Anti-inflammatory effect of IL-1ra-loaded dextran/PLGA microspheres on Porphyromonas gingivalis lipopolysaccharide-stimulated macrophages in vitro and in vivo in a rat model of periodontitis.

Periodontitis is a multifactorial chronic infectious disease leading to a host immune response involving inflammatory cytokines, especially IL-1β, which is the main reason for further developing this disease. IL-1 receptor antagonist (IL-1ra) binds IL-1 receptor, inhibiting IL-1β signaling and reducing the levels of other cytokines closely related to periodontitis, such as IL-6 and TNF-α. Therefore, the use of IL-1ra to inhibit periodontitis development in a system, ensuring its sustained release, might be an effective way to combat this disease. Hence, in this study, a novel IL-1ra-loaded dextran/PLGA microsphere was developed to allow the sustained release of IL-1ra and enhance the anti-inflammatory properties. Therefore, this study's purposes were to develop a novel periodontal treatment for inhibition and treatment of periodontitis and evaluate the sustained-release effect and anti-inflammatory properties of IL-1ra-loaded dextran/PLGA microspheres in vitro by cell experiments and in vivo by animal experiments. The results showed that IL-1ra-loaded dextran/PLGA microspheres were non-toxic both in vitro and in vivo and could be used as a safe and effective treatment. In addition, these microspheres could significantly prolong the half-life of IL-1ra drug, exerting a useful anti-inflammatory effect in macrophages stimulated with P. gingivalis lipopolysaccharide and in rats with periodontitis. In conclusion, IL-1ra-loaded dextran/PLGA microsphere might be a useful tool to combat periodontal disease.