An in situ fused adhesive with integrated antibacterial and hemostatic functionalities for urgent respiratory fistula sealing and enhanced wound repair

Abstract

Respiratory fistulas remain clinically challenging in endoscopic treatment due to the absence of convenient non-compressive sealing materials. Here, we developed an in situ self-fused powder adhesive (PP powder) to address this limitation. This material integrates the adaptive conformability of hydrogel microparticles with the pressure-resistant sealing capability of bulk hydrogels via water-triggered self-assembly. The PP powder exploits electrostatic attraction and topological effects between cationic microspheres (PL-TCEP) and polyacrylic acid (PAAc). This design yields strong tissue adhesion (29.7 kPa), robust sealing (24.7 kPa), and inherent antibacterial properties. Additionally, it promotes efficient coagulation by synergistically aggregating blood cells and autoactivating the coagulation cascade. Furthermore, we have rigorously validated those hemostatic, sealing, healing capabilities and translational potential through liver injury models, bronchopleural fistula models, infected wound models and rabbit tracheal fistula models. This multifunctional platform advances emergency fistula management while providing a paradigm for designing biomaterials addressing complex clinical scenarios requiring simultaneous hemostasis, sealing, and antimicrobial action.

Statement of Significance

This study introduces a rapidly self-assembled poly(amino acid)-based microgel, formed through dynamic ionic crosslinking between cationic poly(amino acids) and poly(acrylic acid) (PAAc). This microgel exhibits exceptional deliverability through narrow channels and hygroscopic self-assembly capabilities, making it an ideal candidate for endoscopic surgical applications, particularly in sealing respiratory tract fistulas. The engineered microgel demonstrates robust mechanical properties, far exceeding the physiological pressures of human airways. Leveraging the spatial architecture of cationic poly(amino acid) microspheres, the microgel not only exhibits inherent antimicrobial activity but also significantly enhances blood cell aggregation, thereby accelerating clot formation more effectively than commercial hemostatic powders. Furthermore, owing to its outstanding biocompatibility, the microgel shows great promise in visceral hemostasis and tissue regeneration, highlighting its potential for advanced biomedical applications.