Se/Ti3C2 nanoparticles with antimicrobial and antioxidant properties: Rapid phototherapy of periodontitis by modulating GPX1 expression in macrophages under NIR

Periodontitis is a chronic inflammatory disease initiated by bacterial pathogens, resulting from complex interactions between microbial infection and host immune responses. In current clinical practice, antibiotics represent the most frequently utilized adjunctive therapy for periodontitis. However, the overuse of antibiotics not only contributes to the emergence of bacterial resistance but also demonstrates limited efficacy in inflammation resolution. In this study, we synthesized selenium/Ti 3 C 2 (Se/Ti 3 C 2 ) through a one-step redox method using Ti 3 C 2 as a template. The Se/Ti 3 C 2 demonstrated significant antibacterial activity against Escherichia coli ( E.coli ), Staphylococcus aureus ( S.aureus ), and Porphyromonas gingivalis ( P.gingivalis ) under near-infrared (NIR) light irradiation, as evidenced by comprehensive evaluations including colony-forming unit (CFU) counting assays, live-dead fluorescence staining, scanning electronic microscopy (SEM) observations, growth curves, and membrane potential staining assays. Furthermore, the anti-inflammatory and antioxidant properties of Se/Ti 3 C 2 were investigated using various methodologies, including 1,1-diphenyl-2-pyridine-hydratedacyl (DPPH) scavenging assay, 2,2′-azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid (ABTS) scavenging assay, glutathione peroxidase (GPX) activity measurement, intracellular reactive oxygen species (ROS) fluorescence staining, flow cytometry, and quantitative real-time polymerase chain reaction (qPCR) assays. Through GPX1 gene knockdown experiments, we demonstrated that the anti-inflammatory effects of Se/Ti 3 C 2 were closely associated with GPX1 expression. RNA sequencing analysis was subsequently performed to elucidate the underlying mechanisms of its anti-inflammatory and antioxidant activities. Finally, in vivo experiments using a mouse periodontitis model demonstrated the remarkable therapeutic potential of Se/Ti 3 C 2 in periodontitis treatment. Therefore, Se/Ti 3 C 2 holds great promise as a potential alternative to antibiotics, emerging as a novel therapeutic material for periodontitis treatment.