Rational Design of NIR-Responsive, Disulfide-Modified Bio-MOF with Antibacterial and Osteogenic Activity

Postoperative infection remains a significant challenge in surgery, often hindering healing. This study aims to design a near-infrared (NIR)-responsive, disulfide-functionalized bioactive metal-organic framework (Bio-Zn@S-MOF) made of zinc cations, adenine, and 3,3'-dithiodipropionic acid (DTPA) ligands. The incorporation of DTPA introduces redox-active disulfide bonds, providing the framework with stimuli-responsive behavior and the ability to release melatonin in a controlled manner under infection-mimicking acidic and NIR-irradiated conditions. Bio-Zn@S-MOFs demonstrate strong antioxidant activity, free radical scavenging over 91.0% within 24 h, excellent cytocompatibility against MG63 and RAW 264.7 cells, and the ability to promote osteogenic differentiation, while suppressing intracellular reactive oxygen species (ROS). These frameworks exhibit remarkable in vitro bactericidal activity, which is further enhanced by NIR light irradiation. Together, these findings introduce a NIR-responsive Bio-Zn@S-MOF that integrates light-triggered bactericidal and antioxidant activities with osteogenic potential, offering a promising therapeutic strategy for infection control in bone tissue.