Abstract: Bone implant-related infections are characterized by high-risk of delayed incidence or recurrence. Current antibacterial strategies often lack selectivity, leading to collateral damage to normal tissues and cells during bacterial eradication. To address this, mesoporous bioactive glass (MBG) was used as a base material in this study. By leveraging the near-infrared (NIR) photothermal response of S-NO bonds to release NO radicals and the antibacterial properties of Cu²⁺, MBG-RSNO powder was synthesized through amino-functionalized conjugation of S-nitrosothiols (RSNO) for NO· delivery, while PMBG@Cu powder was prepared via dopamine polymerization and Cu²⁺ chelation. These two powder materials were further processed through 3D printing to fabricate a PMBG@Cu/MBG-RSNO composite antibacterial scaffold. This scaffold demonstrated a strong NIR photothermal response, with pulsed 808 nm laser irradiation enabling the sustained release of NO· up to 113.71 μg per 100 mg MBG-RSNO and increasing the temperature to approximately 40 °C, facilitating efficient bacterial elimination. Antibacterial performance of the scaffold was evaluated using Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) as representative Gram-positive and Gram-negative bacteria, respectively, under conditions with and without external NIR stimulation. The results revealed that the PMBG@Cu/MBG-RSNO composite scaffold achieved an antibacterial efficiency of 99.9% against both bacterial strains. In summary, the PMBG@Cu/MBG-RSNO composite scaffold offers a promising solution to address infection challenges in bone implant materials and supports bone defect repair.

Key words: mesoporous bioactive glass, antibacterial, nitric oxide, photothermal effect