Multisynergistic antibacterial and anti‑inflammatory effects of silver-anchored polydopamine nanocomposites hydrogel on periodontitis

Abstract Conventional treatment modalities for periodontitis are less effective in removing bacterial plaques and biofilms, which tend to induce an inflammatory microenvironment in periodontal tissue and lead to disease progression. To overcome this limitation, we designed a silver-anchored polydopamine (PDA) nanocomposite hydrogel system (P-Ag@PDA gels, ~ 200 nm) for multisynergistic treatment of periodontitis. PDA nanoparticles could synergise with silver to exert powerful bactericidal activity and reduce tissue damage caused by reactive oxygen species (ROS) or inflammatory factors. Meanwhile, the low-temperature photothermal process facilitated the penetration of nanoparticles into the bacterial biofilm, solving the challenge of biofilm removal in periodontitis. Poloxamer 407 thermosensitive hydrogel helped the nanocomposites adhere to the bacterial surface, overcoming the problem of reduced efficacy due to the rapid loss of the drug in the oral cavity. The antibacterial, biofilm scavenging, ROS scavenging and anti-inflammatory properties of P-Ag@PDA gels were investigated in vitro and in vivo. The results revealed that P-Ag@PDA gels with NIR light stimulation were more effective than tinidazole (TNZ) in attenuating ROS-induced periodontal tissue damage and removing biofilms, while exhibiting similar antimicrobial effects. This study provided a highly promising biomaterial for the treatment of periodontal infections.