Exploring a Novel NFkB-inhibiting Nanoparticle for Periodontitis Therapy

Objectives: Periodontitis is an infection-driven inflammatory disease characterized by gingival inflammation and bone loss. NFkB signaling pathway is pivotal in osteoclastogenesis and infection-induced pro-inflammatory responses. A novel nanoparticle carrying therapeutic NFkB inhibiting peptides (NBD-nanoparticles) will provide us a promising strategy for periodontitis therapy. Our hypothesis is that the nanoparticles is able to inhibit osteoclastogenesis and inflammation and therefore can be used for periodontitis therapy.
Methods: In vitro- In order to test the impact of NBD-nanoparticles on osteoclastogenesis, RAW 264.7 cells were stimulated using RANKL and treated with NBD-nanoparticles. Controls included treatment with mutant NBD-nanoparticles, nanoparticle, free NBD peptide, mutant NBD peptide and no treatment. Seven days later, the cultures were fixed and stained with TRAP, an osteoclast marker, and the number of multinucleated TRAP positive cells were counted.
In order to test the impact of NBD-nanoparticles on pro-inflammatory responses, RAW cells were stimulated with periodontal pathogen P. gingivalis, treated with NBD-nanoparticles or controls, and tested for expression of cytokines critical in periodontitis, such as IL1β, IL-6, TNFα by ELISA. Differences evaluated by ANOVA.
In vivo - NBD-nanoparticles were tested in a murine ligature-induced periodontitis model where mice received a ligation around the second molar, P. gingivalis infection and microinjections of NBD-nanoparticles, empty nanoparticles, or PBS in the gingiva. Gingival tissue was tested for mRNA expression of pro-inflammatory cytokines by real-time PCR. Alveolar bone loss was determined by measuring the CEJ-ABC distance. Bacterial culture from oral swabs confirmed bacterial persistence.
Results: NBD-nanoparticles inhibit osteoclastogenesis and P. gingivalis-induced pro-inflammatory cytokine production. NBD-nanoparticle application inhibits the gingival expression of periodontitis-related cytokines and alveolar bone loss in a murine ligature model.
Conclusions: NBD nanoparticle is able to inhibit excessive NF-KB activation, osteoclastogenesis and pro-inflammatory cytokines production in vitro. This nanoparticle prevents gingival inflammation and alveolar bone loss in a murine model for periodontitis.