Phototheranostic Sutures Integrated with NIR-II Emissive Photosensitizers for Postoperative Complication Prevention and Non-invasive Monitoring

Surgical site infections (SSIs) and poor subcutaneous visibility remain persistent challenges that limit the performance of conventional surgical sutures. Here, we present a universal surface modification strategy to fabricate phototheranostic sutures integrating the NIR-II emissive photosensitizer T-TBT-P with a polydopamine (PDA) coating. The resulting functionalized sutures exhibit potent photodynamic/photothermal antibacterial activity under 808 nm irradiation, achieving bacterial eradication efficiencies above 99% against methicillin-resistant Staphylococcus aureus (MRSA). They maintain excellent mechanical strength, cytocompatibility, and hemocompatibility, while the superhydrophilic PDA layer effectively suppresses the protein adsorption. In vivo studies confirm that the functionalized sutures eliminate infection, accelerate wound healing, and prevent undesirable abdominal adhesion compared with unmodified counterparts. Benefiting from deep-penetrating NIR-II fluorescence extending beyond 1300 nm, the functionalized sutures enable non-invasive, real-time, and high-contrast monitoring of subcutaneous integrity and biodegradation over 35 days. This work establishes a generalizable platform for constructing multifunctional surgical sutures with integrated antibacterial, antiadhesive, and imaging functionalities, providing opportunities for precise and efficient postoperative wound management.