Harnessing bi-layered supramolecular Janus tissue-adhesive/anti-adhesive fibrous hydrogel for efficient hemostasis, wound healing, and suppressing postoperative tissue adhesion

Inadequate progression of primary (bleeding/infection) and secondary (rebleeding/postoperative tissue adhesion) complications at the wound site pose a substantial burden of morbidity and mortality worldwide. Therefore, developing a multifunctional biomaterial dressing for abrupt tissue adhesion and suppressed postoperative adhesion simultaneously is deemed essential. Herein, we designed a bi-layered Janus fibrous hydrogel (J-FH). The bottom layer comprises zinc-incorporated mesoporous silica nanogranules (ZnMSG) reinforced catechol-modified gelatin methacrylate (GC) hydrogel. GC@ZnMSG supramolecular hydrogel easily adheres to wet wounded tissue and possesses hemostatic, mechanical, and antibacterial properties. On the other hand, the top layer comprises dopamine-modified cellulose acetate nanofibrous membrane (DC) sequentially deposited with polydopamine-conjugated zwitterionic sulfobetaine methacrylate (PDA-SBMA). DC@PDA-SBMA fibrous membrane performs the anti-adhesive function by suppressing fouling and preventing tissue adhesion. The findings of animal experiments show that the bottom layer of the J-FH adheres firmly to the tissue surface, preventing bleeding and supporting tissue closure/regeneration. In contrast, the top layer provides mechanical stability, preventing secondary bleeding and suppressing postoperative tissue adhesion. Overall, J-FH demonstrated excellent biocompatibility, antibacterial properties, superior mechanical strength, asymmetric adhesion, robust hemostasis, and accelerated wound healing. It can replace traditional sutures, non-degradable dressings, and double-sided adhesive scaffolds for hemostasis, external, and internal postoperative wound healing.