Smart biomaterials for immunomodulation in periodontitis: advances and challenges

Periodontitis is a chronic immunoinflammatory disease characterized by irreversible periodontal tissue destruction. Its progression is closely associated with immune dysregulation and abnormal activation of immune cell subsets. Increasing attention has been directed toward immunotherapy to improve the limited regenerative capacity of periodontal tissues. Smart biomaterials can sense local periodontal signals and produce spatiotemporal responses for controlled drug release and modulation of the immune microenvironment. However, current research mainly focuses on material design and optimization, whereas systematic comparisons and clinical evaluations of responsive systems remain insufficient. This review summarizes recent advances in smart biomaterials for periodontal immunomodulation, with emphasis on their classification based on endogenous and exogenous stimuli. Challenges involving material stability, biosafety, controlled release, and clinical translation are also discussed. This review may provide insights into the future development of immunomodulatory therapies for periodontitis.