Aggregation-Induced Emission-Based Nanoparticles for Synergistic Photothermal Antibacterial Therapy and Anti-Inflammatory Regulation in Periodontal Infections

Traditional treatments for periodontal tissue infection, including mechanical debridement and pharmacotherapeutic protocols, are ineffective at removing bacteria and may lead to drug resistance and side effects. Meanwhile, these methods cannot reduce lipopolysaccharide production or eliminate free radicals. Photothermal therapy offers a promising alternative for bacterial eradication. Herein, therapeutic nanoparticles (Dex/AA@AIE-2 NPs) containing an aggregation-induced emission luminogen (4TPE-C6T-TD), ascorbic acid (AA), and dextran (Dex) are proposed, which exhibit great photothermal antibacterial efficiency against periodontal bacteria under the near-infrared laser irradiation. 4TPE-C6T-TD shows long absorption in the primary near-infrared region and emission in the secondary near-infrared region, which is satisfactory for practical application in deep tissues because of the void scattering and limited tissue penetration of photons. AA can scavenge free radicals and regulate the polarization of macrophages to the M2 type, which synergistically causes the relief of inflammation. Dex enhances NPs' attachment to bacterial surfaces and their deep penetration into bacterial biofilms. This study provides a therapeutic agent with photothermal-induced bacterial clearance, free radical scavenging, and macrophage polarization regulation abilities, which show huge potential in periodontal tissue infection-related disease treatment.