An Ultrasmall Strontium-Loaded Polydopamine Nanoformulation for Near-Infrared-Enhanced Periodontitis Therapy via Photodynamic Gas-Promoted Antibacterial and Bone Repair

en Periodontitis is a chronic infectious oral disease triggered by periodontopathogenic bacteria, resulting in the progressive inflammation and destruction of the tissues surrounding teeth. To achieve reprogramming of the infectious microenvironment for periodontitis therapy, a nanoformulation was proposed by loading polydopamine (PDA) with ultrasmall strontium through in situ reduction and arginine by Michael addition, defined as PA. Combined with near infrared (NIR) irradiation, it could efficiently scavenge reactive oxygen species (ROS), and downregulate inflammatory factors expression through inhibiting NF-κB pathway. In addition, it also confirmed the effective bacteria killing in NIR stimulated PA by photothermal effects and nitric oxide (NO) generation. Significantly, PA + NIR was also verified to promote alveolar bone tissue repair through strontium ions (Sr 2+ ) and NO induced angiogenesis, together with Sr 2+ mediated osteogenesis. The administration strategy was finally verified to alleviate the oxidative stress derived inflammation, suppress bacterial growth and biofilm formation, as well as promote bone regeneration with high efficacy and biosafety in the periodontitis rat models. All the above findings contributed to the NIR enhanced synergistic treatment of periodontitis, and it may serve as a promising strategy for the treatment of other inflammation related diseases. 摘要 zh 牙周炎是由牙周病原菌引发的慢性感染口腔疾病,导致牙齿周围组织形成炎症和发生损坏。为了重塑感染微环境实现牙周炎治疗,在聚多巴胺(PDA)通过原位还原负载超小锶,以及通过迈克尔加成负载精氨酸,得到一种纳米制剂,命名为为PA。结合近红外(NIR)照射,它能有效清除活性氧(ROS),以及通过抑制 NF-κB通路下调炎症因子表达。此外,还证实PA + NIR通过光热效应和一氧化氮(NO)生成有效杀灭细菌。更重要的是, PA + NIR 还通过锶离子(Sr 2+ )和NO诱导血管生成以及Sr 2+ 介导的促成骨,促进牙槽骨组织修复。最后证明该给药策略可减轻由氧化应激引起炎症,抑制细菌生长和生物膜形成,并促进骨再生。上述所有发现都有助于实现近红外增强牙周炎协同增效治疗,并可能为其他炎症相关疾病治疗提供有前景策略。