Wet Tissue Interfacial Water Triggers Ultrafast In Situ Gelation of Sprayable Dry Powder for Postoperative Anti‐Adhesion.

Postoperative adhesions complicate the majority of surgical procedures, imposing an excess medical burden. The segregation of injured tissue from healthy tissue is considered the optimal therapeutic strategy. However, achieving hemostasis while preventing adhesions in the immediate postoperative setting continues to pose a significant challenge. This paper presents the in situ formation of an asymmetrically adhesive hydrogel barrier via a sprayable dry powder (SDP) that enables interfacial water‐induced, ultra‐rapid gelation. Owing to SDP hydrophilicity and the interstitial spaces between particles, it can rapidly and efficiently absorb interfacial water, thereby facilitating smooth cross‐linking between material functional groups and tissue functional groups. In addition, SDP becomes less adhesive after gelation as a layer of interfacial water forms on the surface of the SDP hydrogel, enhancing its anti‐adhesion properties. Animal experiment outcomes demonstrate that SDP exhibits significant asymmetric adhesive properties before and after gelation, successfully preventing postoperative adhesions. As a result, SDP heralds a novel approach to the development of adhesives that can simultaneously mitigate adhesions and promptly arrest bleeding. [ABSTRACT FROM AUTHOR]