing, antibacterial, anti-inflammatory, antioxidant, and promoting angiogenesis pathways, thereby facilitating tissue repair. This review establishes a mechanistic taxonomy of powder-to-gel transformation based on dominant network-forming interactions and discusses the structure-property-performance relationships governing gelation kinetics, wet adhesion, mechanical stability, and biological outcomes. Representative applications in non-compressible hemorrhage, wet tissue sealing, infected/chronic wounds, and specialized anatomical sites are systematically summarized. Furthermore, a critical analysis of the key transformation challenges in the future was conducted, and future design principles for next-generation self-gelling wound materials are proposed.