A Biomimetic Nasal Mucus Gel System Adaptable for Catalytic Antibacterial Therapy.

Nasal mucus acts as a primary immunological barrier by synergistically integrating physical trapping and chemical antimicrobial defenses. However, constructing an artificial gel system that recapitulates this multifunctionality for catalytic antibacterial therapy remains challenging. Here, we report a mucus-inspired catalytic hydrogel that incorporates lysozyme nanofiber-templated PtCu nanohybrids into a thermoresponsive PEO-PPO-PEO triblock copolymer matrix. The resulting hydrogel exhibits excellent biocompatibility, robust peroxidase-like catalytic activity, NIR-responsive photothermal effects, and strong adaptability to heterogeneous wound microenvironments. By confining enzyme mimics at infection sites, the hydrogel enables sustained catalytic antibacterial action while buffering bacterial toxins, thereby mitigating inflammatory injury and preserving a regenerative microenvironment. This biomimetic system synergistically combines physical bacterial trapping with chemical catalytic killing, effectively eradicating both superficial infections and deep-seated periprosthetic joint infections. Moreover, it promotes wound healing, enhances osteogenesis, and suppresses pro-inflammatory cytokine expression. This work provides a promising strategy for developing artificial immune systems that emulate or even surpass the functional sophistication of natural mucus barriers.