Branched AuAg nanoparticles coated by metal–phenolic networks for treating bacteria-induced periodontitis via photothermal antibacterial and immunotherapy

Periodontitis is an inflammatory disease caused by bacteria. The prolonged and repeated occurrence of this disease results from immune system disorders and leads to the destruction of surrounding tissues. Research on new antibacterial materials that can regulate autoimmunity and promote repair can effectively treat periodontal inflammation. Hence, metal–phenolic networks (MPNs) were loaded onto the surface of branched AuAg nanoparticles (NPs), denoted as [email protected] The procyanidin (PC)-Fe network not only enhanced the photothermal properties of AuAg NPs to achieve effective photothermal antibacterial activity against periodontal pathogens but also alleviated oxidative stress and excessive inflammation. The mechanism of action is as follows: [email protected] promotes the polarisation of alternatively activated macrophages by activating the phosphoinositide 3-kinase/protein kinase B signaling pathway and upregulates nuclear factor erythroid 2-related factor 2, scavenging reactive oxygen species and subsequently inhibiting the nuclear factor kappa-B signaling pathway to regulate immunity. The ability of periodontal inflammatory tissue to repair was improved in vivo. This design provides new ideas for applying MPNs to photothermal therapy and immunotherapy. It presents a new therapeutic platform for treating periodontitis and other infectious diseases.