Exosomes and exosome composite scaffolds in periodontal tissue engineering. Exosomes, derived from stem cells, are a promising alternative to stem cell therapy for periodontal regeneration. They have shown potential in regulating immune function, inflammation, microbiota, and tissue regeneration. Periodontal tissue engineering combines exosomes with biomaterial scaffolds to maximize their therapeutic advantages. This review discusses the progress, challenges, and prospects of exosome and exosome-loaded composite scaffolds in periodontal regeneration. Exosomes are natural nanoparticles that can deliver therapeutic agents and have been used in various inflammatory, immunologic, and infectious diseases. Exosomes can be loaded into biomaterial scaffolds to achieve superior therapeutic effects. Exosomes have been applied in periodontal tissue engineering to control inflammation and promote alveolar bone regeneration. Exosomes are natural envelope nanoparticles secreted by all types of cells, including prokaryotes and eukaryotes. They are important mediators of cell-to-cell communication in the form of proteins, lipids, nucleic acids, and even organelles. Exosomes contain a variety of proteins, lipids, RNA, miRNA, and many other non-coding RNA. Exosomes have been shown to have immunomodulatory properties that facilitate periodontal tissue regeneration. Exosomes can be used as a cell-free therapeutic strategy to substitute for mesenchymal stem cells in various disease models. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have beenExosomes and exosome composite scaffolds in periodontal tissue engineering. Exosomes, derived from stem cells, are a promising alternative to stem cell therapy for periodontal regeneration. They have shown potential in regulating immune function, inflammation, microbiota, and tissue regeneration. Periodontal tissue engineering combines exosomes with biomaterial scaffolds to maximize their therapeutic advantages. This review discusses the progress, challenges, and prospects of exosome and exosome-loaded composite scaffolds in periodontal regeneration. Exosomes are natural nanoparticles that can deliver therapeutic agents and have been used in various inflammatory, immunologic, and infectious diseases. Exosomes can be loaded into biomaterial scaffolds to achieve superior therapeutic effects. Exosomes have been applied in periodontal tissue engineering to control inflammation and promote alveolar bone regeneration. Exosomes are natural envelope nanoparticles secreted by all types of cells, including prokaryotes and eukaryotes. They are important mediators of cell-to-cell communication in the form of proteins, lipids, nucleic acids, and even organelles. Exosomes contain a variety of proteins, lipids, RNA, miRNA, and many other non-coding RNA. Exosomes have been shown to have immunomodulatory properties that facilitate periodontal tissue regeneration. Exosomes can be used as a cell-free therapeutic strategy to substitute for mesenchymal stem cells in various disease models. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been shown to promote periodontal tissue regeneration by modulating immune responses and promoting angiogenesis. Exosomes have been used in periodontal tissue engineering to promote periodontal tissue regeneration. Exosomes have been