The effective treatment for
periodontitis is to completely and sustainedly eradicate the bacterial pathogens from the complex
periodontal pockets. Local sustained-release
antibiotics as a complementary treatment after scaling and root planning can sustainedly combat bacterial pathogens in the
periodontal pockets to help treat the disease, but the increasing concern of bacterial resistance limits its future use. Here, we reported a local antibacterial system based on microsized multifunctional Ag-TiO2-x encapsulated in
alginate (ATA)
microspheres. We confirmed that ATA displayed strong photothermally enhanced dual
enzyme-mimicking (
peroxidase-like and
catalase-like) activities and weak photocatalytic activity under 808 nm near-infrared (NIR) irradiation, which could boost the generation of
reactive oxygen species (ROS) and O2 in the presence of low-level H2O2. As a result, the ATA/H2O2/NIR system exhibited efficient antibacterial activity against Porphyromonas gingivalis and Streptococcus gordonii in both planktonic and biofilm forms. With the help of ROS, ATA could release Ag+ in concentrations sufficient to inhibit periodontal pathogens as well. Moreover, the in situ-generated
oxygen was supposed to alleviate the local hypoxic environment and would help downregulate the
lipopolysaccharide-mediated inflammatory response of periodontal stem cells. The in vivo rat
periodontitis treatment results demonstrated that the ATA/H2O2/NIR system reduced the bacterial load, relieved
inflammation, and improved tissue healing. Our work developed a new local prolonged bactericidal and oxygenation system for enhanced
periodontitis. Avoiding the usage of
antibiotics and nanomaterials, this strategy showed great promise in adjunctive
periodontitis treatment and also in other biomedical applications.